I am new to this forum, but have been driving an 89 Toyota 4wd for many (24) years, it has the 22RE engine. Now I just bought my first 4Runner. It is a 1994 with the 3VZE-E 3.0L 6 cylinder engine. The head gasket was recalled and repaired in 1998, but apparently the repair did not last very long. The previous owner to the guy I just bought the 4Runner from apparently had problems, and sold the "kid" the truck with this issue. As soon as I opened the hood I saw the telltale signs of a head gasket SOLUTION repair gone wrong... white sodium silicate splattered over the front half of the motor. I quizzed him about it, and he finally admitted that they had used the K&M (?) version of head gasket repair solution, but did NOT remove the thermostat. I bought the 94 at a reduced price, and drove it home 30 miles on the interstate at highway speeds. The 4Runner did NOT overheat, and I did not need to add any water along the way. However it did suffer from a loss of power and had issues shifting the automatic transmission.

I just finished flushing the chunks out of the cooling system by taking off the upper and lower radiator hoses and running lots of water through the system until no visible junk was in the system.

I know the right thing to do is either brow beat the local dealership into re-doing the head gasket (fat chance) or tear off the heads and do proper head gasket job, replace the water pump, timing chain, and maybe have the block milled too.

BUT here are my questions.

1) I assume the thermostat is on the lower hose where it goes into the block?

2) Since this engine does not seem to have a real catastophic issue with coolant seeping into the oil, only outgasing through the radiator, I ASSUME it is a small leak.

3) Has anyone had success using "blue devil" for a repair of this (small) magnitude?

Dropping a thousand dollars into this vehicle is going to take some real convincing.

Thanks.

P.S. Does anyone have a digital owner's manual? I already have an FSM, but would like an OM to see how to work the switches etcetera.

So, how does the truck run? You said you drove it home, and it did not overheat, nor is the motor oil getting contaminated? The truck seems slow and underpowered? Well thats normal lol.

It is just losing a lot of coolant and smells of burning coolant?

The reason I ask is, a lot of people misdiagnose a blown head gasket when the real issue is a leaking coolant tube (small) under the intake plenum near the firewall and between the valve covers. The coolant sits between the covers and boils off, making the truck smell of coolant. When the tube has a leak, it can consume something like a quart of coolant a month or even more.

Worth looking into.

I also know of putting a bottle of the dealership Subaru coolant conditioner (the one that subaru requires to keep the car in warranty) to stop mystery consumption on the 3VZE. Also worth a shot, it is a mild Holts stop leak, but not a stop leak that will gum up the system. Subaru has great success with it and I have seen it work on a 3VZE.

These are the small cheap steps, even cheaper than the bottle of head gasket sealer.

Try these first, completely harmless on the truck and on your wallet.

And, you assume correctly about the thermostat. The lower hose attaches to the thermostat housing, which is held on by three nuts on studs. If you have the cooling fan and shroud off, it's not too hard to get it off and out of there.

There are bubbles in the radiator water. While I did drive it 30 miles on the interstate, it did shift poorly, and had some high speed "missing" that was more like a jolt that a smooth miss. The shifting point was seemingly too high 4000rpm, and the previous owner's mechanic had diagnosed it thusly. Am I wrong in assuming that a loss of power due to failed plug and incorrect block temperature will cause late shifting in these 4Runners? The new thermostat that I am waiting to put in is a 195 degree type. From what I have read on this forum it seems to be the preferred temperature. I am a little leary, because Florida is hot and traffic sucks.

I already have taken out the thermostat, cut all but the disc away and put in back with the old o-ring. Since I already have a half bottle of "Blue Devil" my mechanic friend suggested I try it, and then change the driver's side rear spark plug, which the previous owner's mechanic said is the cylinger around which the head gasket was failing... So I really have nothing to lose.

Most of my daily driving is just short jaunts, I do not have a real long commute to speak of. The farthest the 4Runner is likely to go is about 70 miles away to a favorite camping spot this winter...

I feel generally that reporting back on posts and threads really helps a forum, so I will report back once I dump the "Blue Devil" in tomorrow.

Your mechanic sounds legit because that is the most common area of head gasket failure.

this is the only OM i've found.
it's hit/miss when it works.
http://www.toyotaownersmanuals.com/b...nual-1995.html

There is a product called K&W head gasket repair that has been available for many, many years. It works, IF you follow the directions! I have known many people who have used it with great success and longevity. Another product came out that also got rave reviews and that was called Irontite. Not sure if that is still available or not. I am not affiliated with either of these products and have never been a fan of repairing head gaskets this way but sometimes finances are an issue or downtime may be a factor. Regardless, hope you get her fixed and back on the road.

I used the blue devil this weekend, successfully. I used 16oz of the quart bottle I had.

More importantly I spoke to a technical representative from the company that makes blue devil. The explanation I was given as to how their product works is that it only works one time once the temperature gets to 150 degrees Fahrenheit. So any of the solution that reaches that temperature, but DOES NOT come into contact with "air/gases" remains in solution. There should be no large chunks floating throughout the cooling system.
The main reason in the case of this v-6 engine to remove the thermostat (actually I cut the center out of the thermostat and used the o-ring to get it to seal properly) is to allow the product to flow through the block prior to the temperature reaching 150. This also insures that the product won't react with gases in the cooling system potentially caused by "cavitation" around the water pump impeller. This is also the reason that the directions say to let the vehicle IDLE for 50 minutes.

In my case the vehicle was not overheating at all during the use of the product. The temperature stayed right in the middle. The directions also say NOT to use their product in a vehicle that cannot successfully idle for 50 minutes without overheating. Just FYI.

After the first day of just idling the truck with the product flowing through the block, I let it cool down overnight. The next morning I drained 8 ounces of water from the system and added 8oz of blue devil. I let the truck idle again for an hour before taking it for a ten mile test drive.

No I have to replace the thermostat with a properly functioning one, and change out the driver's side rear spark plug. Then I will report back and see if the truck runs better... I think and hope it will.

Excited to hear the results. No justification for running a liquid head gasket repair is needed in a high mileage 3vze. They are a bear to rebuild and it makes more sense monitarily to replace a 3vze used than rebuild it. Not like you are risking ruining an engine of value. I have heard that this stuff can work too. There are videos of liquid head gasket successes all over youtube.

I had a minor HG leak and after lots of research decided to try Blue Devil. It worked great and 6 months later the truck is still good as new!

I am new to this forum my name is Lakin I have a question that is a very simple one.....
When you have the thermostat housing off do you take the thermostat out of the housing and put the housing back on to pour the Blue Devil into the radiator.... or do you leave the housing off while you're pouring?????

I am new to this forum my name is Lakin I have a question that is a very simple one.....
When you have the thermostat housing off do you take the thermostat out of the housing and put the housing back on to pour the Blue Devil into the radiator.... or do you leave the housing off while you're pouring?????