Hdi Misfire But No Ecu Error Reports - Driveshaft Joint

[Neil-BX]

I have a 2009 C5 2.0 HDI (X7), approx 82k miles

This can be erratic but originally on mid-heavy load I would get an engine vibration as if a misfire.

 

This has slowly got worse and yesterday the vibration was slight on just touching the accerator to keep speed and severe engine shuddering on mid-heavy loads. If I brought it to over 3,000 rpm it was drivable.

This morning when I was driving to the garage for investigation, the engine vibration was just detectable and no more. The garage read no errors and all appears to be Ok, they also check the software was the latest for this C5.

 

As part of my own Lexia investigation previously I could not find any errors (as the error log was full because I installed LED number plate lights! reporting short crcuit). I installed a EGR bypass, no change, still shudder. Checking the Lexia log now reported "Excess air"? and "EGR failure/blockage", so the EGR blocker was removed.

 

The C5 was full serviced with new fuel filter 2months wth no reports of low fuel pressures.

Also treated with Forte Diesel and DPF filter cleaners.

The only other interesting point is that fuel usage is less. This has moved from approx 50MPG to 60MPG!

 

Does anyone have any ideas what else to check (that isn't too expensive)?

 

 

I am lost on

[Neil-BX]

Finally found the fault, nothing to do with the engine but a damaged universal joint (at the gearbox end) on the N/S driveshaft!

Now very smooth and no vibration.

 

On inspection of the UJ it one of the bearings brown as if overheating.

[paul.h]

Thankyou for getting back to us, I hope it was not too expensive to fix. I have slightly edited the title to help when searching.

[Neil-BX]

£100 for an exchange drive-shaft. I did it myself as two garages couldn't tell me what was wrong! and I took the risk that one of the garages may have damaged the drive shaft 6months ago replacing a split gaitor on the CV/hub side of the shaft. They did state that they had could not seperate the CV joint from the shaft to get a new CV gaitor on and had to use a glue together gaitor.

 

The replacement was resonably easy, approx 2hrs, as I had the LDS suspension so didn't have to worry about using spring compressors to pull back front hub to allow me to replace the driveshaft.

 

Was was weird is filling the gearbox using the air vent! (I drained the gearbox before hand and refilled with 2.6L 75/80W gearoil).