13 plate 2.0TDi 150 leon FR coolant + Oil loss

[Parkins14]

Hi guys,

For the last few months I’ve been loosing coolant topping up the tank about once a month. I’ve had my mechanic look at it and he pressure tested it and it held for 2 days no drop in pressure what so ever, he assumed it was the tank cap and replaced but it’s still leaking. Under the tank there is some residue and it does get damp but there’s no crack else it would have shown on pressure testing? Could it be too much pressure and it’s realising the coolant down the little pipe that goes through the tank and exits underneath? Now over the last 2 weeks I’ve not been getting hot air out the blowers it’s been tepid at best of times but no wet carpet anywhere?

Been looking around and told it could be the thermostat, water pump or oil cooler how much would it roughly be to have these replaced separately so I can start saving


Cheers

Adam

 

[Muttley]

You say coolant + Oil loss but only talk about coolant. What, if any, are they symptoms for the oil loss?

No hot air usually means low coolant, so low that it's not getting to the heat exchanger in the cabin ventilation system. The way the cooling system is laid out means that the cabin heat fails first, which is a good early warning sign.

If you have water-in-the-oil symptoms then I'd say the oil cooler (which is a water/oil heat exchanger) is a strong possibility.

 

[Parkins14]

You say coolant + Oil loss but only talk about coolant. What, if any, are they symptoms for the oil loss?

No hot air usually means low coolant, so low that it's not getting to the heat exchanger in the cabin ventilation system. The way the cooling system is laid out means that the cabin heat fails first, which is a good early warning sign.

If you have water-in-the-oil symptoms then I'd say the oil cooler (which is a water/oil heat exchanger) is a strong possibility.

Ahh sorry I forgot to change it! I had the oil light come on yesterday driving home from work but gave it 15 mins to settle then checked the dipstick and it’s was fine and when I started her up again the light had gone so maybe just a fault in the sensor?

Okay where should I be topping the coolant up to on the tank between the 2 lines or at the top one? I have been using distilled water because I’m not putting proper coolant in till it stops leaking as I can’t afford to waste money currently.

The coolant does have a brown tinge to it and particular matter inside that’s stuck to the tank and the sensor, I would attach an image if I could, it’s not oily though when I dip my fingers in?

I’ve got the car on finance for another 3 years and at the moment I really don’t want the thing I look after it well, don’t drive like a idiot and in the year I’ve had it I’ve had a new CV joint the rear high level brake light has been replaced the fuel cap got jammed which I had to brake off to fill up which I still haven’t replaced and now this coolant loss should have stuck with my 1.9tdi Passat

 

[Parkins14]

Just a little update I was driving to work this morning and Hurd what sounded like a kettle boiling behind the dash pulled over and popped the bonnet and there was coolant all around the underneath of the expansion tank I checked both pipes and they were properly attached and no fluid around them so it’s coming out of the over pressure hole I think? What would cause this to happen?

Is it because I’ve topped up with water a couple of times and now it’s boiling creating steam which is being forced out?

 

[efeballi]

This sounds suspiciously like the older PD TDI's leaking coolant because of the cylinder heads cracking. When I was chasing the problem, I found that the heat/cool cycle the engine goes through when started and when turned off causes the majority of the leaks. I found the leaking amount to be similar for 10 separate start/stop cycles, while actual distance being driven matters little. If yours is the case, I would prioritize inspection/replacement of the parts closer to the engine block as they go through the most heating and cooling.

Oh, the climate control not working as it should may be caused by something totally different, don't try to hard to find one cause for both problems.

 

[Parkins14]

Okay guys my mechanic fitted a new water pump and flushed and put in new coolant and I've got my heating back but within 2 days the tanks gone oily again so I think maybe it's the oil cooler? As head has been pressure tested and held for 3 days