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CarDoc
CarDoc, ASE Certified Technician
Category: Volvo
Satisfied Customers: 787
Experience:  IMI L3 Motor Vehicle Mechanic
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I have code 6805 coming up.when hard throttle. My mechanic

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Hi, I have code 6805 coming up.when hard throttle. My mechanic has checked ecg, replaced turbo sensor, turbo is fine, done a smoke test, air flow test. Another garage is thinking maybe it's becoming backed up by back exhaust maybe or.the ecg is clogged up at back. Ear code and my volvo goes like a rocket until hard throttle.for hills again. No limp.mode, no lights on dash no revs but ticks over. Then all of a sudden it goes.and check engine service Comes up.
JA: Just to clarify, what's the exact code? And have you tried to reset it?
Customer: 6805
JA: What year is your Turbo?
Customer: Car is 2005 d5 awd
JA: Are you fixing your Turbo yourself? What have you tried so far?
Customer: No my mechanic that also owns a xc90 d5 2005. Turbo is running fine. But ecg was badly covered with carbon.. he's wondering to take egg off and clear it all out?? But reading above it states about blocked or split pipes..
JA: Is there anything else the Mechanic should know before I connect you? Rest assured that they'll be able to help you.
Customer: I only brought car in March and only seen it for 3 weeks!! Lol

Hi, How are you?
I'm Shabaz, one of the automotive experts. I will be happy to assist you today. Hopefully we can get this resolved quickly.

You will be prompted for a phone call by the automated system, only accept this if we can't resolve the issue through messaging, otherwise we can continue our conversation on the message thread.

There can be multiple causes for this fault, and a lot of technicians will overlook the EGR system, but I believe that the main cause is the EGR+hoses being full of carbon so, the EGR may operate correctly but the carbon build-up is causing the airflow inconsistency. Other causes can be the MAP/MAF sensor, split hose, or a loose air intake hose. A leak in the air intake after the turbo will create a hissing sound under acceleration, it sounds like using an air blower attachement for an air compressor.

Customer: replied 8 days ago.
I get a pow sound that like my mechanic has said it's getting back pressure which is causing the lose of power, he's thinking about taking off egr and cleaning it all out, but would rather have a better idea if it could be that.. but as you have said it also could be down to carbon in pipes also. There was alot of carbon build up in the main part of egr. My mechanic also has an xc90 and so does many of his friends so he would like to find the problem so he knows in the future. Thank you for your help.

Not a problem. It could be because of excessive exhaust back pressure, EGR issues can cause excessive soot build-up in the DPF, this increases regeneration cycles too, I have seen this happen in an Astra J 1.7cdti which was regenerating every 5 miles or so because of a sticking EGR valve. You could also try one of them DPF foam cleaners which you spray through one of the sensor ports in the DPF, they work ok when there is a little excessive soot build-up, not so well on heavy build-up though.

Customer: replied 8 days ago.
I don't have a dpf on my volvo its a 2005... diagnostic code.is 6085, boost pressure control faulty flow. So do you have a better idea of where my mechanic can look first. He's had the car 3 weeks and replaced a lot of things for me I wanted doing so it's a decent fully working car.. I love driving it when it's not in the garage...

Cleaning the EGR+hoses and testing its operation via an OBD diagnostic tool is the best option at this point because the fault code relates to an inconsistent airflow, carbon build-up can cause this.

What is your engine size?

A DPF is shown on the parts catalogue for a 2.4D, it may have been introduced on a late 2005 model, if yours doesn't have it.

Customer: replied 8 days ago.
Thats what his plan was but didn't want to start stripping it all down if it wasn't that. Ah great thank you, ***** ***** him to check as all tho mine is an 05 all the parts so far have been wrong and need 55 plate parts.

You can check for carbon build-up where the EGR pipe connects to the intake pipe, if there is carbon build-up there, then there'll be even worse build-up as you get closer to the EGR because the carbon build-up gets less and less as you go further away so, it's all clumping up close to the EGR.

I hope I have answered your question. If you have any further questions, feel free to message me by replying on this message thread.
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Customer: replied 8 days ago.
Thank you so much I'll pass this all onto my mechanic.

My pleasure. All the best and thank you for visiting Just Answer.

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