Lack Of Power

[shotokan916]

Hi All,

 

I recently bought a pretty old (51 plate) 1.9tdi with 106000 miles on. It has been great so far. I'm grateful to this site for the info on the auxiliary heater as we'd have taken it back to the garage thinking something was going to take off, without the comments on here.

One thing I noticed recently though, on one of the rare occasions I get to use it (it's for the kids/dog and for those camping hols coming up instead of going abroad - I commute by bike), is it appeared to suddenly become gutless when I was on the ring road - very little acceleration, at all speeds. On the way home it was OK. I'm hopeful it is one of the myriad of sensors these vehicles seem to have, developed a loose or corroded connection that has started to play up. Can anyone back me up on this hope, and point me towards the likely culprit, or am I barking up the wrong tree?

 

Any advice welcome,

 

Many thanks,

 

Martin

[marinabrid]

get yourself a vagcom lead from ebay and download the free software from ross tech this is easier that trying to work out what maybe wrong

the leads are about

[mikej]

Sounds alot like the maf sensor, next time this happens try unplugging it and see if it makes a difference to the running although as said you may want to invest in vag com

[Dave-G]

Hi All,

 

I recently bought a pretty old (51 plate) 1.9tdi with 106000 miles on. It has been great so far. I'm grateful to this site for the info on the auxiliary heater as we'd have taken it back to the garage thinking something was going to take off, without the comments on here.

One thing I noticed recently though, on one of the rare occasions I get to use it (it's for the kids/dog and for those camping hols coming up instead of going abroad - I commute by bike), is it appeared to suddenly become gutless when I was on the ring road - very little acceleration, at all speeds. On the way home it was OK. I'm hopeful it is one of the myriad of sensors these vehicles seem to have, developed a loose or corroded connection that has started to play up. Can anyone back me up on this hope, and point me towards the likely culprit, or am I barking up the wrong tree?

 

Any advice welcome,

 

Many thanks,

 

Martin

 

That part suggests a probable turbo overboost condition - because it resets itself apon engine restart. To try and determine if this is the issue it is fairly easy to get it to occur again as a means of diagnosing the fault with no specialist kit. If the engine ecu detects too much difference between the requested turbo boost and the actual turbo boost for more than SEVEN SECONDS the ecu will put the engine into limp mode. Restarting the engine will clear the issue every time.

 

Accellerate (prefereably uphill or with a loaded car) in a demanding but not thrashing manner for at least seven seconds, if the car suddenly looses power you either have turbo overboost or turbo underboost. It's generally caused by excessive soot on the turbo vanes - likely as a result of driving like a grandad. The sentence you used here would confirm that: "when I was on the ring road - very little acceleration, at all speeds"

 

The likely fault code is: "17965 - Charge Pressure Control: Positive Deviation" Google it with a pot of coffee. :)

 

Get it good and hot more often and where practical, give it a darned good pasting. Also - when hot keep starting and stopping your engine while parked up somewhere quiet - you should hear a slight "pop" sound from below the engine about a second after you stop the engine: this is the turbo actuator being released by the vacuum that activates the vanes and frequent start~stops when hot will help it clean their edges as they are excercised. The sound is similar to the pop noise you may have made by popping your finger out your mouth as a kiddy.

Edited December 14, 2010 by Dave-G

[shotokan916]

Nice one, thanks everyone. New you'd be able to help. First stop is me using the car for a day or two. Harrogate to Leeds can be quite 'fast' at 6.30am. :wacko:

But agonisingly slow at the other end of the day.

I'll bore you all with an update soon.

[Sher]

Sounds very similar to the intermittent power loss problem I have had since I allowed the main agent service and MOT it for me whilst in hospital.

 

Switching off and then on seems to clear the problem.

 

I don't dawdle, I tow a large Caravan sometimes at 60+mph and travel upto 600miles in 8 hours through France without it 4 times per year. I found that the Glow Plugs were all shot during the recent cold spell. They were very sooty like over rich mixture on spark plugs. Suspect they were shot last winter but I was in Spain most of Nov-June.

Also on the MOT report I noticed the smoke emissions were high.

 

Is it possible that the lack of glow plug operation may have caused the excess soot or are the plugs always dirty?

[chrispb123456]

Sounds very similar to the intermittent power loss problem I have had since I allowed the main agent service and MOT it for me whilst in hospital.

 

Switching off and then on seems to clear the problem.

 

I don't dawdle, I tow a large Caravan sometimes at 60+mph and travel upto 600miles in 8 hours through France without it 4 times per year. I found that the Glow Plugs were all shot during the recent cold spell. They were very sooty like over rich mixture on spark plugs. Suspect they were shot last winter but I was in Spain most of Nov-June.

Also on the MOT report I noticed the smoke emissions were high.

 

Is it possible that the lack of glow plug operation may have caused the excess soot or are the plugs always dirty?

When the plugs are working that burns off most of the soot, some people are under the impression that glow plugs are only for cold starting wrong, they also play a part in reducing emissions and help engine run smoothly when cold, the plugs are still on even when the light on dash has gone out anything up to a few minutes depending on temperature.

[Sher]

@chrispb123456

 

Are you saying that the Glow plugs should not have loose soot on them that can be wiped off on your fingers?

[chrispb123456]

@chrispb123456

 

Are you saying that the Glow plugs should not have loose soot on them that can be wiped off on your fingers?

No I'm not saying they will be completely soot free you will always get black fingers, don,t compare diesel glow plugs with spark plugs from a petrol engine there's no comparison

Edited December 19, 2010 by chrispb123456

[Sher]

Today the temperature overnight was -10C, It took 5 or so seconds of turning over and it fired up lumpily for a few seconds and then settled down. Progress was slow because of the conditions.

 

Eventually the car reached 90C some 7 miles into a 10 mile journey but however hard I tried I couldn't get it to go into Limp mode.

Hopefully I am clearing out the soot and that problem may be fixed.

[Sher]

Today I made an 8 mile journey into and out of Delph in Saddleworth and at no time could I get the car to enter limp mode.

Starting was not instantaneous from cold as I have had to turn it over for 3 or 4 seconds. It was -10C overnight.

 

I will try and check that all glow plugs are functioning tomorrow i.e. check the resistance is around 1 Ohm in situ.

 

If the problem is solved I suspect a fair number of limp mode probs are caused by failed glow plugs.