limp mode.

[moggie93]

Hi all, just returned from doing nearly 1k miles in the last week with no problems at all.I left the house this morning and when i went to accelerate past a slow moving car my car went into limp mode.
I switched it off and then back on again and a normal service was resumed.The car ran normally on my 15 miles spirited return journey.
The car was recently serviced by myself.Oil and all filters were changed.
I scanned the car for faults and none were stored.

How do log the scan of the maf sensor and what other blocks should I log ?


M

 

[simon.m]

iv had this a few times my maf did not show any codes at all may be worth looking at the n75 valve as well this also puts mine into limp mode i got a new one and still does it some times im told its the pipes get old oil in them this goes to the egr one more thing to clean out nothing bad though

 

[moggie93]

Thanks Simon, I've got spare sensors that I've removed from a golf I recently broke.I did notice that it is pretty oilly around the egr valve. Think i may replace that with the one from the golf if it's the same aswell.
M

 

[demus]

The vanes in the turbo got sooty in my TDI, they would move to give boost, but as the revs rose they got stuck and it overboosted, resulting in limp mode, but with no management light, restarted it all was fine again untill they got sticky again...

 

[moggie93]

Little update,I changed my maf and map sensors for my known good ones from my golf.All seemed fine, then on thursday I hooked on the caravan and within a mile the car had went into limp mode.
It then happened another twice on the journrey but after the eml came on.
The eml light stayed on for another 2 days and on the day I was due to come home the light went out.
I never had any problems on the return journey,no limp mode and no eml.
I will scan for any fault codes when SWMBO returns from shopping.
M

 

[stu_m]

Sounds like sticking turbo vanes to me

 

[moggie93]

Hi stu, not really convinced vanes are sticking as its just started happening, car gets driven, I dont just drive like miss daisy. the only other thing that has changed is that I,m running on pump diesel now and not bio as my suppliers machine has broke.
STRANGE.
M

 

[moggie93]

Another update, just scanned car and it's showing fault code 17965, looks like its overboosting.
Can some one tell me where is the N75 valve as I'm going to change it as after fault codes are cleared the fault remains, then. hopefully Mr Muscle to the rescue.

M

 

[stu_m]

I would clean the turbo first it will cost a few quid cheaper the the n75

My brothers car has just done it and he doesn't drive like miss daisy either!

 

[moggie93]

Ok will give it a try with Mr muscle and will change the N75 valve.
I'll use the one from my golf as I never had any problems with it even running a remap.
Do you know where the N75 valve is ?
M

 

[stu_m]

its on the drivers side front just follow the vac pipes

 

[moggie93]

thanks,

 

[moggie93]

Ok I've found 3 sensors in front of the air filter housing..
Any idea which one is the N75 valve?
M

 

[simon.m]

n75 valve is just behind the drivers headlight you will see it cliped on there at the bottom

 

[moggie93]

Thanks . I'll get a new one ordered this week.. Unfortunately I don't have a matching spare..
P/n on it was 8E0 906 628 C does this look right..
M

 

[demus]

While your in there, see how the vacuum actuator rod feels to move on the turbo, should move relatively easily and snap back when you release it