Coolant

[sbchilton]

About 3 weeks ago my 2002 1.4 TDI SE began showing a low coolant warning when I started the car in a morning, It would only come on briefly 3 times out of 10 and only from a cold start. I finally had a look under the bonnet last night to find that the coolant was indeed very low (just below the bottom of the expansion tank).

After a top up last night of plain water it has lost about 4 inches so i'm sure there is a leak somewhere. I checked the oil and that seems to be ok with no "gunge" which I'm told could indicate the head gasket!?! Could anyone advise on possible causes of this leak and if there is anything I can check to help narrow the problem down.

Many Thanks

Scott

 

[Churchy]

Maybe check the radiator - had the same issue on my S4 last few weeks and having been scratching my head for a while I checked the radiator and could see a line of cyrstallisation running all the way down on end.

New radiator going in at end of the week so fingers crossed it will be an end to the problem!

 

[spike]

Hi Scott
It could also be the water pump seal - which needs a replacement pump to fix. Unfortunately this requires removal of the cambelt. If it turns out to be the pump then consider having the cambelt changed at the same time - unless of course it has been done fairly recently.
I think your TDi will have the Webasto auxiliary coolant heater so don't be tempted to put Radweld type sealants in the coolant as it can gum up the works of the Webasto.

Cheers Spike

 

[sbchilton]

Hi Spike
Thanks for that advice, my mechanic friend did my cam belt last year but not so sure he did all the other bits of the cam belt?! Would it be worth buying a new pump and cambelt kit and just do the whole lot?

I checked the coolant level again this evening after another 25miles driving and the level has not moved from earlier today (still about 12mm under the min line). I have topped it back up and i'm gonna see if it drops again. Could the initial drop been because of air in the system?

I ran the engine with the bonnet off until it got to 90 and there was no evidence of leaks showing as it was running. I did notice that there was an orangy limescale on the inside of the coolant tank before I filled it but according to this forum that is quite normal?! Further more I forgot to note that the engine has never actually over-heated (it stays around the 90 mark once it gets going) the only thing was the low coolant light.

Any further thoughts?