14 plate petrol vrs 27000 miles, 6000 of them with Shark stage 1 remap. Problem being every now and again the car feels like its idling lumpy with a odd pop and burble through the exhaust. On throttle it still runs pretty good apart from when pushing hard it sometimes feels lazy between 4th,5th and 6th gears, also I've never haf an issue with coolant or oil until recently with both dropping ever so slightly. Any ideas?

Edited 20 February, 20188 yr by swany

Short answer is, it could be anything.

 

You'll need it plugged into diagnostics to see if there’s any fault codes in the first instance. 

 

As you have their software, Shark may be able to help you as a lot of garages we charge just to plug the car in!

Edited 20 February, 20188 yr by GoneToBeemer

sounds like a misfire but hard to say why. have you put anything on it to see if you have any error codes? these modern cars are so complicated but at least they can sometimes tell you whats wrong if you ask them   . most cheap obd2 readers will give you the engine fault codes if nothing else. not everyone can afford the full vcds or obdeleven diagnostic readers. you can get a basic one for under a tenner from ebay or amazon etc. they work with your phone (android)

but dont expect to change any coding with it just read the engine error codes and see a few hidden bits of engine data

Might be worth contacting the guys a shark, if they have done the remap. They might have had other customers who have had the same thing happen.

Ok. Wee update 2 codes 

Intermittent turbo underboost

Archived fuel trim sensor, bank 1 running rich.

Sounds like a diverter valve symptom. If it's not always closing  properly the turbo pressure will sometimes be lower due to it leaking. There are replacement versions that work even better than the original. There are people who know far more about it than me. this may point you in the right direction. not sure how to definitely diagnose it   https://www.ebay.co.uk/itm/Audi-Seat-Skoda-VW-2-0-2-5-TFSi-GFB-Diverter-Valve-Golf-R-GTi-S3-Not-Dump-Valve/331903449578?hash=item4d46fcb9ea:g:QDcAAOSwEyhZ34bh.

Edited 11 March, 20188 yr by maul

Sounds like a bad remap was it a canned map or conducted on a Dyno just saying as the codes seem to prove they’ve brought up the fuelling without any other gains a bit like a tuning box  , can’t comment on the oil or coolant  though obvious answer would be head gasket. How your mpg? Sounds like it’s running very rich 

personally id get the map removed and get them to load the standard map to see if that’s the issue 

Edited 11 March, 20188 yr by Cm11

Two threads on this now. Exactly the same post from OP

8 hours ago, Tim1631 said:

Two threads on this now. Exactly the same post from OP

 

Merged them

8 hours ago, Cm11 said:

Sounds like a bad remap was it a canned map or conducted on a Dyno just saying as the codes seem to prove they’ve brought up the fuelling without any other gains a bit like a tuning box  , can’t comment on the oil or coolant  though obvious answer would be head gasket. How your mpg? Sounds like it’s running very rich 

personally id get the map removed and get them to load the standard map to see if that’s the issue 

Yeah I thought the same about the map but the car ran great for 6 month I'm still getting the high 30's to the gallon too. A few guys mentioned diverter valve but that wouldn't explain it running rich.

Needs proper diagnosis - if over fueling and boost code errors are thrown - what about a slight boost leak, so measured air is being lost, hence over fueling code and boost code.

 

On my previous Turbo cars when I had a suspected boost leak I would get the car up on my ramps and look for oil misting around the boost pipe joins. Wouldn't do any harm to nip up the hose clamps either whilst your are there - just don't over tighten them.

 

If working under the car always make sure it is a safe environment, I drive the front up on my ramps, handbrake on and left in gear to stop it rolling and axle stands place in-case of a ramp collapse (possibly overkill but as I have them).