mattw86

Hey guys,

Firstly let me introduce myself, I'm Matt from Australia. I typically frequent on ozaudi. I've had a small plauge of issues with my most recent A4 purchase, but this is the major one. Car is a '99.5 A4 1.8TQ with ~230,000k's.

For clarity I have posted this over at ozaudi

After purchasing my car, I found that the thermostat was stuck open so it wasn't getting to temperature, so I replaced it with a Tridon one (not hi-flow).

That fixed my temperature issues, however after a week or so I noticed that my car was blowing smoke (later to be found burning oil) and it was getting worse and worse - I have since purchased a new turbo which is going on soon.

I changed my oil first, as I'd also recently changed whatever was in the car and went with some 5-30 Fuchs Full Synth and with a Mann Filter. So I changed the oil + filter to Mobil One 5-40 and it seemed to have fixed it but alas a couple of days later I had the warning again.

Next was testing with a oil pressure gauge..

At a warm/hot stage I attained;

14PSi idle
65 PSi at 3,000 revs.

This DIRECTLY relates to what AudiHubby over at Audizine attained, he replaced his PCV, PRV and some hosing and sorted it out. However this was on a 2004 1.8t.

Oil Pressure light... can anything else be done?

I have changed the PCV valve with a OEM replacement from Audi and I'm still getting it. Keep in mind this is only when the car is HOT, (oil is at ~90c). If i rev the car up it'll go away.

I'm lead to believe that it's not my pickup tube, as that would get worse as the revs climb. I understand that the oil pickup is an underlying issue, but for now I want to just fix the problem at hand.

I've heard of people replacing their PCV systems/overhauling them to find that the PCV and PRV valves were the issue, hence why I've replaced my PCV valve. It makes sense to me that the PCV system may be the issue as the car was always running cold sometime before I purchased it.

My mechanic/wrecker @ Tas Audi Wreckers thinks that the turbo being blown is what may be causing the low oil pressure, which is also mentioned as being a possibility in the 1.8T Oil Pressure Survival Guide over at Audizine. I also think that it may be to do with clogged turbo lines, but I have no idea if mine are or not. Pretty tempted to just replace them anyway.

So far my thoughts are;

Replace Turbo and Turbo lines + Oil + Filter and see what happens. (Also a bigger oil filter? Does anyone have any part numbers for these?)

Then I'd probably grab a PRV valve and pull the PCV system and clean it out.

After doing that I'd probably end up looking at a new oil pump + pickup and cleaning the pan as a last bet.

Obviously once I think I've fixed the issue and stop getting oil pressure warnings I'll end up testing it again @ Tas Audi Wreckers with the same gauge to be certain.

I have no choice but to drive it also, which I Know is somewhat bad. The good thing is that my oil pressures are fine when driving so as long as I'm not sitting around town too much (Typically highway driving and short supermarket trips) I'll likely be good.

A pressure test gave me an average of 180PSI on all four cylinders also.

Would like to add I had the timing belt and rocker cover gasket replaced recently and I was told that my engine "looks good mechanically".