charles28 117 Report post Posted March 3, 2012 I have had the E39 for 3 months now. I have spent about a grand servicing it, changing auto tranny fluid etc, replaced belt tensioners etc. For the most part the car runs well. I can drive off in the morning and it pulls well down low and feels peppy enough to drive, however once fully warmed up and stuck in traffic etc, the car can intermittently lack power, ie, go to take off to get through a roundabout or at traffic lights the car has no go and feels like it wants to die, then takes off ok once its over 3000rpm or there abouts, next set of lights etc it might be fine, but still doesn't run as well as it does when cold 1st thing in the morning. I know this model isn't a rocket ship, but surely it should always run as well as it does from cold. I guess the 1st step is to scan for errors? Quote Share this post Link to post Share on other sites
BM WORLD 1265 Report post Posted March 3, 2012 is it a i misfire?? maybe oil down in the spark plug holes?? comon issue is leaking rocker cover gaskets. also cam sensors fail due the the insulation on the wire breaking down and casuing them to not work. vanos unit jamming?? Quote Share this post Link to post Share on other sites
charles28 117 Report post Posted March 3, 2012 is it a i misfire?? maybe oil down in the spark plug holes?? comon issue is leaking rocker cover gaskets. also cam sensors fail due the the insulation on the wire breaking down and casuing them to not work. vanos unit jamming?? Now you mention it, I think the rocker cover gasket is leaking a bit, oil is making its way to the A/C compressor. I haven't noticed it mis-firing as such, but I guess it could be, probably hard to hear it considering how well the car is insulated. It runs well until its been driven around for 20mins or so though, perhaps the cam sensors are falling over once the cars fully warmed up, would this usually throw a code? I'm tempted to get a Code reader. Quote Share this post Link to post Share on other sites
oscar90 0 Report post Posted March 3, 2012 My 528i with 180kms did this from cold it would run like a bad of sh*t and would be waaaaaay down on power, turn it on and off once or twice and it ran perfect again. Mine kept showing a fault on coil 4 or something to do with that cylinder...and it was only ever on cold mornings, place I took it to said they'd had 1 other E39 do it and it ended up being the lifter or something in the head they reckoned, was approx 3 years ago so can't remember exactly he said). My mechanical warranty was about to run out so I went and traded it in and got my 540i so I never found out what was wrong with it Also RE; cam sensor when mine was dead on my 540i(different motor i know lol) it would die all of a sudden without warning. replaced it and it hasnt done it since, may help you with diagnosing things Quote Share this post Link to post Share on other sites
Greg111 13 Report post Posted March 4, 2012 Cam sensor will log a fault, sounds alot like that. Also perhaps airflow sensor too? Quote Share this post Link to post Share on other sites
charles28 117 Report post Posted March 4, 2012 Cam sensor will log a fault, sounds alot like that. Also perhaps airflow sensor too? Yeah I should get myself a scanner and see what comes up, will be a handy thing to own anyway. I'd prefer to replace the parts that need replacing rather then just guessing and replacing a whole lot of things. I also have some Vanos seals sitting here from http://www.beisansystems.com/ to deal with some time, one I get the other required tools. They claim problems like "Vanos Seals Failure Symptoms Overall loss of torque and power, particularly in the lower RPM range, < 3k. Bogging then surging at 3k RPM. Uneven power distribution and RPM transition. Engine hesitations in the lower RPM range, < 3k. Louder idle and intermittent idle RPM hiccups. Difficult takeoffs. Loss of power and bogging when AC on. Increased fuel consumption. Vanos fault codes. Double vanos cars with the M52TU engine (98/99-00) experience cold weather cold start idle jolts and possible stall. Quote Share this post Link to post Share on other sites
charles28 117 Report post Posted March 7, 2012 After work today a kind forum member came over and checked for problems with his scanner. It came up with a Cam Sensor Fault. So its likely to be this or the wiring I suspect. I need to get a new valve cover gasket set, new air filter etc, so will be interesting to see how it goes after I replace these along with the Sensor. Hopefully my Fuel economy improves a little too. Quote Share this post Link to post Share on other sites
BM WORLD 1265 Report post Posted March 7, 2012 After work today a kind forum member came over and checked for problems with his scanner. It came up with a Cam Sensor Fault. So its likely to be this or the wiring I suspect. I need to get a new valve cover gasket set, new air filter etc, so will be interesting to see how it goes after I replace these along with the Sensor. Hopefully my Fuel economy improves a little too. unplug the cam sensor pull back the rubber boot and you will see the problem, insulation breaking down and the wires touching together, very comon problem Quote Share this post Link to post Share on other sites
Garryg 5 Report post Posted March 7, 2012 Here is me with the stupid question now..... Where can I find the Cam Sensor?? I have noticed this problem also! Quote Share this post Link to post Share on other sites
BM WORLD 1265 Report post Posted March 8, 2012 (edited) Here is me with the stupid question now..... Where can I find the Cam Sensor?? I have noticed this problem also! part 5 and 18.dual vanos engines have 2 but get it scanned first Edited March 8, 2012 by Brent HARTGE535i Quote Share this post Link to post Share on other sites
charles28 117 Report post Posted March 8, 2012 unplug the cam sensor pull back the rubber boot and you will see the problem, insulation breaking down and the wires touching together, very comon problem I'll look into that and perhaps try repairing the wiring before replacing the sensor if it looks to be the issue. Cheers Quote Share this post Link to post Share on other sites
charles28 117 Report post Posted March 10, 2012 I'll look into that and perhaps try repairing the wiring before replacing the sensor if it looks to be the issue. Cheers I ended up ordering a new sensor. The installation process looks to be fun http://m52camshaftsensorreplacewriteup.blo...l-write-up.html A comment from someone who replaced it "After having driven the car a few days now since I replaced the cam sensor am realizing that I have gained significant "getup and go", that was not there before for quite some time, even before the CEL came on. Suspect the sensor was toast long before the CEL told me about it.......... Especially at low RPM I had been noticing some "knocking" and sluggish behavior that is now no longer there" Quote Share this post Link to post Share on other sites
charles28 117 Report post Posted March 13, 2012 Still waiting for valve cover gasket and cam sensor to arrive. Tonight I decided to remove the airbox, as I had noticed it seemed loose and not secure at all. I soon discovered the intake resonator had a chunk out of it, about the size of a 20c coin. This can't be good, as unfiltered air is being sucked in after the MAF, which could cause issues I assume. For now I have taped it up with strong tape until I find a replacement, the air intake boot (Part that attaches to the resonator) was split a little also, but its still sealing from what I can tell. I went for a good drive after my dodgy repair, car seemed to go a bit better and shows as using less fuel on the OBC, however the issue still remains regarding the cam sensor. There also seems to be a piece missing that goes between the MAF and Airbox, be it a rubber seal or something, who knows, all I know is that it doesn't connect to the map securely and has plenty of movement, for now this is taped up also. Quote Share this post Link to post Share on other sites
polley 916 Report post Posted March 13, 2012 Any intake leak after the MAF sensor will make it run sh*t. Quote Share this post Link to post Share on other sites
