My r56 jcw hesitates on acceleration

[kostas2012]

Hello there!
I am new to this forum and i want to share my problem with you.
My 2008 jcw after an engine wash, does not accelerate as before,the idle is ok but after 3000rpm and on the car accelerates very slow.Before this, the car at 1500rpm has full boost and was very nervous.After engine wash, with full throttle is begining to boost and feel some acceleration at 3000rpm, with a serious delay in response.With the sport button on and off the same issue..For example, i have made an acceleration test with fourth gear 80-120kmh and i recorded 7,5 seconds,and manual says about 5,5 for jcw. I have changed the MAF sensor and no difference at all.This happen 2 weeks ago and the problem is still on..I have 95000km right now.No faults until now..i use shell vpower racing gasoline only.Please any advice???

[CityMiniCarHire]

Check for water around the ignition coils and spark plugs, this would reduce engine performance.

[kostas2012]

Thank you for your advise but I have already cleaned and dry everything including spark plugs,ignition coils,ecu connectors, relay and fuse box,and some visible sensor connectors(maf,map,tmap)..It don t know what else to check..

[The Nun]

Youve probably half drowned it?
You need to cover over all the electrical components with plastic bags etc before turning the hoses on the engine bay.
If it was ok before you washed it then its got to be the jet wash thats causing the problems.

[Jonnyfive]

I hate saying it but jet washing modern engines is a big 'no no' unless you are prepared to cover and insulate everything thoroughly. You will have water somewhere, in a sensor or plug and this is your issue. It may take some time to dry out and even then there may be some water stuck in a crevice or connection which can cause problems.

[dave.pm.young]

I do believe you when you sat you have dried all the plugs out, but did you physically take them out and dry the coils? Wiping them will not clear out residual water. I had the same problem for months. If you have a dealer near by get him to plug in his fault diagnosis, it must be worth 30 minutes of a BMW dealers time!

[kostas2012]

I went to the dealer and the car had no error codes at all..we took out the intake manifold(also OEM bov) and all the hoses to inspect them for boost leaks..no problem on them and after a detailed diagnosis we manage to see that the thermostat was stuck open and the car worked about 70 degrees Celsius all the time.We manualy cleaned and the deposits on intake valves also,so after all these, including new thermostat the car flies again..now is working at 106-108 celsius.Maybe it was randomized after the engine wash to happen.I am one happy MINI owner again! by the way the thermostat has changed before at 88000km and now i have 97000km.Only 9000km life..So if you want the check your coolant temp you can access hidden data on your dashboard..instructions you can find in this youtube.Just type in the search
''MINI Cooper Experts Accessing Hiden DATA ''.

[kostas2012]

Quote: Originally Posted by dave.pm.young (original)

I do believe you when you sat you have dried all the plugs out, but did you physically take them out and dry the coils? Wiping them will not clear out residual water. I had the same problem for months. If you have a dealer near by get him to plug in his fault diagnosis, it must be worth 30 minutes of a BMW dealers time!

what was your symptoms?Is it ok now? the coils was covered in the washing process..
By the way i want to thank you all for your interest!!