D4 VEA 'check engine' light / EGR fault thread

[RoyMacDonald]

Originally Posted by craigv60

I didn't realise it had been introduced so quickly. When Volvo launched the VEA diesel, it was hoping it could avoid AdBlue by using EG cooling and a very active EGR management strategy .... but as we've seen over the past 4 years, it didn't work ...

The reason for the Ad Blue is to meet stricter Nox restrictions imposed by the forthcoming Euro 6 A B and C restrictions. Volvo got the basic Euro 6 working OK in the end with just the EGR. I did notice that the cars that caused the least trouble had radiator blinds though. The old XC60 was the only one that that didn't have one.

I saw an article on the BBC where they compared a petrol and a diesel car's Nox emissions during ordinary on road driving conditions and the petrol had three times the emission levels of the diesel.

Roy

[Bendolfc]

Originally Posted by RoyMacDonald

Volvo got the basic Euro 6 working OK in the end with just the EGR.

If by working ok, you mean enough to pass the very flawed NEDC test but in reality emit more than the permitted limits for even Euro 5 cars in the real world then yes.

It simply isn't possible to meet the E6 requirements with EGR alone and as soon as the new testing was announced, the game was effectively up for those manufacturers doing it.

[iain cooper]

Originally Posted by iain cooper

mine is going in to dealer next week to have engine check light diagnosed.

April 2015 and only 13500 miles.

had to postpone trip to see my grandson in Aberdeen this weekend so a bit miffed.

to be honest disappointed in the brand re this, although I appreciate all vehicle electronics are very complicated nowadays, but still annoying.

First Volvo I've had as been a Landrover man for a good number of years, and didn't expect problems so early


Iain

visit to dealer yesterday and only the cooler and hoses replaced, ( fault code P04D900 ) I thought the egr valve would have been done at the same time ?

surely the egr valve would be suspect as well ?

Clan and others, would appreciate your comments/views re this.

Iain

ps on a more positive note, had a chance to look at the new XC60, and really impressed especially with the awesome interior.

[craigv60]

Volvo only replaced the EGR valves if the valve itself actually failed / got stuck. This seemed to happen more with the first round of failures in late 2014/early 2015.

Subsequent fixes involved coolers that were redesigned internally and the cooling circuit & flow also being redesigned to stop it overcooling the exhaust gases. It's the overcooling that led to sooty gunge building up in the EGR cooler's internals.

[iain cooper]

the problem is that I don't really understand the mechanics of the issue.

the fault code indicated that my egr cooler was blocked ? if so how and why ?

but the egr valve is possibly ok ? if so how and why ?

I would love to understand it, and be confident in the initial issue and the fix.

oh to have been a mechanic rather than a telecom engineer.

Iain

[craigv60]

To meet the stringent Euro 6 emissions requirements, most manufacturers started using AdBlue systems on their diesels from about 2012/2013 onwards. This injects small amounts of a Urea solution into the engine to reduce nitrogen oxide (NOx) emissions.

However, when developing its new modular VEA engine, Volvo decided to reduce NOx emissions by using a sophisticated electronic EGR & cooler system, instead of an AdBlue system. Volvo's approach means that the EGR system is a lot more active than previous-generation systems, piping cooled exhaust gas into the inlet via the electronically-controlled EGR valve, to reduce combustion temperatures and reduce NOx production.

So far, so good, and it all worked fine in pre-production testing.

However, about 6 months after the first deliveries of cars to the public, customers were reporting 'Check Engine' lights coming on. Investigations showed the serpentine exhaust-gas passageways in the EGR coolers (it's like a mini-radiator) were crudded up with gunge, and in some cases this gunge had caused the EGR valves to stick (this happened to my own car after 6K miles).

Volvo's initial approach was to recommend dealers remove the EGR cooler and clean it, and replace valves if necessary. But this didn't stop the problem recurring. So Volvo redesigned the cooler and started fitting it to cars. That didn't solve the problem either.

Eventually, Volvo realised that the EGR system was OVERcooling the exhaust gases and causing condensation to build up inside the cooler passages. This mixed with the soot from the exhaust gas (the exhaust gas for recycling is tapped off BEFORE the particle filter) to form the gunk which would build up and block the system.

This happened a lot faster in cars driven a lot around town because a) they don't get fully warmed up and b) town driving uses a lot more EGR cycles than motorway work.

Basically, the problem occurred because Volvo's pre-production testing was not rigorous enough: they didn't do enough city driving miles with the cars.

So the final fix that Volvo now uses is a revised EGR cooler, and revised plumbing to the cooler which actually warms the cooler up to prevent condensation.

Also, new Volvo diesels are now equipped with AdBlue for NOx reduction.

[iain cooper]

thanks for that Craig, appreciated.

where does the egr cooler sit, and is it easy to tell if it has been changed ?

also where does the egr valve sit ?

I would like to be able to follow the new hose layout, water flow, etc

probably I should have asked the dealer to show me before leaving.

Iain

[volvo for ever]

actually egr's are renewed if sooting or corrosion is there also sticky and also if its not new style

[NigelDay]

Originally Posted by iain cooper

thanks for that Craig, appreciated.

where does the egr cooler sit, and is it easy to tell if it has been changed ?

also where does the egr valve sit ?

I would like to be able to follow the new hose layout, water flow, etc

probably I should have asked the dealer to show me before leaving.

Iain

Check this out.
https://www.volvoforums.org.uk/showp...postcount=1539

[Matt999999]

Hi, wondered if anyone could assist/advise?

Bought a 14 plate S60 D3 R-Design (my first Volvo) from a non-Volvo (but still main chain) dealer in Sept 17. Full service history and only 16,000 miles so didn't take up extended warranty offer as it was (at time) 5 months outside standard warranty but well below warranty mileage (paying for that decision now!). Went in for service at Volvo garage but couple of days before, 'check' light came on (current mileage is 20k). Garage cleared fault light it during service and said it would need to be re-booked in to check EGR. Had EGR valve replaced on Thursday at cost of £800 but after 80 miles, light is back on and stays on. Going to ring Volvo garage on Monday, but obviously a bit concerned about what else it might be? Dodgy sensor? Also, bearing in mind labour cost was over 50% of above cost, I don't really want to pay as much labour again to check same fault?

Was going to try Volvo uk HQ to 'complain' as although outside warranty, mileage is much below 60,000 warranty limit....

Grateful for any thoughts anyone has?

Thanks all