22RE - Head Gasket Leak - Identified by PP

[blackdiamond]

BACKGROUND:
In my 89 4Runner with a freshly rebuilt 22RE engine, I noted a leak soon after I had the transmission rebuilt and switched the engine to Pennzoil Platinum and the transmission to Redline. The leak started slow and had me confused about the origin for quite a while. I finally convinced myself it was engine oil coming from the rear main seal, but it turned out to be the head gasket. I finally visited a mechanic when I noticed a 1/2 quart drop on the dipstick in a short period of time.

The diagnosis was that the block and head had been machined with a surface that was very rough and the copper shim had been installed dry rather than with a special sealent. Unfortunately, the block and head had been machined to the point that the copper shim was required to avoid clearance issues.

OBSERVATION:
I'm sure that one of the reasons that I had to run premium fuel to get quality horespower (by advancing the timing) was partially related to having higher compression from the "excessive" machine work.

QUESTION:
The mechanic said that in his experience, head gaskets installed with copper shims are more prone to developing leaks as a result of the normal heat cycles. If it would have been possible he would have preferred to leave the copper shim out. I'm sure the leak would have developed at some point with conventional, but the PP seemed to be the straw that broke the camels back. In the mechanics opinion, the seal didn't have a chance given the surface conditions and the shim being dry. He block sanded the surfaces and used the proper sealent so I'm considering staying away from synthetics (the engine has no real need for them) on the outside chance that it would be more likely to find a leak path in the future. How crazy am I?

 

[ARB1977]

Synthetics cant casue head gasket leaks...who ever did your engine messed up.

 

[Al]

Head gasket leaks are rare for the 22RE. Did you have a new timing chain/sprockets, and new guides (preferably after market metal ones) installed?

 

[BennyL]

your mechanic told you himself that the copper shim wasn't properly installed. that should end the debate right there.

 

[blackdiamond]

What my mechanic said is that head gaskets with copper shims tend to leak way more often than those without on the 22RE. He is a Toyota specialist and seems to have a lot of experience with them.

I know the synthetic oil didn't cause the leak, but it only makes sense that it would "find" any weaknesses in the seal more quickly that conventional would have.

My friend, who built the engine, said that he had previously rebuilt two and had friends that had done 22RE rebuilds without using the special sealant with success. I think it was a combination of the machine work and the dry shim. The engine had under 3,000 miles on it.

 

[Hirev]

I got to disagree with statement about head gasket leaks being rare with the 22RE.

Including myself I know of 7 people who bought new Toyota pickups back in the 80s with the 22RE. Every single one of the 7, 22REs blew a head gasket from 49K - 79K miles. A Toyota mechanic at the time told me original design of head gasket were faulty. He probably was correct because Toyota did changed the design of their head gasket at least two times.

I think your mechanic is giving you some good advice. And yes installing a copper head gasket dry is a very bad idea.

 

[TooManyWheels]

"I know the synthetic oil didn't cause the leak, but it only makes sense that it would "find" any weaknesses in the seal more quickly that conventional would have."

Umm, no, that doesn't make sense. I think you misunderstand where a head gasket is, where the oil goes, and the difference between a gasket and a seal.

 

[Al]

Originally Posted By: Hirev
I got to disagree with statement about head gasket leaks being rare with the 22RE.

Including myself I know of 7 people who bought new Toyota pickups back in the 80s with the 22RE. Every single one of the 7, 22REs blew a head gasket from 49K - 79K miles.


O.K. Well they had the problem corrected by early 90's I had a 94 and when the infamous timing chain failure. When I took it in I asked the dealer if I should do the head gasket. He told me at that time that is was no issue on the 94.

I had never heard of head gasket failures on the 80's models. The 22RE was touted as one of the most reliable engines on the planet in the 80's.

 

[Brett Miller]

We told you it wasn't the oil's fault..............

 

[mechtech2]

That copper will deform and crush a bit over time, and the head bolts/studs will need to be retorqued.
I don't like to see that 'fix' - I could never trust it.

 

[Spitty]

I have used Toyota 22R's for over 20 years and only had a head gasket fail once, after a severe over heat. I suspect that the quality of some Head Gaskets may be an issue, and personally, I always re-torque after about one hours use with a new Head Gasket.
The Timing chain seems the only weak link with all but the earliest engines, but hopefully, the aftermarket 'steel backed' guide rails are a permanent fix for this problem.