Restoring a '98 Polo

[Roritor]

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.

[Golf Loon]

If you remove the black air cleaner the top of that hose plugs in the air cleaner and the bottom into the block.
carefully remove the hose, they are unusual and usually fragile. The block bolts to the back of the engine with 6mm Allen key bolts I think.. It is best accessed from underneath with the car up on stands. They are usually blocked up, clean it with kero or diesel when removed and then replace it.

For the warm start there should be a small vacuum hose from that to the air cleaner. In Australia you could remove that end section. Carb icing is unlikely to be a problem.

Good luck with the beast.

[Roritor]

Thanks for the quick reply!!

By what mechanism does the hose disconnect from the black box? Does it just pull out? Are there clips or something? Due to the bad angle and my huge hands, I'm having trouble figuring it out and I don't want to damage anything. As for the black box, I can see the bottom fastener when I look up from the underside of the car. Where is the top fastener and how do you access it?

As for the hot air intake, yeah I'll simply block off the hot air ducting. But I'm still curious as to what is supposed to cause the little door to change intake source, between hot and cold? There's a button I can press and he down to move the door but what is ever supposed to control that on its own??

[pontiff]

Thanks for the quick reply!!

By what mechanism does the hose disconnect from the black box? Does it just pull out? Are there clips or something? Due to the bad angle and my huge hands, I'm having trouble figuring it out and I don't want to damage anything. As for the black box, I can see the bottom fastener when I look up from the underside of the car. Where is the top fastener and how do you access it?

As for the hot air intake, yeah I'll simply block off the hot air ducting. But I'm still curious as to what is supposed to cause the little door to change intake source, between hot and cold? There's a button I can press and he down to move the door but what is ever supposed to control that on its own??

Mate... where abouts are you? as it sounds like I could be of real assistance to you.. I have 2 parts cars, 2 6n1's (well 3 at the moment actually), and there is nothing that I dont have 2-3 of in backup for when something fails. If you were around the outer south east, you could bring the car around and we could figure it out, but from what I read....

1) check the timing, is the distributor adjusted correctly? this is one thing that caught me out....
2) short to positive looks interesting, does it come back? could be when something was changed

can you feel the misfire on cylinder 2?

have you check the timing belt? if they had changed the head gasket, perhaps they have not got the belt correctly aligned?

[pontiff]

Thanks for the quick reply!!

By what mechanism does the hose disconnect from the black box? Does it just pull out? Are there clips or something? Due to the bad angle and my huge hands, I'm having trouble figuring it out and I don't want to damage anything. As for the black box, I can see the bottom fastener when I look up from the underside of the car. Where is the top fastener and how do you access it?

As for the hot air intake, yeah I'll simply block off the hot air ducting. But I'm still curious as to what is supposed to cause the little door to change intake source, between hot and cold? There's a button I can press and he down to move the door but what is ever supposed to control that on its own??

it operates like a thermostat from what I understand, it gets to a certain temp then closes itself, i just route the flexi duct back onto itself. if you go for a rwc, put it back (unless they dont see it) as it may get picked up on

I have a spare engine out of the car here if you wanted to see, but yes, its just a little plastic circlip that holds it in IIRC

Oh... and those compression figures are good.. I have an engine in my 6n1 at the moment with 175's for 3 and one down at 155 and it runs just fine. With the AEE running well, they are actually a really pokey car. I have one that has the polo wagon gearbox on which is geared shorter, and that thing REALLY flies... just get it to 100 and it revs its tits off, but up until then, its a lot of fun

[Roritor]

Firstly, I'd like to say that it is super nice of you to offer to personally help me! It is a very nice gesture and is it much appreciated. Unfortunately, I live a ways north of you, in the Macedon Ranges area. I wouldn't even mind bringing the car down but, as of right now, the car has no rego. My mate (who owns the Polo) is waiting on a pay-cheque to purchase a month of temporary rego. I keep badgering him about getting the temporary rego as it makes it difficult for me to work on the car without being able to drive it. So yeah, for the time being at least, I can't take it anywhere...

As for answering your questions:
1) The timing seems to be ok to me. I'll check it again, more closely.
2) Injector short to open I seriously think was from someone doing previous testing. And now that I think about it, it may have even been me, when I very first popped the bonnet and felt the misfire, I think I unplugged the injector. The fact is, once I cleared the codes, not a single code has returned that hasn't been as a result of my intentional unplugging of things for testing purposes. As the car sits and runs now, there's no codes.
3) Can I feel the misfire on 2? Without a doubt. And if I unplug the injector to any of the other cylinders (1, 3 or 4) then it REALLY starts to miss. If I unplug the injector to cylinder 2, there's no difference at all. HOWEVER, if I swap the oil-gunked plug with, say, cylinder 4, then the misfire in two goes away and there's a misfire in 4. That is, until enough oil starts to accumulate in the plug in no 2, at which point it starts to miss there again. If I then remove the plugs from 2 and 4 and give them a good clean up, and put them back in, then the engine purrs like a kitten. For a while, until no. 2 gets gunky again. It doesn't happen right away, either. Which is what makes me think it takes until oil vapour begins to build in the crank case and has no where to go and so starts to shove up past the piston rings. Like I said, ALL the electrodes are pretty dark. It's just that 2 is the worst. At least the others are all dry and there's clear signs of where the spark is occurring on the centre electrode. With 2, it's just oil. At least the other ones are still firing. As an aside, I pulled apart the dizzy cap and rotor arm and used some sand paper to scuff up the contact points and get the black scoring off them. I was pondering whether a weak spark wasn't doing enough to burn off the carbon deposits on the plugs. I am currently awaiting arrival of the replacement cap and rotor. I Ohm-meter tested the plug leads and they tested ok. I sprayed water around them at night and saw no sparking/arcing.

Now, not to insist on being spoon fed the info here, but I can only see one fastening bolt on the underside of the black PCV box. Is the other fastener wedged up under the intake manifold? And is the best method of action to somehow remove the breather hose first, then remove the black box? Or is it better to remove the box and take out the unit as a whole, and then disconnect the hose once it's all out? Because like I said, I have huge hands and can't get any kind of a decent grip on the hose as it stands, certainly not a grip which would afford any sort of dexterous manipulation of any tabs or clips. Grrr...

As for the thermostat in the air intake routing door, I don't reckon that works. It only ever routes hot air, so yeah I'll definitely disconnect that end and then re-attach it for roadworthy.

Now, on to the latest and greatest as this project transpires...I'm embarrassed to even write this but....I sheared off the centre bolt holding the valve cover. I honestly don't even know how it happened. I fastened the outer two and they went on until they tightened down. Then I went to finish tightening the middle (i was doing them in succession, bit by bit for an even torque across the gasket) and the middle one just wouldn't really tighten. So I kept spinning and then SNAP!. Ugh...so embarrassing...So now I'm trying to decide how to get the broken bit out of there. It's way down in there so there's no hope of using pliers on the stump or anything. I'll need to drill it out, I suppose. But that leaves me concerned about getting metal shavings inside the head. I would obviously tape off the area and just have that bolt tube exposed, but yeah. I'm not experienced with drilling out sheared off bolts and am quite terrified of running at an angle and thrashing the threads on the head-portion of the bolt hole. Ugh. Like I said, embarrassing. I've never done this before. And obviously, I'm going to need a replacement valve cover bolt to replace the broken one, once I manage to get the broken one out.

The reason I opened the valve cover was two-fold. Firstly, I wanted to get an idea of how dirty it was in there, as the area in the oil fill cap was sludged to all hell. As it turns out, it's spotless in the head and I reckon the valve cover is secondhand. As to why, I have no idea...

The other reason is because I was curious if the head bolts were torqued down quite sufficiently to the engine block, as there seems to be a slow-but-steady weep of oil from around the entire front side of the head gasket. And recall that the head gasket was changed not that many kms before I got to the car. I'm wondering if that slow weep is normal. But alas, the head bolts are not normal bolts - they're massive torx bolts, which I haven't got. I'm not even sure of the size of them or I'd go buy one...

So I really want to give the car all the TLC it deserves: full fluid and filter flush/replace. Repair interior (the door cards have some holes in them, the passenger side sun visor is broken off and missing, I need a new mirror cut to fit the passenger side mirror, I'd like to wire up a set of rear speaker but hey, at least I was able to pull out the head-unit and get the serial number to get the unlock code!), respray exterior (the entire clear coat is just...gone). And honestly, the work I have done so far HAS made a noticeable difference in how she runs but...my initial approach was that, until I sorted out the misfire I was going to hold off on all those fluids and filters. But now this sheared bolt...ugh...

Once again, if you've read this far then I thoroughly commend you. I have a nasty habit of writing WAY too much. But then I figure, once I spent the time writing it, I'm gonna post it...

[pontiff]

Firstly, I'd like to say that it is super nice of you to offer to personally help me! It is a very nice gesture and is it much appreciated. Unfortunately, I live a ways north of you, in the Macedon Ranges area. I wouldn't even mind bringing the car down but, as of right now, the car has no rego. My mate (who owns the Polo) is waiting on a pay-cheque to purchase a month of temporary rego. I keep badgering him about getting the temporary rego as it makes it difficult for me to work on the car without being able to drive it. So yeah, for the time being at least, I can't take it anywhere...

As for answering your questions:
1) The timing seems to be ok to me. I'll check it again, more closely.
2) Injector short to open I seriously think was from someone doing previous testing. And now that I think about it, it may have even been me, when I very first popped the bonnet and felt the misfire, I think I unplugged the injector. The fact is, once I cleared the codes, not a single code has returned that hasn't been as a result of my intentional unplugging of things for testing purposes. As the car sits and runs now, there's no codes.
3) Can I feel the misfire on 2? Without a doubt. And if I unplug the injector to any of the other cylinders (1, 3 or 4) then it REALLY starts to miss. If I unplug the injector to cylinder 2, there's no difference at all. HOWEVER, if I swap the oil-gunked plug with, say, cylinder 4, then the misfire in two goes away and there's a misfire in 4. That is, until enough oil starts to accumulate in the plug in no 2, at which point it starts to miss there again. If I then remove the plugs from 2 and 4 and give them a good clean up, and put them back in, then the engine purrs like a kitten. For a while, until no. 2 gets gunky again. It doesn't happen right away, either. Which is what makes me think it takes until oil vapour begins to build in the crank case and has no where to go and so starts to shove up past the piston rings. Like I said, ALL the electrodes are pretty dark. It's just that 2 is the worst. At least the others are all dry and there's clear signs of where the spark is occurring on the centre electrode. With 2, it's just oil. At least the other ones are still firing. As an aside, I pulled apart the dizzy cap and rotor arm and used some sand paper to scuff up the contact points and get the black scoring off them. I was pondering whether a weak spark wasn't doing enough to burn off the carbon deposits on the plugs. I am currently awaiting arrival of the replacement cap and rotor. I Ohm-meter tested the plug leads and they tested ok. I sprayed water around them at night and saw no sparking/arcing.

Now, not to insist on being spoon fed the info here, but I can only see one fastening bolt on the underside of the black PCV box. Is the other fastener wedged up under the intake manifold? And is the best method of action to somehow remove the breather hose first, then remove the black box? Or is it better to remove the box and take out the unit as a whole, and then disconnect the hose once it's all out? Because like I said, I have huge hands and can't get any kind of a decent grip on the hose as it stands, certainly not a grip which would afford any sort of dexterous manipulation of any tabs or clips. Grrr...

As for the thermostat in the air intake routing door, I don't reckon that works. It only ever routes hot air, so yeah I'll definitely disconnect that end and then re-attach it for roadworthy.

Now, on to the latest and greatest as this project transpires...I'm embarrassed to even write this but....I sheared off the centre bolt holding the valve cover. I honestly don't even know how it happened. I fastened the outer two and they went on until they tightened down. Then I went to finish tightening the middle (i was doing them in succession, bit by bit for an even torque across the gasket) and the middle one just wouldn't really tighten. So I kept spinning and then SNAP!. Ugh...so embarrassing...So now I'm trying to decide how to get the broken bit out of there. It's way down in there so there's no hope of using pliers on the stump or anything. I'll need to drill it out, I suppose. But that leaves me concerned about getting metal shavings inside the head. I would obviously tape off the area and just have that bolt tube exposed, but yeah. I'm not experienced with drilling out sheared off bolts and am quite terrified of running at an angle and thrashing the threads on the head-portion of the bolt hole. Ugh. Like I said, embarrassing. I've never done this before. And obviously, I'm going to need a replacement valve cover bolt to replace the broken one, once I manage to get the broken one out.

The reason I opened the valve cover was two-fold. Firstly, I wanted to get an idea of how dirty it was in there, as the area in the oil fill cap was sludged to all hell. As it turns out, it's spotless in the head and I reckon the valve cover is secondhand. As to why, I have no idea...

The other reason is because I was curious if the head bolts were torqued down quite sufficiently to the engine block, as there seems to be a slow-but-steady weep of oil from around the entire front side of the head gasket. And recall that the head gasket was changed not that many kms before I got to the car. I'm wondering if that slow weep is normal. But alas, the head bolts are not normal bolts - they're massive torx bolts, which I haven't got. I'm not even sure of the size of them or I'd go buy one...

So I really want to give the car all the TLC it deserves: full fluid and filter flush/replace. Repair interior (the door cards have some holes in them, the passenger side sun visor is broken off and missing, I need a new mirror cut to fit the passenger side mirror, I'd like to wire up a set of rear speaker but hey, at least I was able to pull out the head-unit and get the serial number to get the unlock code!), respray exterior (the entire clear coat is just...gone). And honestly, the work I have done so far HAS made a noticeable difference in how she runs but...my initial approach was that, until I sorted out the misfire I was going to hold off on all those fluids and filters. But now this sheared bolt...ugh...

Once again, if you've read this far then I thoroughly commend you. I have a nasty habit of writing WAY too much. But then I figure, once I spent the time writing it, I'm gonna post it...

PM me your email address for quicker responses, but you are having a time of it aren't you....

when you get that valve cover bolt out let me know, I'll pull one off the spare motor I have and send it to you.

if you pull off the air filter, the rubber hose that plugs into the side of it, are you getting any vapour coming out of that? if you do you will know about it as it smells a bit. is there really much oil up there? is the vapour being re-injected into the engine (like its suppose to do) but the sheer volume is excessive?

yeah just re-route that pipe.. some people leave it connected and remove the thermostat in the housing and just tape it off so it looks like works but realistically does nothing.

attach some pics of what you're trying to do also if you can as it makes it easier if we can see what you are seeing. I'll try and take a photo of the back end of the engine that I have out of the car so you can perhaps see what we mean.

its interesting though that its only cylinder 2 not the rest of them unless the compression rings are worse on that cylinder but they all look the same so thats a bit wierd.

Do you have a timing gun? check the timing and make sure its set at 6 degrees BTDC (there are markings, all be it small ones, on the lower plastic crank cover), but as you say, if it purrrrs when the plug on 2 is clean then its not that anyway.

are you getting vacuum pressure coming out of the side of the intake manifold going to the brake booster? just unplug the rubber hose and check it....

can you attach a pic of the plug when it runs rough?

you can get an unregistered vehicle permit for the purpose of 'repairs' but its probably best saving the $41 that would cost and buy oil and a filter

[John_T]

Hi mate!
How has this restoration been coming along? I hope all is well. I've got some spare parts. if you need send me a pm.

=)