Coolant leak...possible air lock?

[Corvr6 0]

After a cooling fan change on my VR recently my coolant system developed a leak,I was p****d as it had a new rad in april this year(before my ownership though). :x

It's seeping through the join where the small black housing fits onto the top of the rad.I have taken it back to the garage who changed the cooling fan,they tried fitting a new seal and using some quick drying sealant to help.The seal held during the initial warm up,but after a few days the seeping is back noticeable when cold. :cry: I now have a VW seal and will get this fitted tomorrow,to see if this will stop the seeping.Any suggestions to help make this water tight appreciated. :crazyeyes:

The coolant level seems to stay just above the min mark.It used to hit 110 if I ran it hard and then start to cool back down,but the temp gauge does not rise much above 80 now however I drive it. :?

I have also noticed a few drops of oil on the gravel.

The electric cooling pump is working as coolant can be seen returning to reservoir. :|

Could it just be an air lock thats got in through the seeping join? :?

or something more sinister? :shock:

[corradovr6sc 0]

Is the leak from the rad thermostat or the top rad hose?

 

Vr6s commonly leak from the sump gasket. Also check the oil cooler seals, rockercover gasket, even possibly the head gasket.

[Corvr6 0]

It seeps from the black housing on top of the rad not the hose.Am I to understand the black housing that the top hose connects to holds the thermostat?I wonder if the garage replaced it? :shock:

More info:

The cooling fan comes on when the temp gauge reads 90,it used to be much higher before it came on.

The electric cooling pump starts up with the ignition on from cold,although it dosn't sound too healthy,like the speed is varying?

It dosn't come on with just the ignition when its warm,is that normal?

The top rad hose gets really hot,while the lower rad hose only gets hot when the cooling fan has kicked in,sound normal?

I just haven't had the car long enough to get really familiar with its workings. :oops:

[dazzyvr6 0]

the thermostat lives down by the water pump i belive :?

[Corvr6 0]

I have ordered the service manual from amazon.Cost works out to about £60 got 30% discount on it. :)

Maybe if I knew what I was lookin at I'd have half a chance of solving it. :oops:

I'm not too mechanically minded,so I'm more likely to do more damage than good without knowing some basics. :mad:

£60 is peanuts compared to the damage I could imagine myself doing. :wink:

[corradovr6sc 0]

The top hose is clamped to a black plastic 90 degree pipe which is bolted to the radiator. The fan switch (thermostat) is directly below this, about half way down the radiator and has an electrical connection into it. Don't think the fan should come on at 90. Mine comes on at 100+ unless it has been replaced for a lower temp thermostat. I think the auxillary water pump runs all the time when the ignition is on and runs permanently after 108 degrees (not too sure on this). If the speed of this pump varies you could have an airlock as it might be spinning in air.

When I changed my coolant I got the coolant up to operating temperature and unscrewed the cap on the expansion tank to release any airlocks.

[Corvr6 0]

Thanks m8,I don't think any components have been changed,so I'm sure I have an air lock.Car is having sports suspension fitted today so will ask them to fit the new seal and remove air lock. 8)

 

Edit(better late than never)

Leak actually fixed by fitting new VW seal in black plastic housing on top of rad,the rubber seal is slightly bigger than the generic size 3mm the garage used(3.1 or 3.2mm I think)

Edit