C5 power down

[electroboy]

My first post since purchasing a lovely 2007 C5 2.0Hdi (thanks WRB!):

Since an oil and filter change (yes it's the correct oil), the motor just seems to lack the same punch, but it's still perfectly drivable. I reset the service interval thing in the instrument panel but didn't do anything else - is it possible this car has gone into some kind of 'slow and steady' mode simply as a result of an oil change?

I don't yet have a Lexia type system to plug into it (thinking the one from Germany might be the one to get) but so far as I can tell there are no warnings or signs that it is not operating normally other than the loss of power.

Advice, other than "take it to a dealer", would be much appreciated!

Geoff

 

[David S]

There are vacuum pipes down the front of the engine and there is a Y-piece in the bundle that can crack. Start there. Have a look at those or do a vacuum leakdown test if the problem arose just after the oil change, the filter being down the front of the engine. It's a very common issue with the 6 speed 2.0Hdi C5 with the DW10B engine. The car will feel gutless and usually declines to change up to top gear. A few bits of rubber tube and a washer hose Y or T-piece would fix it.

 

[electroboy]

Do you mean this little fella?

 

[garethb]

My 03 c5 petrol had a similar issue. After replacing the water pump (was working but sounded like the bearing was starting to go just before I changed it), back to normal. No errors or anything, just really sluggish but perfectly driveable. Also changed timing belt at the same time but belt looked pretty good before I removed it so guessing water pump was the issue.

 

[ScotFrog]

There are vacuum pipes down the front of the engine and there is a Y-piece in the bundle that can crack. Start there. Have a look at those or do a vacuum leakdown test if the problem arose just after the oil change, the filter being down the front of the engine. It's a very common issue with the 6 speed 2.0Hdi C5 with the DW12B engine. The car will feel gutless and usually declines to change up to top gear. A few bits of rubber tube and a washer hose Y or T-piece would fix it.

Does this apply to the 2.0 L HDi diesel too David? My 2002 C5 regularly runs in sluggish mode on a cold start but if I allow it to warm up for 5 minutes before driving is as good as gold. This problem only started after a service which included an oil and filter change.

SF

 

[electroboy]

Well after David's suggestion I found that white plastic 'Y' piece was not only cracked, as soon as I touched it the thing fell apart. What a diabolical little piece of Italian rubbish. With judicious use of a 4mm drill bit and a heat gun I managed to get the remnant barbs out of the nasty little hard plastic vacuum tubes without causing further leaks. Down to the local hardware shop for a little garden 'T' piece and hey viola!

I cleaned up the intake gadgetry/butterfly etc. whilst at it, and the car now pulls like a train.
All praise to David S, may peace be upon him!!!

Geoff

 

[David S]

That's a very neat job. Well done. Not exactly an expensive repair and a major improvement.

This only affects the DW10B 2.0HDi in C5,C4 and Picassso models with RHR in the VIN. So, no it will not be your issue Scotfrog.

Edit: The vacuum hose set looks something like this, with the white y-piece being near the middle.



Same issue on a 307 with the DW10B / RHR engine here:
https://www.aussiefrogs.com/forum/i...of-power-turbo-fault-code-p2562-p0299.120528/

 

[seasink]

These gas fittings are available in brass: