16 FSI misfire and something I have noticed

Bumblebee

Member
I have noticed that my FSI runs quite a bit smoother on start / warm up and then starts to get a bit up and down on a constant rev or idle? I also thoughts I could hear a feint hissing somewhere near the rear of cylinder 1-2 area, but it could just be induction noises as the air intake runs across head in that area to the MAF unit at back of the block.

Question is. Am I just being paranoid about stuff, or has anyone ever had something similar and the diagnosis was ???

I am going to have a go at using VCDS lite later and see if I get anything different to P0302 coming up as the norm.

Also is there something available to stick through the fuel lines to blast out any crap from the injectors etc? You can tell I am reluctant to strip the intake side and replace injector 2 if its just years on normal unleaded the PO ran her on?????

TIA

A2 learner :)
 
Despite all the problems our fsi had/has/touch wood, I never experienced a misfire. Could it be that the sounds you are hearing be piston #2 pumping air all the time?
 
Hi,

One of the last problems I had with my FSI was having a moving idle speed that was quite dramatic.

This ONLY happened when the engine was hot.

I did a standard garage smoke test on the engine to find air leaks. It didn't find anything.

A higher pressure smoke test was done at a second garage which did find air leaks.

This and other FSI suffer from air leaks at the base of the oil dipstick area.

I recommend you replace the oil separator/engine breather and look into any air leaks. (these are all around the same area of the car)

FSI fuel injectors are simply not great. I replaced mine, which helped a lot but not with the symptoms you are experiencing.

Kind Regards,
Craig
 
Hi,

One of the last problems I had with my FSI was having a moving idle speed that was quite dramatic.

This ONLY happened when the engine was hot.

I did a standard garage smoke test on the engine to find air leaks. It didn't find anything.

A higher pressure smoke test was done at a second garage which did find air leaks.

This and other FSI suffer from air leaks at the base of the oil dipstick area.

I recommend you replace the oil separator/engine breather and look into any air leaks. (these are all around the same area of the car)

FSI fuel injectors are simply not great. I replaced mine, which helped a lot but not with the symptoms you are experiencing.

Kind Regards,
Craig
Thanks Craig. I did check the oil filler seals as well as they can get loose / worn but that's quite snug.

I'll try and see if there are any obvious ones. I know there are a few vacuum/ hoses on the back nearer the bulkhead, it's all worth checking.


I know the PO as she was a colleague and admitted it ran mostly on 95 octane fuel, so it may just be coked up and the injector has packed up.....

I like to have a go at all jobs myself and increase my knowledge and experience on my cars. My LT is a lot more old school with carb, plugs, points etc, but I guess I'm trying to put off a strip and change injector weekend as the weather's not the best to tinker on your driveway outside 🙄😜
 
Thanks Craig. I did check the oil filler seals as well as they can get loose / worn but that's quite snug.

I'll try and see if there are any obvious ones. I know there are a few vacuum/ hoses on the back nearer the bulkhead, it's all worth checking.


I know the PO as she was a colleague and admitted it ran mostly on 95 octane fuel, so it may just be coked up and the injector has packed up.....

I like to have a go at all jobs myself and increase my knowledge and experience on my cars. My LT is a lot more old school with carb, plugs, points etc, but I guess I'm trying to put off a strip and change injector weekend as the weather's not the best to tinker on your driveway outside 🙄😜
Sounds great, just note I wasnt talking about any seals that you can gain easy access. These leaks come from under the engine. The base of the oil stick. Old plastics that fail from age.

Good luck!
 
Also is there something available to stick through the fuel lines to blast out any crap from the injectors etc? You can tell I am reluctant to strip the intake side and replace injector 2 if its just years on normal unleaded the PO ran her on?????

Millers offer Petrol Power Ecomax additive which is widely available:

I know that @dj_efk swears by the diesel equivalent.

Millers also have Petrol Injector Cleaner, although this is harder to track down than the Ecomax:

I have no personal experience with either of these products, which may or may not work for you.
 
Millers offer Petrol Power Ecomax additive which is widely available:

I know that @dj_efk swears by the diesel equivalent.

Millers also have Petrol Injector Cleaner, although this is harder to track down than the Ecomax:

I have no personal experience with either of these products, which may or may not work for you.
I can advocate the diesel equivalent as well. My dads 1.2 and his previous 1.4 ran for cumulatively 500,000 miles without ever having any injector issues. I bought Tonka with 180,000 on the clock and within 2,000 miles of using the Millers it sounded better but most crucially, the MPG involved 7%
 
My FSI runs on Mr Shell's finest, contains detergents that should help. Although it a mortal sin to use 95 E10 on an FSI, I don't see why it should block the injectors. What is the mileage of yours, @Bumblebee
Mac.
 
Millers offer Petrol Power Ecomax additive which is widely available:

I know that @dj_efk swears by the diesel equivalent.

Millers also have Petrol Injector Cleaner, although this is harder to track down than the Ecomax:

I have no personal experience with either of these products, which may or may not work for you.
I've put Millers in it as it was recommended before, and also used it in my old LT straight 6 petrol, but as its been on the road, its not been driven enough to probably help????

I have seen things where things are squirted in whilst the engine is on a high tick over, and understand that garages use a pressurised additive they blast in the fuel rail to flush out some crap, but this may all be US of A stuff on you tube.

I had the stupid idea of an endoscope last night to see if the end of the injector in Cyl 2 can be seen to see if its all fouled.........

I guess I am just trying to avoid the strip and try and unclog it if its clogged, but it could be an electrical fault in the injector anyway if that's it.
 
I can advocate the diesel equivalent as well. My dads 1.2 and his previous 1.4 ran for cumulatively 500,000 miles without ever having any injector issues. I bought Tonka with 180,000 on the clock and within 2,000 miles of using the Millers it sounded better but most crucially, the MPG involved 7%
I think long term for sure it will have this additive used for a cleaner engine etc.....
 
I've put Millers in it as it was recommended before, and also used it in my old LT straight 6 petrol, but as its been on the road, its not been driven enough to probably help????

I'm sure I've missed a post somewhere, but I'll ask anyway. For clarity, can this car currently be driven on the road or not?
 
If the lower manifold has never been off, then from what I understand from others' experience here, nothing beats taking it off and cleaning it all up and checking each and every hose + connection.

I do indeed swear by Millers' products but I'm not sure that's going to help you. Worth a try and you may experience some improvement however.
 
If the lower manifold has never been off, then from what I understand from others' experience here, nothing beats taking it off and cleaning it all up and checking each and every hose + connection.

I do indeed swear by Millers' products but I'm not sure that's going to help you. Worth a try and you may experience some improvement however.
If there's no vcds errors relating to the inlet manifold flaps etc, why think it has problems?
What make are the coil packs?
Mac.
 
Back
Top