VW Golf MK5 - coolant depleting?

The Ayatolla

Hi folks,

Hoping for some advice. I've gone to a main dealer with this issue (twice), but here's the gist.

1. My coolant light came on one day, I pulled in and filled it up with VW Golf G13 (recommended by main dealer). All good, light went off and I carried on.
2. Around 2 months later, same thing happened again. Engine was not overheating, but I filled up again.
3. I brought to main dealer, thinking I had a leak somewhere. Main dealer did a pressure test, found no problems.
4. Main dealer recommended I change water pump and timing belt. I got a good deal on this, and it was due, so I went for it. I've 170K km on the clock.
5. All going well, around two months later the light came on again. Thankfully I always carry a near full bottle of G13 coolant.
6. Brought back to main dealer. Main dealer did pressure test again, found no issue. Main dealer expected an issue with the radiator, saying it was condensating / weeping.
7. A new radiator was recommended. New radiator fitted for around 220 euro.
8. I gave it two weeks, and again, coolant levels seem low. I've topped it up again. Main dealer said it could be an air lock in the system after all the work done, and that the top up of fluid should sort it.

Should I be worried?

Gonna give it another 2-3 weeks now to check coolant levels. It's full to the recommended mark now.

Toyotafanboi

To be honest I thought air lock after the timing belt and water pump replacement, I probably would have topped up and waited before jumping to replacing something else.

That said, radiators are popular to fail in the Mk5's so it's no harm to have that done anyway. I'd still go with air lock for now. Top it up and keep an eye on it, unless it drops again I wouldn't worry.

The Ayatolla

Thanks for the quick reply, will revert if I see any more issues

jca

Did the radiator fail the pressure test or not? Sounds like the dealer is just replacing parts to me. Is it petrol or diesel? If it's diesel the flimsy oil cooler would have been my first port of call. I couldn't see an airlock taking 2 weeks to come to light tbh. Leaving the cap off and letting the engine warm up gently while topping up as required until the thermostat is open and the temperature gauge sitting nicely on 90° should be fine, they aren't an airlock prone car. Any sign of the dreaded greying of the engine oil? Is the heater working ok?

The Ayatolla

Heater is fine, engine oil looks fine.
Dealer never mentioned it failing the pressure test.
It's a petrol, 1.4L.

jca

Don't wait for the low level warning light this time. With the car on level ground and cold take note of the coolant level then check it daily. Just try to get an idea of how fast it's dropping (hopefully it's fixed) being a petrol there's no oil cooler to worry about. Another suspect would be the plastic expansion vessel after cracking, this can be tricky to diagnose as the crack can open up when it's hot and close up on cooling.

The Ayatolla

Thanks, will check it over next few days on the flat!

If it is the vessel, how much would ya be talking?

jca

The Ayatolla wrote: »

Thanks, will check it over next few days on the flat!

If it is the vessel, how much would ya be talking?

They aren't that expensive around the 50-60 mark I think. Don't go spending any more money unless your sure it's the vessel, I hate seeing jobs becoming a parts replacement exercise at some poor divils expense as it inevitable turns out to be something simple.

biko

If a car doesn't show up anything on the pressure test but still lose coolant it can be the cap itself leaking.
But it's quite unusual.

try burping car like below
http://forums.vwvortex.com/showthread.php?5344875-how-to-burp-the-coolant-system