Lack of Power 1.9TDI

[ChaseMcClaine]

Ok.. Had my TDi a few years now.. its just passed its MOT at 177k (97')

I have a problem with the power in the engine.. When I am accelarating the power doesnt seam constant as if something it holding it back or not pulling enough air.

I have change the MAF and N75 Solonoid. And no resolve.

I have taken it to Audi and they said change the MAF I did.. No change, I did a bit of readon on here and changed the N75..

This is kinda getting fustrating as I took my Stainless Magnex exhaust off and put origional one back on and no change..

Anything else I can check as all the pipes are clean and clear..
IT is some sort of eletrical as when the engin off and back on it has power but then drops off again.. usually around the 60MPH mark.. Hitting 80MPH it gets to 75/78 then it just powers down as if something has closed..

Im bored of audi saying "it could be this that and the other" I need a final answer as them getting me to buy parts I don't need is really killing my wallet.
Any thoughts??

 

[Daz A3 TDI 130]

Thats a really strange fault. Its not something common with Audi's they r usually very good, even into high mileage. Has it had recent servicing?

A friend of mine who also drives a diesel had a similar fault, but that was a nakered turbo. Not too sure what turbo life on these is like.

Good luck though!

 

[ChaseMcClaine]

The car it's selve get a service every 6 - 8k, just hads its MOT was fine.
Had no major problems with it apart from this.

The only thing I can think of now is either the Turbo it's self or The ECU.

When I take it to audi they say MAF, MAF, MAF and its not from the diagnosis.

New turbo £500, new ECU dont' want think.

Would it be an idae to go down the scrappy and find a TDi for a turbo and ECU? or isn't 2nd hand any good?

 

[The Slug]

turbo last between 100-130k so ive been told. Based on VNT17.

 

[CraigM]

My VW Bora tdi had a very similar problem and it was caused by the anti shudder valve (http://www.mcmillan-uk.com/VW/DSC02645.JPG) closing as the plastic rod was broken which starved the engine of air. Probably not that, but worth checking yours isn't broken/or not fully opening.

Also worth trying dielectric grease on the MAF connector as suggested here:

http://forums.tdiclub.com/showthread.php?t=81288

 

[confusionhunter]

Hey that grease looks like its had some good results.... where can we get some in the UK? Maplins??? anyone tried it on here?

 

[CraigM]

I have just bought some from ebay to try on mine. I got mine from:

http://cgi.ebay.co.uk/Permatex-Bulb...ryZ72203QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

 

[Rev-head]

Right need to start with the basics

have checked when accelarating is there lots of black smoke out the rear
of the car (over fueling?)

If you have replaced the MAF that is put to bed then......unplug it and see if it runs any better if it does faults lies in that area

Check every inch of your Inter-cooler hoses(take them all off and put them on again) for cracks or tears were it could be loosing pressure....Be careful when driving the car at the moment if it has a fault around these areas your turbo will have to work double as hard and it could damage it if you are flooring it

Water in your tank did they take the fuel filter off to see if you had water in it?...this can cause stuttering loss of power and sometimes hard to start

As Craig has mentioned the EGR Valve might be sticking you can tell by getting someone to rev the engine and you watch the Diaghram slide along the pin

PIC BELOW EGR VALVE NO1

 

[confusionhunter]

Just bought some of that grease from the ebay link... nice one.....

 

[CraigM]

Well mine arrived today and I have just squirted it all over the MAF connector - you don't get much in a tube so I filled all the connection holes in the plug with grease and then put the remaining grease over the pins on the sensor before reconnecting it. I also made/unmade the connection several times to ensure there was good contact through the connections and then went on a test drive.

I don't know how it does it, but it has made a huge difference - the power delivery is a lot smoother and the engine is more responsive than before. This is really worth the few quid to try it out - and no I am not not the seller on ebay trying to get more business!!

I have also found another supplier here which sells .33OZ tubes instead of the .10OZ tubes on ebay: http://www.ur-motoring.co.uk/acatalog/gasket_sealents_super_glue_windscreen_fix_.html

And sorry to ChaseMcClaine for going slightly off topic - hope you get yours fixed.

 

[confusionhunter]

Damn its much cheaper too! Got my grease this morning, but I want to make sure My MAF is ok first so I'll do some tests wich VAGCOM.....

 

[necroeire]

Can someone post some pics of the connectors and how much grease you used? Also can anyone else advise on what other connectors to apply it to?

 

[confusionhunter]

Tried the dielectric grease tonight ..... I took some VAGCOM readings before and after..... makes no difference to the readings at WOT but it does seem to drive better at part throttle weird or what...?!
Cant explain it......

No pics but if you look at the air box... then follow the tube that goes to the engine..... at the start of the tube connected to the air box is a black cylinder thing that the air goes through..... thats the MAF.... there should be a multiplug on that.... pull it off dab a small amount of dielectric grease on each pin... plug it in.. unplug it again and repeat the procedure... I did it three times to try and get the stuff all over the pins....... job done.....