tangalife 1 Report post Posted January 26, 2013 Hi guys, I have noticed of a power loss between 2-3.5k RPM. When accelerating there seems to be a lack of power but appears to pick up and go after 3.5k RPM. Is the same when I put my foot right down as well. It seems like my fuel consumption has gone up and, not sure if I've only just noticed now, but you can perhaps smell fuel when idling (at least when the car is warming up). Has anyone had similar problems? 1997 e39 540i automatic. Quote Share this post Link to post Share on other sites
yng_750 247 Report post Posted January 26, 2013 just something to quickly check is the Crank case vent valve. if they die it sucks air out of the engine, bypassing the airflow meter. easy to check. if its broken it will create a large vacuum in the engine. try to open the oil cap when its running, large vacuum will stop you lifting it up, or as i did pull out the dipstick while it running, you would hear loud sucking/gurgling if its damaged. good place to start Quote Share this post Link to post Share on other sites
tangalife 1 Report post Posted January 26, 2013 thanks for that will give it a go. failing that, I might try disconnect the o2 sensor as similar problems ive searched online suggest bad pre cat o2 sensor. Is it safe to just disconnect the o2 sensor to go for a test drive? Or am I best to just straight replace them? Quote Share this post Link to post Share on other sites
tangalife 1 Report post Posted January 26, 2013 just something to quickly check is the Crank case vent valve. if they die it sucks air out of the engine, bypassing the airflow meter. easy to check. if its broken it will create a large vacuum in the engine. try to open the oil cap when its running, large vacuum will stop you lifting it up, or as i did pull out the dipstick while it running, you would hear loud sucking/gurgling if its damaged. good place to start seems to be exactly this. just took it for a drive, appeared to be sluggish when cold which I understand rules out the o2 sensor as when faulty it will behave normal while cold but not when warmed up. I pulled out the dipstick and could hear gurgling and sucking. Took oil cap off, it was easy to take off but you could hear air and it spat oil out. Quote Share this post Link to post Share on other sites
yng_750 247 Report post Posted January 26, 2013 yea very common issue in these cars unfortunately when they start sucking oil even small amounts it kills o2 sensors and plugs so people often spend money they dont need to after reading the codes. i just did mine without too much issue its the whole rear cover on the intake manifold. very much a part you need to get OEM, aftermarket almost always warp and fail. will cost around $190 from the dealership for cover and gasket. part numbers are 11-61-1-729-728 for gasket and 11-61-7-501-563 for rear cover. check out and fairly in depth. if you dont think its something you can do id say give botany motor worx a call they should be able to give you a price http://www.botanymotorworx.co.nz/index.html if your car isnt smoking at start up yet id say you can still drive it but to save spending heaps of money on plugs and o2 sensors your better to get it done sooner rather than later. but yea any other questions feel free to ask, i literally finished doing mine 5 mins ago Quote Share this post Link to post Share on other sites
BM WORLD 1283 Report post Posted January 27, 2013 also a bad air flow meter , have new ones if you want to try one. Quote Share this post Link to post Share on other sites
tangalife 1 Report post Posted January 27, 2013 (edited) Thanks for the help Jason H, much appreciated Wonder if I should change the AFM first, or just do both as preventive anyway? Lucky i still have my old run about so I can park the Bimmer up for the time being. Edited January 27, 2013 by tangalife Quote Share this post Link to post Share on other sites
yng_750 247 Report post Posted January 27, 2013 id say still do the ccv first you know for certain that its ripped the diaphram inside, all it can do is get worse. fix that then see how it runs AFM is very easy to swap but alot of money if its not broken Quote Share this post Link to post Share on other sites
tangalife 1 Report post Posted January 31, 2013 (edited) K ive noticed two things: first - not sure if its sopose to - but the ICV is emitting a loud beeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeep noise when the key is switched to on position. I can only assume that it is a normal noise. Going to give the ICV a clean out tommorow Also this loud whistling noise when the car is running: www.youtube.com/watch?v=ABi8lgL-SJY. Could it be the valve cover gasket? The prev owner changed tensioners so might not have put back on properly? Edited January 31, 2013 by tangalife Quote Share this post Link to post Share on other sites
Eagle 1661 Report post Posted January 31, 2013 Buzz is normal. Id say do ccv valve first as well since it sounds like its bad, check for any vacuum leaks and get it scanned it. If any of that doesn't fix or id the problem then you can start swapping parts like afm etc to find the issue Quote Share this post Link to post Share on other sites
tangalife 1 Report post Posted January 31, 2013 Buzz is normal. Id say do ccv valve first as well since it sounds like its bad, check for any vacuum leaks and get it scanned it. If any of that doesn't fix or id the problem then you can start swapping parts like afm etc to find the issue Cool. I did the oildipstick test, no sucking when I put my thumb over.... Going to try a vaccum leak tommorow as the prev owner replaced tensioners perhaps and left a leak when putting it back togeather. Quote Share this post Link to post Share on other sites
tangalife 1 Report post Posted February 1, 2013 txted the old owner today, he reckons he changed the ccv so its fairly new. might try change fuel filter. icv was clean as well. Quote Share this post Link to post Share on other sites
Jono51 59 Report post Posted February 5, 2013 txted the old owner today, he reckons he changed the ccv so its fairly new. might try change fuel filter. icv was clean as well. sort the vacuum leaks, but get it scanned and live data if you keep unplugging things , 02 sensors, afm, etc whilst running , thinking that you will rule them out, will in fact log fault codes, so when it is scanned you will have a whole host of fault codes that will lead you in the wrong direction, assuming you are in auckland I suggest you talk to Glenn Quote Share this post Link to post Share on other sites