D4204T Help! V50 2.0D, intermittent power loss - no fault codes

[Martin_Butcher]

Hi,

I have a V50 2.0D (05 reg) which I bought at the turn of the year with about 25k miles on the clock. With the exception of the below, its a lovely car.

However ... on several occasions the engine has experienced a significant power loss as described below. I have read a lot of posts on this board, but none of them quite match up so I have posted the below to see if anyone can offer advice.

The symptoms are like this:

1) Driving along normally - say 60ish in 5th gear,

2) You accelerate, and as you are accelerating suddenly the engine power just disappears - but no warning lights, messages etc.

3) Back off the revs, engine power comes back so you can maintain speed, however if you start to accelerate again and demand more power, again the engine power will disappear

4) This will perhaps happen 5 - 20x if you keep repeating the above sequence but then the car returns to normal and all the power you can want (without needing to stop the engine). Then it won't happen for another month or so.

Now last time this happened (nice straight bit of the fosse way!), I noted that at the same point the engine lost power you could hear a sound of releasing air (a bit like when you release a pump from a tyre) coming from the engine compartment area.

I took the car into TMS Volvo in coventry and no fault codes. They inspected various parts (not sure what) but the summary was bring it back when it becomes repeatable.

Would welcome any thoughts.

My thoughts at the moment are:
1) Its not a problem that generates a fault code (that must narrow it down some, unless diagnostics has failed as well)
2) It probably not a hose as that would likely happen all the time, not happen for 5 mins in the middle of a journey and then mysteriously disappear.
3) urrrm??

I would be most grateful for any help!

Thanks,

Martin

[Martin_Butcher]

Well, I am taking the car to the garage again on wednesday to see what else happens. I must admit that I don't have high hopes...

I would also welcome anyone's views on how to deal with this. At the moment TMS are basically saying, we're really sorry, but we can't help until there is a fault code.

As I see it, the car is in warranty, it has a fault, it is a dangerous fault, volvo should fix it. Volvo way, we're really sorry but we can't fix it.

Is there anything more they can do that plugging in a fault reader? Should I be asking them to take the car back?

Thanks,

Martin

[grass hopper]

hi Martin,if its a euro 4 possibly faulty particulate trap sensor,the fault code will be stored,but if not,worth replacing and test.

if the fault happens often just leave it with the dealer to fix and test.

[Martin_Butcher]

Hi Grass Hopper,

It is a Euro 4. The fault is happening about every 500 miles or so, so it is a bit of a difficult one to leave with the dealer to test. You take it, they drive it and say 'no faults, test drove fine!' Which it does 99% of the time.

Volvo have said no fault codes to date. Is this a simple thing to replace a particulate trap sensor?

Thanks for your advice,

Martin

[grass hopper]

hi Martin,it is very easy to change,fits at the side of the battery cover,2 hoses and one screw and 1 connector,and not too dear.

changed many of these,but it normally logs a code ! and usually you have to switch of the engine to reset back out of limp home mode.

another possibility is a intermitant faulty/sticking EGR valve.

faults like this are horrible to diagnose for a technician if its only every 900 miles,and very frustrating for you.

it might be worth asking who you bought it off if they had any problems and if anything has been replaced.but i guess they will say it was ok.
regards GH.

[Martin_Butcher]

Hi Grass Hopper,

intermittent faults are the worst. I am a eletrical engineer (big stuff) and have had to diagnose a few faults like this. Normally just end up hanging more and more test gear on until you find the problem / anomaly.

Is it possible for volvo to do anything like this - fit additional diagnostics - manually force a DPF regen sequence and see if this makes the problem occur again?

Unfortunately, the people I bought it from are the volvo garage that are looking at this problem, so I sure it was fine prior to sale! I will ask them to let me know if it has had any parts changed on the engine though - they should be able to tell as it has a full volvo service history.

I have also been posting on the Honest John website. An email from HG said 'probably just a DPF regen occuring' and a separate post on that website also said the same. This seems a bit extreme for a normal event.

I have also been wondering could driving style impact this? I tend to do mostly local miles (and love 6th gear because it is so quiet), then longer journeys when this seems to happen.

Thanks for all your help.

Martin

[Omami]

Struggled with intermittant power loss and lack of acceleration in my V50 2005 diesel Volvo for more than a year. It had been regularly serviced and looked after.
Changed the EGR valve last year. Acceleration of car seemed better, but did not cure the problem.
Luckily the intermittant fault developed again while the car was being serviced. They managed to connect the diagnostic tester while it was running, and discovered that the Exchange DPF filter was clogged up and needed replacing.

We hope that this will have been the cause, and the problem is fixed.

Probably not many people are still driving an 11 year old car!

[Stephane]

I have the same problem. One day the power died. Brought it to the dealer and they said I might need a new electronic controller! €900! They tightened connections and said to keep going for as long as possible, which I did. I had the problem intermittently since but have managed to scramble by through only using very light acceleration on gear changes - if I get a slump in power I can strangely get it back by going up the gears! It will almost take on a cruise control status! If I stop the car and come back to it I can find the problem has gone again. Clearly electronic, but judging by forums there is an inherent issue. I never had this problem with two previous Volvos the 2003 S40 and 2007 V50. This one is the 2011 V50

[dosi]

I had problem with power loss whene I accelerate, in volvo v50, 2.0d, 100 kw, 2005 year. I send car in vovlo servis 2 time: 1 st time they change some vaccum pipe but nothing, i had the same problem and for the second time they change turbo valve and now it is ok.

[max65]

hi dosi,
in your case the power loss was intermittent ?