Korey

When are you supposed to replace the head gaskets on the 3.0 V6? I've searched here and in Google and haven't found any straight answers. I know about the service campaigns but mine was supposedly replaced by Toyota around 65k miles, right before I purchased it (I'm the second owner). The HG blew around 125k at the #6 cylinder, which was replaced then and now it has just over 180k This makes me wonder if the HG was actually replaced before I bought it cuz 60k doesn't seem like a lot of miles on a HG and I never really drove the truck hard.

I plan on doing the timing belt/water pump soon and was wondering about the HG which is a pricey job. I was even thinking about getting DT headers to help with the #6 cylinder area getting too hot from the crossover pipe, thus weakening the HG.

Would appreciate your opinions.

millball

Headgaskets last until they fail. Sometimes the engine wears out before HG failure.

I've never heard of of changing out good ones preemptively.

scope103

Like Millball says: There is no service interval for the Head Gasket. It is designed to last the life of the truck. 60k does sound a little low, but there are no guarantees in life (and a replacement gasket will always have a tougher job than the original, because the surfaces are no longer "new," and installing one in your garage is different than installing one in the factory).

If it were me, I'd just trust the work you did at 125k and hope for another 125k.

Korey

Are there any ways to check the HG other than a compression test? I would like to take this truck on road trips if necessary. Maybe I should just become an AAA member. lol.

RJR

No real way to test it for impending failure. They either leak or they don't. If it does, it's time to replace it.
Basic things that determine how long the HG will last:
- quality of the gasket itself; was it a Toyota OEM?
- flatness of the block and heads; were they checked and/or milled?
- proper torquing of the head bolts; do you know and trust the person who did it?
- adequate cooling of the engine - all cooling passages clear and thermostat working properly.

If all that was taken care of properly the last time it was replaced, the HG should last 200K miles or more. If not, who knows...

My truck has 200K miles on it, and as far as I can tell, is on the original HG. I don't hesitate to drive it anywhere - did a trip across Kansas last summer at 75mph and 90 degree heat. Sometimes you just gotta have faith.

Punchy

My 92 had the recall done at 65K mi, It has 310K on it now.

Korey

The work was done by a very good mechanic experienced with Toyota Trucks. He had the heads milled, and replaced both gaskets with Toyota or equivalent parts. Replaced the knock sensor and pigtail while he was at it, but that didn't stop the dreaded code 52 from appearing about two years later.

Punchy, that's interesting. Maybe mine was not replaced during the service campaign after all. I will have to call the dealership and find out.