Bleeding the water system maybe??

[neal1980]

Is there a recommended way of doing this?

My car got very hot tonight 110degrees, the fans had cut in but temp would not go down. I recently had the car apart for a cam change and did change the thermostat at the same time. So im thinking also maybe the thermostat is faulty, not opening etc.

I did also break the temp gauge sender at the back of the dizzy, i replaced this from a TVR dealer so Im sure it should be right. If the car got this hot would you expect it to tick over as normal. After stopping for a few mins it started straight away also.

Any help appreciated.

[tvrbob]

The important thing is to ensure the system is primed, i.e no air in the system. You won't achieve this through topping up the expansion pot. The only way to prime these systems is through the high point on the swirl pot.

With the engine off, undo the swirl pot brass screw and check for coolant level. Coolant should be brimming the swirl pot; if not then top up, replace the lid, agitate the top hose for a minute then recheck the swirl pot level. When the swirl pot need no more water make sure the expansion pot is 1/3 to 1/2 full (any fuller and there won't be enough expansion space) run the engine.

Once the engine is hot turn it off and leave to cool then recheck the swirl pot level. Top up as required and repeat. Once the swirl pot is found to be full after running and cooling the engine your system is primed.

[GreenV8S]

Remember to bleed the radiator as well as the engine.

[spend]

Before embarking on yet another 'bleeding' thread, its probably prudent to ask if your fans cut out Neal?

Dave

[neal1980]

I didnt give it chance to cut out as long as the engine was running they kept going. But they didnt seem to cool then engine the temp kept rising.

When I started the car today fans wernt on.

It is possible to put the thermostat in the wrong way maybe??

Neal

[tvrbob]

Bleed the system first. Simple to do, it's a common Chim / Griff problem; your symptoms indicate circulation stalling which is a consequence of air lock

[neal1980]

Ok whats the best way to bleed the system then, i can get the front quite high in the air on my drive if this would also help?

Thanks

[peteA]

[quote=neal1980]Ok whats the best way to bleed the system then, i can get the front quite high in the air on my drive if this would also help?

This wont make a difference or very little...

One thing thats easy to forget and doesnt seem to have been mentioned is to make sure the heater valve is open (ie - in the hot position)...if you have drained it with the valve in this position there may be some old coolant trapped in there or if you have filled it back up in this position, there is likely to be air trapped at or near this point..?

Make sure the valve is open and carry out the procedure described previously.

Apologies if you have already done this...

[tvrbob]

neal1980 said:

Ok whats the best way to bleed the system then, i can get the front quite high in the air on my drive if this would also help?

Thanks

tvrbob said:

The important thing is to ensure the system is primed, i.e no air in the system. You won't achieve this through topping up the expansion pot. The only way to prime these systems is through the high point on the swirl pot.

With the engine off, undo the swirl pot brass screw and check for coolant level. Coolant should be brimming the swirl pot; if not then top up, replace the lid, agitate the top hose for a minute then recheck the swirl pot level. When the swirl pot need no more water make sure the expansion pot is 1/3 to 1/2 full (any fuller and there won't be enough expansion space) run the engine.

Once the engine is hot turn it off and leave to cool then recheck the swirl pot level. Top up as required and repeat. Once the swirl pot is found to be full after running and cooling the engine your system is primed.

[tvrbob]

peteA said:

neal1980 said:

Ok whats the best way to bleed the system then, i can get the front quite high in the air on my drive if this would also help?

This wont make a difference or very little...

You obviously haven't encountered the dreaded airlock. It's a very common issue with cars that have expansion pots fitted low down compared to the engine. Yes there are other things that can cause problems but I suggest he try a common and easy solution first. Airlocks cause circulation to stall, in my opinion that's pretty significant.

[GreenV8S]

tvrbob said:

peteA said:

neal1980 said:

Ok whats the best way to bleed the system then, i can get the front quite high in the air on my drive if this would also help?

This wont make a difference or very little...

You obviously haven't encountered the dreaded airlock. It's a very common issue with cars that have expansion pots fitted low down compared to the engine. Yes there are other things that can cause problems but I suggest he try a common and easy solution first. Airlocks cause circulation to stall, in my opinion that's pretty significant.

I suspect it was the 'get the front up in the air' bit which the quote was referring to as not making a difference. Venting and bleeding the cooling system is obviously critical.

[tvrbob]

GreenV8S said:

I suspect it was the 'get the front up in the air' bit which the quote was referring to as not making a difference. Venting and bleeding the cooling system is obviously critical.

Oops sorry

[spend]

The higher the filling point the better IMHO! I do raise the front - but maybe the pre-serps different arrangements make this more suitable, I would'nt do it any other way. Squeezing like sh1t on the pipes also helps...

Dave

[neal1980]

ok its been bleed and ive taken the innerards out the themostat to illiminate it and its still getting hot.

Its going to 100c but the fans are cutting in and out at temp. Is 100c too high ? do i have a problem?

Posible head gasket failure even?

[bigdods]

check that the fans are both sucking not blowing. Been several cases of miswired fans with one blowing the other sucking which just circulates the hot air.

Possible your guage is over-reading if the fans are cutting in and out normally....

[neal1980]

Fans are def sucking. Think i need another way of testing the temp of the water with the car running.

What is the temperature range thats acceptable for it to be running at?

Thanks