2.5 TDI AEL engine in a Volvo V70 with no power before boost

aleksanderk

Member
Joined
Mar 18, 2019
Location
Norway
TDI
Golf mk4 1,9
Hi!
Since my last thread gave me lots of usefull info, I'm making another one because you guys seem to know a lot :)


It's not quite related to this forum since the car in question is a Volvo, but it has the 2.5 TDI AEL engine that was commonly used in Audi A6 and VW Transporters. Volvo called it D5252T.


The car is running poorly before the boost hits, but takes off (kinda) when it hits. If I'm in 5th gear and pedal to the floor it can take 12-15 seconds to get from 70 to 80 km/h on a relatively flat road.


The boost comes on at around 2000rpm. And boost pressure at full boost is 1bar.


I've checked for codes but there is nothing. Timed the injection pump and that is OK. With the MAF disconnected it will not go into boost at all, so i will say that it's ok.


- Took off the inlet manifold and burned it clean. The EGR was OK and is functioning (no difference with it blocked off either).
- Tried Liqui Moly Diesel purge and a new filter, without any difference.
- No exhaust leaks.
- MAP sensor reads pressure fine.
- No blown fuses.
- TCV solenoid is functioning as it should
- All vacuum hoses are connected correctly
- No vacuum leaks and no pinched hoses.
- No boost leaks either.

The car always starts without any problems. A little puff of blue smoke on cold start, but I think thats reasonable for a car with 430 000km on the clock.

The car gets an oil change every 10 000km with Castrol 5W-30 and a Mahle filter.

4th gear pull from around 50km/h: https://www.youtube.com/watch?v=hxjvMbebew8&feature=youtu.be
This is a pull in 5th gear. Red line is boost pressure.















Any tips on how i can restore the power in my trusty Volvo would be appreciated!


If you need some more info I will provide it asap :)
Thanks!
 
Last edited:

aleksanderk

Member
Joined
Mar 18, 2019
Location
Norway
TDI
Golf mk4 1,9
Doesn't anybody have any ideas for me? :p


The timing belt should have been replaced. Could it be that a stretched belt could mess up the correlation between the cam and crank?
 
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