Mk4 Golf GTI 1.8t misfire
Discussion
We have had this car in the family since it was a year old. Took it to a garage for a timing belt and after it came back it was misfiring. It went back to the garage and they couldn’t find a problem, said timing was spot on.
Been to two other garages since who agreed the timing is ok. One then did all four coil packs, which made no difference.
The misfire seems to be worse from warm starts and is generally at low revs. Car still has plenty of power when not misfiring.
At a bit of a loss what to do. The last (VW specialist) garage said he would have to start taking the engine apart at great cost because he had checked all the obvious stuff.
It’s too good to scrap (80k miles)
Any one had this and or got any recommendations please?
Been to two other garages since who agreed the timing is ok. One then did all four coil packs, which made no difference.
The misfire seems to be worse from warm starts and is generally at low revs. Car still has plenty of power when not misfiring.
At a bit of a loss what to do. The last (VW specialist) garage said he would have to start taking the engine apart at great cost because he had checked all the obvious stuff.
It’s too good to scrap (80k miles)
Any one had this and or got any recommendations please?
2 GKC said:
No apparently not. It s a misfire on one cylinder only.
No codes for a misfire? Not unless someone has been playing funny buggers with ECU.Is the misfire consistent? Swap plug from 1-4 and see if it moves the misfire with it. Injector test depending on what fuelling looks like, should be able to see what they're doing through diagnostics.
Where in the country are you?
Dr G said:
No codes for a misfire? Not unless someone has been playing funny buggers with ECU.
It should definitely give a code and even a description of which cylinder. My S4 had an intermittent misfire, would only do it under full throttle and when it did, it would disable the cylinder and run really rough until engine off/back on.VCDS clearly told me Cylinder 5 misfire, a new coilpack fixed it.
Even my Son's old 2004 Polo gave me a Cylinder 3 misfire when a coilpack failed, so I don't believe a Golf doesn't.
Dr G said:
No codes for a misfire? Not unless someone has been playing funny buggers with ECU.
Is the misfire consistent? Swap plug from 1-4 and see if it moves the misfire with it. Injector test depending on what fuelling looks like, should be able to see what they're doing through diagnostics.
Where in the country are you?
Bristol area. The garages all seem mystified by it. It’s not really consistent, from cold start it takes a while to appear and tends to be at low revs but can be really bad, shaking the car Is the misfire consistent? Swap plug from 1-4 and see if it moves the misfire with it. Injector test depending on what fuelling looks like, should be able to see what they're doing through diagnostics.
Where in the country are you?
All of the things mentioned in this thread so far could be the issue.
Did the other 2 garages check the timing properly with a locking tool?
Can you get the codes read by someone with VCDS or a proper diagnostic setup? As said above, it will almost certainly have a code logged. Then you can switch plugs and coils around to try and understand where the fault is.
The N75 can be a culprit but its impossible to say without seeing the car.
Depending on where you are in the country there are a number of renowned VAG specialists. My personal preference is Stealth Racing in Southam.
Did the other 2 garages check the timing properly with a locking tool?
Can you get the codes read by someone with VCDS or a proper diagnostic setup? As said above, it will almost certainly have a code logged. Then you can switch plugs and coils around to try and understand where the fault is.
The N75 can be a culprit but its impossible to say without seeing the car.
Depending on where you are in the country there are a number of renowned VAG specialists. My personal preference is Stealth Racing in Southam.
Are you sure that it is miss firing? Lumpy running can sometimes cloud the same issue. I have seen this many times and there are quite a few issues that give this feeling. One issue i found was a fuel pressure sensor when hot gave erratic parameters to the ECU which caused rough running for a few seconds on start up. Another was a leaking injector which caused a cylinder to run rough for several seconds also, both did not generate a fault code and cleared after some time and engine ran great, took a while to figure the cause.
Forums | Audi, Seat, Skoda & VW | Top of Page | What's New | My Stuff