Good Ol' Tdi Loss Of Power

[Guest galaxy lady]

Hi All, since my y reg TDi was serviced I have noticed that it has no power. Took it back for checking and they could find nothing wrong with the turbo etc.

All the posts here suggest it is the 'MAF'. I will get my husband to replace it (GSF a good place to get one? any one know the part number?)

 

When it used to fly along, I'd get home and switch it off and underneath it sounded like a turbine winding down. Now this noise is no longer there - is this linked?

 

The galaxy used to fly up hills now it won't go above 60 in 3rd. Down hill it'll exceed the legal speed limit easily. its done about 65k miles

 

Help please :(

[seatkid]

MAF failure is usually gradual and the power decrease happens over several weeks or months.

 

If total loss of power coincided with a service, then complain to them!

The whine was your turbo winding down, if it has gone then you have no turbo boost hence lack of power. (this is not a MAF symptom). Its probable something has become disconnected, a vaccuum line or electrical plug.

[Guest galaxy lady]

Hi, thanks for the reply.

 

The power loss wasnt instant, it been getting bad, but only noticed it after the service. If its something loose to the turbo would this show up on the garages machine?? they have said nothing is showing, two garages have had a look.

We are thinking of getting the maf and fitting it ourselves, do you think this would help??

Thanks :(

[seatkid]

If you can still get to 70mph, but when you go up a hill you struggle, then YES its a good chance its the MAF. But first, check the air filter, a blocked air filter will cause the same problem (when was it last changed?)

 

p.s. when checking an air filter, take it out and look underneath - the top side may be clean but the the other.......

[Ivor_E_Tower]

Problem arose after a service - first thing I would do is pop the bonnet and check that the MAF wiring hasn't been disturbed, and that the air cleaner assembly looks like it has been re-assembled properly, with the correct air filter fitted the right way round. Garages have a nasty habit of not doing simple servicing tasks correctly.

[Guest 1 interceptor]

Hi,

 

Try disconnecting the MAF sensor, does the car run slightly better or worse ?

 

If it runs better, then MAF is past its sell by date,

 

If it runs like a pig, then chances are the MAF is ok,

 

By doing the above, what happens is the ECU goes into limp mode, and if the MAF has failed then car will appear to run better, let us know how you get on.

[Guest vr6galaxy]

When it used to fly along, I'd get home and switch it off and underneath it sounded like a turbine winding down. Now this noise is no longer there - is this linked?

 

possibly the aux heater if its from underneath?

[tim-spam]

If yours is a facelifted model, disconnecting even a failed MAF will make the car run worse (unless it's completely failed, in which case it will remain the same), so this is not a definitive test. My approach would be that at 65k miles it's probably due for a change anyway, so just do it and see - it only costs around

[wytonpjs]

I'm new to it but find someone close to you who has access to VAG-COM and get them to look at the MAF readings. In playing around with VAG-COM trying to find out what is causing my turbo to switch off I have been amazed by just what it can do :blink: - one of its abilities on the shalaxy is to tell you exactly what the MAF sensor is seeing in response to what the ECU is asking for :lol: . Results still need interpretation but it a lot better than shelling out money unecessarily.

 

If you are anywhere near to Huntingdon (Cambs) I would be happy to have a go in hooking it up :blink:

 

PS Concur the "jet Engine" noise winding down after you switch off is NOT the Turbo but is the Aux Heater. Its that time of the year again when they cut in more noticeably. Be grateful that your is working properly - there are a lot of people out there who like me last winter have learnt a lot about these mysterious devices that are not listed in the Owner's Manual - usually when they fail and produce car-enveloping clouds of smoke :angry:

[Guest galaxy lady]

thanks Wytonpis, we are in hampshire so a bit far!

We are going to try the maf and see if a new one works, we took it off and it drove better without it!!!!!

put it back on now, are going to get the new one sat, will update you when we have fitted it!!!

 

:angry:

[dave_m]

As the fault has occurred after a service i would check the vacuum pipes connected to the Turbo components as this is what happened to mine.

 

One of the pipes got damaged by a mechanic when my cylinder head was changed.

 

Ford could not find the vacuum leak and they had the car 4 days........... I found it after 5 minutes after advice from people on these forums :rolleyes:

[Guest galaxy lady]

Hiya, how do we find these pipes?? when you look under the bonnet it all seems sealed.

[wytonpjs]

Check out seatkid's excellent post at:

Reference Guide for Turbo Boost Problems and Vacuum Pipes

 

:rolleyes:

[seatkid]

We are going to try the maf and see if a new one works, we took it off and it drove better without it!!!!!

Thats it then, change the MAF!

[Guest galaxy lady]

:D

 

It was the MAF!! thanks to you all for helping the car goes like a dream now!

 

 

From a "very happy Galaxy Lady"

 

:blink: