Tdi Loss Of Power (again) - Resettable

[GSMGuy]

Well, firstly, apologies for the delay - had to reinstall windows on the main PC :huh:

 

Received the TMAP yesterday, thanks Peter... Fitted in a couple of mins and reset all fault codes and did a reset to factory defaults also for good measure.... So off for a run...

 

Accelerating hard once warmed up a bit (Aux heater kicked in nicely :huh: ) And got to about 60ish in 4th......

 

Bam, same old same old....... Have cleared codes on 4 occasions now and still does the same - so guess it's not the TMAP either...

 

So, Boost control valve replaced with new one.. MAF substituted for known duff one, which made it worse and now TMAP changed... This is really doing my head in now.....

 

Oh Peter, for some strange reason, the 2nd DVD is full of errors, have tried it in the lappy and the 3 DVD drives on my PC, all still the same.....

 

 

 

So been able to install the proggy, but not the data :huh:

 

Mike

[seatkid]

Did you reinstall the mini air filter? That seemed to make a diffference and I think points to a vacuum related fault.

 

I think you need to strip off the vaccuum pipes. Remember a leak anywhere in the vacuum pipework will affect it. I know I have a small leak where on my vacuum pump outlet joint......leaks to the brake servo are also common.

[GSMGuy]

Aye - put the mini AF back on - will remove it tomorrow and try it, as its a 2 sec thing... will post more...

 

Peter got your PM, keep trying fella!!!

 

 

Mike

[seatkid]

How the investigation going?

 

Next thing we haven't covered yet.......what if your intercooler is all made up with gunge? Excessive boost=>trip?

[wytonpjs]

Final update!

 

Had a pig of a journey from Cambridge to just north of Perth last weekend and back - total just short of 1,000 miles by the end of the weekend ;) Weather was foul - torrential rain and more importantly, the Galaxy was not happy :( Power was down, top speeds were limited (particularly on hills) and gear changes (AG5 autobox) were very lumpy (wrong speed/load).

 

Anyway, although the turbo did not trip (and it didn't trip again whilst shed-dragging last week :) ) something had to be done. In desperation I went to my local Fraud garage and ordered a new (exchange) MAF sensor (

[tim-spam]

That's one of the problems with maf faults. If the problem is contamination of the thin film causing an insulating effect, the engine control system thinks it's fine and so no fault codes are logged. It just behaves as if the air density is extremely low and reduces fuelling accordingly, hence the lack of power. I'm glad the maf change has resolved your problem.

[Masked Marauder]

That's one of the problems with maf faults. If the problem is contamination of the thin film causing an insulating effect, the engine control system thinks it's fine and so no fault codes are logged. It just behaves as if the air density is extremely low and reduces fuelling accordingly, hence the lack of power. I'm glad the maf change has resolved your problem.

That's one of the problems with maf faults. If the problem is contamination of the thin film causing an insulating effect, the engine control system thinks it's fine and so no fault codes are logged. It just behaves as if the air density is extremely low and reduces fuelling accordingly, hence the lack of power. I'm glad the maf change has resolved your problem.

Aye, the component has not failed, it is just mis-judging how much the film is cooling because of the crud on the outside, and so thinking there is less air going through than there is.

 

The only real way to test it without swapping it out is using VAG-COM to map out the MAF values and the turbo boost full throttle across a given RPM range and compare it to what it should be.

 

http://www.bigtrucker.co.uk/images/maf80.jpg

http://www.bigtrucker.co.uk/images/boost.jpg

[wytonpjs]

Technically I agree, but I did the plots posted above some time ago and achieved similar results which led me to believe that MAF was within tolerance. Another indicator that the MAF was probably ok was that my economy was quite poor - I believed that if the MAF was faulty and was delivering less fuel than really was required (ie leaner in petrol terms), then the economy would probably not show any change (reduction in fuel going in due to MAF being balanced roughly by the increase in fuel due to harder driving in trying to get reasonable performance).

 

Anyway, in this particular instance I became a little disillutioned with VAG-COM (or more accurately my ability to interpret it) - you will recall that earlier on I was absolutely certain from VAG-COM's evidence that the TMAP was at fault! I then decided to go with the balance of historical evidence that there is in this excellent forum and to change the MAF on spec given that

[Guest nozzer]

I have a similarly irritating intermittant fault with my Galaxy TDI which has cost a great deal of money to not fix.

The problem: when I take the car out from cold, if I accelerate hard up the hill near to where I live it will suddenly lose power and I will struggle to make it up the hill. If i keep under 40mph for the steepest part it is fine. If the power goes it will reset by pulling up, turning off the ignition and restarting, similar to wytonpjs

when towing. Occcasionally this happens when the car is warm, especially if it is raining heavily.

Tried so far: my local Ford dealer has kindly checked the vacuum pipes, air filters, replaced the break pedal sensor and the air mass sensor (is this the maf?) all to no avail but at serious cost. Because it is intermittant they can't even find a fault!

For the last six months I have just lived with it- I can avoid it happening most times if I don't hammer it, but i worry that one day I will need the power and it will let me down. I have another garage to do servicing now, but reading through all this technical stuff it seems they could cost me a fortune to work out what is wrong and I have not done any mechanics myself for about 15 years.

Anyone any suggestions or recommended garages in the Sussex area?

[seatkid]

This common problem is caused by the turbo boost pressure not reaching its correct value when demanded (either too high or too low). The ECU protects the engine by switching the boost off completely (until reset by the ignition).

 

It is caused by a fault in the turbo's vacuum control sytem or sometimes by a faulty/sticky turbo vane control mechanism (though this is rare).

 

1st check the vacuum pipe going it the vacuum reservoir is not loose (small sphere at front of engine) see here

 

then check all the vacuum pipes are secure and tight on the turbo control solenoid - see here again.

 

If that is all OK then change all the vacuum pipes and the minature air filter that is connected to the "ATM" connection of the turbo control solenoid via a short pipe.

 

It is not enough just to visually check these pipes, a perished pipe can leak or be blocked internally and you would never know. Often the problem is due to leaks at slack or even disconnected pipe connections. Please note the vacumm sytem is the same that feeds the brake servo so there is also a possibilty of leaks in that area.

 

The Ford dealer should know better. Once you fix it, if it is a vacuum pipe (and its 90+% likely) go back and play merry hell whith your dealer and demand your money back!

[Guest nozzer]

Thanks very much Seatkid, especially for the diagrams. I'm sure that that was the first thing Ford were supposed to check about 18 months ago, but I'll go through your procedure and see if there is a problem. I'll then ask my reliable garage to replace the pipes and filter if required.

Will let you know if I crack it, although you will probably hear my whoops of joy. I don't know why I didn't think of this back then.

Cheers again!

[Guest ajc]

Just replaced my MAF Sensor which has improved performance a lot but it's still not 100%. I'll have to check my vacuum tubes and also the CAT to see if they're both OK. VAG-COM came up with an interesting message on my MAF sensor fault -implausible value!

[Guest nozzer]

Managed to take a look inside today armed with your photos, Seatkid. I can't get to the turbo control solonoid (far too tricky for me!), but can see that the vacuum reservoir on the front has a slightly different connection than in your diagra. It isn't loose, but do you think if I sealed the gap with something it would help?

Otherwise will have to book it in to the garage to replace all pipes and the filter. Any idea how much this might cost?

[pikey]

Hi,

I have an almost identical problem,

On a couple of occasions this winter, when it was very cold and damp, I started the galaxy 02 115 44k and drove off hard, this resulted in the car going into a "limp home mode" until the ignition was reset!

The car drives perfectly o.k at other times.

I have followed a number of forums but no one else has had this issue until now.

Fraud have told me that it is the MAF but i am not so sure!

Hooked up vag-com and it reports an overboost condition.

My worst fears are that it is the variable vane in the turbo sticking.

 

pikey :P

[seatkid]

Hi,

I have an almost identical problem,

On a couple of occasions this winter, when it was very cold and damp, I started the galaxy  02 115 44k  and drove off hard, this resulted in the car going into a "limp home mode" until the ignition was reset!

The car drives perfectly o.k at other times.

I have followed a number of forums but no one else has had this issue until now.

Fraud have told me that it is the MAF but i am not so sure!

Hooked up vag-com and it reports an overboost condition.

My worst fears are that it is the variable vane in the turbo sticking.

 

pikey :P

Its usually just down to leaking or collapsed vacuum pipes/joints. Check the pipe connected to the ATM connection of the Turbo Control Solenoid. This is connected either to a mini air filter or back to the main filter box. If this is blocked, or the filter(s) are blocked you will get overboost that will trip "limp home" mode.

 

MAF's gives totally different symptom, reduced performance that gets slowly worse and worse.(over weeks or months)

 

for pics and other info see here and here and here

[pikey]

Thanks seatkid,

I will go through and check the all the vacuum pipes and solenoid.

Any suggestions why it will only happen on very cold damp mornings?????

The photos make it all clear to me, especially as I have never owned a diesel before.

Had the cam belt changed recently, perhaps something has been disturbed!!!

 

pikey

[GSMGuy]

Ooh SK, I can feel my Royalties rolling in already....

:ph34r:

 

Mike

[west1234]

Hi I have the same galaxy but i was not towing any thing and it has the same code from the snap-on tool. turbo pressure control limit exceeded.

 

Have to resovled the problem and if do can you tell me what you have done.

 

thanks ron

[f0ster]

Hi I have the same galaxy but i was not towing any thing and it has the same code from the snap-on tool. turbo pressure control limit exceeded.

 

Have to resovled the problem and if do can you tell me what you have done.

 

thanks ron

 

 

the reason that the fault is worse in cold weather is probably due to the fact that oil has got in to the vac pipes and cannot be easily bypassed by the air,

my car does it a lot in winter, in summer on a hot day there is no fault,

[wicpp]

I am also facing Lack of Power problem and my ford galaxy is driving in limp mode. I drives very good up to 50 but then it becomes very difficult to increase speed and now it never goes above 70.

 

I have been able to find one fault code that is P1550. And the fault is consistent if I clear it and driver my car for 5 minutes it comes back again. The fault code details are as follows:

 

17958 - Charge Pressure: Control Deviation

P1550 - 35-00 - -

 

I have cleared all the fault codes and detached my MAF sensor and then driven the car even then I see this fault along with another fault code P1144 which means MAF is detached so the fault comes even without MAF. Considering all this most probably MAF is ok and vacuum hoses are leaking or valve N75 is faulty. But now the problem is I do not know the exact location of vacuum hoses. From TIS I can not find detailed procedure to replace vacuum hoses. All I can find is that some end of vacuum hoses is attached to Air Filter Box and the some end is attached to Turbo Chargers and I think that valve N75 is under Fuse Box and I think that vaccum pump itself is behind some indicator light. Can somebody here give me the pictures telling the exact location of vacuum hoses and valve N75? I will be very thankful if somebody can point me to procedure of replacing vacuum hoses in TIS? And from where I can buy N75 for my ford galaxy?

 

I have posted this problem in form "Lack of power" but due to no reply I have posted it here as well.

[carl.pearce]

We had the same problem turned out to be our mass airflow metre, so got one off ebay and fitted, now all is ok.

[Malo]

the power loss problem is often down to sticky veins in the turbo, its worse in colder weather because the air is denser & the turbo can create more boost, the problem normally happens in higher gears when the turbo has more time to generate more boost.

sometimes if its in the early stages then a fuel treatment can help, if not the turbo may have to be removed and overhauled, a company called 'Midland Turbo' can do the VNT turbos.

[rcbarb1]

I have a similar problem, only I have loss of power pritty much all the time. I have just been reading through this, and other threads, and it would lead me to think that the MAF is the issue. Am I right in thinking that if I remove the connections and the performance is the same or better, then the MAF is likely to be the fault?

 

Richard

[darton]

Dont know if this will help, but during an unrelated job on my 1.9 tdi,I forgot to replace the air inlet pipe (the one with the MAF in it) The next day I drove to work,20 mins into journey lost power as described 50mph and would not do 70mph totally limping to work!. got there and discovered my mistake,refitted said pipe,restarted and all was well.maybe any leaks of air into the system could upset the output readings from the MAF. Not sure if this helps, :lol:

[trumpettrouserspablo]

Dont know if this will help, but during an unrelated job on my 1.9 tdi,I forgot to replace the air inlet pipe (the one with the MAF in it) The next day I drove to work,20 mins into journey lost power as described 50mph and would not do 70mph totally limping to work!. got there and discovered my mistake,refitted said pipe,restarted and all was well.maybe any leaks of air into the system could upset the output readings from the MAF. Not sure if this helps, ;)