Diagnosing coolant leak

[asteconn]

Hello all,

 

Recently acquired a 1U Octavia Elegence TDi. Really chuffed with it. However, the blasted thing seems to be drinking coolant quite precipitously.

 

Where and how should I go about checking for leaks? Are there any particularly obvious places that I should check first? I'm not adverse to working under the bonnet, and I'd rather fix it myself if its feasible to do so.

 

Thanks!

[vrsjub]

You need to remove the under tray (if it's still there) and see if there is any coolant sitting in the cover? If not I'd be checking around the bottom of the cam belt cover in case the water pump is leaking? If not check around the bottom edges of the radiator for coolant staining. Or where the top of the gearbox there is a coolant housing on the block which can leak so check on top of the gearbox for coolant stains etc. If not get a coolant pressure tester from somewhere and see if there is any leaks under pressure?

If not sometimes these 1.9tdi can suffer with head gaskets but fingers crossed it won't be that!

Hope this helps

[asteconn]

Thanks! Oil is clean, checked when I bought and recently. I believe that the angle the car is parked at may contribute to it, as when it was on the drive I had the warning light come up, but not when on the road. I'll do some investigation.

[asteconn]

Another (possibly pertinent) symptom I discovered this evening: I don't think my car's heater is working. It's equipped with climate control - cooling seems to work, but when I put the heat up this evening, no hot air was blowing though.

 

I couldn't see any obvious coolant stains at the locations advised, so what I think I'll do is have a fun couple of hours under the car checking for leaks tomorrow.

[ruffday]

Check the footwells it could be the heater matrix.

[asteconn]

Footwells are dry, but I think that I have found the leak. It's dripping onto the steering rack mount, so it could be the heater matrix or any of the tubes going there. Here's a video:

 

Edited 28 September, 2014 by asteconn

[FLAPPERJACK7]

Looks like it's coming from the feed and return pipes to the heater matrix. Either a pipe split or a poor seal at the join.

[FLAPPERJACK7]

Unlikely to be the matrix but possible. I can only remember changing one mk1 octavia matrix in the past 18 years so quite rare for the matrix to leak.

[darrylg]

Another (possibly pertinent) symptom I discovered this evening: I don't think my car's heater is working. It's equipped with climate control - cooling seems to work, but when I put the heat up this evening, no hot air was blowing though.

I couldn't see any obvious coolant stains at the locations advised, so what I think I'll do is have a fun couple of hours under the car checking for leaks tomorrow.

Low coolant level seems to stop the heating working.

I've had this one.

[asteconn]

Yeah, I suspect that the lack of heat is an air lock rather than an issue with the heater itself, as I do occassionally get some heat out of it.

 

What's the best way to check the pipes and seals without taking the engine to bits? Or is that a necessity given the leak's likely location?

[FLAPPERJACK7]

Cooling system needs checking with a pressure tester. ..fits onto header tank you pump it up to 1 bar and look for a leak.