What should I do?!?!

Hey guys i've been having some issues with my stock GTI. Since thursday my engine when in a cold start, starts with a misfire and then when the rpms regulate and stays at 900 rpms the misfire stops. So I drive out and everything is normal until I see a red light and I put the car on neutral to start breaking. The rpms drop and motor shuts off. Mind you i'm still running at around 40mph and radio, a/c fan but no a/c, and power steering still working but motor shuts is off and I put it into second to get the rpms to go up and the motor starts again. Kind of like if I was pushing it to start. If I don't, as we may say, push to start it while running and I do a complete stop I have to turnover the car because the motor is off and it starts back up with no misfire or anything just that the rpms are higher than they should be they start at around 1500 and take a little while to drop back down to 900. Please let me know what you guys may think I will be uploading some videos and posting the links here so you guys can see what I mean.

https://youtu.be/gRWNLjL1IOo

Forgot to mention that the codes that the check engine throws are P0300, P0301, P0302, P0303, and P0455 I have not checked to see if I do have a boost leak but will do in a few days

what's missing is mileage, last maintenance done, type of gas used, current state of exhaust system, have you completed a de-carbon of the intakes? Original spark plugs? original coil packs?

your codes show misfire through all cylinders so there's definite a problem there, i'd check the coil packs & sparkies as that's a DIY w/o a dealer but for the P0455 i believe that speaks to your fuel system according to the powers of Google... smell like gas anywhere around the vehicle?

We definitely need more info on your milage. To be safe you could buy new plugs and R8 coilpacks as it's a 5 minute DIY (tighten plugs to 30 nm on your torque wrench). If it persists a carbon clean may be in order.

The fuel filter can be replaced too for cheap with the uprated 6.6 bar one along with an oil change and filter.

All of the above can be done by yourself if you have a socket set and jack w/ jack stands!

geramy1232 said:

Forgot to mention that the codes that the check engine throws are P0300, P0301, P0302, P0303, and P0455 I have not checked to see if I do have a boost leak but will do in a few days

Click to expand...

Could be pcv, carbon build up...lpfp, failing injectors (due possibly to carbon. A bad pcv will throw misfires on all cylinders in many cases...carbon build up iirc can do the same. You could do a simple can of crc intake cleaner, get the rpms up to 2500 or so (I held mine with a broomstick) and spray short Burts of 5 or so seconds behind the maf sensor, just to see if it makes any difference at all...if it does it might give you an indication of a carbon issue...pull the front pcv hose off...clean it and blow into it, if you can blow through with no resistance....it's shot (obviously do this while the car is off). While it's running, pull the oil cap off, make sure there's strong resistance to pulling it. It shouldn't be super easy...another sign the pcv is bad. Check for vacuum leaks, all hoses, make sure there's no degradation of any hoses, boost pipes, no missing clips that vw uses to secure them, etc.

Thank you all for your quick response I have done the de-carb because we had also changed the intake manifold with the new revision and not so long ago changed the spark plugs for the ngk bkr7eix and didnt have no problems. I have smelled a lot of gas when I fill up, it smells like its coming from the back seats where the fuel pump is under the rear seats but after a few minutes it goes away.


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Sounds like a pump issue, lpfp in the tank or the module that controls it.

Thanks for the reply guys had checked all of the hoses after running it and it was the pcv breather tube. Don't know how that happened but that's what it was.


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I was just reading, and was going to post "Check the PCV and its enter and exit tubing because typical if something has loosened that retains crankcase pressure"...but then I got to 'your post'. LOL
FrigginT nailed it with his first possibility.