HELP! Golf mk4 2.0 GTi Engine problems!!

[Richie_Rich]

Hi there all, i'm new to the site, must say loads of interesting info!

I was wondering if any bods know about Mk4 Golf Engine probs/Sensor failures?

A few weeks ago my engine management light started coming on and going off at will, about a week ago a nasty smell started and the light stuck on. The car drove fine no loss of power it just over reved on start and at idle occassionally.

I took it for a diagnostic and service and the diagnosis was that it had been burning oil and this had fouled up the lamda probe, I had this replaced and the light turned off, the car seemed fine, still over reving a little when starting,but not smelling or using any oil. Then after a cold night it struggled to start, the engine management light cameback on again (after turning it over a few times), but this time no smell and running fine.

VW now say its Piston rings, but i've heard something about Air leaks in the engine, and mass air flow meters becoming a problem?1?

Any help, or advice would be greatly appreciated.

Cheers, Rich :aargh4:

[Veedubber]

Did you ever find out? I have the same car and my light's been on for a week (is it on orange or red, yours?) and the dealer says it has a non-standard cat on but they'll put a VW cat on for £600. It's running fine other than the light (which obviously means it might be about to run not fine)

[Richie_Rich]

Hi there, still not found out, but light comes on and goes off now so thats encouraging, but to be honest I would take what VW say with a pinch of salt, look into stuff elsewhere, cos as I explained, my piston rings are defo not gone because car not using any oil now, VW wanted £800 to fix.!!! - Ps my light is orange

[shooey88]

the emmisions light on can be numerous different faults. get the fault code to point you in the right direction of a possible sensor/ electrical fault?

[Eshrules]

the EMS (engine management system) light is indicative of a fault.... in order to diagnose the fault properly, we need to know the codes. the fact that you had the lambda sensor replaced and this rectified one fault, could well be totally un related to this now present fault.

if i were you, get someone with vagcom or a fault code reader to hook up your car and read the codes.

there are quite a few people on here who will oblige, if your near stalybridge/ashton under lyne im always willing to help for a few beers ;)

[Veedubber]

...to be honest I would take what VW say with a pinch of salt, look into stuff elsewhere, cos as I explained, my piston rings are defo not gone because car not using any oil now, VW wanted £800 to fix.!!! - Ps my light is orange

:) After the initial panic I had on speaking to VW and going there this week, I've asked around a lot more and come to the same conclusion! Not about your oil, I mean, about VW... I have found a local man with a fault reader thing and he is going to tell me this weekend what the fault is.

Maybe you can find someone local to you to do the same?
Everyone seems to have been very helpful:beerchug:

[Col]

The 2.0 does have a reputation for using oil as a result of the piston rings exactly as the dealer has suggested.

A design fault, yes but they'll never admit it.

[Veedubber]

The 2.0 does have a reputation for using oil as a result of the piston rings exactly as the dealer has suggested.

A design fault, yes but they'll never admit it.

Course not! Does the 2.0 have a reputation for anything else or can you tell me where to find out? I absolutely love it but I think people seem to like the TD GTi (or TDi or whatever) more. I got a nasty polo 1.2 from the dealer yesterday and oh what joy to get my lovely dub back!

[Richie_Rich]

Cheers for the responses and helpful hints guys!!! I did a compression test on the engine last night, Piston Rings - DEFINATLEY NOT!!, got a local company called Motor Tek that say £40 an hour to put it on their computer - which i'm doing tommorow, so will post back with outcomes!!!

All this to sell a car - ahhhh!!!!, need to get this light off so I can sell and get an Audi S3!!!, went out in one with a guy from work and they are mean machines!!! - fingers crossed tommorow i'll be a step closer!!!

[Col]

[quote=Richie_Rich;38595]Piston Rings - DEFINATLEY NOT!!quote]

I wouldn't be so hastey in making that conclusion.

Reason being...

If either the piston or oil control rings are letting oil past, that oil is going to help give nice high readings whilst doing a compression test.

What you need to do to be sure is a 'leak down' test. This is where a bore is pressurised and it's pressure observed over a period of time. Much more accurate than a compression test.

Also having read your other post as well my gut feel is...

The CAT and Lamda problems are probably linked and could possibly be caused by the oil problem.

Personally I'd accept what VW have said, obtain in writing their diagnosis and take it back to where you bought the car. You say you have a warranty, use it, you only got it in Feb.

If you don't sort this underlying problem, you'll probably end up replacing the cat and lamda again before to long.

Do a google search about the 2.0 oil problem if you are still in doubt.

[Richie_Rich]

"Personally I'd accept what VW have said, obtain in writing their diagnosis and take it back to where you bought the car. You say you have a warranty, use it, you only got it in Feb."

I've had the car 2 years!! - And bought it privately, never mentioned warranty!!

But you could be right, the guy did mention that the compression test could be inaccurate, and my appointment at the diagnostic company had to be canceled due to work.

Is it worth even considering fixing the problem (piston rings) as a means to getting a good price for the car?? or would it be best to cut my losses and get rid before it starts smoking and smelling again??

Any advice welcomed!!:aargh4:

[guyg]

I think BigCol is on the right track - I saw an article not too long ago regarding these engines, particularly the AQY and one other that I can't remember.

There was a design fault on the oil control rings fitted to these engines over a period of years. Apparently, VW now supply modified rings under the original part number [hoping no one will notice?].

A symptom of this problem is [oil] contaminated lambda sensors and the resultant dash light comming on.

You will get a good compression test even if you're burning oil...

I will try and dig out the urls and post them here.

Cheers

Guy

[shooey88]

yeah iv seen a few where the piston rings go inline with each other.

quick way to check....is remove the spark plugs and see if any of them are soiled with oil....normally only one of the clyinders fail with piston rings in my experience.

[guyg]

Found the article-

http://uk-mkivs.net/forums/thread/126674.aspx

Cheers

Guy

[Richie_Rich]

Cheers for the info guys!! I was speaking to an ex-VW guy yesterday, he said the AQY was prone to this, so it may be time to say bye bye and cut my losses!!

Appreciate all responses, Cheers,

Rich:(

[simon hare]

Hi there, I have the apk 2.0 engine in my 2000 VW Bora. Bought with 104k now on 129k. After 5 years of searching for the cause of fouled up plugs/excessive oil burning/moisture in the oil & breather system, I have finally bottomed the fault. I had the head redone a few years ago because of a stuck open valve, both lambda sensors have since been replaced along with various other bits and bobs. Most recently i did the valve stem seals myself, but still no change (god you should have seen the sludge inside the engine! oil changes were regular). Compression tests were inconclusive, but a leakdown test proved blowby past the rings.

Right well, this was the root cause of the problems:-

The top compression ring on all pistons were stamped up incorrectly and installed upsidedown (scraping on the downstroke and allowing gases by them on the firing stroke). As a result of the blowby, middle and bottom rings were also stuck in their respective grooves on all pistons. No amount of italian tuning or atf fluid would have freed them! I cleaned everything up, checked the wear limits (all within spec) and fitted a new set of rings/headgasket The oil burning has all but halted but the new rings still have to seat properly. Just for information this engine was made in mexico around year 2000 so at least be wary of these i'd say. 21270
In the pic can be seen the top stamping on the top compression ring, but it can also be clearly seen that because the outer is tapered & not flat, this ring would act more like an oil scraper than a compression ring. Good work Volkswagen!!!
21269