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I have a 1986 C Golf GTi 1800 that I have to top the coolant up on with about a pint of water a week. We've replaced loads of hoses, even the cap on the filler bottle, and it still loses water. There's never any trace of water anywhere, there's nothing in the oil so it's not head gasket. Anyone with any clue? It's really starting to bug me now as this has been going on for ages now. The car runs like a dream and this is the only problem I have with it.
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Have you checked around the bottom of heater area for wet patches you may have matrix leak.just a thought?
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I have owned 2 GTi's, one a B reg and one a D reg and both at some time required the expansion tank to be changed due to hairline cracks which slowly allowed the coolant to seep out. They both cracked on the underside so it was tricky to see the leakage. Have a good look, they are about a tenner from German and Swedish if replacement is needed...
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Apparently MK2 Golfs have a know problem with the heater matrix leaking, there is a VW modification available to stop the coolant system from over pressurising.
We have a 'C' reg MK2 1.6GL that has been in the family from new, I have just had to change the heater matrix and add the VW mod this week, it is fairly straight forward, although the Haynes manual that I recently purchase is not 100% correct in the procedure for changing the matrix !
If the problem is the heater matrix and is left long enough the inside of the car will eventually do a good impression of a boiling kettle when the heater is used, scaring the life out of the occupants first time it happens !
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Have you actually done any head gasket pressure tests?Cos I had exactly the same symptoms as you on my Golf Mk2 Driver 1.6,and also had no water in oil,and no overheating,but when tested for head gasket,showed signs of building up pressure,and although I didnt want to believe my mechanic,he turned out to be right,and now car uses next to no coolant:had a TINY spot on the head gasket(almost invisible),which under pressure was making all the coolant dissapear.
Tony
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A lot of these and similar problems are caused by the radiator cap. VW fitted those by pass things on recall cars, but many believe the expansion tank cap to be the main culprit. If your cars have the original radiator cap i suggest you go to VW or Europarts and buy a new one. I did when i had a mk.2
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Hi all
I've also got a watewr leak problem with a mk2 gti, except it's pretty obvious where the leak is on my car. When the engine gets hot steam appears from the vents on the expansion tank (I assume they're vents, the two slot/holes on the back of the tank?) and then water rushes up the tank and pours out of these vents. This continues until the tank is empty. This situation is sometimes brought on simply by turning off the engine.
This started happening immediately after I had the temperature sender replaced, hence it's a reasonable guess that this has something to do with it. I'm trying to get it back in the garage where the sender was replaced to see if they can sort it, I'll keep you posted. If, in the meantime, anyone has any comments or ideas as to why I'm getting such a violent water leak, I'd be extremely pleased to hear them.
Cheers
Matt
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The only vent as such is the cap.if steam coming from anywhere else will be expansion tank split.from what you said possible thermostat prob.though would replace tank/cap/thermostat first.if occurs after may be more serious.?
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Was mech1
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If there's no evident external leak , the engine has to be burning it as part of combustion , however small the loss is , and if there's no mis-fire at present .
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Steve.o, thanks for comments.
There appear to be two slot/holes in the bak of the expansion tank, although these could just be for easier injection molding or for attachment in other cars - on my mk2 they're not attached to anything. Water pours out through these, so I asusmed they were vents, however if they're not then it apears there is quite a bad split in these.
If sucxh a split was in evidence, would this cause the water to pour out when the engine is warm? I assume there is some considrable pressurising of the system as the temperature approaches operating levels - could such a split cause the coolant to eject so violently?
Cheers
Matt
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Yes any pressurising will be released through the tank split.Rather than the pressure cap.Idea of xpansion tank is to take the expansion of water as it heats up.reason why when engine hot you should not undo the cap as pressure will spray water at you.as you have a leak would suggest replacement as my above post.if that hasnt cured it.may be more to it.but at the moment sort the tank/cap out first.
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Was mech1
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Steve-o
Once again, thanks for comments.
I'll get a new tank fitted, can pick ione up for £10 from GSF. I'm still a bit hazy as to why this happens, I've heard of hairline cracks in expansion tanks before but never something like this. In a differnet thread I heard someone describe alomost identical symptoms and suggest that it was due to the thermostat- I understand this diverts hot water to the radiator, and any preventation of this would cause hot water to recirculate the engine, causing overheating and pressure rises. Is this a fair summarisation?
First things first, new tank tomorrow
Many thanks
Matt
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Further to my last message, I should add that the water is being ejected with some force, it is not simply leaking - the entire expansion tank takes less than 10 seconds to be cleared through the split. Is this a sign of overpressure, or is this to be expected?
All comments gratefully received
Matt
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Sounds like head gasket??
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Was mech1
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I pray not. This problem originated from a replacement temperature sender, will give them a serious earbending if it turns out to be head gasket. No problems before it went to have temperature sender done (to cure poor idling) and now loads of problems.
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Only other thing may be they drained off coolant.to fit sender.refilled and left air lock.which would do that.I would take it back and get them to check it out.I hope I havent confused.But think you should have made your own thread on this.tends to get confusing when a thread is hi jacked ie two problems on one thread.
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Was mech1
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Fair point, will start new thread shortly
Matt
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I did say thermostat in the first post.it would occur if the stat is opening late ie when pressure/temp has built up stat sticking closed.that will cause it.but you mentioned water escaping from the tank not cap.but would replace thermostat anyway.they arent expensive
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Was mech1
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thanks for comments steve.o
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