Rough running since new injector

[DSK]

I was thinking along those lines and then thought perhaps 1 injector would just perform better than the others and the difference not lead to the level of running differentiation described by the OP. But since diesel engines are different to petrol a matched set could be the answer. Perhaps try sourcing a complete 2nd hand set from a Volvo breakers to prove the theory?

Fwiw, whilst my cars are petrol, when I change the injectors, its always done as as a complete set prior to any tuning modifications.

[DSK]

As for alternative garages and you don't mind a bit of a journey, I can highly recommend Kings Volvo in Westbury (owned and run by ex MRG Volvo staff), most of us on T5D5 and some from this forums have been there and their work is and level of skill is second to none. Their prices are decent too for us.

I would be very surprised if they couldn't nail your issue in a couple of hours tops.

In fact why don't you give Tony at Kings Volvo a call on 01373 822637, describe what you have had done and the problem you have been left with. He will probably be able to get you on the right track at the very least.

[sonichedgehog2]

Thanks everybody!

Not completely discounting Kings Motor Services and I thank you for the suggestion DSK but it is a 3h journey each way, and if would prefer only to speak to a garage (or any tradesman) if there was a reasonable chance I was going to use them.

I spoke to my mechanic. As I thought, he doesn't have the old injector (runs one of the tidiest garages I've ever seen) and in fact had to part exchange it for reconditioning to get the replacement. It's possible that if I had had the old injector repaired none of this would have happened, but that ship has now well and truly sailed. I asked him to check with his supplier whether they could have supplied the wrong part, but... As said, he's kept our family fleet of old bangers on the road for years.

I've put my trusty diagnostic tool on (which I think was what the £138 at Volvo would have been for) and
1. Exhaust gas recirculation control Circuit A high (google: "no high voltage change to indicate the EGR is opening or closing. ")
2. EGR different. Pressure sensor signal too low.
Found thread https://www.volvoforums.org.uk/archi.../t-233162.html and my brain has now exploded. However one of the contributors noted that after EGR cleanup the fault recurred after 5km.

I cleared the fault codes and they didn't appear when I restarted the engine, but I know that when I reach operating temperature range the "engine management system needs service" error will pop up and I expect that the codes will generate again. I bet that's the same issue as the 5km referred to above.

So I'm now thinking about blanking the EGR valve (which AFAIK cuts in at operating temperature). I did it once, successfully, on a petrol engine, on the assumption that its purpose is enviro/ emissions and not engine function. Thread https://www.volvoforums.org.uk/showthread.php?t=214686 suggests that it's worth a try....?

[sonichedgehog2]

Following a bit more research my mechanic will fit the blanking plate, won't charge much, but we agree it's at my risk because it's my idea. He doesn't want to buy or recommend the product.
My instinct is play safe and get a plate with a hole, to allow the DPF to operate, eg https://www.ebay.co.uk/i/121253753435?chn=ps. Although it seems a complete blank eg https://www.ebay.co.uk/i/162285602502?chn=ps would get better performance I don't want to get into DPF removal or remapping to get the ECU to ignore it.
I'm going to take the plunge anyway and fully understand it it goes wrong it's down to me, but any comments here will be really appreciated. Thanks again for all the help so far.

[SwissXC90]

Blanking off the EGR won‘t solve anything

It is an illegal modification of the emissions control systems and an instant MOT fail. As well as increasing the emissions and harming the planet.

Solve your problem through proper diagnosis. Fix the EGR problem. Then use proper Volvo diagnostics to monitor the engine performance and monitor the individual injectors.

[sonichedgehog2]

"It is an offence under the Road vehicles (Construction and Use) Regulations*(Regulation 61a(3))1 to use a vehicle which has been modified in such a way that it*no longer complies with the air pollutant emissions standards it was designed to*meet."

While my car was misfiring it was probably not meeting even MOT standards let alone the appropriate standards for the car, whatever they were. If Volvo were going to charge £138 to plug a computer in and read me the fault code, I hardly think they were going to provide any useful information about compliance with the standards applicable to this car when it was manufactured, let alone fix the problem, for a sum of money that made any sense in relation to the car's value.

I think others on this thread have in effect nailed the problem. It is likely to be different levels of wear between injectors. With the EGR in place, the fault was diminishing with intensive use but still a problem. With it bypassed the noise is reduced, hesitation barely detectable, and performance much better. Among much material I have read "EGR valves reduce the available oxygen in the cylinder, this in turn increases the production of particulates (fuel which has only partially combusted)." I appreciate that the internet is full of material of varying reliability but I suggest that the merit of an EGR in reducing emissions is questionable. Not to be confused with a DPF, removal of which is irresponsible.

And we all have the right to our opinions and to respect the environment in our own way. Mine is to keep a perfectly good car out of recycling and landfill, and suspend the need to manufacture a new car to replace it at great cost in terms of resources and energy.

To return to the possibility of diagnostics, nobody has unlimited time and money, but from spending much time on this problem I now believe even more strongly that the industry is driving us to replacement rather than repair. Even more disgraceful is that the fact that the car sensors and software indicated an EGR fault, but the issue is still there (albeit tolerable now)with the EGR valve not operating at all. And the concurrence of the fault developing with an injector change is further evidence that this "diagnosis" is codswallop.

I have retained the parts in case my MOT tester requires the EGR to be reinstated. I will post the result of the MOT test in March, together with the emissions test for both this and the previous MOT.

I also believe that, as others have suggested here, as these cars age, we should be budgeting for replacing injectors as a set, probably concurrent with a drive belt change.

[DSK]

Thank you for the update, it helps detailed whats been done along the way, what improvements have been made etc for the knowledge base.

Good to hear the car is running better!!

Since around 2005 cars have been made to be repaired regularly, at great expense (expensive part) and then thrown away as people will just buy a new one. Hence why I'd spend £20K any day on an old, functional classic than any new car, (despite new cars having their merits despite the cheap builds).

Going back to injectors, just for information, below are the OEM injectors for the S70R at approximately 115,000 miles. (I've seen a lot worse flow rates on petrol cars with 60,000 miles!)



After cleaning;

[sonichedgehog2]

As promised:
Smoke test March 2019 Average reading 0.25 1/m
March 2018 - 0.35

I don't understand the units but there has been some improvement - and I can't tell you whether this is because of, or in spite of, removal of the EGR valve.