Horrible overheating issue

Hello TVT!!! Thanks for what everyone does to help keep our vans rollin.

Ok...I replaced fan clutch, t-stat, and water pump with all OEM parts yet my van still overheats with 6-8 miles of driving. Idling in my driveway the van's temp needle will hover around 50%. If I take the van out for a drive, I am lucky to get 8 miles before the van hits about 85% on the temp needle. The overflow container begins to violently bubble so loud I can hear it before popping the hood.

I am starting to wonder if Im having a partial HG failure that shows itself once the van gets hot (expands) showing holes that are non-existant at lower temps or if the extra comprssion from accelerating is pushing the compression gases into my water jackets.I have seen none of the typical signs of a full blown HG but Im lost as to what else to do with my Yota Beast.:cnfsd:

Any insight would be wonderful. Thanks.

Im gettin a beer to help with my brainstormin and mostly my sanity:drunk:

Welcome to the site. We just had a discussion about cooling issues. Here is a link to that thread: http://www.toyotavantech.com/forum/s...rom-Vancouver-!

Much of what was outlined there applies to you. I didn't discuss head gaskets (that was part of the 10% I didn't discuss) but it is a possibility. Does any coolant blow out your overflow before the temp gauge hits 75%? Does it lose any coolant other than when it overheats? Is there white smoke coming from the exhaust? Can you smell antifreeze at the exhaust when the van is running?

Pull your spark plugs and inspect the electrode areas. They should all appear the same. If you have one that's noticeably different (beat-up looking and/or super clean), that's an indication of a mildly blown head gasket at that cylinder. Tim

Quote:

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Originally Posted by timsrv

Welcome to the site. We just had a discussion about cooling issues. Here is a link to that thread: http://www.toyotavantech.com/forum/s...rom-Vancouver-!

Much of what was outlined there applies to you. I didn't discuss head gaskets (that was part of the 10% I didn't discuss) but it is a possibility. Does any coolant blow out your overflow before the temp gauge hits 75%? Does it lose any coolant other than when it overheats? Is there white smoke coming from the exhaust? Can you smell antifreeze at the exhaust when the van is running?

Pull your spark plugs and inspect the electrode areas. They should all appear the same. If you have one that's noticeably different (beat-up looking and/or super clean), that's an indication of a mildly blown head gasket at that cylinder. Tim

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Thanks for the fast reply Tim.
The temp needle can be at 50% and I will have a rumbling in the overflow that will drain it dry. It doesnt seem like the van needs to overheat to blow coolant into the overflow. I havent noticed any other coolant loss yet ,but, tonight I did hear some liquid that sounded as if it was coming out of the hose of death area( time to cut an access :LOL2:) I also noticed my heater blows cool and I do get an occasional puff of white smoke from the exhaust upon start up.

I will def check the electrode areas tomorrow as well as cut an access to the hose of death.

Thanks Tim. From the posts Ive read from you. I decided to buy as much yota OEM stuff I can get. Take for instance my water pump. Brand new aftermarket pump from napa was $40. The OEM pump from the yota dealer here in town $54....wasnt a hard decision to buy yota's pump.

If it's blowing coolant out the overflow at 50% of temp then that sounds like a bad head gasket. Pulling plugs and checking electrodes should confirm this. If the plug inspection is inconclusive you could use a sniffer to look for exhaust gas in the cooling system. An auto repair shop can do this for a fee or you could purchase a kit from Napa and do it yourself.

I just did another "hose of death" last weekend and took some more pics. I'm posting them to the "Hose of death" thread now. Here's a link: http://www.toyotavantech.com/forum/s...=2244#post2244 Tim

I doubt this would be the problem, but you should always start with the easy stuff first. Make sure you have a new rad cap. If your cap isn't holding in pressure, that will work against you.

Oh, and I forgot to add, make sure your radiator is ok. I could drive my van at low speeds, say below 45mph, and it was fine, but as soon as I went faster it got really hot. I had the radiator recored, and saw vast improvement. Now I may just need a new fan clutch in order to be able to drive 75 or 80, but even when I do that I'm probably only at 60% right now.

Sure sounds like a BHG

Thanks for the responses everyone :)

I've decided to go ahead with replacement of the head gasket along with my cracked exhaust manifold. I am also pulling the radiator to have it recored but was wondering.

Should I buy the parts to install the e-fan upgrade since Im going to have the yota torn down anyways? And also. Im not a big fan of A/C so I was thinking of removing its components. Is it worth the time?

If you don't think you'll ever want AC, then yes, it's worth getting it out of there. I wouldn't worry about the evaporator(s), but I'd pull the condenser(s) and the compressor out. This will allow for better ventilation to the front of your radiator and it would be nice to drop the extra lbs.

As for switching to electric fans 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 so. 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.

Most of the time when you develop a cooling system problem it's a common failure like an internally clogged up radiator, debris blocking airflow through radiator, fan clutch failure, bad thermostat, cooling system leak, bad radiator cap, etc, etc, etc). Fortunately, all is fine again once found and resolved.

Another possibility is to leave the clutch fan and install an electric pusher fan in front of the radiator. I put a single 15" pusher there on my 86. It stays off most of the time but I turn it on while running the AC on a hot day. An added plus is it could be rigged up to a t-stat (like shown below) for automatic operation while it's needed. If you wire it to a battery circuit (on while ignition is off) it will keep the engine compartment cool after shut-down and will prevent the "hot soak" problem from occurring.

If you decide to go completely electric, here's my home made fan shroud project that I installed on my 89 cargo van. Flex-a-Lite makes a universal kit with shroud included, but I much prefer the perfect fit of a custom unit.

The shroud is made of 22 ga galvanized sheet metal and soldered at the seams with 50/50 solder. It is made to perfectly fit (2) 10" electric fans. Here it is before cutting out the fan holes. Note: There's a relief in the lower left so there's room to run the transmission cooler hose.
http://i8.photobucket.com/albums/a23/timsrv/shroud3.jpg

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

An internet search revealed that the "S-blade" style fans move the most air and are also the quietest. For these reasons I ended up going with this style fan. These are rated at 1900 cfm @ 6.8 amps each (the highest CFM available for 10" fans).
http://i8.photobucket.com/albums/a23...shroudfans.jpg

http://i8.photobucket.com/albums/a23...hroudfans1.jpg

To get direct contact with coolant (for best temp control) I removed the plug that was in the head (marked extra unused port).
http://i8.photobucket.com/albums/a23...TempSender.jpg

The adjustable thermostat I'm using to make my fans turn off and on is a capillary type with a 1/4" sensor probe on the end. To make the transition from the 1/4" sensor to 16mm X 1.5 pitch threads (the size of the extra unused port), I purchased a brass adaptor at the local hardware store. It originally was 3/8"mpt on one end and 1/4" compression on the other (these are readily available). I also purchased a 16mm X 1.5 die and simply chased the slightly larger 3/8" threads to convert to metric. The larger size 3/8 pipe thread was almost too big to chase without turning in a lathe, but with a little effort and patience this can be done by hand with only a vice and hand threading tools. After chasing, the new metric threads are perfect. You cannot even tell it was ever a standard 3/8 pipe thread :P . See the t-stat and modified brass adaptor below:
http://i8.photobucket.com/albums/a23/timsrv/t-stat.jpg

Here is the brass adaptor and the probe installed into the extra unused port.
http://i8.photobucket.com/albums/a23...r/IMG_8970.jpg

And here is the completed project.
http://i8.photobucket.com/albums/a23...r/IMG_8968.jpg

http://i8.photobucket.com/albums/a23...r/IMG_8971.jpg

I have been driving this for almost 3 years and I'm happy with the performance.

Tim...that is one clean engine. Your shroud and e-fan set-up is sweet. Kudos!

I think I will go with the pusher fan recommendation since I just replaced the fan clutch. I like the idea of having it run while the engine is off so that is a must.

I will also be removing the A/C. I live in the south but oh well, the ocean breeze is nice, the van will be happier, and I can hang my arm out of the window :LOL2:

There was a post written, Im almost positive by Tim, which mentioned the purchase of these parts for an easier life:

Toyota Part Number
Studs
-90116-10058 Qty:3
-92122-40610 Qty:6
-90116-08128 Qty:2

Nuts

-90179-10070 Qty:3
-90179-06194 Qty:6
-90179-08059 Qty:2

I have read sooooo many thread/topics lately they are starting to blur together lol.

What were these parts for Tim?

I'm going to replace my exhaust manifold too so I'm interested in purchasing these if they will make this head gasket/exhaust manifold replacement easier.

Thank you much Tim

Your new manifold will arrive as the casting only. No studs or nuts are included. You will need to remove the heat shield from the old one and transfer to the new. The 6 studs and nuts that hold it on will almost certainly break off when you remove it. Then there are the 2 studs and nuts that hold on the o2 sensor/plate, then there's the 3 studs and nuts that hold the down-pipe to the manifold. Even if you are successful in removing the old studs and nuts I wouldn't recommend re-using them because they lose strength over time due to the severe service of these locations. Tim

Quote:

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Originally Posted by timsrv

Your new manifold will arrive as the casting only. No studs or nuts are included. You will need to remove the heat shield from the old one and transfer to the new. The 6 studs and nuts that hold it on will almost certainly break off when you remove it. Then there are the 2 studs and nuts that hold on the o2 sensor/plate, then there's the 3 studs and nuts that hold the down-pipe to the manifold. Even if you are successful in removing the old studs and nuts I wouldn't recommend re-using them because they lose strength over time due to the severe service of these locations. Tim

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Thanks for the insight.
Im going to take your advice and buy those parts, it would be silly not to based on your conclusions...it just makes sense.

Sorry if I got a bit off-topic...my van needs a lot of TLC

Here is a pic of my blown head gasket.

http://i1095.photobucket.com/albums/...ketfailure.jpg

Looks like you made the right call. That thing is blown bad. I'm surprised you didn't see a bunch of coolant leaking down the back of your engine block. Tim

Quote:

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Originally Posted by timsrv

Looks like you made the right call. That thing is blown bad. I'm surprised you didn't see a bunch of coolant leaking down the back of your engine block. Tim

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At first I thought the "hose of death" was where my coolant was coming from on the back side of the engine. I replaced the hose and coolant came out in a stream right where my head gasket had failed. So far the block and head look good

could I use that port for an aftermarket temp gauge? How did you remove the plug from the engine(looks like an allenwrench)

Yes, this would be a good place for an aftermarket temp gauge. Due to the length from the engine to the dash I would recommend going with an electric gauge. They are a bit more expensive, but it's a lot easier running a wire than running a capillary tube with a bulb (and you're not limited by a pre-set length). If I remember right you'll need an 8mm allen wrench and a bit of luck to get that plug out (they can get stuck in there good). The thread size is 16mm X 1.5 pitch, so you'll need a sending unit with these threads or a suitable adapter to make the transition. Tim

I figured the plug would be seized ill soak it w/liquidwrench. Im planning to cut new threads on a3/8"adapter where should look for a 16/1.5 die? Thankyou so much!

Dies can be found many places including Amazon. My thermostat was a special case because it was a capillary tube type and that type of compression adapter was not readily available. An electric sending unit will most likely be threaded and adapters for those should be much easier to find. As long as you are purchasing an electric temperature gauge, it will likely come with the required bushing/adapter. If not, most performance oriented auto parts stores will have the correct adapters in stock. Even Napa should have the right one for the job. Tim

FWIW, the brass fitting you see in the lower left position (where the OD thermo switch should be) is the sending unit for my aftermarket electric temperature gauge. This port is also 16mm X 1.5 pitch and the adapter I needed came with the gauge kit.
http://i8.photobucket.com/albums/a23...r/IMG_8970.jpg

Quote:

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Originally Posted by timsrv

If it's blowing coolant out the overflow at 50% of temp then that sounds like a bad head gasket. Pulling plugs and checking electrodes should confirm this. If the plug inspection is inconclusive you could use a sniffer to look for exhaust gas in the cooling system. An auto repair shop can do this for a fee or you could purchase a kit from Napa and do it yourself.

I just did another "hose of death" last weekend and took some more pics. I'm posting them to the "Hose of death" thread now. Here's a link: http://www.toyotavantech.com/forum/s...=2244#post2244 Tim

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Hello all, I've got similar happenings with my 87' that I'm hoping you can give me some insight on. I'm able to drive it around the city with literally no issue, coolant does it's thing; pushes into the overflow then sucks back into the radiator after cooling down. However, after driving for about 2 hours (temp stays right where it should) coolant will start pushing out of the overflow and onto the ground. Not until the radiator gets low on coolant will the temp start climbing.

So I started by replacing the radiator cap and all hose between my neck and overflow tank. Coolant looks clean peering into it. It passed a combustion test although I do see small bubbles peering into the neck while running and revving. Just checked my plugs and they look as they should. No white smoke or coolant smells coming from the exhaust. Put a temp gun on the radiator and hoses to check for inconsistent temp, but all was good.

I'm convinced it's head or gasket related and I'll gladly do the job, but just want to be sure and rule out any other possibilities. Thx in advance! Jared

Sounds like a small gasket leak for sure, which is the beginning of the gasket failing. The longer you drive, the more pressure (typically from a break between the combustion chamber and the cooling ports) is building up in the cooling system, giving you bubbles at first and push out of the overflow later. I drove mine like this forever before finally doing the whole thing -- I was in denial until it got steadily worse!

I never saw smoke, never had any real issue with running poorly - though it did feel sluggish, just the bubbles and the occasional overheat due to lack of coolant. This was what my gasket looked like when I removed it:

https://imgur.com/8a8cd446-7e7a-4fa7-8d62-91ad0ff2da89
https://imgur.com/a/TU2Jj1nhttps://imgur.com/a/TU2Jj1nhttps://imgur.com/a/TU2Jj1nhttps://i.imgur.com/jvxrzco.jpg

At this age, the failure seems like a feature, not a bug. If you fix the gasket, make sure to reference the site for all the other things that need repair to keep the cooling system in top shape.

Quote:

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Originally Posted by Beatrice87

Hello all, I've got similar happenings with my 87' that I'm hoping you can give me some insight on. I'm able to drive it around the city with literally no issue, coolant does it's thing; pushes into the overflow then sucks back into the radiator after cooling down. However, after driving for about 2 hours (temp stays right where it should) coolant will start pushing out of the overflow and onto the ground. Not until the radiator gets low on coolant will the temp start climbing.

So I started by replacing the radiator cap and all hose between my neck and overflow tank. Coolant looks clean peering into it. It passed a combustion test although I do see small bubbles peering into the neck while running and revving. Just checked my plugs and they look as they should. No white smoke or coolant smells coming from the exhaust. Put a temp gun on the radiator and hoses to check for inconsistent temp, but all was good.

I'm convinced it's head or gasket related and I'll gladly do the job, but just want to be sure and rule out any other possibilities. Thx in advance! Jared

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It doesn't sound like a bad gasket yet, but.........on these older vehicles, I can understand (can even agree with) just doing a head gasket to rule it out and make the van more reliable. And I'm not talking about only the head gasket. Pulling the head gives you an excuse/opportunity to service/replace everything that can become problematic over the years. Even if the head gasket job wasn't required, it will some day (these only last so long) and knowing it's new will ease your mind while on the longer trips.

That being said, doing a thorough job using genuine and/or quality parts can be a bit expensive and time consuming, so it will require some planning. If you go that route, I would recommend doing the following:

*Take the radiator down to a radiator shop and have it boiled out & tested. Follow the advice of the radiator specialist. If it tests good, you can re-use, but if you have some extra money now would be a good time to have a high efficiency core installed. If you're thinking of just going all-out, then search the site for "Ability Radiator" as there are some good threads on the subject.

*Replace the Thermostat with a genuine Toyota part: https://www.toyotavantech.com/forum/...n-s-thermostat

*Replace the clutch fan with an Aisin: https://www.toyotavantech.com/forum/...3762#post13762

*Replace misc coolant hoses: https://www.toyotavantech.com/forum/...=2052#post2052

*Follow the advice outlined in this thread: https://www.toyotavantech.com/forum/...ng-Head-Gasket

Here's a thread I made during the last major service I did to my van's engine. It's a bit more extreme than your situation, but it has some good information there you might find helpful: http://www.toyotavantech.com/forum/s...ngine-Overhaul. BTW, I did that when the van had 204k miles on it. I'm now over 265k miles and other than some unrelated issues & routine maintenance, that van has been trouble free (but I still open my hood every 2k miles to check/top off oil)

If you're on a limited budget, then I'd focus more on identifying and replacing only the part(s) responsible (or the ones that break while gaining access :doh:). Good luck. Tim

Quote:

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Originally Posted by Grappler

Sounds like a small gasket leak for sure, which is the beginning of the gasket failing. The longer you drive, the more pressure (typically from a break between the combustion chamber and the cooling ports) is building up in the cooling system, giving you bubbles at first and push out of the overflow later. I drove mine like this forever before finally doing the whole thing -- I was in denial until it got steadily worse!

I never saw smoke, never had any real issue with running poorly - though it did feel sluggish, just the bubbles and the occasional overheat due to lack of coolant. This was what my gasket looked like when I removed it:

https://imgur.com/8a8cd446-7e7a-4fa7-8d62-91ad0ff2da89
https://imgur.com/a/TU2Jj1nhttps://imgur.com/a/TU2Jj1nhttps://imgur.com/a/TU2Jj1nhttps://i.imgur.com/jvxrzco.jpg

At this age, the failure seems like a feature, not a bug. If you fix the gasket, make sure to reference the site for all the other things that need repair to keep the cooling system in top shape.

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Thanks for all the advice and links! I bought my van almost 2yrs ago from a fellow in Nyc, that owner put a freshened up 4y in it that was professionally done. I bought it with around 20k on that motor and 200k on the actual body. Ran excellent until one hot day I was chugging up a hill and bam my temp spikes to almost red. I stopped immediately and noticed coolant gurgling out of the overflow and that my electric fans had stopped working. I can't imagine almost overheating it one time would damage a head gasket, that's why I was searching for a different cause. I've got access to a shop in two weeks, I'll keep yall posted on what I discover.

And @Grappler, did yours push coolant out the overflow then?

Quote:

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Originally Posted by Beatrice87

I can't imagine almost overheating it one time would damage a head gasket

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It absolutely CAN.

And, too, a slightly compromised HG can lead to "almost overheating" all by itself — ie, perhaps the damage was already done.

I understand and support the search to confirm what is going on — a head job isn't cheap or quick, and it would suck to pay for that or do it yourself and then discover the problem still exists. HOWEVER ... your van's coolant must be going SOMEWHERE, and a tiny HG breach will result in what you describe. Unless you can find where the coolant is leaving the water jacket OR some way that air is getting into the water jacket (causing temp increase due to inadequate cooling system pressure), the HG is the only thing left that makes sense.

Gwen

Replaced my head this weekend and noticed my vacuum valve port on the new head is smaller than on the old. Anyone else run into this? I'm guessing I should use a brass reducer to adapt it, but I was having trouble figuring out the thread pitch on the new head.... thanks for the info in advance, always helpful!

Hi all, I'm having an overheat issue. I had a catastrophic overheat on a longish trip, that involved my water pump blowing up on the highway. towed the car home, replaced water pump (Aisin) fan clutch (aisin) thermostat (Toyota) radiator hoses (gates) and fresh coolant. that was 18 months ago and its run great ever since. a few days ago while driving it overheated, luckily close to home. I let it cool off and limped home. I just checked temps with an IR thermometer at idle. 120 on top hose 94 on bottom, 80 in the radiator and 300 on then engine head.

it seems to me like a circulation issue to me. v belt is fine and coolant looks clean. all the major cooling system parts are relatively new. I would love to hear thoughts on what might be going wrong?

I figured it out sort of. overheating was caused by a lack of coolant in the radiator (duh), but there was plenty in the overflow tank. I drained it, refilled it and the engine is running fine. I replaced the radiator cap but there still seems to be coolant boiling off and not returning to the system as it cools. I'm thinking there must be a pinhole leak that I'm not seeing somewhere in the overflow system that is preventing vacuum from sucking the fluid back in.

Check the hose that runs from your radiator to your overflow tank, it could be clogged with gunk preventing flow.

Also check the metal tube that comes off the radiator coolant filler assembly. The metal tube on mine was rusted/corroded
and clogged which prevented flow to/from the overflow tank.

mine is a bit rusty on the outside, but the hose is clear

Cooling systems, at least the flowing part, work on basic hydraulics theory.

So if you have a jug, filled with fluid, attached to a device that is also filled with fluid, assuming there is no air in the system then when the coolant expands, the jug should fill and when the coolant cools it contracts, (the reservoir level drops as coolant returns to the engine.)
When the coolant fails to return to the engine, it means there's a reason that the fluid can't flow back, either an air leak or a blockage.

Solving problems is about eliminating possibilities, nothing worse than introducing new variables when you're trying to solve one problem.

Was that new cap a new Toyota cap, something from the local supplier or a spare from your parts bin.
I only ask because the first option guarantees a known part
The 2nd one could be hit or miss depending on the ability of the parts guy and the spec's of that particular cap
3rd only works if you're SURE you know the status of your used part.

Another thing to ponder:
Old/hard rubber hoses will be less likely to be able to form a seal over a little corrosion (They are also incredibly cheap/easy to replace.)
Also note that that particular hose could feasibly leak air under suction but not leak coolant when under pressure, leaving no evidence of its fault.

Quote:

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Originally Posted by pryter

I figured it out sort of. overheating was caused by a lack of coolant in the radiator (duh), but there was plenty in the overflow tank. I drained it, refilled it and the engine is running fine. I replaced the radiator cap but there still seems to be coolant boiling off and not returning to the system as it cools. I'm thinking there must be a pinhole leak that I'm not seeing somewhere in the overflow system that is preventing vacuum from sucking the fluid back in.

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Sorry, also forgot to mention: Back in the day when I was having a terrible time trying to figure out where my coolant
was going (similar problem to yours) my mechanic was doing the "hose of death" project and discovered that the coolant outlet plate (on the back of the engine which is attached to the hose of death) was corroded and had tons of tiny pinholes in it. So the theory is that while hot and under pressure, the coolant was being forced out the pinholes and evaporating on the rear of the engine leaving no visible sign of a leak.

Something to check if you have no luck elsewhere.

Attachment 10591

Another commonly overlooked problem is pitting/corrosion inside the filler neck where the rubber seal of the radiator cap contacts it. Check that surface carefully to make sure the raised ring in there is not compromised.

Pressure is a much more reliable way to move fluid than vacuum. Expanding coolant has no choice but to flow the path of least resistance. That path is typically through the overflow hose and into the recovery tank. After shut-down, as the fluid cools it contracts in the engine and that creates a vacuum. If there are no breaches anywhere in the system and your recovery tank hose is below the fluid level, it will suck it back into the engine. However, if there is even the smallest of pin-holes in the system, since air moves easier than liquid, it will suck air and leave the coolant in the tank. Tim