Engine low power possible miss fire or turbo problem maf

[031.9tdi130]

Hi again, think my car has a problem. Seems a bit flat as if the turbo starts and then just goes flat. I have taken it for a spin up the road and used my newly purchased lead and vcds lite (unregistered) to log some data from blocks 3, 10 and 11. Compiling it all into one chart is a little confusing so am going to try attaching several different ones and hope that someone here can tell me whats up. Hope this works....

[031.9tdi130]

Just to add a bit more information. There have been no fault codes showing at all in my one week of ownership.
There is plenty of oil at the back of the engine when viewed from underneath, possibly coming from high up i.e rocker cover but has made a right state of the area around the turbo outlet. Going to be cleaning this area tomorrow to try and locate the source of this oily mess. I did the graph logging while accelerating up a steep hill in 3rd gear. baby in back and laptop being operated by the missus...   
Please please please if anyone can decipher the charts I have attached I would be very happy...to me it looks to be a faulty MAF, but dont want to spend Ã,£25 on something that wont make any diffrence, also are the cheap ones on ebay worth it??

[insanitybeard]

I can't help with deciphering your charts but oil leaking from the upper rear engine area is quite often from a gunked up EGR valve, mine is leaking slightly for this reason (I'll be removing the inlet manifold during the summer for a clean up), it could also have happened if somebody has been a bit careless with the oil can when topping up the engine oil. The boost pipe (feeding the intercooler) coming off of the turbo can also leak slightly leading to slow oil misting over time. Are all of the boost hoses secure and not split (which can cause loss of boost pressure and consequently performance issues)?

As for the loss of performance, common causes as you say could be MAF or the variable turbo vane mechanism sticking as per this thread, does it feel like the engine is running rough or is it just lacking power under acceleration? Regarding cheap MAF sensors, my opinion is no, waste of money.

[Chrispb]

Well done on converting your crs file to a graph.
Only problem is it don't show the required measuring blocks at the right engine speed and throttle opening
You need to log 003. 010. & 011 together accelerating flat out from 30 mph and keep the RPM around 2850 to 3500 for as long as possible, repeat it a few times so we get a clearer picture of what's happening.

If you are thinking of buying a new MAF do not get a cheapy Ebay job as you will end up with more problems than you have.

[031.9tdi130]

Thanks for the quick reply guys,  do you want me to overlay all 3 graphs or do the same (prehaps with a key as to what colour line is what ) I will try and find a better hill, i am restricted to using the one close by at the min due to a faulty lap top  battery, its not the best hill as I am passing the local primerary school at 3500rpm in 3rd near the top.. new one has been ordered..

[031.9tdi130]

Today I shall be inspecting the egr valve and checking the security of the breather pipes, etc. Can I blank the egr valve using a small metal plate? Did this to my focus tddi and it has made a huge diffrence, epecially to the mpg. I am also running on a ratio of 200:1 cheapo mieral 2 stroke oil which I might increase as the cleanimg properties will increase and help with possibly turbo vane issues. I had the turbo off of the focus and looking at the wastegate flap it was gleaming metal thanks to my insistance or using 2 stroke every fill up, not to mention how quiet the pump is now and how smooth it pulls from low revs.... I  have only done an oil and filter and had the tracking aligned since owning the vehical so power loss is not a result of me having disturbed anything although I cannot speak for the competance of previous 'mechanics' who fitted a new steering rack and ps pump etc while diagnosing a faulty altealternator pully......

[031.9tdi130]

So I have located the source of the oil leak, seems the egr was the culprit. Took it off and cleaned it inside and out, did not look too bad untill i started to scratch away.  All back together now with a metal blanking plate fitted and all seems ok. Bus was running pretty well this morning and just as well after I cleaned it all.  Still want to do the inlet manifold as that would definately benifit from de-dunking.  I think my concerns are to do with a rattle resonating back through the air box from around 2000 to 3000 rpm. Underload it is less rattly and more noisey boosting turbo then it goes quiet. As if the boost has gone, but it still seems to get a move on so without some more time playing with vcds logging graphs I wont know.  The breathers were well attached with minimal leakage here given its done 101, 000 miles...  I guess after a vcds logging session the next step will be to strip and remove the manifolds and turbo inspect clean, replace anything worn and refit. The actuator is moving freely I rekon allbit under load from the spring. 

[031.9tdi130]

OK so sunday evening, country roads (lanes) 5th gear and 4500rpm while playing vc log in my slippers - not the best scenario but I now have some more logs all converted into graph form blocks 3 10 and 11. first one were holding gears accelerating uphill going almost flat. second up steep hill holding 3rd and then 4th then levels out before I can pull enough rpm to go into 5th (steeep hilll). 3rd graph just a quick blast form standstill up through gears. Please if anyone can can me if there is anything obvious going on here, (except speeding of course - private roads by the way....) I would much appreciate it. to me there seems to be a big difference between the maf specified and maf actual . But I know nothing please help...

[031.9tdi130]

oops attached wrong file...this is test 3

[Chrispb]

Mark will be the expert on reading these meanwhile could you post the whole csv file as it is as I think we may need more detail.

[031.9tdi130]

not having any luck as the files are not saved within the logs folder in .csv format for some reason....not the ones I just did...Cant understand why my maf  readings are so different between actual and specified. one of the being almost completely flat and the other being very high consistently right the way across not dropping as suggested should be happening in another post. does the flat line in the maf reading equate to the flat performance that I can feel when driving?? I can only wonder...I have noticed that my specified and actual intake pressures are now much closer since cleaning the egr valve, and fitting a blanking plate to prevent eg from entering the inlet ever again...but performance is much the same. I can only imagine that my maf meter is possibly shot and not able to read above a certain amount of volume and therefore the ecu is only allowing the injectors to flow a limited amount of fuel for any given rpm, load or intake pressure... either that or I just came up with a hypothesis (diagnosis) that fits my perceived symptoms using my newly found and limited knowledge to shoe horn a problem into a box. comments appreciated..

[031.9tdi130]

maybe these will help....

[Mirez]

The CSV file will be the excel file you have before you make those graphs

If not, then you want to plot the MAF actual against the MAF specified on one chart with nothing else. That'll give you a much more accurate graph to work off.

[031.9tdi130]

Ok so here is the Maf actual against maf specified.
What do you think? Faulty MAF sensor or something else?

[031.9tdi130]

Still wondering if anybody can help me understand if the graphs I have posted show a faulty MAF sensor. Any help would be massively appreciated..Thanks.

[insanitybeard]

It needs one of the other guys more experienced with VCDS than I to give their input, but have you read this? There's a specific section relating to the MAF graphs.

Looking at the comparison between the 'good MAF' and 'bad MAF' graphs in the linked article, I would say the amount of discrepency in your posted graph between MAF specified and MAF actual is excessive and looking more like the bad graph in the linked article than the good one.

[Chrispb]

That looks like block 003
From my own experience when I had a higher MAF actual than specified was because the EGR diaphragm was faulty but as you have fitted a blanking plate making the EGR inoperable which is affecting the reading on block 003 also the spec readings for 003 should be at idle.

The readings for blocks 010 and 011 are at full 100% throttle around the 3000RPM

Block 010 you should get between 850-1050 Mg/H Mg/Str the higher the better and intake pressure 2000-2200 Mbar

Block 011 turbo boost, again full throttle at around the 3000RPM compare your actual and specified this is the one that shows whether vanes are sticking

[031.9tdi130]

Thanks for the replys again guys, I think I am getting there now.  I am getting in excess of 1000 mg/str at and around 3000rpm according to block 10. Also my specified and actual intake pressures are very close to each other all the way through the rev range. I do wonder if my egr is leaking at the diaphram though. My reason is there is oil coming from the vent holes on the side, surely  this  means that charge air escaping under boost?   I have fitted a blanking plate to the underside or egr connector, but this only prevents exhaust gasses entering the inlet, surley if the egr was leaking at the diaphram then this would still affect things somewhat?

[031.9tdi130]

Any views on this? Thinking of swapping out my MAF for another from my farthers galaxy tdi 115 and redoing the test to see if there is a difference, and doing test in both cars to get some comparison. Maybe that will give me the answers I am looking for....

[insanitybeard]

It'd be worth doing the swap and going for a drive to see if it made a difference to the performance, alas, the 115ps and 130ps MAF's aren't interchangeable, the MAF (and airbox outlet pipe) diameter is larger on the 130 so a MAF from a 115 won't fit.

[031.9tdi130]

How about changing the sensor within the body of the maf?

[insanitybeard]

Worth a go, it may or may not be the same, I can't answer that I'm afraid. I can't see why it would be different but then I can't understand why they made the airbox outlet pipe and MAF body larger on the 130 and 150 TDI's when the inlet tract further downstream (manifold and EGR) is the same as the 115!