Head Gasket failure??

[Jonny1*2]

I've been having a few issues with the clio of late. Mainly overheating. Firstly it was an issue with the stat, so that was changed, and replaced with a new renault stat which was also duff. So i've now replaced it with a new one (checked it in a pan first) and i'm still getting issues. I have bled the system 4 times now and coolant seems to be disappearing somewhere. Like clockwork, the needle shoots up and STOP light appears after 10minutes of driving. I ease off, and the needle drops after 30seconds. Then it never does it again. I figured it was just air in the system somewhere, but i'm not sure now as i've just popped out to do a full change and I could smell fuel in the reservoir. Thoughts?

Only other issues I'm having is that below 2K the car is a bit hesitant and on deceleration in gear to a junction its jerky below 2k. Kangarooing doesn't look great Any ideas? Could this be related? Just to add, the engine is high comp and cammed now running OEM ECU and TB.

 

[Fred@BTM]

bin the stat and see if it still does it (just as a test!)

 

[Jonny1*2]

bin the stat and see if it still does it (just as a test!)

Take it out all together? Does the housing not leak as the stat has the gasket in? Or do you mean get a new one? It wouldn't explain the fuel smell I assume?

 

[Chip-mk1]

Compression test it if you suspect the gasket, but its very unusual for them to go on an F4R

 

[Jonny1*2]

Car has been rolling roaded recently with the overheating issues and power is good. Presumably if compression is down so too will be power?

 

[Tony Hunter]

Not always the case Johnny, Ours made good power, and that was down on one cylinder, that's why we left it.

 

[Jonny1*2]

Oh. Is there not something that can be put in the coolant to confirm leak?

 

[Carlv8415]

Oh. Is there not something that can be put in the coolant to confirm leak?

I believe there is a tool you can get to check. You put it over the top of the opening in the header tank and it has a chemical in it that goes green if combustion gases are detected. But surely if head gasket had failed the gasses would bubble in the header tank ?

 

[Tony Hunter]

Any garage should have a test kit.
Just take it down the local and ask them to check it.
Take 2 mins.

 

[Jonny1*2]

Any garage should have a test kit.
Just take it down the local and ask them to check it.
Take 2 mins.

Could do yeah. It made the same power as when it was made which makes me wonder. It's just the smell in the header tank is worrying as I can't think of any other way it could get there

 

[Fred@BTM]

Take it out all together? Does the housing not leak as the stat has the gasket in? Or do you mean get a new one? It wouldn't explain the fuel smell I assume?

yeah take it out and silicone the housing back on, see if it still does it

 

[Jonny1*2]

yeah take it out and silicone the housing back on, see if it still does it

Ok I'll give it a go. I assume it will prove if the stat is fine, but anything else?

More crap in the reservoir tonight. Little bit of oil residue it appears. Oil level is fine and doesn't seem to be increasing. Coolant needs topping up every couple of days. No drips when parked. No smoke from exhausts. There is a slight smell of coolant at junctions (although I've assumed this was from change). I removed the sump guard yesterday and the needle didn't go as high on the journeys to and from work, but still at 10min in.

 

[Jonny1*2]

Water pump is leaking, so that might explaining some issues. The loss of coolant looks minimal from this area though. my mate pressurised the system and the tank almost emptied and the coolant didn't return once the car was turned on. It didn't leak out and even he was stumped as to where it went.

 

[Tony Hunter]

Have you drained the oil, and had a look in there?

 

[Jonny1*2]

Checked the level before and after and no raise in level and oil looks clear

 

[MG cup]

Water floats on oil so it's highly likely it's in the sump. It doesn't even have to be a head gasket, if the thermostat housing gasket has gone it can mix oil and water there without any leak to the outside.

 

[Jonny1*2]

Water floats on oil so it's highly likely it's in the sump. It doesn't even have to be a head gasket, if the thermostat housing gasket has gone it can mix oil and water there without any leak to the outside.

Good shout mate, but wouldn't the oil go cloudy?

 

[MG cup]

It would emulsify after a time but if there ain't much water leaking externally or appear to be burning it then it has to be going some where, fluid doesn't compress.

Have you checked the interior carpets for being wet (maybe a heater matrix and would explain the smell your getting) and do you also have the heaters on full hot while you have bled it previously.

You won't get an idea of what the oil is like (other than smell) most times until its drained.

 

[Cookson]

Oil floats on water. Mong

 

[jack_davey]

use a block tester, I have one and would offer to test it for you if you were closer

 

[MG cup]

Oil floats on water. Mong

Right enough don't know what I was thinking. Same still applies with all listed things to check.

Thanks for your input now FO

 

[Jonny1*2]

Cheers mate. No leak from the matrix that I can see. Heaters are indeed hot and were during bleed. The smell only comes when the window is open, so that's probably coming from the pump leak

 

[MicKPM]

Have you done the block sniff and compression tests yet Jonny? The water pump issue won't be helping things but its pointless throwing money at that just now if there's a chance the main gasket is leaking.

 

[Jonny1*2]

Have you done the block sniff and compression tests yet Jonny? The water pump issue won't be helping things but its pointless throwing money at that just now if there's a chance the main gasket is leaking.

I was going to come and see you mate, so I wouldn't class it as thrown away . It's strange, I ran it yesterday with no issues, coolant level stayed consistent, but this morning it did it's thing and the coolant has gone max to min again. Not done compression test as my mate didn't think there was an issue as the pressure test on the coolant system passed. Sniff test?

 

[MicKPM]

Sniff test is just what we call the test around here that looks for trace gases in the coolant resevoir.

Give me a shout if you're in the area and I'll gladly sort a slot out for you.

 

[Jonny1*2]

is it possible to get a tiny leak on the gasket which reseals once all the pressures/temps are up?

 

[MicKPM]

Yes of course as metals expand/contract with heat which is one of the reasons we use gaskets and sealants.

 

[Jonny1*2]

Might have caught it early then. Fingers crossed. I'll drop you a PM soon (or would you prefer through the website?). Need to get my other car working at this weekend (typical both go in the same week).

 

[MicKPM]

Website is best as I find PM notification a bit hit and miss on tapatalk. We'll get the Clio fixed though ;-)