1.8T coils again?!

[Gilo]

Hi,

I've got a 2003 Leon Cupra 20VT (180). I've had it for about 3 months now.

I've always had this splutter / kangaroo / 3 cylinders problem when the engine is cold. There is also a slight hesitation on acceleration once in a while.

I've read loads of threads on this and so far I've:

- replaced coolant temp sensor (was black, now green)
- replaced all spark plugs (all looked ok)
- started to replace coils

When on holiday recently, #3 coil died (left us stuck for 2 hours - wife not impressed!). It had actually snapped in to two pieces. That is now replaced with a new "R" rev coil pack.

The other coils are at Rev J (x2) and an L. I've bought another "R" rev coil and have systematically swapped it to each cylinder over the past week.

This morning was #4, and I still have the problem. I guess I could have two (or three coils) in there that are faulty, but what else could be causing my problem?

MAF? I replaced the MAF on my 1.8T Passat, but that was at 80k miles. My Leon has only done 40k! Surely it's not covered in crap already!

My neighbour mentioned that it could be something to do with a choke sensor? Is there such a component?

Cheers Guys. I want to get this sorted and I want to try to do it without a visit to my dealer.

G.

 

[Hicks]

Mine's gone in to the dealer to try and sort out this exact problem. Plus the fact that it failed the MOT on emissions.
It was really bad this morning at low revs, and it's also happening in 4th/5th gear.
I'll let you know what they have to say about it.

 

[Gilo]

Thanks! It would be great to hear what they have to say about yours.

 

[Hicks]

I suspect the MAF because I already replaced the coolant temp sensor, it's had new plugs recently, and the coil packs were changed a couple of years ago under warranty.
Problem is, last time I looked there were no fault codes logged.

 

[invisiblekid]

I've got the same problem. Slight hesitation at about 1800rpm usually in second.

I've had all coils done, new plugs in my 60k service and temp sensors. I'm going to do my MAF when I get an induction kit I think and see how I go. I also have no VAG-COM errors.

 

[Gilo]

Hey Hicks - what did the dealer say about your problem? Did they say that the MAF was faulty?

On a general note - are the MAF sensors known for failing electrically, rather than just getting dirty?

Cheers,

G.

 

[Hicks]

No mention was made of the MAF sensor. Shows how much I know.
They said they needed to replace a couple of other sensors:-
Throttle valve pressure drop sensor, part #6Q090960600A
Front lateral acceleration sensor

 

[Gilo]

OK - cool, and is it fixed?!

How much were these parts / labour?

G.

 

[Hicks]

£293.22 inc VAT and labour

I haven't told them to do this work yet because the car has other problems which I'm trying to clear up first.

 

[Stan 24v]

Could well be the MAF. This would also explain why the emissions could be out, as it could be telling the engine to overfuel, and therefore the emissions would be too high.

Does it get worse if its damp? If so then it could be leads/coils as they let in water whehn knackered and it causes the engine to miss.

It could even be a badly seated spark plug, or knackered plug. have you tried reseating them, or inspecting them?

 

[Hicks]

Could well be the MAF. This would also explain why the emissions could be out, as it could be telling the engine to overfuel, and therefore the emissions would be too high.

Does it get worse if its damp? If so then it could be leads/coils as they let in water whehn knackered and it causes the engine to miss.

It could even be a badly seated spark plug, or knackered plug. have you tried reseating them, or inspecting them?

Not worse when damp, but worse when cold.

With the MAF being such a common cause of failure, you would have thought the dealer could try a spare part. What I could try myself though is disconnecting it and see if that improves the situation.

I doubt the spark plugs are causing this as the car has just had a major service, and I got the problem even before the service.

 

[Gilo]

My LC is booked in to my local dealer tomorrow to try to figure out what the problem is.

I did consider continuing to buy and fit parts, trying to solve the problem without knowing what the fault is. But, I've decided to draw a line, and get Bay Horse Motors to do their thing!

I'll let you know what they report.

G.

 

[invisiblekid]

Could well be the MAF. This would also explain why the emissions could be out, as it could be telling the engine to overfuel, and therefore the emissions would be too high.

Does it get worse if its damp? If so then it could be leads/coils as they let in water whehn knackered and it causes the engine to miss.

It could even be a badly seated spark plug, or knackered plug. have you tried reseating them, or inspecting them?

Mine is worse when damp and cold. If I drive really, really carefully until the engine is warm I don't get the problem, but if I'm slightly heavy footed I get the hessitation and it's like that until I restart the engine - that to me sounds electrical doesn't it?

I too had my sparks done at my 60k service. Although, I need to call in and get my book stamped so I'm going to make sure they did them. Will inspect them over the weekend.

Where else should I be looking?

Hope this isn't hijacking the thread - as the issues sound similar.

 

[Hicks]

My LC is booked in to my local dealer tomorrow to try to figure out what the problem is.

I did consider continuing to buy and fit parts, trying to solve the problem without knowing what the fault is. But, I've decided to draw a line, and get Bay Horse Motors to do their thing!

I'll let you know what they report.

G.

Why not let them run the diagnostics and then fit the parts yourself if it's simple. I'm getting a new N75 from a local VAG parts supplier, costing me £35. The dealer wants £152 to fit this part.

I would be very interested to know what they think is causing the problem.

 

[Gilo]

Hi Guys,

I dropped the LC off at the dealer last night so that it would be there for them with COLD engine this morning.

They discovered that the Throttle Pot (body?) was dirty and was not allowing the butterfly valve to operate correctly at low revs. They've also reset the ECU to base values because the car will have adapted over the recent weeks to the throttle body fault.

The diagnostic check also registered a sporadic fault on the MAF sensor. They've checked the MAF sensor today and it is functioning correctly so they've not replaced that at this time.

So, diagnostic and clean throttle body comes to £69.32 total.

They're confident that this is the fault.

They've said that if the problem comes back, the MAF will be what they will check first. This will be £82.13 fitted. Apparently, they only charge 1 unit @ £5.90 + VAT to fit the MAF - he said it takes them 7 minutes to fit!

They also mentioned that there is a Technical Note from Seat on this Throttle Body cleaning - it's a common fault.

I hope that helps.

Actually, I've not picked the car up yet, or started it from cold, so I'm only basing the above on what the technician has told me.

Tomorrow morning will be the test!

I'm glad I went to the dealer now. I wouldn't have picked up this throttle body fault myself. My next plan was to replace the MAF (blind) - but now I know the current status of the MAF. I know it's not 100% - but it's good information.

Gilo.

 

[DodgyDave]

throttle body is very common ... clean mine a few times a year (although i do take it on track and drive it rather hard), £10 fro a can of carb cleaner and a bit of time will get it done.

When doing you will probly get a CEL - use VAG-com to reset/clear it.


David