Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Lazydocker]

Not an Omega problem but hoping that someone here will be able to assist me in my thoughts...

The sister-in-law's Passat has been resident on my drive for a long time now due to the cats overheating and the car catching fire! I did post about this a long time ago... Anyway, finally been supplied with new breather hoses and plugs, leads etc to try and get it back on the road... Wasn't expecting this to be straight forward as it's been stood for 20 odd months!

Fitted all parts, put a drop of oil down each bore and turned over by hand to ensure it wasn't seized, then started car today... Which was surprisingly easy!!! It ran like a bag of spanners, which I expected, and then seemed to clear itself... For a few minutes Then it seemed to gradually drop cylinders to 3 I reckon!

Anyway, the cats got hot again, as I expected, but was getting white powder with little metal bits out of the tail pipes. I reckon the cat internals are FUBARed and blocking the flow... What do you guys think? I should add that the entire ehaust system is getting VERY hot too... I had the heat shields and the underseal smouldering again today

It's also been throwing up ABS faults but these are probably caused by a vac fault from the rough running.

I should add that this car has had a slight miss for the entire time they've owned it but the maintenance has been a bit hit and miss One of the plugs was missing almost an entire electrode

What do you reckon guys and gals? I'm hoping to take the exhaust off at the cats tomorrow and try running it up (with ear defenders!!) to give a good pointer as to whether this is the problem

[theolodian]

You need to scan the error codes.  The cats are trashed, but that is almost certainly due to other problems.

[JamesV6CDX]

Cats knackered due to ongoing misfire?

[Lazydocker]

You need to scan the error codes.  The cats are trashed, but that is almost certainly due to other problems.

No engine warning lights at all!... Ever!  Just the ABS one!!

It's going to go to a VW specialist to have a play but I'm still not convinced that, having replaced all of the HT side, the problem isn't back pressure from the cats :-? :-? :-/ :-/

[theolodian]

You need to scan the error codes.  The cats are trashed, but that is almost certainly due to other problems.

No engine warning lights at all!... Ever!  Just the ABS one!!

It's going to go to a VW specialist to have a play but I'm still not convinced that, having replaced all of the HT side, the problem isn't back pressure from the cats :-? :-? :-/ :-/

I am a bit surprised about that.  Most error codes won't actually throw the engine light, but these kinds of problems should!  The engine light is only there to tell you that there is an emissions problem, which obviously there is.

The cats will mask the cause at this point, but you need to solve what killed them in the first place.

[Lazydocker]

James, yes the cats seem oppsed and it did have an ongoing miss fire... Having looked at the HT leads and plugs I'm not surprised!

There's definitely no warning lights coming up! I guess I'll have to wait and see what happens when I take the cats off tomorrow!

Don't suppose anyone knows if VW's can be paper clipped?

[theolodian]

James, yes the cats seem oppsed and it did have an ongoing miss fire... Having looked at the HT leads and plugs I'm not surprised!

There's definitely no warning lights coming up! I guess I'll have to wait and see what happens when I take the cats off tomorrow!

Don't suppose anyone knows if VW's can be paper clipped?

Nope, but a generic scantool should be sufficient.

[Lazydocker]

James, yes the cats seem oppsed and it did have an ongoing miss fire... Having looked at the HT leads and plugs I'm not surprised!

There's definitely no warning lights coming up! I guess I'll have to wait and see what happens when I take the cats off tomorrow!

Don't suppose anyone knows if VW's can be paper clipped?

Nope, but a generic scantool should be sufficient.

Bu66er... Not bothered getting anything like that as I can paper clip my Mig  

[Lazydocker]

Anyone else have any thoughts on this???

I'm still thinking about it and I'm hoping (for her sake) that cats are going to solve this for them... She's found them for £250 the pair, which isn't as bad as it could have been (we were expecting £200 each) but just wandered if anyone has a recommendation for cats?

[hoody]

they are prone to coil pack failure,if i remember they may have seperate coils for each cylinder and really make horrendous noises when they fail,and they dont last that long either

[Phil B]

If I were you mate I wouldn't be putting news cats on there until you have solved the problem higher up. If the cats are getting ridiculously hot is it possible they are receiving unburnt fuel, perhaps because of the non-firing cylinder?

Is it also possible that HT problems don't flag errors in the EMS?

Phil

[Kevin Wood]

If I were you mate I wouldn't be putting news cats on there until you have solved the problem higher up. If the cats are getting ridiculously hot is it possible they are receiving unburnt fuel, perhaps because of the non-firing cylinder?

Is it also possible that HT problems don't flag errors in the EMS?

Phil

Yep, sound advice. On the basis that the current cats are breaked I would break a hole through the honeycomb so there is no question of a blockage and see if it drives without the slightest hint of a misfuire before replacing the cats.

Kevin

[Lazydocker]

they are prone to coil pack failure,if i remember they may have seperate coils for each cylinder and really make horrendous noises when they fail,and they dont last that long either

Had new coil packs shortly before the fire... That was the first port of call on the HT side as I was aware of VAG's weakness being coils

EDIT: The HT side is now all new... Coils, plugs and Leads so I think that can now be ruled out

[Lazydocker]

If I were you mate I wouldn't be putting news cats on there until you have solved the problem higher up. If the cats are getting ridiculously hot is it possible they are receiving unburnt fuel, perhaps because of the non-firing cylinder?

Is it also possible that HT problems don't flag errors in the EMS?

Phil

Yep, sound advice. On the basis that the current cats are breaked I would break a hole through the honeycomb so there is no question of a blockage and see if it drives without the slightest hint of a misfuire before replacing the cats.

Kevin

Hadn't thought of punching through the cats... I was just going to remove them and try it!

The new cats will only be getting fitted once we are sure the miss fire has been cured.

TBH, for the short time it ran properly yesterday there was no hint of a miss... Just a lot of rattling and banging in the cats from the loose internals!

My only concern with punching through is that they sound like they've broken up, especially with the stuff being blown right through, so I don't want to end up with the rest of the exhaust system filling up with cat internals as they are trying to fix it on a budget, hence the 18month delay in getting parts!

[Lazydocker]

Interesting update...

Just been out and started it from cold and it purrs like a v6 should... Can still hear the cats rattling but it ran like a dream!

There are lots of other strange electrical gremlins at the moment but it did run well! I think this may back up my theory that the rough running is now caused by the cats!

What do you guys think :-? :-? :-? :-? :-? :-?