Lack Of Power

[cheekymonkey]

Hi - I,m not new to the site, probably 8months or so, but it's my first post ever- so i hope that i am doing this right. I have enjoyed the site, but still can not find the solution to my problem. i have a 2002 Galaxy tdi (115) zetec- when i drive the car under load ( i.e hard accelerating up a hill, reaching 3,500 rpm or overtaking on a motor way) the car looses what i feel is the turbo and what i am told goes into limp mode. If i stop the car, turn the ignition off and then back on again the car is back to normal. i took the car to several "diagnostic" garages and the fault code that they give me is " turbo over boosting" but can not tell me anymore!!

I have changed the maef sensor and that has inproved the cars proformance, but nothing else. Recently i have heard a tinney noise from the engine - generaly when the engine is cold, and from the right hand side as i sit in the drivers seat. The noise seems to happen when am changing gear (2nd to 3rd ) or about 1800 rpm with a sort of juddering effect ( wonts to go but cant ), but above that rev range and it's fine. i have explained this to so many people, mechanics, technicians and looked extensively on the site and still no futher foward - please someone come to my aid, i cant be the only person with this fault.

[?Bleeno?]

Hi cheeky ........... have a look at this post regarding turbo overboost and this will give you an idea of what to check out on yours. From my own personal experience the Boost control Solenoid was the problem due to my own stupidty.

 

http://www.fordgalaxy.org.uk/ford/index.ph...0310&hl=N75

 

The turbo on the PD engine is a VNT type where the turbo vanes move to prevent turbo lag. If they don't move enough then theres a good chance the turbo will overboost and cause the car to go into limp mode. Have a look at the post and this will give a few more ideas.

 

Best of Luck

[cheekymonkey]

Hi Bleeno - Thanks for the reply - i was on the verge of, i dont know - no hope! My problem does seem to be a little different in the respect that my turbo will cut out when the engine is hot or cold-when i have done hour of motorway or 2 minutes up the road. I go to overtake, i accelerate and bham!! No turbo, but it's definatly seems to be a load problem, the extra load causing an eletrical component to switch the turbo off - if i immedatly switch the engine off and the fault is instantly cured. I have been told the EGR valve, the boost control solenoid / filter(as you kindy mentioned) and the turbo!! The noise is also another clue - a sort of shring as i change gear, again this will happen hot or cold, but goes away if costant driving - only to reappear if in a traffic jam. i hope if i carry on writing these posts, someone will have an answer for me. If i took my car to a vw dealer for instance- could they be more enlighting, would they have a VAG Com?and tell me the problem.

[?Bleeno?]

Hiya matey I understand from the link I gave you that the same problem only occurred when the engine was cold ...this was a TMAP sensor (2nd MAF) problem IIRC. From what you have said yours is definately kicking into Limp mode where the ECU ignores most of the sensor info and uses stored settings. In doing this it protects the engine from over-revving and prevents the turbo from operating. You can reset the current fault by switching off the ignition and then back on but if the fault code re-appears then you're back in limp mode until the fault is rectified. Did you read this latest post? http://www.fordgalaxy.org.uk/ford/index.php?showtopic=15484 ....... This is what's happening to yours. The shring noise I don't think is related and to me sounds like the thrust bearing or the clutch release bearing. A way of checking this is to sit in the car with the engine running and listen carefully when you just dip the clutch without selecting a gear. If the noise disappears when you dip the clutch this is a good sign that the thrust bearing is dry and needs either lubricating or replacing. Yes a VW dealer will be able to diagnose the problem but the garage has already told you the turbo is overboosting. So the first thing I would do is to start checking vacuum pipes from/to Boost Control Solenoid (BCS), VNT diaphragm, check the air filter to the BCS (behind and below the MAF on the bulkhead) and check the VNT movement. There's always hope matey ...just stick with it and you'll surprise yourself. Good Luck.

[Neils TDi again]

As for suddenloss of power during overtaking or hard acceleration you may find you have a dirty throttle pedal potentiometer this causes a mismatch error and limits engine performance until the ignition is cycled and the ECU can re-establish continuity to the throttle pedal position sensor.

 

it has two resitive tracks to safely determine the position of the pedal and hence the amount of acceleration that is required. If one track is dirty in an area which is sledom used (full down on the pedal) then it will record it as a first trip error and limit the performance in case it is a reall error, by several full foot down applications you may indeed cleanb enough off the track to remove the error however the replacement is only a few quid and is a sensible solution.

[Emily's dad]

My Alhambra suffered simlar problems.

Fortunately it is still under warranty and the fault was diagnosed as the N75 Pressure converter for the turbo, changed free of charge.

Fingers crossed.

[Davo]

I am getting tht funny noise when changing gear. I am not getting the loss of power. I would love to know what the noise is. I hope it's not my turbo about to fail. The noise is hard to describe: the best I can do is that is sounds like some boy racer in the distance is setting off too fast at the traffic lights on a wet day and slipping the tyres a bit. I don't think it is the clutch because it seems to be when the engine is decelerating rather than when I am putting my foot on the clutch. (I will test that by decelerating the engine with the car in neutral.)

[bj2004]

i had the cutting out under load and acceleration was all fixed by courtesy of Mr Ford and a new turbo although after reading this forum a cheaper option would have been cleaning the VNT and changing the N75 valve if its out of warranty i think you have far more chance of a garage diagnosing the right fault and not the cheapest to keep you quiet

have fun