TDi Loss of Power

[begbie]

Hi people,

Looking for some help here. I drive a 56 plate 2.0TDi Reference Sport. On a motorway journey yesterday, I put the foot down to overtake and there was no response. Total loss of power. I couldn't get above 60mph. It was as if the turbo wasn't working or the engine was being starved of air. It drove like a straight diesel.

When I turned the engine off at my destination and restarted again, it was back to normal until today when it happened again on another motorway journey. I just let the car roll along in neutral and restarted the engine again which worked.

So, short journeys are ok, it's the long one's that it occurs with.

Any ideas???

 

[Seatmann]

Here bud, have a look through this, it's a guide for fixing limp mode which is what you experienced. Very common.

http://www.myturbodiesel.com/1000q/multi/limp-mode-TDI-fix.htm

 

[begbie]

Here bud, have a look through this, it's a guide for fixing limp mode which is what you experienced. Very common.

http://www.myturbodiesel.com/1000q/multi/limp-mode-TDI-fix.htm

Holy ?£&@! There's a lot of possibilities on that guide! What I can take from that initially, is that it could be a split intake hose. I started to hear a whistling noise when accelerating a few days ago. I heard this same noise a couple of years ago which turned out to be a split intake hose and was fixed under warranty.

I also had an engine management light come on last august which was diagnosed as a dirty throttle valve. I tried to remove the body to clean the valve but couldn't get to one of the three bolts. I just cleaned the valve disc from the one side that I could reach with my fingers so maybe this is gunged up again.

I don't have enough experience (or confidence) to try fixing this myself so I might just bite the bullet and take the car to a garage. Worst thing is that I was going to sell the car next week as I'm off to work abroad! I think the car knows I'm doing that and it's punishing me for it!

Thanks for the help though.

 

[/dev/null]

Might be worth asking in the vag-com requests section if there is anyone near you willing to do a scan for you. At least then you can see whether it's something as simple as a sensor or something a bit more worrying.
You should have had the glowplug lights flashing when it went into limp mode?

 

[begbie]

Might be worth asking in the vag-com requests section if there is anyone near you willing to do a scan for you. At least then you can see whether it's something as simple as a sensor or something a bit more worrying.
You should have had the glowplug lights flashing when it went into limp mode?

No, I didn't notice any other lights come on. What did happen this morning though is that the tyre pressure warning light came on and when I checked the pressures, only one tyre was low, but only 4psi low. When I put it back to pressure and pressed the tyre pressure set button, it won't reset! The car has gone in a major huff with me!

I've bought a VAGCOM kit from eBay - will it maybe tell me what the problem might be with the engine as well as the tyre pressure?

 

[/dev/null]

Extremely unlikely that the tyre pressure would cause limp mode. Do you know you have to hold it in for a few seconds to reset?
If you get the light on, try driving it home and don;t turn the engine off when you get there. Then scan for fault codes. The reason I say don't turn the engine off is that some codes clear automatically depending on their fault level. Also, try not to make it too far a drive as they can clear over distance too!
Might be worth scanning now though - if it was a high priority fault then the chances are it will still be logged.

 

[begbie]

Extremely unlikely that the tyre pressure would cause limp mode. Do you know you have to hold it in for a few seconds to reset?
If you get the light on, try driving it home and don;t turn the engine off when you get there. Then scan for fault codes. The reason I say don't turn the engine off is that some codes clear automatically depending on their fault level. Also, try not to make it too far a drive as they can clear over distance too!
Might be worth scanning now though - if it was a high priority fault then the chances are it will still be logged.

Yeah, I held the button in. I'm not linking the tyre pressure to the limp mode, it's just that lots of things are goin wrong at once. It feels like the car's falling to pieces!

Will driving with this limp mode problem cause more damage? I want to get it to a garage ASAP but it could be a couple of days.

 

[Seatmann]

Holy ?£&@! There's a lot of possibilities on that guide! What I can take from that initially, is that it could be a split intake hose. I started to hear a whistling noise when accelerating a few days ago. I heard this same noise a couple of years ago which turned out to be a split intake hose and was fixed under warranty.

I also had an engine management light come on last august which was diagnosed as a dirty throttle valve. I tried to remove the body to clean the valve but couldn't get to one of the three bolts. I just cleaned the valve disc from the one side that I could reach with my fingers so maybe this is gunged up again.

I don't have enough experience (or confidence) to try fixing this myself so I might just bite the bullet and take the car to a garage. Worst thing is that I was going to sell the car next week as I'm off to work abroad! I think the car knows I'm doing that and it's punishing me for it!

Thanks for the help though.

Lol

 

[Big_Mikey_G]

When i had this same problem, it turned out to be an issue with my Turbo.

The vanes on the turbo were sticking due to carbon deposits on it and the car was overboosting and putting itself into limp mode.

In the end i had to change my turbo anyway, as i was getting the whining sound from worn bearings and eventually the turbo blew out. Not saying this will happen to yours as the whining sound may not be the turbo bearings, could just be a split hose.

But the overboosting problem sounds very familar. I think when i got the stealers to log any fault codes it returned code 16618 which is an N75 solenoid valve problem problem.

If i remember rightly, you can get the turbos serviced and cleaned to sort the problem with sticking vanes. Its greatly cheaper than replacing a turbo if thats what it turns out to be.

 

[/dev/null]

If a car is in limp mode then it's because the ECU thinks there is something seriously wrong with the engine (or other component of course) that it needs to protect itself from, so it would always be best to drive it as little as possible until you know what the issue is.

 

[begbie]

Update:

Got the AA out to the car this afternoon. First check, before even running a diagnostic was for oil level......which turned out to be very low The guy told me that this can sometimes cause limp mode.

Second check - run a diagnostic for fault codes. It brought up two; P0234 (turbo/supercharger overboost) and P2108 (throttle actuator control module). The guy cleared these fault codes and hey presto.....another fault code appeared; P2100 (throttle actuator control motor circuit/open). So, from initially feeling like a right for not checking the oil, it turns out that the fuse protecting the throttle actuator control motor was fecked and that's what was causing the other fault codes.

I've still to drive the car home and check that everything is OK again, but there's a wee lesson to be learned before going straight to the major problem areas - check fuses and oil levels!

Now all I need to do, on the advice from the AA guy, is to buy a can of EGR valve cleaner and spray it (whole can) in the air intake hose (downstream of the air filter of course!) while someone revs the engine at 1800 - 2000 rpm. He said that this should clean the valve of all the crap that might also be stopping the valve closing properly and causing engine shudder when switching off the ignition. If it works, it'll be a lot cheaper than taking to a garage for cleaning or replacement.

And, breathe! Sorry for the novel!