Renault Diesel overheating, any ideas?

[siwebster]

Hi, hope somebody out here can help, my fathers 98 Espace 2.2 Diesel is overheating, again! It's had the heater matrixes replaced as they were leaking and all was fine for a short period. It's now overheating on even the shortest runs, couple of miles at the most. Not sure if this is a common problem or easily solved, but any advice and knowledge would be well appreciated.

Other info I have is that when the problem first arose the local garage put radweld in it, but I would have thought it would have been drained when the heater was sorted. I know radweld stays active until it's used up or has blocked up everything it can, is there a chance this may have blocked a smaller inlet or outlet, possibly from the radiator or header tank, that might be stopping water from circulating, or are we looking at something much more complicated and expensive? It also seems that when it overheats, it boils over but the radiator isn't hot, which would mean that coolant isn't circulating round the system. We're fairly sure the water pump is in good working order, so could be a blockage? There's doesn't appear to be any water mixing with the oil, ie no mayonnaisey substances, so don't think it's the head gasket.

Any ideas?

Cheers

Simon

[stevieturbo]

siwebster said:

There's doesn't appear to be any water mixing with the oil, ie no mayonnaisey substances, so don't think it's the head gasket.

Any ideas?

Cheers

Simon

That winds the fk out of me.

Just because there are no signs of water/oil mixing, does not mean the HG hasnt blown.

There are dozens of symptoms to a failing HG, and that is but one, and not that common either.


Think about it this way.....its French, so good chance the HG is blown.

[siwebster]

Apologies for 'winding the fk out of you', my knowledge is limited, I'm sure you had to learn these things at some point too.

Would anyone be able to point me to any other ways of identifying a leaky head gasket, at least then I can either rule it out or make a decision whether to get it repaired?

Is it a sign of HG failure if radiator is cold but engine is boiling over? Would that not more likely be some sort of blockage?

Cheers

Simon

[BlueAardvark]

If radiator is cold and engine overheating it suggests the thermostat is faulty and stuck shut.

[stevieturbo]

siwebster said:

Apologies for 'winding the fk out of you', my knowledge is limited, I'm sure you had to learn these things at some point too.

Would anyone be able to point me to any other ways of identifying a leaky head gasket, at least then I can either rule it out or make a decision whether to get it repaired?

Is it a sign of HG failure if radiator is cold but engine is boiling over? Would that not more likely be some sort of blockage?

Cheers

Simon

There are lots of symptons, that a competent garage should be able to test for.

If the HG is leaking a little..it could cause air locks in the cooling system, which would present as some items being cold due to water not circulating...along with water loss.
If It was pressurising too...it could cause leaks.....which radweld might fix for a time.

Radweld could cause a blockage..if loads was used.

Or it could be water pump, thermostat, or various faulty parts.

Again...a competent garage should be able to diagnose. Best way is with a sniffer test on the cooling system to see if any exhaust gasses are present.

[siwebster]

Thanks for your help, will investigate tomorrow.

Cheers again

Simon