Help needed as I have run out of ideas
 

So I have had an ongoing issue with my xc90 for the last 4 years of my ownership it’s been to a couple of Volvo specialists and Volvo themselves with no definitive answers.

It’s a 2004 d5 executive semi auto. 163 Euro 4
The fault:
Intermittently the car will go into limp mode under acceleration it will sometimes recover on its own but will always recover by turning it off and back on.

Symptoms:
On initial few moments of the journey the car will dump the boost like a early 90’s cosworth chatter and all... after a few mins of driving it stops happening.

The mpg is around 22mpg average over 5000k mixed driving.

Diagnostics:
Code reader records P0244 Turbocharger Wastegate Solenoid A Range/ Performance

The engine pads have been isolated from the vacuum circuit.

With a vacuum tester if have checked the behaviour of the vacuum solenoid (air box) at idle gives 25 on the gauge and 1000 rpm 0 vacuum.

I have tested the actuator with the vacuum tester and it holds vacuum at 25 and the actuator moves freely as does the vnt arm on the turbo.

The turbo control solenoid has been replaced with a genuine Volvo replacement

The intercooler isn’t that old and looks in good shape. And as most of the time the car behaves would indicate it should be fine.

Help please I am at a total loss of what else to try..

Hook it up to Vida and take it for a drive whist reading live data

What is the MAP reading in psi with engine off ignition on and then at idle?

Guessing I will need Vida to see this not something I can measure with a multimeter etc....

Remove the turbo, inspect and clean the vanes, ensure moving freely and refit the turbo

(easier written than done I know...)

Give the intercooler hoses a really good inspection, sometimes a very small crack will open when accelerating and close again when eased off, allowing you to switch off and reset limp home by turning engine off, check the underside of the hoses and the hidden parts you cant see from the top or front.

Not a multimeter no but an ELM327 dongle can be had for under £10 and the results read on your phone.
Useful diagnostics aren't expensive.

Sounds like you have the same issue I had on my V70 D5 163, where the VNT worked fine when tested manually with a vacuum tester, but under load it got stuck, throwing limp mode and reset with engine off/on.
I found that if I repeated the cycle 3 or 4 times in quick succession it seemed to work for a while and behave itself. After exhausting everything else I swapped the turbo for a spare used one I had and the problem was solved.
The last page or two of the thread below covers it. It's likely if yours is read by VIDA rather than a generic reader that you'd have the same fault code.
https://www.volvoforums.org.uk/showt...=132443&page=8

Alan.

Well the car finally packed up the other day I swapped the maf and map sensors out and it was running again and since then I have had no issues

The maf was the original one from the car that I had swapped out while trying to fault find the issue so the only real change was the map sensor.

I’m now seeing 30.1mpg average and it’s driving so much nicer and not a single episode of limp in 2000miles including towing are caravan which it always happened with that on the back.

Sounds like you have sorted it - Hurrah!!

Well done for not giving in - I don't think I'd have the b@lls

Seems like Cheshire5 was in the right area back in July...

Cheers

Dave