Diesel Volvo Problems
02 February 2006, 11:27 AM
#1
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Diesel Volvo Problems
Our 2002 Volvo V70 D5 is very lumpy in the cold and has dropped about 4-5 mpg over the last few weeks. It went to the dealer who said 'must be the injectors £1500 please'. Dad told him where to put his injectors and booked it in with the local diesel specialist. They tested the injectors and they're fine, so they went to do a compression test. Unfortunately the engine has abnormally small glow plugs so they've had to order an adaptor, which is on its way.
Does anyone have any idea what could be wrong. I thought it could just be gunked up injectors as it is at about 70000 miles of mostly motorway miles, but obviously it isnt. Any other ideas?
Adam
Does anyone have any idea what could be wrong. I thought it could just be gunked up injectors as it is at about 70000 miles of mostly motorway miles, but obviously it isnt. Any other ideas?
Adam
02 February 2006, 12:13 PM
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No experience with the D5 motor but plenty with VAG diesels.
If it's not giving loads of blue smoke then the compression's probably OK.
The main problems / things to check I would say are:
- mass airflow sensor failing (symptoms are loss of power and refusing to rev above 3K rpm)
- airfilter clogged or not sealing properly in the airbox (diesels suck a lot more crap in than petrol cars, I was horrified by how much **** there was in my Passat airbox & filter after 20K miles and the filter wasn't due until 40K)
- pipework from turbo to intercooler to inlet developing a leak at the joints (easy to find as it will have oily drips around it)
- one of the vacuum hoses that controls boost or exhaust-gas recycling coming loose
- could be a temperature sender faulty, causing overfuelling
If it's not giving loads of blue smoke then the compression's probably OK.
The main problems / things to check I would say are:
- mass airflow sensor failing (symptoms are loss of power and refusing to rev above 3K rpm)
- airfilter clogged or not sealing properly in the airbox (diesels suck a lot more crap in than petrol cars, I was horrified by how much **** there was in my Passat airbox & filter after 20K miles and the filter wasn't due until 40K)
- pipework from turbo to intercooler to inlet developing a leak at the joints (easy to find as it will have oily drips around it)
- one of the vacuum hoses that controls boost or exhaust-gas recycling coming loose
- could be a temperature sender faulty, causing overfuelling
02 February 2006, 12:18 PM
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It smokes quite a bit when cold and when booted. I'm not sure whether its lost power as I dont / cant drive it.
Airflow sensor makes sense, and was suggested on another forum, although it has been to the dealer and they should have picked up on it surely.
Adam
Airflow sensor makes sense, and was suggested on another forum, although it has been to the dealer and they should have picked up on it surely.
Adam
02 February 2006, 01:04 PM
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hmmm ... on VAG cars its very common for MAFs to be shot, but not show fault codes on diagnostics, even if the dealer is looking for it.
The only reliable way to tell is by substitution or a log of actual MAF values versus ideal curves while driving.
The only reliable way to tell is by substitution or a log of actual MAF values versus ideal curves while driving.
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