Restoring a '98 Polo
Ok, not sure if this is the correct area of the forum to post this. If not, I apologise in advance and ask that a moderator correct this.

The post is long as I give the history of the car and what I have done on it so far. For those who don't wan't to read it all, the issue I'm up against now is I can't figure out how to remove the PCV system (or CBV or whatever VW calls it) in order to clean it. If you have info on this, PLEASE comment!!


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Now, for those who are interested as to why I am at this point, here's what's happened so far...

I have recently been tasked with the job of restoring a good mate's '98 VW Polo MKIII (Mark4) 6N1, with the 1.6L 8V AEE Engine and the DKE manual transaxle. It has low kms for its age (about 95,000). However for the last six years or so, it has been sitting up, only moved around the block once a week or so to avoid a parking ticket. So obviously it does start. The history of it was regular usage until about '06, at which point it underwent major servicing and repairs, including head gasket. I am not fully aware of the reasoniong behind this. My mate knows nothing about cars and he remembers the mechanic telling him that the head gasket must be changed out, as it had not been changed out even once since the purchase of the car. smh...
In any event, he says it drove like a champ for about a year, at which point it started with an engine misfire. So he stopped driving it and started moving it once a week.

Enter myself. I insist that we ought to figure it out. So first thing I did was inspect the spark plugs. They all seemed a bit dark/black but dry, except for #2 which was completely covered in oil on the electrode. The tops of all the plugs were dry. The plugs look relatively new, in that they are not worn or deformed or damaged.

So my next test was to check for worn rings, especially in #2. So:

- I ran a compression test, the numbers look good enough so then I was really stumped:

.......Cyl 1 Cyl 2 Cyl 3 Cyl 4
Dry:..170..175...175....175
Wet:.190..195...195....195

- While I was mulling that one over, I ran a detergent oil flush and changed the oil and filter. I noticed that there was heavy sludging signs under the oil fill cap and that the oil was pretty low on the stick. The oil that was in there was clean enough but many years old. He reckoned it hadn't been even 50km since the last change, but it had been years. When I popped the valve cover afterwards, I was surprised to find a very, very clean head, however the underside of the valve cover was pretty sludged. Then I noticed some handwriting on the external surface of the valve cover which makes me think it might be from a junkyard or something. I don't know.

- I changed the fuel filter. It was the original that was on there. Those clips were fun...
- I ran some 98 octane petrol and an treatment of injector cleaner.
- I changed the cabin air filter, as it was absolutely disgusting.
- I removed and thoroughly cleaned the throttle body and then ran the throttle body alignment on it afterwards, using the Ross Tech VAGCOM software.
- I scanned for trouble codes.

Address 01: Engine Labels: 032-906-030-AEE.LBL
Controller: 032 906 030 AB
Component: MARELLI 1AV 2227
VCID: 4AE7E12B65A7
2 Faults Found:
00529 - Engine Speed Signal Missing
03-10 – No Signal – Intermittent
01249 – No 1 Cyl Injector -N30 - Short To Positive
31-10 – Open Circuit/Short To Earth – Intermittent
Readines: N/A

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Address 15: Airbags Labels: 1J0-909-60x-VW3.LBL
Controller: 1J0 909 603-E
Component: AIRBAG VW3 2227
Coding: 00069
Shop #: WSC 00788
VCID: 2B2984AFCA1D
1 Fault Found:
00532 – Supply Voltage B+
07-10 – Signal too Low - Intermittent

Which I found strange, because none of those error codes seemed to have anything to do with what I was dealing with. I decided they were related to an earlier repair and cleared them. I then got no trouble codes, despite the fact I was still getting a misfire on cylinder 2.

At this point I began to play around with swapping spark plugs around. At first, it seemed that any cylinder into which I placed the oil fouled plug from no. 2 would then cause that cylinder not to work, while the plug from the other cylinder now had no. 2 firing. I then thoroughly cleaned off all of the oil from the buggered plug's electrode. At this point, the misfire went away. That is, until the plug in no. 2 got covered in oil again. Then the misfire came back. So clearly, all the injectors are fine, all the plugs are fine, while dirty. It is simply that too much oil is getting into cylinder no. 2. The oil is not overfilled.

My only remaining thought is that the PCV system is clogged, thus forcing the oil vapour past the cylinder rings. I have noticed quite a heave oil film all around the air cleaner box and all the way down the air intake tubing, however this is normal for these cars, as I understand there is no valve to stop the oil vapours travelling up the breather once the car is turned off, leaving all the oil vapours to condense in the air cleaner box. However here is where I am stuck. I cannot seem to figure out the bizarre PCV system is assembled on this car. Firstly, the valve is idiotically placed on the BACK of the engine block, UNDER the intake manifold. The breather hose goes down and plugs into a black plastic box on the back of the crank case. Right before the hose connects to the black box, it has a bulbous section. In any event, I am unable to sort out how to remove this system in order to clean it. I have scoured threads and, while many say they have cleaned it, none say how. I have posted on several threads and no one can tell me.

One last thing I can't sort out is the in-line valve which actuates the door to control whether the air intake is being sourced from the cool, outside air or the hot, exhaust air. With the spring at rest, the door is closed against the cold air, and is only allowing the hot air. At what point does this change and how? I see no mechanism which would control this. As far as I can tell, the air intake is always being routed through the exhaust, regardless of how hot the engine is. As well, the air intake ducting coming from the outside looks to have not been used in ages. It's completely covered in dust.

Anyway, for those that bothered reading this far, I thank you!! Any comments or advice would be greatly appreciated.