polley 916 Report post Posted April 2, 2011 Started fine this morning when I backed it out the driveway. Went to start it before and it fired and that was it. Has fuel Has spark It sounds like it is spinning over faster than normal but that could be my ears playing tricks on me. So my guess is no compression on all cylinders and that the timing chain has let go or some thing similar. The Vanos unit has been quite rattly for along time, is it possible for these to completely fail and not spin the intake cam shaft? I am in the progress of taking the valve cover off, by my 10mm socket is too big to get the two middle nuts. Quote Share this post Link to post Share on other sites
kerry 10 Report post Posted April 2, 2011 did the engine bay get a clean?. had the same issue and water got into ecu = fried Quote Share this post Link to post Share on other sites
thorburn 121 Report post Posted April 2, 2011 Possible but not likely. Useually the seals just fail stopping it from advancing the cam Quote Share this post Link to post Share on other sites
polley 916 Report post Posted April 2, 2011 did the engine bay get a clean?. had the same issue and water got into ecu = fried Nah, hasnt been wet at all I dont think. And it has fuel and spark. I will check out the ecu tomorrow and see if it is wet at all anyway. Do you have any m52b28's in stock? ( just in case haha). Quote Share this post Link to post Share on other sites
polley 916 Report post Posted April 2, 2011 Possible but not likely. Useually the seals just fail stopping it from advancing the cam Hrrm. I guess I really need to get the timing cover off to check it out or throw a compression tester on it. Quote Share this post Link to post Share on other sites
Silver Fox 43 Report post Posted April 2, 2011 If it has fuel and spark then you'd think it is missing timing or compression, so probably cam or crank sensor or ECU? Quote Share this post Link to post Share on other sites
polley 916 Report post Posted April 2, 2011 Hrrm, I thought if either the ECU, or crank sensor was stuffed it wouldnt have either fuel or spark. It should run without cam sensor, just not in sequential. Quote Share this post Link to post Share on other sites
Silver Fox 43 Report post Posted April 2, 2011 When I removed the vanos on the race car I set the cam sensor wheel 180 degrees out and it did the same as you describe, so , on that basis it may need it to run? Quote Share this post Link to post Share on other sites
polley 916 Report post Posted April 2, 2011 When I removed the vanos on the race car I set the cam sensor wheel 180 degrees out and it did the same as you describe, so , on that basis it may need it to run? Oh right, I think if the cam sensor is faulty and does not work it should run, just not in sequential. What might of happened with your race car, is the ECU may have been confused with the cam signal being out 180* as it would not be able to sync it with the crank sensor. Tho it maybe the case that it does indeed need the cam sensor to run. Quote Share this post Link to post Share on other sites
polley 916 Report post Posted April 2, 2011 (edited) What does everyone use to remove the 4 middle nuts? All of my sockets are too thick and dont quite reach the nut. I borrowed a smaller socket set and that still dosent fit. I am tempted to grind a socket down :/ Edit: I have already removed the 4 in the middle, I was trying to pull the studs out haha. Cover still wont come off, seems to be really stuck Edited April 2, 2011 by polley Quote Share this post Link to post Share on other sites
_ethrty-Andy_ 2132 Report post Posted April 2, 2011 They don't need the cam sensor to run, I think it's just their effieiency and a second reference point. I don't have one on my e30 m52 Quote Share this post Link to post Share on other sites
polley 916 Report post Posted April 2, 2011 Got it off, cams are spinning. Guess it is somthing electrical :S Quote Share this post Link to post Share on other sites
polley 916 Report post Posted April 2, 2011 Its running now. NFI what the problem was. Had fuel and spark last night and wouldnt run, checked the timing chain this morning, put it all back together, pulled the ECU out and checked for signs of water, put it back together and was going to check for fuel and spark again but it started up fine so yeah. Took it for a wheelie round the block and its going fine. Quote Share this post Link to post Share on other sites
thorburn 121 Report post Posted April 2, 2011 Without the cam sensor it runs in wasted spark. Ecu has no idea if cylinder is on compression stroke or exhaust without it. Could it have been over fueling because of a shorted wire in the maf or tps etc? Quote Share this post Link to post Share on other sites
polley 916 Report post Posted April 3, 2011 Im not sure, will have to wait and see if it plays up again. Quote Share this post Link to post Share on other sites
mark247 39 Report post Posted April 3, 2011 Ah well, that's not so bad after all.. Quote Share this post Link to post Share on other sites
hotwire 352 Report post Posted April 3, 2011 Its running now. NFI what the problem was. Had fuel and spark last night and wouldnt run, checked the timing chain this morning, put it all back together, pulled the ECU out and checked for signs of water, put it back together and was going to check for fuel and spark again but it started up fine so yeah. Took it for a wheelie round the block and its going fine. My bet - it was flooded Quote Share this post Link to post Share on other sites
