Ok, so I'm having a little boost problem on my 1989 930. I had been out a few days earlier with no problems, except the oil warning light came on near the end of the drive out, but only during fairly hard braking. Decided to check the oil, but didn't get a chance when I got back. Before I went out I checked the oil and topped up with almost half a litre.
First drive today...
Went out and the first time I got a chance to put my foot down slightly in third gear and she just didn't respond well and was jerky at just over 2000rpm, feeling like she wanted to go but just couldn't. When I got a chance I turned around and headed for home. Up a steep bank she just didn't want to accelerate in the turbo at all and sounded like the waste gate was just permanently opening and shutting.
Got home and the engine seemed to be running fine except she was ticking over at about 1500rpm. Checked oil which was about 1cm over the bottom line. Gave her a few revs and she normally pops and bangs a bit but she didn't, just revved like a normal car. Had a look under the car near the turbo with nothing obvious to see. I came in to let her cool and google the problem.
Second drive today...
About an hour later I went back out. She started fine as normal, engine nearly fully cold, few revs and she popped and banged like normal and the revs were sitting just below 1000rpm, like normal. Took her out and as soon as she was just warm I tentatively accelerated, turbo spun up and there was no jerkiness, wouldn't say she seemed to accelerate as normal but I was soon going at the legal limit, so maybe it was just me being overly conscious of the acceleration. Drove her a bit more and she seemed fine until I turned in to head home and when I dropped the clutch the revs went straight to about 1600rpm. I pulled in as soon as I could and she was again ticking over at 1600rpm. Turned back the way I came and the jerkiness was back at 2000rpm.
She is boosting to about 0.5 bar before she seems to not be able to hold boost. She is still ticking over high and the oil level according to both the dash and the dip stick is not much over bottom, with oil pressure sitting at 1 at tick over.
Has anyone had anything like this before or got any suggestions?
I should say that she isn't standard, K27 turbo with oil catch tank, larger intercooler, 965 cams, sports exhaust just to mention a few. She is definitely not a garage queen although I won't get her out when it's wet or salt is on the roads.
Thanks in advance.
Chris
Ok, update. After a bit of thought about the problem I jacked her up and took a good look at the turbo etc, nothing seemed particularly out of place but a jubilee clip on the intercooler silicone hose was very loose and had slipped down, I put it back in position and tightened it up.
After letting the roads dry after a rain shower I took her for spin, nothing had changed from above, except I am wondering if the clutch is slipping rather than the turbo not boosting. Up hill (i.e. more load) she is worse and the symptoms seem to kick in earlier. Would the clutch slipping produce these symptoms? I can't see how it would be linked to high tick over though (admittedly I am not a mechanic!).
Any thoughts gratefully received.
First drive today...
Went out and the first time I got a chance to put my foot down slightly in third gear and she just didn't respond well and was jerky at just over 2000rpm, feeling like she wanted to go but just couldn't. When I got a chance I turned around and headed for home. Up a steep bank she just didn't want to accelerate in the turbo at all and sounded like the waste gate was just permanently opening and shutting.
Got home and the engine seemed to be running fine except she was ticking over at about 1500rpm. Checked oil which was about 1cm over the bottom line. Gave her a few revs and she normally pops and bangs a bit but she didn't, just revved like a normal car. Had a look under the car near the turbo with nothing obvious to see. I came in to let her cool and google the problem.
Second drive today...
About an hour later I went back out. She started fine as normal, engine nearly fully cold, few revs and she popped and banged like normal and the revs were sitting just below 1000rpm, like normal. Took her out and as soon as she was just warm I tentatively accelerated, turbo spun up and there was no jerkiness, wouldn't say she seemed to accelerate as normal but I was soon going at the legal limit, so maybe it was just me being overly conscious of the acceleration. Drove her a bit more and she seemed fine until I turned in to head home and when I dropped the clutch the revs went straight to about 1600rpm. I pulled in as soon as I could and she was again ticking over at 1600rpm. Turned back the way I came and the jerkiness was back at 2000rpm.
She is boosting to about 0.5 bar before she seems to not be able to hold boost. She is still ticking over high and the oil level according to both the dash and the dip stick is not much over bottom, with oil pressure sitting at 1 at tick over.
Has anyone had anything like this before or got any suggestions?
I should say that she isn't standard, K27 turbo with oil catch tank, larger intercooler, 965 cams, sports exhaust just to mention a few. She is definitely not a garage queen although I won't get her out when it's wet or salt is on the roads.
Thanks in advance.
Chris
Ok, update. After a bit of thought about the problem I jacked her up and took a good look at the turbo etc, nothing seemed particularly out of place but a jubilee clip on the intercooler silicone hose was very loose and had slipped down, I put it back in position and tightened it up.
After letting the roads dry after a rain shower I took her for spin, nothing had changed from above, except I am wondering if the clutch is slipping rather than the turbo not boosting. Up hill (i.e. more load) she is worse and the symptoms seem to kick in earlier. Would the clutch slipping produce these symptoms? I can't see how it would be linked to high tick over though (admittedly I am not a mechanic!).
Any thoughts gratefully received.
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