Internal coolant leak nightmare

[Dancing Fish 0]

First of all, I have read the coolant sticky and it doesnt particularly help.

 

I have a coolant leak. There are NEVER any pools of coolant under car or any noticeable leaks. The system has been pressure tested, and the only thing it showed was a miniscule rad leak. The rad has been replaced. Coolant is still leaking though - somewhere.

 

However, there is no brown foam in the coolant and the oil looks fine. So head gasket doesnt seem that likely.

 

So where else can it be going! What internal leaks into the engine can there be that are burnt off that i wont find and that aren't the head gasket????????

 

The tank holds pressure, so presumably it cannot be this. The tank cap is blue.

 

I love my car, but its getting on my tits, and eating my money!

 

One other thing that i do not think is related is that it sounds really tappetey when it starts from cold. Like a 1l fiesta! Goes after it warms.

 

Any ideas? Use your imaginations people!

[TomB 0]

I had a similar problem recently, and I'm afraid it turned out to be the head gasket. As in your case, there was no evidence of oil in the cooling system or water in the oil.

However, I found the hose at the bottom of the expansion tank was prone to a slow (almost undetectable) leak, and replaced all the hose 'spring clips' with jubilees just to make sure.

A couple of questions though. Is the car overheating at all? Mine was well behaved and show no evidence of overheating unless I was driving enthusiastically :oops: Then the temp light would come on and the oil temp would get up to about 130 degrees... Is there any loss of power after it's warmed up? Does it ever have any difficulty starting?

Good luck man,

Tom

[Dixxy 0]

i had very similar symptoms with my old valver and i'm afriad it was the head gasket. Do you get any signs of over heating?

[Dancing Fish 0]

No signs of overheating no.

 

How did you find out it was actually the head gasket? Once you had taken the head off? Was the gasket obviously knackered?

 

Or was it a case of replacing everything else and it was the only thing left?

 

DF

[Dixxy 0]

it was the only thing left to do. When i took the head off i couldn't see where it had gone at all. Compression tests also didn't show anything up. Its not too expensive to do the head (just gaskets, bolts and a skim) so i thought i'd do it..... problems solved

[Rpmayne 0]

Maybe the head gasket could have gone between a coolant channel and a cylinder so it could be burning off the coolant but would show no signs of the oil / water mixing.

 

A compression test should show that I would have thought. Or some garages have a tester you put into the expansion tank and it can tell whether there are any exhaust gases in the coolant (by some liquid changing colour). More likely it would pressurise the coolant system and blow the expansion tank cap though, as happened on my ex's polo.

[saysomestuff 0]

what about in the car? heat exchanger could have a small leak and be dripping/steaming into the cabin, do you have a condensation in the car?

[Dancing Fish 0]

Erm,

 

What's a heat exchanger and where is it and how would the moisture get in the car?

 

There is a rattling kind of noise coming from the glovebow kind of area. I presume this is one of my speaker wires that i have fitted rattling but could it be internal leak?

[Kevin Bacon 5]

Leaking gasket - As RP Mayne says, just because there's no oil/water cross contamination, it doesn't mean the fire ring between the cylinder and the coolant tract hasn't been breached.

 

It's common on the 16V, always bursts between cylinders 3 and 4.

 

This is why VW have upgraded all their head gaskets to steel, including the 16V.

 

You may have a hairline rupture which won't be immediately noticable, smell the coolant. Does it smell of exhaust?

If the exhaust leaks passed the fire ring in a big way, you will definitely know about it..... tonnes of constant steam from the exhaust, glycol deposits on the rear bumper, coolant smell in the air, running like a bag of schitt and the the expansion tank can split in half.

 

The heat exchanger is the radiator behind the dashboard. If that leaked you'd have sticky and wet carpets and steam pouring throught the heater vents.

 

I'd say you have a weep somewhere that isn't exhibited unless under pressure.

[saysomestuff 0]

surely with a small crack in the matrix (only leaking under strain), the coolant would evaporate so no pouring steam or wetness? Just an idea, he did say use our imaginations! :lol:

 

It could be worth bypassing it for a day and seeing if the level maintains.