6c polo Gti issues

[APgti]

Hi all,

I have a couple issues Im looking for some advice on. I have just had the waterpump and thermostat replaced due to the usual common fault of them leaking.

Prior to this going in for the work, and still the same now after picking it up is that the heaters are blowing cold. They will get hot but only after a good 10 minutes plus of driving. I was hoping the waterpump / thermostat being replaced would solve this but appears not so wondering what else it could be?

Also, a seperate issue, the side of the engine where the oil filler cap and belt covers are, is covered in misty oil whoch is getting worse. I have ordered a new cap with the seals to see if this helps but I have noticed an area where it is 100% peaking from through the bolt area. Picture added below. I believe these may just need a seal replacement? If so, can anyone tell me part numbers and how many there are, and if it is a diy at home job or will it need to go i to a garage?

IMG_6312.jpeg (2.77 MiB) Viewed 7864 times

[Bepis]

You may have already sorted this but for others reading.

Oil leak and misting will be a combination of failing seals on the cam cover and potentially a failing PCV valve where one of the one way valves within is sticking causing boost to pressurise the crankcase (I'm on my third ). Both are not too difficult of a job in themselves but just have other bits in the way which make the job a bit annoying. Exhaust cam magnet having the aircon pipes right there and the PCV having wiring and coil packs in the way which can be removed to ease access. I made a thread a while ago detailing the job: viewtopic.php?p=601573#p601573

Part numbers:
Oil cap: 06K103485D
Outer cam magnet seal: 06K103583
Inner cam magnet o-ring: WHT007212B
Bolt for cam magnet: N10451409 Torque spec of 9nm
PCV: 06K103495BL
PCV-TIP line: 06K103213M

As for the HVAC blowing cold its hard to say without being with the car but the fact it does get warm just slowly points toward a coolant flow issue to the heater matrix. Double check if your coolant expansion tank says "Mit Silikat" and check that the silica bag is A) there B)intact. If it has failed the silica balls will have made their way into the heater matrix and blocked it requiring further diagnosis and replacement. If there is no silica bag it could potentially be an air lock from the water pump and thermostat replacement. Filling these engines with coolant can be a pain, a dealer will use ODIS to prepare and bleed the system diagnostically and as well as vacuum filling it to minimise air locks and even that isn't perfect.

There is also the after-run coolant pump which is used to feed the heater matrix, if that was failing or air locked you would get a fault code for overspeed or malfunction not 100% sure if it would bring the MIL on. Next time you turn the car off listen for a humming near the passenger side of the dashboard.