Quote:
Originally Posted by V70Gavin
My car had the EGR valve replaced (50% goodwill) but no work to the cooler. So I guess have the EGR valve at the front of my mind when trying to work out how to solve my friend's problem.
The fact that her car was diagnosed as needing a new manifold and that they had to clean out much soot, suggests to me that the EGR valve was (and still is) sticking open. And so I fear that this manifold will go the same way unless we tackle (what I think is) the source of the problem.
Her car remains in "Reduced Performance" mode despite having a new manifold fitted.
Good point about the fire risk recall, I was reading the thread (esp your posts)on it last night. I will check the status of her car with Volvo today.
Do those error codes (DTCs) ring any bells with you? Could they help identify the cause of the "reduced performance"?
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Soot build up in the EGR system and intake manifold is normal and doesn't in itself suggest that the valve is sticking open. If it does stick open then that will affect the running and actually made mine undriveable. If the valve sticks shut (same as the cooler getting blocked) then the engine will run fine, but there will be a dashboard warning. When working normally the valve does allow a controlled flow of exhaust gases into the intake.
I'm not an expert on Volvo codes (I'd be far more confident with Honda codes) but...
'P00BC - MAF circuit range/performance' indicates that the expected MAF is out of the range expected by the ECU map, which will happen if the EGR flow is too high or too low (e.g. the amount of fresh air intake being displaced by recycled exhaust is outside the expected limits). When my car broke down I got several same/similar codes indicating that the MAF was low (I carry a code reader in the car) hence I was able to provisionally diagnose that the EGR valve had stuck open whilst waiting for the recovery agent.
'P2009 - Intake manifold air control actuator bank1 - circuit low' - I'm not sure, but the P20nn series of DTCs usually relates to IMRC ('swirl valve') issues, being in the wrong position or moving too slow, etc. However when my intake manifold was replaced due to the integral swirl valve being sticky I had no codes. But I used to get these all the time with my old Honda!
'P0471 = Exhaust gas pressure sensor - range/performance problem' - never seen this. Bear in mind that the EGR valve being unexpectedly open will affect exhaust manifold pressure as the exhaust then vents into the intake. Additionally these engines do have a not uncommon issue with the EMAP pipe becoming blocked with soot and therefore preventing the sensor properly reading the exhaust manifold pressure. The intake manifold check recall did also include cleaning of the EMAP and TMAP sensors (and pipework?)