Is it the infamous hot soak......

Thanks to Tim for directing me here.

It is quite possible I have the hot soak on my newly acquired TV.

I am new to these vans.
The PO did replace the FPR but it still happened to me. So possibly could have been a bad replacement part or replacing the FPR won't help.

I will be paying more attention to the gasoline I use. I do not think concoco uses ethanol but I will double check.

What about using fuel treatment like sea foam or like products? Anyone attempt to saturate their fuel system with this to see if it helps?

I have also installed an 89 FPR on my 86 van & it was not enough to make a noticeable difference. I also tried different brands of gasoline & that didn't seem to make much difference either. As a result I believe gasoline with a high boiling point is a thing of the past. Ventilating the engine compartment did the trick for me. To test yours, you may want to lift the engine access when making your stops during the day. If this eliminates your starting issues, then your problem is heat soak. Tim

PS: As a general rule I don't believe in, nor do I use automotive additives. Some may work, but I think most of them are a waste of money. Just my $.02.

Quote:

---

Originally Posted by timsrv

PS: As a general rule I don't believe in, nor do I use automotive additives. Some may work, but I think most of them are a waste of money. Just my $.02.

---

I agree for the most part. But sea foam works. I have seen it work in all my two stroke yard tools, motorcycles, and cars. In larger applications like vehicles I think it is more of a prevention thing than anything else. I have never done the carbon clean. I have had people put 2 stroke oil gas in some ATV's and motorcycles that really bogged them down. I put sea foam in the gas and it cleaned it right up. I also find that when I use seafoam in my tanks I getting a small amount better MPG. Not significant but that is not why I use it personally.

As far as most other products they are garbage. I posted a thread about BG products because I recently saw some amazing stuff happen when their products were used.

My buddy had a land rover disco. Infamous for leaking. BG make a coolant seal......yes I know they are terrible and can mess up your systems. I agree. However the BG stuff is made with an organic compound derived from a plant. When that compound hits air in the cooling system it seals it nice and tight. It is pretty amazing stuff. He has been driving with this stuff in his cooling system for 30k miles now. No issues. Instead of a 4k dollar fix it cost 10 dollars. I could not believe it. So now I always run their super cool in my jeep.

Those are the only "gimmicky" additives I endorse because I once was against them all until I saw results.

Hopeflly my TOYO OEM T-STAT replacement will help

This is a great thread!

I know the cooling system stop leak products work, but as a mechanic I have also seen them plug-up radiators, heater cores, & make thermostats stick. These issues don't usually occur right away, they slowly take their toll (like hardening of the arteries). I don't have experience with the specific brand & formulation you mention, but suspect it would/could do the same.

As for the Seafoam, So far I'm keeping an open mind. In order to keep my master certified tech status I am required to regularly attend manufacturer sponsered seminars & troubleshooting clinics. It impresses me that Onan actually endorses Seafoam and recommends it's use to help de-carbonize their engines. I purchased a bottle of it a couple years back, but so far I haven't run into a carbon build-up issue serious enough to justify it's use/test it's effectiveness. Tim

I have been watching this thread for a while now, so thought I'd throw an idea out there. My buddy's dad ran a radiator shop many years ago (closed in the mid 80's) and one of his radiator leak solutions was black pepper. I've proved it out on a couple old Chevy pickups, as a workable solution. So, if you find yourself in the middle of nowhere with a leak, and a can of pepper, you can get back to civilization. :)

Quote:

---

Originally Posted by skibum

I have been watching this thread for a while now, so thought I'd throw an idea out there. My buddy's dad ran a radiator shop many years ago (closed in the mid 80's) and one of his radiator leak solutions was black pepper. I've proved it out on a couple old Chevy pickups, as a workable solution. So, if you find yourself in the middle of nowhere with a leak, and a can of pepper, you can get back to civilization. :)

---

That's nutty!
Do you know the "science" behind doing this?

I don't know the science, but I would imagine that the pepper rushes toward the leak and clumps there. It's not a permanent solution, but it did work. I used to keep a can of pepper, a jug of antifreeze, maybe some power steering fluid up in the "trunk" area afforded by the roomy grill :).

Quote:

---

Originally Posted by timsrv

I know the cooling system stop leak products work, but as a mechanic I have also seen them plug-up radiators, heater cores, & make thermostats stick. These issues don't usually occur right away, they slowly take their toll (like hardening of the arteries). I don't have experience with the specific brand & formulation you mention, but suspect it would/could do the same

---

Yeah I have seen it too and steer people away.

The difference in the BG is it is an organic plant material and it does not clog up any systems and seals the holes.
At 30k miles and no system clogs I would say it is an advancement in quick stop products.

I used some and it worked for 10k miles on a vehicle without issue and then I sold the vehicle to a buddy and it still is not leaking.

It is David Blaine in a bottle!

Hi Tim, where / how exactly did you mount fan? Is it mounted to the water pump or to another pulley? I have an 87 AT not a 5 speed where do you recommend I mount fan, also I see your using a 3300 uf cap is there also a spec for the diode is it just controlling direction of current flow, and is it necessary to have the override switch with temp sensor thanks Ralph

Quote:

---

Originally Posted by toytime

Hi Tim, where / how exactly did you mount fan? Is it mounted to the water pump or to another pulley? I have an 87 AT not a 5 speed where do you recommend I mount fan, also I see your using a 3300 uf cap is there also a spec for the diode is it just controlling direction of current flow, and is it necessary to have the override switch with temp sensor thanks Ralph

---

Toytime:
I hung mine as a 'pusher' fan on the front of the rad years ago using the zip tie things that pull through a washer pressing against the fins that are sold exactly for this purpose. Years and no issues.
1986 AT 2wd
bill

As shown on page 2 of this thread, I just mounted the fan to the radiator using THESE. They poke through the radiator fins and hold the fan securely to it.

I'm not an electronics guy (no former training) I just experiment with stuff until I'm able to make it do what I want. A different size cap and/or diode might work better and/or last longer than what I used, but my method has been working well (I've been very happy with it). If/when I do this again I'll likely use a higher temp switch (like a 195 deg F), but the one I used is okay. Occasionally I'll need to start & move my van after the fan has already timed out, but the coolant temp is still above 170 deg, so the fan runs for another 15 minutes (unnecessary drain on the battery). Still, battery has never gone dead, just think it would be better with a 195 temp switch.

I never use the override switch, so in retrospect I would likely not install this if I do this again. Tim

:doh: Ok now I feel like an idiot I glanced over the pic's and thought you added the fan blade on the left mounted to the engine wow talk about a brain cloud thanks guys for setting me straight. Ralph

You all rock :thmbup:
I'm truly amazed :clap:

and also :dizzy:...
Alas! I am a lady... and would rather :doh: or :wall:myself repeatedly then attempt this job mainly because I feel it's likely very simple for someone who's done it already (or a mechanic) and would take me quite a bit longer to wrap my head around :cnfsd:.

That said, I'll be traveling most/if not all of our country for the next 6 mos. and would LOVE to pay someone to do this for me along my route...

Here is my likely route and dates when I'll be in each state UNTIL (then I'll be leaving the next day to go onto the next listed state):
Iowa FEBRUARY 1st
New Hampshire FEBRUARY 9th,
Nevada FEBRUARY 20th,
South Carolina FEBRUARY 27, (maybe)
Texas MARCH 1st,
Michigan MARCH 8th, (maybe)
Florida MARCH 15th,
Illinois MARCH 15th, (maybe)
Ohio MARCH 15th, (maybe)
New York APRIL 19th,
Pennsylvania APRIL 26th,
California JUNE 7th, then to
D.C. JUNE 14th, then back to to
Philadelphia until JULY 29th

:LOL2:

In the meantime I'm going to drive my van... when I stop, I'll lift my seat to let the heat escape... and see what happens when I get back in and try to start my van again.

Once I'm clear it's a hot soak issue, (which I'm near 100% certain it is) I'll look back here and hopefully have some offers with locations for someone (several someones??) to do the work and hopefully you'll be in the flow of my travels. I'd be happy to purchase the parts and deliver them to whatever address is best for "you" or buy them and keep them with me until I get to someone who is willing/able to get the job done...
TIM?
:drool:

On the other hand if "you" are confident anyone can do this... if you would kindly send me simple, concise, step by step instructions (cut and paste from all these scattered posts would work too), with step by step images (yes, I know I'm dreaming on that last one!) on how to do this myself... I'll do my best to make it happen or perhaps find someone local to make this happen. I'm good with putting computers together... and have worked on cars from time to time (change the starter/help my dad with plugs/etc.) so I just may be happy enough to tackle this myself if "you're" confident that I can do it.

Much appreciated!
And now that my head is exploding :yikes:I'll move on for now... :wave2:

Thanks!
Summer Rose

My mechanic who has been working on my van suggested I open the gas cap and let the heat escape that way...

Is that an easier fix then lifting my drivers seat or is he not understanding the issue?

Thanks again!

SR

No, the place that needs to be cooler is the fuel rail (it's on the engine). Venting at the tank would have no positive effect. One thing you could also do (just temporary) would be to floor the throttle just as you turn it off. Let it begin to rev before turning off the key. The throttle being open causes vacuum to drop and this in-turn increases fuel pressure. This increased pressure (at the moment of shut down) will increase boiling temperature of the fuel in the rail. Tim

Got it. Thanx :)

Care to install a fan, etc. for me when on my travels?
:drool:

I understand if you're too busy... It's possible my mechanic will do it when I come back to Cali in May/June...

Thanks again!

A few years back when the economy was dead I diversified for a while and one of those extra things I did was auto repair. Thankfully the RV business is booming again and I've got my hands full with that. So unfortunately this means no extra time for wrenching on cars (except for my own). Good luck. Tim

By the air filter, there is a wire you can jump that'll cause the fuel pump to turn on. I was thinking about installing a time-delay relay to that. That way, when you turn the key to the "On" position, it'll run the fuel pump for a couple seconds. A lot of modern cars do this, but not our Vans. The fuel pump doesn't start running until you start cranking. It seems to make more sense to let the fuel pump run a cycle first so fresh, cool fuel can enter the lines and pressurize the system.

Quote:

---

Originally Posted by timsrv

Lol, I'm surprised you made it through all that. Sometimes I get started and just can't stop :lol:. Heat soak is hard on your starter and embarrassing when witnessed by others......other than that it's just a nuisance. Over time, the excessive heat in the engine compartment will harden rubber and plastic parts. Tim

BTW, high octane gas won't help. If your engine doesn't ping on the 87 octane stuff, then more octane is just a waste of money.

---

Three months later and I'm still with this problem, I've only had a couple of days to work on it dough, but it's starting to bug the heck out me. I've already checked fuel pressure and the EGR they seemed good. The one question I have is does "heat soak" happen over night because that's where my problem is at. Becouse everything is cold then gas, fuel rail, or would gas evaporated leaving air in rail? I also tried leaving engine cover/seat up all night just to see if that cured the problem, but it dint help. Any advice

By definition heat soak is a problem created by heat. Problems encountered when cold are not heat soak related.

Thank you, I can check this possibility off the list.

I'm considering doing the conversion to a pair of side by side electric pull fans like Tim and others have done. The one detail I have reservations about is missing out on the variable speeds that the old mechanical fan turns at (i.e. slow/medium speed at normal temperatures and extra-fast when the engine's racing).

It seems like if an electric switch triggers the fans at normal operating coolant temperature near the filler neck (190? 200?) then it's cooling down the engine when it doesn't need max cooling. If it's set for "temp too high" then.. it's just lazy and not working for the van the rest of the time? Either way it would seem like it would just cycle the temp between too hot, too low then back up again. Am I wrong?

Is there a simple way to set this up (using only the one extra 16mm port with submerged thermo control) where one fan goes on for intermediate cooling and the second turns on for max cooling? Has anyone done this? I realize I could have two separate variable fan controls, but it seems messy and there's only that one extra port.

This just seems like a more practical way for the fans to operate and nicer than listening to two fans switch on and off at maximum speeds.

I've tried searching for things like "2 stage electric fan control" etc. with no luck. :dizzy:

I'm using this one now: https://www.amazon.com/Flex---lite-3...3043290&sr=8-1. So far so good........here's a link that shows how I installed it:

https://www.toyotavantech.com/forum/...=9094#post9094

Quote:

---

Originally Posted by timsrv

I'm using this one now: https://www.amazon.com/Flex---lite-3...3043290&sr=8-1. So far so good........here's a link that shows how I installed it:

https://www.toyotavantech.com/forum/...=9094#post9094

---

Ah, thanks Tim, that's the thread I should've posted on!

That controller unit looks neat, I'm particularly interested in the cut-on at 60% speed feature. That kinda thing is what I was looking for, but you mentioned that you don't think it really matters?

Out of curiosity, did you run this setup on the same van you put the extra previa-heater-core-grill-radiator on?

Quote:

---

Originally Posted by Kyle

Ah, thanks Tim, that's the thread I should've posted on!

That controller unit looks neat, I'm particularly interested in the cut-on at 60% speed feature. That kinda thing is what I was looking for, but you mentioned that you don't think it really matters?

Out of curiosity, did you run this setup on the same van you put the extra previa-heater-core-grill-radiator on?

---

Yeah, I don't think it really matters. The reason being is running at 100% is just barely enough to keep up with the van's cooling needs (at least in the summer). In the winter there might be a slight advantage, but the power draw works out the same........only difference being a constant lower current draw vs a momentary full current draw. At the end of the day it's used the same amount of energy. I do think the variable speed controller is a bit more durable, but don't know that for sure (because I'm not currently using that van). And yes, it's the same van with the add-on Previa heater core.

There are pros & cons to whichever way you wish to go (clutch fan vs electric). Based on what I've done so far, I hate to say it, but I doubt I'd go through all this again as I don't think electric is any more effective at cooling. Regardless of which way you go, nothing I've done has completely solved the hot running issues. For 95% of the time both ways work fine. It's those super hot days when you're running the AC while stuck in traffic or climbing hills. With both methods I've still had to shut off the AC at times. Adding a single fan to a van with a working clutch fan is enough to keep the heat soak under control, but it is nice to have the extra room you get from deleting the clutch fan (and the oversize factory shroud). I guess the added benefit to electric is those fans can also be rigged to run after shut-down to help control heat soak. Tim

Quote:

---

Originally Posted by timsrv

There are pros & cons to whichever way you wish to go (clutch fan vs electric). Based on what I've done so far, I hate to say it, but I doubt I'd go through all this again as I don't think electric is any more effective at cooling. Regardless of which way you go, nothing I've done has completely solved the hot running issues. For 95% of the time both ways work fine. It's those super hot days when you're running the AC while stuck in traffic or climbing hills. With both methods I've still had to shut off the AC at times. Adding a single fan to a van with a working clutch fan is enough to keep the heat soak under control, but it is nice to have the extra room you get from deleting the clutch fan (and the oversize factory shroud). I guess the added benefit to electric is those fans can also be rigged to run after shut-down to help control heat soak. Tim

---

Ha, well that kinda puts the damper on my enthusiasm to go through with the swap. I want to get rid of heat soak, but also just give the van the most robust cooling system I can. That clutch fan fully engaged is pretty dang powerful.

Re: heat soak, another wacky idea I had was to put a little 12v (hot water rated) pump in the heater core coolant circut. If the pump was on a timed switch along with the blower motor I could just hit one button on the dash and the heater would dump heat out of the engine for 15min, or however long it's set for, while the engine's off.

I guess it'd be kinda annoying to have the heat on full blast in your car while you're in the store, and I don't know if it would actually even dump a significant amount of heat (esp. from the fuel rail area) to avert vapor lock.

Sometimes there's just too many options...

I was looking into electric fans last night, trying to find out the cfm. I found the Derale 16110 10" H.O. witch in Tim's set up would move 1600 cfm at 18.4 Amps. Then I realized that we have tried all sizes, single, dual with or without custom shrouds but I have yet to see someone bolting a 17inch directly to the plastic Toyota shroud 2 or 4WD.

Derale makes the 16917 an H.O. 17" (actual 16-7/8"), extremely low profile (2-5/8), dual speed Bosh motor, pumping out 2400 cfm at 23.5 Amps. At 16-7/8" it should drop right into our 17" shroud :thmbup:.

Flex a Lite does even better with their 118 flowing 2500cfm at a low 18.3 amps (same as the dual 10") but it's single speed and a little thicker at 3-3/16.

What ya think? :)

You might consider an alternator upgrade before taxing it with a continuous ~20A. These Denso's are a bit fragile, otherwise I think it would be a great improvement. I look forward to seeing what you come up with. Tim

PS: There's a couple threads here were we talk about putting a Delco Remy CS-144 on the van. I've done it and in one place I posted a PDF drawing of the bracket and wiring mods required. Just search the site for "Delco Remy"

I was worried about that!
Is the dual fan set up on you welding van with the "mother of all alternator? with the bigger wires? and the relais here and controllers there....
Man, I don't know if I want to eat that elephant, even one piece at a time :lol: I'm a bit of a Sparky when it comes to electricity.
Plus any power gain from not running the fan belt has got to be negated by the big alternator, right?
Not to mention the clutch fan doesn't produce heat but the "bigternator" must make load of BTU ? Exactly what we don't want more of.
Too bad this 17" Derale looked pretty sleek for a while here.:yes:

Energy is energy. Running the fan directly off of the front pulley has it's merits (simple, less likely to break). However it's dependent on engine RPM, so if/when you're overheating, you must also run the engine faster to effectively move air. Running the engine faster burns more fuel and creates more heat, so it's a bit of a catch 22.

Alternators can run hot, but I don't think we're talking anywhere near the BTUs of running the engine at 2,000 or more RPMs (required to move large volumes of air). Even if the alternator can't keep up at idle, if the battery is strong it will run the fans until RPMs come back up, so that's not a big deal either. Aside from being a relitively easy retrofit, the Delco Remy CS-144 is a strong and solid alternator. You can find used ones right out of the salvage yard that have factory output of 140A or more and are capable of surviving continuous duty in high heat/high output conditions.

All things considered, there are lots of variables to the way people use their vehicles and everybody has different preferences. A factory Denso alternator (new or rebuilt from Denso) isn't a terrible unit. They just get a bad rap due to all the questionable and/or poor quality aftermarket rebuilds. Factory Denso units will tolerate abuse to a point, but nothing to the extent a CS-144 will. Tim

Tim:

As my 86 LE is being finished up and now will live and operate in Florida, my concern about Hot Soak has escalated.

With that in mind and April coming around the corner when temps here will really begin to climb I am making ready for a serious Hot Soak issue with my LE.

That being said and studying your detailed response with extra cooling added to the van for after engine off conditions gave me some thoughts.

This is quite a project and if needed I can do it but I thought of something else.

In your opinion, can an external air source (fan) drive air directly to the suspect area that is the cause for Hot Soak.

A similar model is used in piston aircraft by way of external electric fans moving lots of air through a Scat hose to the location in need for the extra amount of air. So my thought is to follow that model and add an external 12 volt squirrel cage fan located low under the ower steering reservoir and pumping air up into the fuel line area. I took your picture and guessed where the suspect area is.

This would eliminate the need to pull the fan out and build up the necessary mounts for the 2 new fans.

It can run on the same type of thermostat as you demonstrated here.

Any thoughts, or suggestions?

Thanks Tim
Attachment 6739

The fan set-up I'm using in post #34 is my daily driver and works well (doesn't require removing stock fan and/or building a shroud). I don't doubt your idea will work, it's just already cluttered in there. If you do that, try to direct the air to flow between the halves of the intake manifold (where the fuel rail and the injectors are). I'm always interested in new/different ways to solve problems, so if you go that way please keep us updated as to how it works out. Tim

I posted this on the subject; http://www.toyotavantech.com/forum/s...ll=1#post31776 The thing I'm still questioning is: Do I blow fresh air in or do I pump hot air out? Witch way would be the most efficient? hummm....?

If we're talking about a small but directed airflow, I would think pumping cool fresh air in would be more effective. If you move air out, that would do the same thing, but would initially be drawing air from other heated areas, thus reducing short term effectiveness (at least in the specific area of the fuel rail). Tim

I was able to at least experiment with that. For sure blow in, not out. You will pull heat off the block first and will take some time to cool. By pushing, the block will not cool down any quicker but the suspected fuel line area will get the cool relief.

I will no doubt build a controller with some circuitry to switch this bad boy on and off. This tiny controller, as an example has 5 times more power than the entire EFI in the van (30 years later). So there are countless things we can do just by writing code.

I will try to get on the mechanical side of things by next month.


mt

Somehow in my head I keep seeing hot air relentlessly radiating upward from the mass of metal under the fuel rail and both ways at some point are making sense. It seems that, according to MyToy, aeronautic engineers prefer blowing in cool air, but fan makers clame more efficiency in extracting hot air :cnfsd: so the little voice keeps telling me: That hot air "pocket" has nowhere to go, if you take it away, cooler air will be drawn in its place, same as inside a paint spray booth or a sand blaster tank No? The contained environment makes it difficult to push things out. Interesting.....

With a bilge fan set up it would not be hard to figure out, flip the fan around and mesure temp drop directly on the fuel rail

All good points and must be considered. There is however one other area that needs to be considered also. That is the level of sinking the heat (retaining it) within each component. Since we only need to reduce this temperature for short time period the time it takes to cool down the fuel components, ie fuel lines and such, are much smaller than the entire block of the engine. You are correct if we were planning on cooling the entire block, which would take 10 years with a push or a pull fan. But no, we only need a few minutes of cooling. The sinking power of the block verses fuel components is quite substantial. By blowing (pushing) cooler air hits these components at the same time, yet the fuel components will be effected the fastest and that is what is needed under these conditions. Early experiments somewhat proved this however until it is physically implemented anything can happen. Although heat rises, we are blowing so much cooler air over these components, we only need a small amount to satisfy the vapor lock. The right way to do this is with a temperature sensor on the fuel lines themselves set to some pre-deterimined temperature. This can be done digitally along with some timing numbers as per what Tim mentions on power up and power off. Here is where software is a good thing and can be done very accurately. After the initial tests, then measurements would have to be made to determine the correct numbers. Then it is the task of writing code that can satisfy it.

Not easy in the electronics but may be less disturbance to the engine area mechanically for the install.

Just some thoughts. Another month before my LE gets out of body and paint. Will start that process when she comes home.

My company owns its own Printed Circuit board machine that can do double layer boards. If I can get it to that level, we can store the file and make them on demand.

MT

If I wanted to wire a fan to run-on after turning the engine off, how would I connect it to a relay? Should I run power from the battery to both terminal 30 (which is usually constant power from the battery) and also to terminal 86 (which is usually switched power)?

Quote:

---

Originally Posted by scotty

If I wanted to wire a fan to run-on after turning the engine off, how would I connect it to a relay? Should I run power from the battery to both terminal 30 (which is usually constant power from the battery) and also to terminal 86 (which is usually switched power)?

---

w/o the engine circulating coolant, what would this achieve? unless you were referring to the interior cabin fan?

Edit: oh never mind, guess i should read more than one post in a thread. :doh:

Quote:

---

Originally Posted by timsrv

I started using my 86 van again after 13 years of it sitting in the black berries. I remember 1 or 2 times I had heat soak issues back in the 90's but nothing like now. As stated earlier I believe this is due to changes in the gasoline market over the past few years (lower boiling temperatures). Anyhow, even this time of year it's been giving me fits so I put my mind to finding a cure. I didn't want to spend a bunch of money and time with electric fans, shrouds, thermostats, etc so I came up with a compromise. I've been running/testing this for about a week now & it's been working flawlessly.

I had an old 11" electric fan laying around & decided to use it. I took my fan shroud off & took some measurements. I found there was more than enough room to install the fan directly to the engine side of the radiator so I put it there :dance2:.

http://i8.photobucket.com/albums/a23...psd96bcb88.jpg

http://i8.photobucket.com/albums/a23...psb0cf7a23.jpg

---

Hi Tim - I found this thread while researching electric fan options to cool my van when sitting in traffic with my A/C on. I like this electric fan location the most, and wanted to reach out and see if you think this fan location is reasonable for a second fan while driving around.

My fan clutch is in great condition and keeps the van cool with the A/C off (and when driving with the A/C on) but my temps will creep to 201 F when A/C is on and I am sitting still in the GA heat.

Would you share your input on if this electric fan location would theoretically work for my use case, assuming I hooked up a pull fan. Any thoughts or concerns would be appreciated!

Thanks,
Hugh