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Old Nov 28th, 2021, 12:45   #1
G5pot
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Last Online: Jan 13th, 2022 20:07
Join Date: Nov 2021
Location: East Mids
Default D5 Euro V 2015 XC60 - my Rough Idle problem solved

Hi

New to the forum. Been trawling the internet and forums and done the research for D5 rough idle and of course there's loads of rabbit holes. Rather than post to ask and dig another hole here's how I solved mine in the hope people might come across it and give them some ideas if experiencing the same symptoms. It's just one solution of many problems that I can see exist with the D5 and this last gen EuroV is not without! Spoiler alert...no surprises.

It started on a long 500mile motorway run all was perfect before- after 400 miles I reduced speed to 50mph and out of no where the engine spluttered at 2500rpm when asked to load up. Really bad vibration felt through the car and I thought it was going to stall. But it kept going and I replicated the problem on every try. Got home ok but on idle was violently rough. Started the next day to see and it was still there, smooth through the rest of the range just idle warm and cold was rough. No check engine light and basic readout on torque app showed everything fine?

D5 2015 euroV (HDF engine cover and oil fill at the top right) XC60 AWD auto

Summary of symptoms:
Rough Idle
Always on start and when cold
Intermittent when hot
No check engine
No difficulty starting
No smoke at all start idle or driving
No hesitation through the range
No smell
Good Fuel in the tank
Passed MOT Emissions with this rough idle


Initial thought was fuel as filter hadn't been changed in my ownership but was still inside the service interval (of which was main dealer and up-to-date). Also thought it was a coincidence that this was the first time I'd used Morrisons Diesel that this was happening and it was just after the fuel panic buy. I thought sh1te fuel and empty station tanks - probably a load of water and deposits gone through the fuel system thanks to forecourt tanks being low level and sediment being stirred up and run dry.

No water when drained and volvo fuel filter black but ok nothing unusual but a new filter didn't solve the problem. I spent a couple of weeks doing the Italian tune up trying to use up the Morrisons fuel and replacing with £1.70/l v power. Also most STP diesel and injector cleaners at a high ratio it was almost neat!
It seemed to get better after this and was now more intermittent. Always rough on cold start then sometimes yes and sometimes no at traffic lights and drive throughs and, sometimes more violent sometimes just a slight miss.


So I thought injector(s). However it wasnt hard to start and there was no smoke and no smell. That's where I did a load of internet trawling and most problems seem to be before Euro5. At 80k miles for mine - yes they might have done but I couldn't believe an injector would fail that soon. Didn't bother with a leak off test as buying the kit I may as well have just taken it to my local specialist to do it who'd plug it in. Screwdriver and ear and everything sounded normal, checked all wiring connectors and wiggling made no difference and all injectors passed a basic resistance test with multimeter. So possible but unlikely...

Vacuum test...yeah I enjoyed that. Lit a hamlet and had a glass of metaxa but couldn't see any leaks. Although it was noted some tubes had signs of rubbing and wear from their various clips and holders which I'll keep an eye on. Possible engine mounts but didn't see anything. I do have the popping in the oil cap but all that to me is subjective on how loud it is etc so Vaccum nothing obvious.

Then did the usual cleaned the MAF with IPA which was clean anyway, recleaned the Manifold pressure sensor which I'd done.before and was surprised how much gunk had reformed on it but no difference.

So that left me at EGR and the more I thought about it and the nature of randomness seeming fine one minute then not the next the more it pointed to that. I left this avenue till last, after a month or so exhausting other possibilities because when I brought the car 12months ago I did a full service and strip of throttle and egr to clean as I do with all my car's so I didn't think it could be that gummed up! In fact prob 4000miles since I made the egr sparkle?

So took off the motor first and made sure it moved which it did no problem both the motor and the actuator *small* bit of lithium dry grease to ensure it kept moving. Then pulled off the throttle which was clean but had a film of wet oil. Sorry to disappoint but no revelation when I saw the EGR valve looked ok bit gummed up, maybe more than what I would expect for 4k miles but went on to clean it anyway whilst in situ. The back of the valve perhaps had a bit more gunk on it but again what did raise an eyebrow was how wet and sticky the gunk was, and I mean like fresh sealing tar you could string it out which is unusual. Ive always known it to be like stick road tar that would come off in clumps. Anyway checked the valve moved ok and reassembled. And much to my dismay it didn't make one iota of difference, to which point I gave up and phoned specialist to book in and plug in and see what VIDA says.

But then...having been driving it for 2 weeks now the problem hasn't returned and it's back to being smooth idle and smoother through the range that I hadn't noticed before. I'm guessing there was a bit of relearning to do with the ECU after unplugging the EGR. Still abit rattley when cold but it has been close to zero. Appointment is in a couple of weeks to the garage and will keep it to just check EGR operation and make sure DPF is still regen-ing. Will post update if anything of note

So what I'm trying to say in a nutshell is...and this is just my experience on this engine. I think it was EGR related and I can't pinpoint it exactly as it wasn't anything obvious. Maybe a sticky motor and actuator or valve all caused by Morrisons fuel which I won't ever use again!? Maybe just unplugging it helped? maybe a combination of all the above. I'm good with engines but I'm too old now to be crawling under cars and too poor to buy every manufacturers computer interfaces to read the data.

I know it won't be an epiphany to some but i hope someone comes across this thread and helps them when they're doing their own research, just to match up some symptoms.

As an aside while I have my microphone here...I Like my XC60 great looking car and great Mway cruiser but it is basically a Ford now and I probably won't be getting another. Ever looked under a the hood of an Evoque a Mondeo and an XC60 and see the similarities? Ever looked at a TD5 and puma Defender Engine and the D5? A real shame as the build quality isn't there anymore having replaced 3 out of the 4 door locks and a leaky rear window on this XC60.

Last edited by G5pot; Nov 28th, 2021 at 14:06.
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