Intermittent engine power

[Rapido925M]

The wastegate valve is part of the turbo but it's often just a case of disconnecting the actuator and manually opening and closing the valve a few times using the actuation lever. This can clear away any rusty or sooty deposits that may be preventing the wastegate valve from operating properly.
Also as above, check the boost control valve and vacuum pipes connected to it first

Thanks. I trust my garage; a long established family business working primarily with commercial vehicles. When I called in on Monday, Terry (the owner) remembered what they had done but didn’t give me the details. I shall ask him later.

Would this account for intermittent activity or would it be a permanent problem?

Gordon

 

[dunnah01]

Thanks. I trust my garage; a long established family business working primarily with commercial vehicles. When I called in on Monday, Terry (the owner) remembered what they had done but didn’t give me the details. I shall ask him later.

Would this account for intermittent activity or would it be a permanent problem?

Gordon

It would be intermittent at first but get more and more frequent over time. The waste gate is a crude disc of steel sealing a hole in the cast iron turbo outlet tract. It has a hard life and soot from diesel and rust over the years can cause it to stick open a bit. This leaves no turbo boost and a big drop in engine power.
When the actuator moves the waste gate to control turbo boost it may seat properly next time it closes or it may stick a bit. If it seats properly you'll get normal turbo operation and engine will be normal but if it doesn't seat properly it will leak and you won't get much, if any turbo boost and a drop in engine performance.

 

[benimardriver]

For some time I have felt that the turbo hasn't been working all of the time, causing me to change down on the slightest incline and having no power when trying to accelerate. a couple of weeks ago I took it to my local trusty garage who found a loose clip on an intercooler, which they tightened. Following a smoke test and a test drive they proclaimed it satisfactory.

When I collected it I wasn't particularly impressed but I wondered if I was imagining what it used to be like. However, other things got in the way and it was only today that I managed a decent run. It barely accelerated up a slip road on to a dual carriageway and I could only just get up to 60mph going down a gentle slope. I called in at the garage and they have suggested fitting a new fuel filter: this one has done 10k miles in 4y.

As I left the garage the engine roared and pulled like an express train: it climbed that gentle slope at 62mph and kept accelerating happily. All the way home it felt like my old van.

My son has suggested it's my fault for using cheap diesel and I should let the tank run almost empty then fill with "decent" fuel (plus some Redex).

Any thoughts please?

TIA - Gordon

The garage is looking to source a new filter and find time to fit it before I head to the Lake District on 1 March.

Mine was down to turbo waste gate actuator rod becoming detached from the lever arm of the waste gate Valve . Could also experience same symptoms if valve becomes stuck open

 

[h8ten]

I haven't seen it mentioned already, apologies if I missed it. Could it have been a blocked breather pipe to the fuel tank causing a vacuum build-up in the tank and so starving the engine of fuel? One way to check if it happens again is to try removing the filer cap and if there is an intake rush of air then this could be the problem. I've had this on a petrol car years ago.

 

[Sidders]

Have they plugged it in and read for fault codes Rapido925M?
Could be completely unrelated but when we bought our previous Motorhome it had a very similar issue - though ours was going into limp mode at around 2.5k revs in higher gears. Previous owners mechanic apparently said ‘they all do that’ and ‘it’s unburnt fuel that causes it’ (or some similar tosh). It was really annoying, particularly as we always venture into the highlands of Scotland and you need power on some of those hills.
My usual go-to trusted garage suspected fuel contamination and changed fuel filter as well as putting cleaner through the tank - this didn’t fix it. I eventually booked it into a diesel specialist (Argyle Diesel in my case) who had the proper diagnostic tools for my particular model (ivecos can be a pain for this and most general mechanics don’t have the proper kit). It was the rod that controls the waste gate on mines that was sticky due to lack of use - very common on Motorhomes that don’t see much use apparently. The part was lubricated and I was given some away and shown what to do - relatively easy. It did get better the more I used it but frustratingly didn’t disappear altogether. I was ready to replace the turbo at over £1k until I heard of a place that can fix them by applying a heat gun of sorts to loosen off. I went with that and it’s fixed it.
I’d be tempted to get it into a diesel specialist (if your go-to garage can’t diagnose/fix it) that works on these all day and understands them and go from there - I’m glad I did.

I can’t believe the previous owners of mines just drove it around like that for quite some time and thought it was ok/took their mechanics word for it…..it drove me mad

Good luck

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[Rapido925M]

The fuel filter didn’t do anything apart from take money out of my account .
They are considering what to do next BUT we are at Center Parcs next week with all of our family and then need to get to Kendal for 8pm on Friday 1Mar having picked up granddaughter from Leicester at 1pm.

I know I should have dealt with it sooner but we’ve had a hard couple of years AND I’ve managed to get 200 miles to Teesside in it so I may just have to sit in the slow lane

Gordon

 

[RobertJary]

We've the same MB engine, OM611, in our 2005 Frankia. Your garage should be able to read the fault codes - our local commercial dealer has the diagnostic equipment to connect to the MB diagnostic port, not OBD II, but a 16 pin circular connector below the glovebox. They've diagnosed 2 faults, one with the turbo vanes sticking which required a remanufactured turbo and one with a faulty ABS pump (needed a new ABS control unit now only available from MB). The fault with the turbo vanes resulted in poor performance. The reason for the sticking vanes is due to low mileage, 45k in 15 years. My 2002 E class had the same engine but did 40k miles each year. At 350k miles, the turbo was still working, as were most other parts.

 

[Marauder]

mine was injectors

 

[Rapido925M]

HOORAY!
After three visits to "my" garage they believe that they have found the fault: deterioration of a vacuum pipe. They have also replaced the transducer BUT they cant fasten it in place as the bracket has rusted away and they cannot get a welder in to replace it. The rust may have been caused by a build up of pine needles, rotting and producing acid.

One vacuum pipe could not be replaced because it "disappeared into the nether regions". Fingers crossed that this is the end of the problem.

Thanks to all who have provided ideas and suggestions.

Gordon