S40: varying turbo boost

[fatboy92]

hi all.
thanks for reading me.

my good old V40, 1.9 diesel has had the turbo and egr valve changed a couple of months ago.
Since then, I have a strange hesitation problem during constant speed cruising. Squash the mushroom and it goes like sh@#$ t of the shovel. When going uphill at about 2000rpm, it will even shake me about.

My mechanic thinks he has fixed it by cleaning the pressure sensor, but it always comes back.

Would anyone of your great d-i-y-ers and mechanics have an idea, where to look?
After the turbo and egr (1800 €) I just had another reparation for 1000 € and I feel reluctant to put it back in the garage.
Many thanks for whatever time you spend with my subject.

fatboy92

[baldmosher]

Welcome to the "minor but annoying issue with turbo" club

There's a whole host of things to check, couldn't tell you where to begin, but the first port of call would be someone with a code reader, to eliminate those issues first.

It does sound a little bit like the problem I had with the fuel regulator though. That came up with a fault code, so easy for my local Volvo specialist to diagnose. Does it also "hunt" (wobble revs) at idle, or are you only ever seeing it at 2000rpm?

[def]

Could it be a boost leak?

[skyship007]

Originally Posted by fatboy92

hi all.
thanks for reading me.

my good old V40, 1.9 diesel has had the turbo and egr valve changed a couple of months ago.
Since then, I have a strange hesitation problem during constant speed cruising. Squash the mushroom and it goes like sh@#$ t of the shovel. When going uphill at about 2000rpm, it will even shake me about.

My mechanic thinks he has fixed it by cleaning the pressure sensor, but it always comes back.

Would anyone of your great d-i-y-ers and mechanics have an idea, where to look?
After the turbo and egr (1800 €) I just had another reparation for 1000 € and I feel reluctant to put it back in the garage.
Many thanks for whatever time you spend with my subject.

fatboy92

Which make of turbo and EGR was fitted ??

I'm sure that a good garage which has run up such big bills will know how to get a Volvo lunchtime discount and get the codes read.

I suspect Vadis/Vida say that the boost sensor should be changed if the turbo is replaced.

[fatboy92]

Hi baldmosher, def and skyship007,

thanks for your answers.

The problem persists even, when I am at 90 (km/h sorry I'm in France) on the motorway. It is feeble but still feel-able.

The mechanic is moving right now, so no access to his garage for a couple of weeks. But of course he will look into it, but I'm just afraid he will try to fix it just "a little bit", perhaps trying to cover up a little mess-up.

The Volvo garage I was faithful too, until the turbo broke, will likely not make any efforts without pay. They asked me to pay the diagnostics for the turbo problem (somewhere close to 80 €), where I knew exactly that the turbo no longer rotated. Then they gave me a price quote for 2200€, which didn't even take into account the broken EGR valve and that made me leave. I don't mind paying a little more, but that is abuse (IMHO).
So I found this garage via a friend of mine and I think the guy is serious, but of course he doesn't have the code reader.

So right now, it's still there and I am kind of stuck. It is less pronounce in cool weather, though.

The make of the turbo is unknown to me. The garage got a refurbished one, but I can find out, what it was. He said it cost about 800€. I am, after all, in Renault land. The motor sounds great and I have gotten around a few issues with the driver seat belt, the electronic module for heating and divers dents in the body. Apart from that I think it's still running great.

Well, thanks again, I shall give you the results of my quest as soon as there are some.

fatboy92

P.S. I don't know how you found my thread in the forest of subjects and posts, but thanks.

[timmytarmac]

Hi yeah sounds like your in the club. Apparently there could be issue with the fuel pressure sensor or Inlet Air Temp sensor which could cause problems I believe I read something the other day regarding when it's cold and running differently but like sky said Mass Air Pressure sensor might need doing. Could you take it to volvo and only have the codes read and then tell them to FO

[fatboy92]

Hi all,
for everyone, who has spent any time on thinking about this, many thanks.

Turns out, the problem was diminished to close to nothing by doing a longer trip (200km in 3 hours). I can still tell there is a lag in power when accelerating from down below, but the car runs normally now, no more funny behaviour.

Thanks again
fatboy92

[waynearees]

Done this myself yesterday and it does work just fine, I put the wrong code im Friday and it displayed 'OFF' so I parked up, took my key off the remote and left it at position 'I' with the radio on, locked my car and left it 2 hours to watch the football, returned at full time and entered the code as found in my handbook and now have my music back...

[timmytarmac]

Originally Posted by fatboy92

Hi all,
for everyone, who has spent any time on thinking about this, many thanks.

Turns out, the problem was diminished to close to nothing by doing a longer trip (200km in 3 hours). I can still tell there is a lag in power when accelerating from down below, but the car runs normally now, no more funny behaviour.

Thanks again
fatboy92

How is your mpg. N75 causes alot of problems so does the maf see other threads

[skyship007]

Originally Posted by fatboy92

Hi all,
for everyone, who has spent any time on thinking about this, many thanks.

Turns out, the problem was diminished to close to nothing by doing a longer trip (200km in 3 hours). I can still tell there is a lag in power when accelerating from down below, but the car runs normally now, no more funny behaviour.

Thanks again
fatboy92

Good to hear, as it might just have been partly caused by Carbon or gum near the injector tips or Carbon crud in the CAT etc. Nothing like some good WOT time to clean out the big C.
A bad boy old diesel can need nearly 10 hours at 75% of redline to really shift all the Carbon and crud in the cylinders and exhaust.
With old diesel fishing or sailing boats, I always used 30 mins of max (4K, not 4.5K for the 1.9D) cont, for every 12 hours trolling at low power for a burn out.

Time for some real good oil next!

(Gone for days now, due US plug changes for laptop and kaput old US Mobi that a horse trod on).