V50 Engine Turbo : Engine Vibration After Dealership Work

[Neil France]

Hello all

I'm a Brit living in France, having brought my 2011 Volvo V50 from the UK. It has the D4162T engine with approximately 126K miles.

A couple of years back, the local garage persuaded me that the "Engine performance reduced" message we were occasionally getting had nothing to do with the particulate filter being full, resulting in a very expensive turbo change plus 4 x injector change.

These problems were finally brought under control by our local Volvo dealer, in that the particulate filter was changed, performance reduced message disappeared, fuel consumption back to normal. However, what remained was the smell of exhaust at idle, i.e. with the car, engine running, but stationary.

On a trip to the UK, another Volvo garage diagnosed the smell as coming from a loose/compromised seal on a resonator pipe - this was replaced but failed to cure the issue.

The car was taken back to Volvo here in France, where they diagnosed the problem as coming from badly installed injectors and recommended re-seating the injectors using new seals as well as replacing the small diameter pipes that feed diesel to the injectors. I apologize for my layman's vocabulary - I'm not a mechanic or someone who tinkers with cars.

When they started this work, the foreman called to say that the garage who installed the new injectors (not Volvo, but a "specialist" diesel garage) had installed them so tightly that they'd broken the "rims" - this is a translation from the French, but I'm guessing they mean the lip of the injector support - I've attached photos.

The job has just been completed and I went to pick up the car at the beginning of this week. No smell - great. However, in the higher gears (say 5th and 6th) if one lets the revs get too low (but before the dashboard indicator appears that advises a gear shift) there's a noticeable vibration. To me, again as a layman, it's almost as though the engine is running on 3 rather than 4 cylinders - a bit of an exaggeration, but hopefully you'll know what I mean.

Immediately returned to the workshop and the foreman came back out on the road with me and suggested that, now that the fuel delivery system was completely pressure-tight, it was likely that the vibration was simply due to low revs and the necessity for a gear shift - i.e. just change gear earlier and don't let the revs drop too low.

After one day, took the car back to Volvo and asked them to fix it as, in my opinion, there was something wrong. They've had it four days now and have just called to say they can find nothing wrong - no faults show up on the diagnostics and they say they even changed the injectors from a similar car and had the same result.


I've attached cropped images of the invoices for the work done - I'm assuming, probably naively, that Volvo part numbers in France are the same as Volvo part numbers everywhere else.

Does anyone have any ideas?

[Lukasguy]

This may be a long shot but did they relearn/adapt the injectors to the car when they replaced them? This has to be done for them to run optimal. My guess is that they didn't do this if they did this poor of a job replacing them. They have to be coded in AND an adaptation drive has to be done.

At what revs does the car vibrate? When I had bad injectors it vibrated/ran sluggish at around 1800-2000rpm. It was very noticeable when driving in 3rd or 4th when the speed limit was at these revs.

[Neil France]

Lukasguy - thanks for taking the time to reply. I've just driven back from the dealer with the car - same state as before. The foreman there says he cannot accept there's a problem until he checks my car against another, so he's arranged another visit for the end of this month when he'll compare another customer's V50 against mine.

But to answer your question, I assume (!) that they have done the necessary re-calibration of the injectors. When they were replaced by the local "specialist garage", Volvo were quick to point out that the new injectors had not been updated on the car, although the specialist garage said that, if they hadn't done that, the car would not have run.

The worst vibration occurs in 5th and 6th gears. For example, whereas before at around, say, 65 km/hour (40 mph) and on a slight incline in 5th gear, one could accelerate easily to 70+ km/hour (45 mph) ready for the gear change to 6th to be advised, then the vibration occurs. There is nothing indicated on the dash to say a gear change down is advised. I'll need to test again to advise on RPM readings during problem episodes.

Strong application of the accelerator increases rather than decreases the vibration, until the car reaches, say, 85 - 90 km/hr (53 - 56 mph) and one backs off on the accelerator.

Setting cruise control on a motorway at 110 km/hr (70 mph) works fine and inclines are handled without problem. On a reasonably level stretch of road, setting the cruise control at 90 km/hr (56 mph) also works OK.

I don't know if it's relevant, but indicated average fuel consumption has also deteriorated slightly: from about 58.3 mpg before the work was done to 56.1 now.

[TheMenace]

It'll be worth having them check the diesel filter when you take it back in (if they haven't done already) - sometimes it can just be something that simple

[Neil France]

Thank you for your comment, TheMenace.

Following on from Lukasguy's earlier question asking at what RPM the vibration occurs, I went on a run this morning of about 15 kms (just under 9.5 miles). The road is more or less straight but undulates a fair bit, sort of like an "S" on its side.

Putting the car in 6th gear and on cruise control at 90 kms/hour (56 mph), and allowing it to manage the hills by itself, i.e. with no accelerator input from myself, then the vibration starts at around 1600 rpm and continues until about 1800 rpm, when the vibration tails off. This is pretty much the same in 5th gear and on an incline - not in terms of speed, but in terms of rpm.

In 4th gear and below, the vibration is harder to induce.

I'm beginning to think the turbo could be at the root of the vibration. This was changed in February 2020 as part of the particulate filter fiasco. With the most recent work, the garage insists that the only thing touched were the injectors and the fuel feed pipes, and they are therefore likely to dismiss a potential turbo issue as being the cause.

[Brione]

Just a thought, have the engine mounts been checked for excessive wear?

Cheers

Brione

[IainG]

Hi
There is a test in Vida that cuts out the injectors one at a time to see if there is an imbalance in the effect of each injector. Might possibly show up a discrepancy.
Not sure if this test can only be done at idle or at different revs?

Iain

[Neil France]

So, took the car back to the Volvo dealer last Thursday. To give them their due, they had, as promised, arranged for another customer to bring their V50 in so that they could compare results between the two. Their engine analysis showed, they said, absolutely no difference between the two cars, with VIDA printouts showing zero faults found. I’m assuming their primary intent is to demonstrate that the work they had previously done on the injectors was not the cause of the vibration issue.

The foreman then took me into the workshop where the car was up on the lift. The only problem they can find was that (and here my knowledge of mechanics will let me down) the “half shaft”(?) that is, the shaft that drives (or at least, connects to) the front driver’s side wheel, has some play in it, admittedly when the foreman really pulled at it. His theory is that, when accelerating, the play in the shaft is causing the vibration. The estimate to replace this part is around £1,400+ equivalent and that, to my irritation, includes around £250 for the investigative work they did on Thursday. Irritating to me because they could do this work and not fix the issue so, in my view, it’s a little premature to be charging for this.

So, as a layman trying to apply some logic to this conundrum of whether I throw more money at this, I have my doubts as to whether this is going to fix things.

Firstly, it’s surely a bit of a coincidence that there was no vibration on the morning of the day I took the car in for them to fix the initial exhaust/diesel smell issue but the vibration was there the same afternoon.

Secondly, if the vibration is related to the small amount of play in the half shaft then surely it would be speed-related rather than RPM-related? To reiterate, once the car is up to around 70mph there is no discernible vibration. Similarly, the vibration starts to ease off from around 1,800 RPM onwards in gears 4 through 6, since in gears 1 through 3 the engine is in excess of 1,800 RPM almost immediately.

Anyone have any further thoughts?