Xu9J4 Overheating

[dynacord 6 1 Cars]

hi,

 

so I fitted a new polished head with new valves, etc. new bolts, new head gasket, new water pump

I had to replace one liner with the piston because the previous piston was not looking okay (rough surface, something like a valve hit).

 

i started the car first without the thermostat, bled the cooling system and the hose from the radiator to the thermostat body started inflating itself.

 

thought the head gasket is not properly clamped, so fitted a new one with the 20nm and 3x100 degrees bolt stretching method. also fitted a new thermostat. Now the fans don't run when they should run (around 80-85degrees), and the hose is still inflating itself.

 

I'm sure it's not the head gasket because it's brand new and the engine was running for about 15 minutes..

 

not quite sure if I can run with 3 DKZ and one D6C liner (for some reason the previous owner fitted dkz liners)? maybe an air lock somewhere through the system?

 

thanks, alex

Edited April 11, 2012 by dynacord

[kyepan 291]

Check thermostat is opening, (top hose hot)

 

Check fan is working using the extra connector on the fan loom, bridge pins 1-3 and then 2-3, fan should run on low, then high speed.

 

Go from there.

[welshpug 1,626]

was the head checked for trueness and skimmed? also has the block been checked for trueness and liner protrusion checked?

[dynacord 6 1 Cars]

thanks for the fast replies, the top and all other hoses are hot, it was doing this without a thermostat fitted

@welshpug: not quite sure what you mean by "trueness"? the head was checked and skimmed, I haven't checked the block, though. I'm also wondering if the new liner is standing a little higher than the others. anyway, the water is not mixing up with the oil as it should be doing this if the head gasket was gone, right?

[welshpug 1,626]

water and oil do not always mix when the gasket goes, I recently repaired three RFS engines which had no water+oil mixing at all.

[Anthony 1,000]

I haven't checked the block, though. I'm also wondering if the new liner is standing a little higher than the others. anyway, the water is not mixing up with the oil as it should be doing this if the head gasket was gone, right?

This would be my guess - the protrusion on the replacement liner is incorrect causing the headgasket not to seal.

 

On alloy block XU engines I have rarely seen oil/water mixing as a result of head gasket failure - usually just see it using large quantities of water and/or pressurising the cooling system, which sounds like is what is happening on yours hence the hose swelling up.

[Tom Fenton 1,526]

Sorry to say it but sounds like head gasket problem caused by the liner protrusion as well.

 

I've had head gaskets go on 1900 alloy Mi's on me twice, both times the car just suddenly started to use LOTS of water and overheat very quickly from startup, also inflating the hose as you say.