V6 Cooling system:Air Locks

[SE9V6]

would be greatfult if any1 can give any info whatsoever on issues with the V6 cooling system? and solutions?

Basically, i struggle to get any amount of heat from the heater, even when the engine is hot and the fan is running.
The feed pipe to the heater matrix is so hot that you cannot hold it, but the return pipe is only moderately hot.
If i rev the engine, the heat in the return pipe rises as does the amount of heat coming from the heater.
I know that the matrix is not blocked, as i removed both the feed and return pipes and connected an hose pipe at one end and had water running through it feely.
After doing this, for a short period of time, i was getting plenty of hot air from the heater, but soon after, i started getting less and less again.
I can only presume that it must be air locked somewhere, and that it eventually gets to the matrix and stays there?
thanks guys

[Allys Cally]

run the car up to temperature with the expansion cap off, this should allow any trapped air to find it way round the system and into the expansion tank. if there is air trapped you should see it bubbling into the tank

[SE9V6]

thanks for the replies guys,
yeah all pipes are connected to the right places

tried running it up to temp with cap of loads of times alley, but when temp gets up, it bubbles like mad and forces loads of coolant out which i then add back, but still the same after.

previously, the oil cooler split and let oil into the coolant system. after changing the cooler, i flushed the coolant system several times using holts speed flush, and have ran it with dissolved dishwasher tablets in the coolant to break down any remaining oil in the matrix or pipes for 2 or 3 months.
I recently emptied it out, flushed it again and refilled with fresh coolant and its still crystal clear so i'm presuming that all the oil is gone!
the fact that i do get a small amount of heat from it when the engine its revving suggests that the matrix isn't blocked itself, but get hardly any heat at all when its at idle, even if the the cooling fan is on????

[SE9V6]

yes all the heater controls work ok, i can get both cold and hot(when car is revving) air out off all the vents.

As for the hoses being mixed up, tbh i am unsure, as the pipes are connected in the same places they were when i bought the car back in 2004, but wether these are right, i dont know :/

I might take a look at my mates and see where his are connected to

Thanks for the advice mate, much appreciated

[Fraz]

After you had oil cooler problems. Did you also change the thermostat?, it may well be getting some of the gunge to block it

I would also do as suggested and check the heater hot water valve is fully opening. It's by the clutch pedal on the heater box

Sent from my HTC Wildfire S A510e using Tapatalk 2

[SE9V6]

thanks for all your help and advice,
, yes the whole radiator does get hot, and i really dont think its the water pump as there is plenty of pressure all round the system regardless of wether its hot or cold.

In regards to there being a partial blockage, i suppose this could be a possibility, as the amount of hot water going through the matrix would increase as the revs build.

Don't get me wrong, i do get warm air from the heater as soon as the water temp begins to rise, and it does get warmer as the water does, but the air never gets actually hot unless the water is around the 100 degrees mark where the fan comes in and the engine is being revved to 3k or above.

I am in the midlands, Leicestershire to be exact .

Fraz, i can't see it being anything to do with the thermostat, as if it was, surely it would not open and the whole system would overheat as it wouldn't be circulating through the rad?

As for the valve/flap on the heater box, if that wasnt fully opening, then the amount of heat i get would be limited to a certain point, but like i say, if the temp in the cooling system his high, and the engine is revving, i get hot air, but not at idle or when its at normal running temp.

Think i am gonna change both feed and return pipes to the heater matrix,and confirm that they are connected to the right places, give the matrix another flush out and then run it up and try to clear any air locks and see how i go.

Thanks again for all your help guys, if any of you can think of anything else it may be then please feel free to post it, as i appreciate any ideas.

[Fraz]

I had a car doing the exact same thing, turned out to be the thermostat was not fully opening and also at times staying fully opening so the car took longer to warm the water to temp ...only got warm air when you reved it ...only if fully closed will it overheat

have you got thermometer to check the water temp??

[v6 steve]

didnt we have an engine that never had a thermostat and it wouldnt heat up unless we kicked its bum, once we put the new one in all was good trying to remember which car that was

[EddeyDancer]

I've had the thermostat out on my V6, for a year...

Seems to be running well, but it does take longer to warm up...

Will fit a Cooler Running type, some day...

[SE9V6]

so i confirmed that the pipework is all connected to the right places by comparing it to my friends V6.

The next thing i intend to eliminate is the thermostat, by fitting a new one.

Where is the thermostat positioned???????


Thanks

Ash

[EddeyDancer]

Where is the V6 Thermostat positioned???

In a rather difficult location to get at...

It will involve removing the 3 Manifolds, in order to get to it...
Then trying to seperate the Thermostat Housing, from the Extension Pipe is another Mission...
If the Pipe breaks, you'll have an even bigger headache trying to fit the new pipe...

I changed the Thermostat last year, and took plenty of pics...
I suggest you view my Profile, and do some research before you even start...

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