Thread: What to expect when replacing TD5 head gasket

Hi akula,

After only 80,000 as long as the head was fitted correctly very unlikely to be the gasket.
AMC heads are very robust and reliable and shouldn't need any work after that amount of K's.
Check that the steel tube in the expansion tank is not blocked as this may lead to pressure in the cooling system, however the symptoms you describe do usually indicate a head or gasket problem.

Nick

My mechanic did a combustion gas test today and it came back negative.
It is still losing coolant past the hose clamps - tighten one and another leaks.

Over pressure could be from partial blocking of pipe work somewhere. I remember reading a post somewhere a few months ago about someone who had a length of small diameter hose that had been installed near the expansion tank return inside the coolant hose to restrict the flow and/or allow firmer clamping (a bit hazy on the details) this hose had come loose and slid down inside the coolant hose to restrict the flow.

Draining and disassembling looking for obstructions could be useful.

Either that or water pump impeller is deformed/ incorrect part / overspeed (although I can't figure how) and might be worth a look.

Originally Posted by Pippin

Hi akula,

After only 80,000 as long as the head was fitted correctly very unlikely to be the gasket.
AMC heads are very robust and reliable and shouldn't need any work after that amount of K's.
Check that the steel tube in the expansion tank is not blocked as this may lead to pressure in the cooling system, however the symptoms you describe do usually indicate a head or gasket problem.

Nick

Coolant flowing Freely through the steel tube in expansion tank as far as I can tell.

Originally Posted by ScotchRocks

Over pressure could be from partial blocking of pipe work somewhere. I remember reading a post somewhere a few months ago about someone who had a length of small diameter hose that had been installed near the expansion tank return inside the coolant hose to restrict the flow and/or allow firmer clamping (a bit hazy on the details) this hose had come loose and slid down inside the coolant hose to restrict the flow.

Draining and disassembling looking for obstructions could be useful.

Either that or water pump impeller is deformed/ incorrect part / overspeed (although I can't figure how) and might be worth a look.

I will look for blockages around the expansion tank, the t-piece and the fuel cooler.

The water pump is not that old and an original part. Is there a way to test it without removing it?

If you've got a solid stream coming through the bleeder into the expansion tank ,and you remove the bleeder from the top hose with engine idling and get a stream pushing out then your water pump is ok, what coolant type and what temp is showing on nanocom ( max ) ?.

Originally Posted by discorevy

If you've got a solid stream coming through the bleeder into the expansion tank ,and you remove the bleeder from the top hose with engine idling and get a stream pushing out then your water pump is ok, what coolant type and what temp is showing on nanocom ( max ) ?.

I am not sure I follow the method of testing the pump. In my car the expansion tank bleeder is fed by a small (non original) hose that runs of the top of the radiator on passenger side.


I use green HOAT (as it was in it when I bought it and never got around to flush and revert to OAT).


When coolant system not leaking:

88-89c at ~100kmh on undulating terrain

89-90c in stop and start traffic


When coolant system leaking coolant:

89-91c at ~100kmh on undulating terrain

90-93c in stop and start traffic

Revy is referring to the bleed screw in the top hose of the radiator, located between engine outlet (where the Coolant temp sensor is at the front left of the engine) and radiator inlet. When you drain and refill you open this screw and do some expansion tank juggling to make sure there is no air in the system. If you have an engine saver it will be where the sensor wire comes off.