Right, I ereplaced the dizzy with one from a scrapyard, haven't run it since then. When my buddy had a look when I was having power loss he diagnosed it as the distributor. I did the dizzy cap and rotor arm at the same time but not the HT leads. VCDS comes up with no codes for the engine other than a basic setting not performed. 01087 if I remember correctly. Nothing to do with cylinders or anything like That.

Think I'm gonna pick up a compression tester after work tomorrow and head out to the car, do the test and post my findings on here. I believe it's something to worry about it the PSI is under 100 for each cylinder, right? Or more than 10% difference across all four or something like That.

I've got a litre of coolant in the boot so if I do go anywhere I'll take that and a bottle of water. Is the sniffer test but literally smelling for oil etc? The company's always been done, a little high of anything. No mayo in the cap, had a fair amount t of creamy think in the like to the airbox but I imagine that's just condensation. Should I do anything about that?

As for the spark plugs, I took the old ones out and I think it was water on 2 & 3 and oil on 1. The new ones I've fitted are 14mm NGK plugs. I say fitted, they're not actually in properly at the moment as we were last trying to diagnose the problem.

After we fitted the new engine he said something about the timing, but I can't remember what.

The "sniffer" test is a coloured liquid that changes colour (Blue to yellow from memory) in the presence of hydrocarbons, and that is a good indication of the gasket failure, the tester uses a giant turkey baster to suck the air in the top of the expansion bottle and it passes over the liquid and if it changes then there is hydrocarbons in the water system and the way this can happen is the gasket has failed or there is a crack in the head, so when used inconjuction with a compression & leak down test it's a pretty definite way of diagnosing the state of the gasket/head

Basic settings not performed, would that not be ignition timing? I believe on the 6n this needs to be performed while the car is hooked up to VCDS. I'm sure there is a 'how to' somewhere on here.

If that is not set up properly then that alone could account for your lack of power.

Also you say 2 of the plugs had water on them? I hope it was petrol and not water.

Nige- Bit more technical than inhaling my coolant then! I'll look into that. Going to do a compression test tomorrow.

Kwijibo- He seemed to think ignition timing was the problem. I'll hook it up to VCDS this weekend and see if I can do the basic setting. I'm not sure what it was, I wasn't there when he took the plugs out. He might not have said water, I may have misunderstood.

You guys have made me awful hopeful that it's not the head gasket, if it turns out it is I'm gonna get all emotional!

Seriously though, thanks for all your help. I'd be very lost without you guys opinions.

Edited 12 December, 201411 yr by mbusby993

A good nose might be able to smell petrol vapours but by that time it's pretty well definitely a shot gasket !

Have a look at this http://www.clubpolo.co.uk/forum/index.php?showtopic=330460#entry2608765 I've posted a document on how to set the timing on this engine series, and it does involve using VCDS & a timing light

Thanks Nige, I'll get my hands on a timing light.

To be honest I just wanna get back behind the wheel after 8 weeks away!

Had a similar issue with mine, I was certain the gasket was gone, so bought everything andd when I was taking it apart, I found the leads had cracks in them. Swapped for a spare set and it ran perfectly.

As yours has been standing for a while I would get it running and let it idle for a long hike to get good and hot, so let the fan run twice. Then do your basic tests again as there may be moisture in things that will dry out, plus you can monitor the coolant etc.

Also from experience these engines love new ignition parts, so keeping the plugs new keeps it happy, and it throws all sorts of things St you when they are half way gone. Put the same plug in another car and it will work perfectly for a long time.

So as you don't know the history I would change all the ignition parts, so plugs, leads, cap and rotor arm. Also moisture does like to hide inside the cap. I remember having to clean the contacts almost every week at this time of year.

Also, the only difference between APQ and AEX engines that I have noticed is the oil pump, the AEX used the early chain type pump and the APQ uses the later direct drive type. Aside from a few minor wiring differences and lambda locations they are the same engine.

I've changed to plugs, cap and rotor arm. I'll tighten the plugs up, pop the air box back on and run her for 15 minutes before doing the compression test. Get some oil flowing. Just picked up a tester.

I'll think about changing the leads now you've said that. Thats the only ignition part I haven't changed yet. The dizzy wasnt new, but the cap and rotor arm were. I haven't run it since then though, as I was worried about the head gasket. I'm on my way to my girlfriend's parents now so I'll have a crack at it this afternoon. Maybe take the 2 minute trek down the road to pick her up from work tonight to see he it's pulling.

Edited 13 December, 201411 yr by mbusby993

When you purchased your new spark plugs, if you asked for the correct ones for YOUR engine, then everything should be OK............BUT (yes, I know, there's always a 'BUT'!)

There is more to plugs being 'correct' than the make and the thread (14 mm) - The length of thread can also vary.

The thing to remember, is that the HEAT RANGE varies, so whilst your plugs may physically fit other makes and models, the heat range (essentially, how much INTERNAL insulator is exposed) may well not suit others.

As I have said, if you asked for plugs for YOUR car, they are almost sure to be correct - so don't loose any sleep over it!

Regards

I'm fairly certain my spark plugs are correct. The car started on the button today when the battery was fully charged. Unfortunately the battery I have that I was going to fit today doesn't actually fit. It was bigger than the 063 type I had in There and I couldn't make the fuse box fit on to the battery. To put an end to this I've ordered a BOSCH S3 battery from ECP and will be fitting it on Thursday.

As the battery was crap, I didnt get very far with my compression test. I got one cylinder done. Came up around 180psi and exactly in the middle of the 'green' so cylinder 1 is okay. Got the engine started, ran it to 90 degrees and the fans going.

It was smelling a bit, the engine was rocking about in the bay a fair bit, had knocking and a fair amount of white smoke at the exhaust. I've got some videos of the noise at engine and at exhaust.

Not got any idling problems, she idles nice and steady. The video of the engine has pretty poor sound quality, and the motion light kept turning off, but you can hear the tapping. The tapping at the engine takes place at the same time and rhythm as the exhaust is blowing. You'll be able to tell from the videos.

All I can really do for now is wait for the battery To turn up and finish the compression test. But I thought I'd share the videos with you to see if there's anything that stands out!

Exhaust blowing Polo 6n:

Polo 6n Engine Tapping:

Idling normal:

Edited 13 December, 201411 yr by mbusby993

Sounds to me like the tapping might be it missing on one cylinder. Have you checked the state of the leads?

Also the smoke out the back isn't that bad, if it is missing it will just be fuel and general emissions.

Head gasket issues would usually mean thick clouds of white smoke and also the temperature would shoot up to well over boiling point.

Check the state of the leads and replace with new if you can and while you are there take the plugs out again and inspect them.

The ignition timing not being set properly as you mentioned before won't be helping matters either.

My girlfriend's step dad guesstimate that it may be a cylinder not firing. If that is the case how what would be my next step? HT leads are £18.90 on ECP so I'll try and pick up a set. Shockingly short on cash right now, it's the wrong time of year for car troubles.

Once I've got the new battery fitted later in the week I'll do the compression test properly, take it on a short trip to see how it performs and go from there. There's a definite pattern to the tapping. It will run smooth for 30 seconds then run rough for 10-20 and so forth.

Still not losing coolant or getting mayo etc. Even the gunk in the air box pipe has gone. It was running like a dog though.

How do I sort the timing out? I'm learning so much so fast but there's still a lot I haven't done. I'm happy with how competent I'm becoming with stuff like this though.

Edited 13 December, 201411 yr by mbusby993

If it were my car I'd change the HT leads first and see if that improves anything. At least then you know all the ignition components are new and should be working perfectly.

For the timing you'll need to go into some base settings in the VCDS program while hooked into the car. Then loosen the 2 x 10mm bolts that hold the dizzy onto the car so you can move the position of the dizzy.

Then with a timing light hooked into cylinder 1 find the timing mark on the crank pulley and move the dizzy until the timing is set. The document that Nige8021 posted should explain it better.

Yeah I'll look into the leads. I'm fast approaching the point where I've spent as much on fixing the car than I spent on it in the first place. Though I suppose that's the danger of picking up a car for £380.

Will I be able to do that with the freeware version of VCDS? I haven't had a look at the document Nige linked yet as I'm on my mobile data and it was taking a while to load it.

I'll have to get a timing light too.

Edited 13 December, 201411 yr by mbusby993

If the box for basic settings in the Engine ECU page isn't greyed out then the lite version will work, basically it puts the ECU base timing to 6 deg then raises the idle to 1100rpm, then with the timing light you adjust (slacken the bolts and twist) the distributor till it also aligns on the 6deg mark on the crank pulley, then tighten the dizzy mounting bolts, exit VCDS basic settings and then ignition is set :)

Fantastic, I'll get on that soon.

I'll post some updates once I've got the compression test done.

Just to confirm, I'd this the sort of thing I'll need? Obviosuly title makes it seem so, but the last time I assumed I bought an incorrect model.

Draper 52616 Xenon Timing Light by Draper http://www.amazon.co.uk/dp/B0001K9V3Q/ref=cm_sw_r_udp_awd_GHlJub0FAZ8HK

That is the one I use on the mk3 so I dare say it will be good enough for the mk4 as well.

Perfectly good for doing the timing on any model of any year/make :) Should find similar models in any motor factors & being as it's close to Chrissy some might have a bigger discount ? :)

Just to confirm, I'd this the sort of thing I'll need? Obviosuly title makes it seem so, but the last time I assumed I bought an incorrect model.

Draper 52616 Xenon Timing Light by Draper http://www.amazon.co.uk/dp/B0001K9V3Q/ref=cm_sw_r_udp_awd_GHlJub0FAZ8HK

that one is fine , if you plan to be messing around with more cars then one with an ajustable advance dial would be better to have

That one will do for now, I'll see if I can find a decent one for as cheap as possible. Starting to feel the squeeze now!

If I'm a cylinder down, is that more or less expensive than the head gasket? And is there a chance I could be a cylinder dowb BECAUSE of the head gasket or anything like that?

could be anything..start with the cheap stuff , but yes could be head gasket /valve /piston troubles

I'm gonna do the HT leads when I'm back on Thursday, everything else on the ignition is new. Well, the dizzy came from a scrapyard, but it's been changed.

Its annoying that, as I was banking on the battery I had fitting, I've been pushed back by another 5 days. I just wanna get to the bottom and get it running again.

Edited 14 December, 201411 yr by mbusby993

So last night I ran it for 15 minutes to get the engine up to temperature. It didn't go over 90 on the gauge.

This afternoon I've had a look under the oil cap and hey, I've got creamy gunk under the filler cap. Could just be condensation, but it's suspect.

Edited 14 December, 201411 yr by mbusby993

Running it for 15 minuets would NOT dry out any condensation and may just be long enough to form even more of the stuff.

When you get your timing light, you MAY be able to find other ignition problems with it, other than checking the timing.

As you know, the pick up clamp goes on number one plug lead for timing purposes.

Whilst it is on there, you should get a regular 'flash' from the light ( this is regardless of whether it is pointing at the timing marks or just at any other area)

After checking for this regular flash at idle speed, try it at other speeds - No need to make the engine scream, just use speeds up to about 2,000 RPM - The speed of the flash will increase, but there shouldn't be any 'missed' flashes.

Now do the same with the pick up on the other plug leads, checking for regular flashes.

(Note. The timing marks will NOT show up when the clamp is on numbers 2 and 3 leads)

This test is NOT infallible, but might point to lack of sparks which can cause a misfire.

What it won't do, is to tell you WHY there are missed flashes, these could be due to faulty plugs, faulty leads, faulty distributor cap - or even, if there are missed flashes on ALL leads, faulty coil, king lead, rotor arm or distributor. But at least you would know that it was ignition related.

Regards