chriscalvert

Hi Guys. My first post.
I have come here while investigating the causes of head gasket failure. My second one has just occurred and I don't know yet whether it is related to the first. I will be ordering gaskets and stubs hopefully from engnbldr shortly.

Reason for post is to tell you why my first gasket went in case it might help others fix theirs. Long story but basically I had oil in the water and it made a right mess. Eventually found that there was a design fault in the LHS head at the rear (in New Zealand it is the passenger side but for you guys the drivers side). This is going from memory because it was a few years ago.

Somewhere in the vicinity of the rear cylinder you will find an oil passage and water passage close to each other BUT on the corresponding mating surface you will find that the gap between the two passages is much larger. The gasket in the same area (from Toyota plus several other suppliers) has a very narrow and slightly thinner (possibly a manf issue) bit of gasket to seal this area. My mechanic fixed the problem by welding up the narrow gap side and eventually finding a gasket with a wider bit to seal the gap. All the gaskets except one have been incorrectly made and the head (I think it was) has a poorly designed casting in this area. So the head gasket blows between the oil passage and the water passage. If you just replace the gasket then it will eventually blow again (as mine did at the time).

It may well be that there are other causes of the gaskets blowing but this is one of them. It is a major design fault on Toyotas part.
I am looking forward to seeing what has caused this latest blowout.

jp123

I've done a lot of research on the head gasket issue before I bought my 4runner 3VZE. From what I can recall, Toyota implemented a new head gasket material in order to comply with EPA standards. The matrial they used seemed to break down over time and cause the failure.

They supposedly have changed the material to something that is stronger and is used in the new parts after the recall. The design of the restrictive stock header has been hypothesized by many on the board to promote the failure of what was already a poor headgasket design.

I bought mine after the old owner fixed a blown gasket with 130k on the engine. It has seemed to be ok after 2 years & 30k mi. I think I have about another 100k to go in order to find out if the HD fails, but I assume that I'll have other problems by then!

AkitaDog

iTrader: (1)

I'm also facing a blown headgasket again! My first one was about two years and 60k miles ago. I was told it fails due to extreme heat generated by the header and crossover tube meeting right at that cylinder.

This time it does not appear to have leaked water in to the crank case yet. Will know more when I tear in to it.

I find this very frustrating to know that this will happen again.

snap-on

you are both partly correct. a material change (which is why the very first trucks in 88 didnt have much problems) and from the heat buildup makes the head expand. WIth the relitivly soft head bolts they strech. as such the clamping force is lost on the HG and the gasket catastophicly fails due to lack of clamping force and weekend HG material.

A number of changes have been developed in the aftermarket world. 1) diffrent gasket material 2) the use of diffrent head bolts 3) the use of headers that elimiate the hot spot at the rear of the motor.

while any one of those items may prevent future failer, all three should give you a motor that is as reliable as the ol 22re. (least IMO)