Engine: D5244: Ecm6805

[boombox]

Seem to be having intermittent problems with this error. Always under high revs for example putting foot down to join motorway traffic.

I have done a lot of research into it on this forum and elsewhere and have come to the conclusion it could well be caused by partially blocked up EGR valve pipes.

Do people recommend the cleaning spray that Halfords sell?
Alternatively could I blank off the EGR or would this procedure not work on this engine?

It's a 2004 V70 2.5 D5.

I'm in Yorkshire and would dearly like to see someone, preferable a competent indie who could diagnose and repair this problem without presenting me with a huge bill for something they've decided is the likely problem without actually knowing for sure, only for the problem to reappear a month or two later.

Thanks

[Longhouse21]

I take it that your research included the sticky at the top of the forum?
There are a list of checks to make:
vacuum system - check for leaks at engine mounts, and pipework; correct vacuum & operation of the TGV and engine mount control valves; split hoses, soft hoses on the cold air charge system; intercooler leaks;
Also check the air intake & exhaust system as ECM6805 points to an imbalance between calculated and measured air flow - blocked air filter; blocked exhaust, MAF & MAP sensors.
The fuel system has been implemented in some cases - check injector operation (leak back test); fuel filter & delivery system.
I've suffered with this twice and both instances it was an aftermarket CAT failure so I went back to a second hand Volvo unit.
ECM6805 can be difficult to track down...

[boombox]

Originally Posted by Longhouse21

There are a list of checks to make

Thanks for your reply, Longhouse21. Can I ask your opinion on the EGR cleaning sprays? Are these a good idea? Is it just moving the muck into a more delicate part of the engine?

[outnumbered]

you can get the egr mapped out.
you can block the Egr but leave a small hole in the centre for some of the gases to escape, this might help the emmision light not to come on .
you can clean the Egr yourself.
Mike

[gammakeith]

As longhouse says ECM6805 is not a lot of help for diagnosis so its a case of working through the possibles. In addition to his excellent list of things that can cause it I will also add sticking turbo vanes. Basically, the vanes do not move quickly enough to the low boost position when really booting it so you get overboost and the above code (along with temporary limp mode).

If you observe the turbo actuator when the car starts if should rapidly and smoothly move to the high boost position. If (like mine) it slowly lurches to position then your problem is likely to be sticking vanes.......

Keith

[Longhouse21]

At one point, I stripped out the EGR valve assembly and the mixing chamber on the front of the engine (the bit that most people refer to when they perform a clean).

As Mike (outnumbered) says, you can clean it out yourself. I "washed" through the EGR assembly & mixing port with carb cleaner spray with it removed from the car. The bit I didn't get to clean was the area downstream of the mixing port into the inlet manifold as the downstream pipework looked relatively clean on mine.

[sreviz]

Originally Posted by Longhouse21

At one point, I stripped out the EGR valve assembly and the mixing chamber on the front of the engine (the bit that most people refer to when they perform a clean).

As Mike (outnumbered) says, you can clean it out yourself. I "washed" through the EGR assembly & mixing port with carb cleaner spray with it removed from the car. The bit I didn't get to clean was the area downstream of the mixing port into the inlet manifold as the downstream pipework looked relatively clean on mine.

As others said , it is hard to track.
6805 fault can be many reasons. Invest in mityvac mv8500. This will pin point if there is any vacuum related issue which leads to 6805 fault.
With this you can eliminate Turbo governor, turbo valve or solenoid, front engine mount, rear engine mount, vacuum pump itself.
Using this gauge you can measure the vacuum which I
Remeber 25hg at every point.

If you eliminate all above it might be thehose blown or sticky vanes .

Hope this helps.

[Longhouse21]

Originally Posted by sreviz

...Invest in mityvac mv8500. This will pin point if there is any vacuum related issue which leads to 6805 fault.
With this you can eliminate Turbo governor, turbo valve or solenoid, front engine mount, rear engine mount, vacuum pump itself....

You can also use it to check for sticking vanes. Connect to the turbo vacuum port and gradually increase the vacuum. The control rod should move smoothly up & down throughout the range and somewhere within ViDA it gives the stroke length / vacuum.