I have a Marea Weekend TD75 that suddenly started overheating and I would welcome any suggestions as to the cause.

When the engine overheats the radiator is cold and the air from the heater is not particularly hot. The overheating occurs fairly rapidly even at low engine speed.

We removed the thermostat assembly and tested it in boiling water and it appears to be working ok and water flows through the radiator.

The engine oil and remaining coolant appear uncontaminated.

Is this likely to be a head gasket problem? and if so what kind of job is this, are there any special tools required?

Thanks.

how is it overheating, is it boiling in the head?

uno 1.0ie RAAAWW!

I think so; the temperature gauge was well into the red, the fans were running and steam was escaping via the expansion tank filler.

I refilled the expansion tank after letting the engine cool for 30-45 minutes and managed to drive about a mile or two at low revs with the heater full on (but not very hot air coming out) before the coolant began to boil again.

Standing in front of the car the left side of the radiator was totally cold and the right side was just warm.

I haven't checked the water pump yet.

sounds like theres lots of air in the cooling system i also seem too remember that these are a bugger too bleed properly.
i might be wrong but is there a long cast alloy cooling pipe that runs the length of the engine just above the exhaust manifold, there should be a good bleeding screw on there if im right.


uno 1.0ie RAAAWW!

Thanks for your help. You're right about the layout of the cooling system. And the thermostat....

I've only owned the car for about 2 weeks and it's been perfectly ok in that time with the cooling system and heater working perfectly. Is it possible that it could suddenly have developed an airlock?

A stuck on close position thermostat doesn't allow the coolant to reach the radiator causing engine overheating...and head gasket burningB)!


Do I turn fast enough!?

he's already tested it,sounds like an air lock or blockage on the cooling system

A Dog Is Not Just For Christmas
Sliced Thinly It Can Last Till Easter

Update: We refitted the thermostat and had the radiator checked and cleaned (no problem there) and refilled the sytem hoping to bleed all air out.

The problem still remains: no heat from the heater and no water flow anywhere.

The radiator inlet pipe is hot but the radiator is stone cold.

Will take a look at the water pump today, it seems like an unlikely failure to me but we're running out of ideas.

Well, externally (what I think is) the water pump appears ok; no leaks or wobbles.

I'm not familiar with the details of the plumbing on the car but I assume that if the thermostat is not opening the heater would still deliver hot air.

Can anyone confirm this to be the case?

Update: the plastic impeller on the water pump shaft had become loose.

I can see this is an old thread, but it sounds like you have the same problem as I have.

The plastic impeller coming loose I suspect is a symptom not the cause. The cause is a leaking headgasket, pressurising the system with exhaust gas, this causes the waterpump to fail.

If you do return to the forum, would appreciate an update.

Did your water expansion tank bubble as soon as the engine was started? This only occurs after the system has been bled properly, then it fills with gas again and the bubling slows or stops in the expansion tank, then the coolant starts to be forced out through the weakest points.

Mine is a TD 100, anyone got any comments for me? It is bubbling into the expansion tank and high pressure builds up very quickly along with a dramatic increase in temperature. This is definately the head gasket right?

I checked a price for head set inc bolts, HG, and full set of seals, came to just under 100 quid. I'm just wondering if it is worth getting it done or leaving it as a future project for me to do, or scrapping it. There is also a grinding noise when you release the accerator (when driving) re-apply accelerator noise dissappears, press brake pedal noise dissappears, I suspect this is the (new 2 mth old) water pump now broken.

The noise occurs with clutch in or out. I'm going to test to see if the noise is still there if I turn off the engine (in neutral).

loose plastic impeller is a common enough fault with water pumps - enough flow at idle but overheats on the road. replace the water pump and see what happens.. hopefully head and gasket will be ok.

Owen.