Thanks Tim,
found his thread and have all the part numbers etc.
J
Thanks Tim,
found his thread and have all the part numbers etc.
J
Cirrus - You may want to make note that Tim's set-up, while a good design in theory, left him with two blown engines. Its one of the first things he mentions in regards to the design.
I think when I finally install an electric fan I won't be removing the clutch fan. It is way too efficient at cooling the engine. Others have installed a smaller auxiliary fan, in addition to the clutch fan, to just deal with the hot soak. If the thermostat fails then you're not out an engine... you only have to deal with hot soak. I realize the clutch fans have their problems too & failed units have been the cause of many engine deaths as well.
Also, so you know, there are companies out there that will build you a shroud when you order the fan. I don't have any of this information collected at the moment but I know out in San Diego you can very easily find someone to take care of this for you if you don't have the tools, material, or motivation.
One last thing that I pondered, in regards to Tim's experience with his thermostats - I know there are units that hook-up into the radiator hose. Perhaps these thermostat's - while not as 'clean' in design - are more reliable. I'm not sure, but its something that I wondered.
Good luck, & let us know what you decide to do & inform us of the results.
Thanks Foreverly,
previous owner said cooling was not and issue and that seems to be the case so far, but my hot soak issue is bad. So far Ive settled on pumping the gas paddle 3 to 5 times and then try to start. Starts after 3 tries or so then I give throttle until it smooths out after a minute or so. I am having a hard time finding a mechanic who works on them but I PM'd Trestlehed to get his guy as we live very close to each other I think. I am going in for an oil change on Tuesday and will ask them too about adding a fan but I don't think they are very familiar with TV's. Also, I have to smog it so I am thinking of waiting until I see how I do at that first! I have my fingers crossed! Thanks for the heads up. I will search for the aux fan threads.
john
John, you might want to read through some of the Hot Soak & Electric Fan threads over at TVP. If your hot soak is that bad you might want to try some of the other remedies until you get yourself a fan.
Instead of going to a regular mechanic you might want to find a classic car guy as Hot Soak is a problem on many late model vehicles. I helped my friend restore his 1943 Ford that his grandpa bought brand new. He had hot soak problems all the time with that car here in Austin.
Some of the coastal towns in TX have gas stations that stock ethanol free gas. Have you checked your area for ethanol free gas stations? There is a website out there that lists them all by state.
Who said anything about blowing engines? When my thermostats failed it did lead to overheat conditions (both times) but these were not severe overheats, just enough to get my attention, annoy me, and leave me with a confidence problem with the capillary style t-stat design. The flex-a-lite variable speed electronic t-stat I'm trying now gives me that "warm fuzzy" feeling, but only time will tell if it's going to last. That being said, foreverly's position does have merit. I go back & forth in my head when it comes to clutch fan vs electric. There are pros and cons to either way you go. A correctly functioning clutch fan will move more air at high RPMs, but the engine also works harder generating more heat while doing that. The beauty of the electric fan set-up is it will cool at maximum rate while your engine is at rest. To me that's the clincher that sells me on electric. Of course there's a down-side. An electric fan set-up will increase the load on an already fragile alternator.........and if the alternator fails.........battery goes dead quickly...........and no more electric fan.........or anything else (bad). It sucks when that happens.Originally Posted by foreverly
Of course the other advantage to electric is it can be used to combat the heat soak issue (clutch cannot). If you aren't ready to give up your clutch fan, an alternative could be installing a pusher fan to the front of the radiator (or AC condenser if you have one of those in front of the radiator). The t-stat could be set up the same as mine or it could be put through the fins in the radiator. FWIW, initially I ran my t-stat by putting the probe in the radiator fins. It worked okay but I didn't like the response time. Heat transfer was delayed and performance was poor (thermostat would not consistently kick in until van was already running too hot). Submersing t-stat probe directly in the coolant was the answer. Direct contact with coolant gives instant response and fans come on predictably every time. Tim
Thank you for correcting me. My memory is sometimes warm & fuzzy too, I apologize.For some reason I was in the understanding that you blew head gaskets before you realized the fans weren't working properly.
Thank you for the additional information regarding T-Stat placement.
I thought I'd comment on a work-around, if someone hasn't gotten around to upgrading the fans/cooling. I've experienced the hot-soak occasionally. When I feel that there is potential for the problem, I would let the starter run on for a couple of seconds more than a "normal" starting duration. There is the "intuitional" turn the key and quit when the engine starts, that you do every morning or after a considerable cool-down. By adding maybe a second or two, to that interval, with the starter assisiting in getting the fuel moving through has worked for me.
I'm citing this from memory, though, as I don't really seem to experience the issue much/at all any more. I'm not sure if it is coincidental, or not, but the problem seemed to clear up after I replaced the thermostat with an OEM Toyota thermostat (coolant, not fan control). I know I've heard Tim (and others) specify using that OEM thermostat and wonder if it is intended to help with this? It is constructed much differently than a Napa (or other) aftermarket thermostat.
Anyway, my $.02
Hey Cirrus, I just replied to your PM so check your inbox.
In the mean time, here is a thread concerning a "Cheap and Easy" heat-soak remedy.
Just prop your engine lid open after driving to vent the engine bay. Keeping the windows cracked about an inch or so is a good idea so when you get back to your van it's not an oven inside:
http://www.toyotavantech.com/forum/s...ng-some-parts!
Last edited by trestlehed; 02-05-2013 at 02:57 PM. Reason: .
"You came in that thing?... You're braver than I thought!" - Princess Leia
Well that link goes to the thread about making the engine lid / seat holder out of bulk wire, but I think what we are all beating around the bush about is you may want to cut & ground the temp. switch wire.
Tim mentions it in his blog post about hot soak. It is the switch that has one scrawny wire going to it below the radiator cap.
I haven't tried it - it may help a bit but from what I've gleaned its not going to fix the hot soak problem. I wish I could get my hands on one of those updated fuel pressure regulators though.
I was really hoping to hear from Arp on this thread. His posts at TVP indicate he has been through the gamut but in the end installed an aux. fan, keeping the clutch fan. I'm really curious about his setup.
Oh, I just found his contact info, but he sold his van...
ok I'm back by special request
I did sell my van with a fully functional hot soak fix which had been working nicely for about two years. I tried to keep it simple, kept the stock fan clutch setup and added a single pusher fan to the front of the radiator. Don't have the van or details but here's what I remember.
I went to the local Schucks (now O'Reilleys) and asked for a single aux. radiator fan of the correct size to fit on the front of the radiator (Thinline fan or something like that, there's not much room up there), and a thermostat kit to hook it up to. The adjustable thermostat unit had a metal probe maybe half the dimensions of a pencil which I zip-tied to a return fuel line right above the fuel rail (where I assumed the fuel vaporization ocurrs). Very simple, didn't submerge in coolant or anything like that. The fan had these attachments (rod like I think) that went through the radiator fins and a disk went over them on the other side and held the fan on. I attached the thermostat to the firewall right above the air element and hooked it up to unswitched power at the little + electrical connector box near the engine/air cleaner box (I believe there was a fuse in line here).
I set the adjustable thermostat so that it generally did not come on when the vehicle was operating (except once - see below). But usually, especially on hot days it would come on a few minutes after shutting the engine down as heat built up in the engine compartment. Depending on how hot the day/engine was it would cycle on and off for up to half an hour after engine shut down. I told people the elves were vacuuming in the van. Never had a problem with hot soak after this. Of course you need to make sure you keep a good battery in the vehicle with this set-up, although I never had a problem with that either.
Seriously, this was one of the easiest jobs I ever did on the van, only took a few hours I think (usually anything I did on the van stretched towards midnight if not the next day), and the results were spectacular. The hardest part was getting to the bolts holding the radiator on so I could rock it backwards and install the fan on the front of it (no need to remove it completely or disconnect hoses). I went through all the other ideas for a fix and all were unscuccessful until this one.
One advantage to this approach is you now have both kinds of cooling systems, if one fails you can fall back on the other at least temporarilly. My replacement vehicle (2004 Dodge Dakota crew cab) has both the fan clutch and aux. fan stock, though the needle has never strayed far from the 1/3rd spotand I've never heard the aux. fan come on. It may be overkill on this vehicle unless you're towing a load.
One summer after the fix I had a fully loaded van (for camping with the family) and the family, car top carrier the whole bit, pulling the grade out of Zion canyon in stop and go traffic, maybe 30 mph when moving. It was around 110 -115 F outside. AC full on. The worst possible conditions on Earth for overheating! My attention was riveted to the temperature guage. A few miles before the tunnel the needle got to 3/4's with the fan clutch already fully engaged, and I started sweating bullets. Then I heard the electric fan kick on and the guage maintained until we made it to safety (cooler temps) in the tunnel. I'm convinced the electric fan kept me from an overheat on that day.
Good luck Y'all!
Thanks to everyone who has replied on this thread......... ARP, thats sounds like a winner. I have an Oreillys right near work so I will pop in there tomorrow. I have AC so that may hamper things a bit but I am sure I will figure something out. Thanks again to everyone for pitching in with ideas. I will fully document what I do and post pics. etc.
Cirrus
I think I set the thermostat to trigger at 185 F, and that was real close to resulting in operation as described above. Each van might require a little different setting.
I had AC also but not rear air where I think there's a condensor on the front of the radiator? The front of my radiator was clear.
Thank you Arp - this fix might be easier than the original TSB.
Cirrus - be sure to measure the gap before the radiator so you know how thick of a fan will fit in that space.
After a few other projects I'll be right behind you on this one, so let me know what fan & t-stat you end-up with.
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.
Since my intent is only to ventilate the engine compartment after shut down I don't need to worry about a custom shroud or a thermostat. I decided running the fan for 15 minutes after shut down would be sufficient, so I purchased a 12V "delay off" timer. The timer I chose was the Durite #0-740-57 programmed for 15 minutes. This relay was way overpriced, but I liked it due to the type of trigger it uses & because it fits into a standard Bosch relay harness. Coupled with a standard Bosch relay, a capacitor, & a diode I was able to construct a circuit that would activate the fan for 15 minutes every time the van engine is shut off (see PDF file attached to this post). Here's what it looks like:
Due to space and ease of installation I decided to put it behind the glove box. My van is pre-wired for an ice-maker but doesn't have one, so I'm using the ice maker harness to supply 12V ignition switched power source (this circuit is only activated when the key is in the "run" position). Also lot's of good places here to tap ground.
I put the override switch down by my right knee. This switch will activate fan only when key is in "Run" position. I probably won't use this, but it might come in handy during the summer while I'm using my AC.
It's pretty cool to have this thing come on and go off based on time. My other van with the thermostat control will switch the fans on/off for about 20 min after shut down. I like the constant 15 minutes of fan much better than the on/off, on/off of the thermostat set-up, so now I'm thinking of adding this delay to my other van with the t-stat control. Tim
Awesome Tim!
I think the override switch is a great idea. Does the switch have an 'off' setting too? There doesn't seem to be a reason to run the system during the winter. & even sometimes during the summer, I think I would want to have quiet moments.
I didn't wire an off switch into the system but I also was thinking it would be nice. I had to move the van a couple times this weekend (just a few feet), but then the fan runs for 15 min.. It would be easy to do, but then easy to forget it's off. I may incorporate a temperature switch so it only activates when the engine compartment is over 200 deg. It's still awesome the way it is (compared to heat soak). I was experiencing start problems almost every time the van was warm. Since I put this in it hasn't happened once
If I remember right I think I pulled it from something in a salvage yard years ago. Here's a similar one on eBay: http://www.ebay.com/itm/New-Turbo-Sw...4edc82&vxp=mtr
I did some research / cross referencing & came up with a temperature switch that activates (closes contacts) at 170 deg F. Since I have my thermal switch for the "pressure-up" disconnected & grounded, I'm going to put this switch into that port on my filler neck. The switch I found is AIRTEX Part # 1S4382. It has M16 X 1.5 threads (same as our sensor ports). Other numbers that came up in the cross reference are: 21595M4960, 21595M4961, 88923732, & SW542. I'm going to wire it in series with the ignition coil side of the timer so the 15 minutes of automatic fan will only occur after the ignition has been turned on/off & engine coolant temperature is above 170 deg F. It was a bit expensive, I found it on www.rockauto.com for $49.79. I suspect if I would have searched a bit more I could have done better. I'll post pics of it installed & report back on performance. Here's a file picture I found of the switch:
I installed the temperature switch tonight & wired it into the circuit. The over-ride switch will still work like before, but the automatic 15 minutes of fan after shut-down won't occur unless the coolant temperature is over 170 deg F. The only "hiccup" was the probe end of the switch was too big diameter to fit into the bore of the "pressure-up" switch. So I took the filler neck off and drilled the bore out to 1/2" and then it fit fine.
The bore was smaller for the old switch because Toyota uses the smaller bore to seal against the shoulder of the brass switch. Since this switch doesn't have a shoulder I'm using a copper crush washer to seal the new switch.
Here's the switch after I've installed and wired it.
Here's the path I chose for the wire run. Note: To protect from chaffing I'm using a piece of pex tubing where the wire passes through the body.
I wired this switch in series with the coil side of the timer relay. Here's a PDF file to show how the switch is wired into the timer circuit. Tim
Very Cool. This is better than having an off switch.
But I love what would have made this impossible for me is just a little hiccup for you. Congratulations on sticking with your idea & seeing it through.
Posting Permissions
Reply With Quote
