complicated m20b25 overheating problems, again...

[xikyle]

So, ive replaced the fan clutch, the t-stat, the radiator and bled the cooling system. I just did a head gaskets and seals kit so i dont think its the head.

it also seems to need constant refilling of the cooling system and a regular bleed (which always lets out tons of foam).

when the car is moving, the temperature is fine! (when the cooling system is bled)

occasionally when im idling, the car is fine. other times the car overheats slowly to the point where i can smell vaporizing coolant (it could be from spilling a little on the manifold and block when i fill the reservoir)

ANYBODY HAVE ANY IDEAS....

[jlevie]

it also seems to need constant refilling of the cooling system and a regular bleed (which always lets out tons of foam).

The need to frequently add coolant could mean there is a leak, but that and foam from the bleed screw say to me that there is a head gasket leak that is pumping air into the cooling system. If which case the loss of coolant occurs when the cap lifts to vent excess pressure.

[xikyle]

i just had them replace the head gasket though.

[jlevie]

Did you have the head checked for cracks and surfaced while it was off? Was the blocked for warp?

[xikyle]

im not sure if any checks were performed. im taking the fucking thing back to the shop.

[jlevie]

If the head was off for a gasket failure, decking of the head is virtually mandatory, as would be a check for cracks. If an overheat was involved in the gasket failure checking the block for warp is also mandatory.

I find that even a head that hasn't suffered a gasket failure or an overheat will need a minimum cut to completely flatten the head.

[scottinAZ]

also check to make sure they are using NEW bolts when they install the head. they are one use only, and reuse WILL result in IMMEDIATE head gasket failure

[xikyle]

they are going to check compression for a possible crack in the head, or potentially (but much less likely) the block.
i applied some stop bar's leak (fancy stop-leak)
we will see if this helps.
I cant imagine that having that stuff in my coolant is good for heat dissipation but its better than having a cracked head

[MR 325]

Any mechanic with a brain will always have a head cleaned, pressure tested, and resurfaced while it's off. Make sure your mechanic did these things.

If you smell coolant I can guarantee it's an EXTERNAL leak. Find the leak.

[xikyle]

these people failed me something epic. they didnt compression test the motor at all when they had the head off because it "looked" good. i will never take my vehicle there again.

[xikyle]

to give this thread closure. the motor is making about 60% (90psi) of compression. the rockers are loose on the shafts and the cam is worn. and the reason it likes to creap into the red is the water pump.