7MGTE That hasnt blown its gasget!

[blackmk3]

YAY!

took my mk3 supra into the local radiator shop today and got a zee-tee or sumthing test done he put the mecanism over the radiator cap and the liquid turns yeloow if carbon monixide is present but it stayed blue! i was quite surprised really! compresson being between 120-138psi

[Lloyd]

Personally I wouldn't believe that test. It generally only tells you if its blown good and proper or if its been leaking for a while. In saying that, if its running sweet and there aren't any bubbles in the radiator then you should probably be fine.

Oh, and if it does blow then get the block machined as thats a fairly big part of why they blow in the first place

[blackmk3]

yeah im just glad that its not so important to do at the moment so i kan sus a few other things the car needs and come back to the head at a later date

to b honest i dont really trust it either but yea it seems ok running fine slight miss but the leads are toast (next pay days task!)

[Crimson Tears]

I'd still retorque the head just to be safe.

[Malcolm]

it's probably blown, they actually came out of the factory with blown headgaskets. Non-blown was an option that you had to pay extra for

[Mr. Mainstream]

do they like to blow in these engines? if so where and why

[Malcolm]

the main cause is believed to be that the head bolts aren't torqued to high enough values from the factory, so the gasket isn't as heavily compressed as it should be. I talked to a guy who used to work at Thames Toyota assembling cars (back when they used to do that), and they had a couple of recalls on various cars (corollas and starlets I think he said, with 2E and 3E engines?) because of this problem.

I've seen them go both between cylinders and between cylinder and water jacket. It's not really a huge problem, as a headgasket is reasonably easy to replace, but if it's allowed to overheat the alloy in the head can soften (heard of a heat treatment known as tempering? Well this occurs) and it will continue to blow/leak. Also I had a 7M where when the gasket was replaced someone had taken a gouge out of the block where the gasket sits (possibly trying to remove the old gasket?), so although the headgasket was fine, it was still acting like a BHG. also the head was stuffed, as described earlier. If I had paid anything for the motor I would have been pissed

[blackmk3]

been there and done that mate she was pretty even abound 57ftlbs so its not sitting at 75ftlbs

but yea i understand that the gasget is proberly still blown but at least its not a huge mungere big gaping wound out of the head gasget maybe just a slight weap or sumthing like that

[Lloyd]

Just bear in mind too that a little leak is only going to get bigger. If you've got a slight leak due to damage on the head or block surface then its only going to eat away at it more and more until one day it just completely gives out without warning. If you know its slightly blown then it would be best to fix it right away or not drive it until you've fixed it.

Head gasket is cheaper than a rebuild.

[deaf_rattle]

the head bolts are prone to stretching and in extreme cases can be undone by hand.

[Pelo]

New head bolts torqued up might help...?

[Crimson Tears]

Yeah, but you'd be lucky. When you undo the headbolt, you are going to allow the head gasket to lift. The safest way would be to do one bolt at a time, and in the order the repair manual specifies. Still, no guarantees that it will seal again.

[blackmk3]

as far as i know the head hasnt been damaged im pretty sure its never been off before...