» Site Navigation | | » Recent Threads | | | | | | | 07-24-2008, 06:50 PM | #1 | Member Join Date: Jun 2008 Location: Chicago Posts: 96 | Normal M44 Engine vacuum Hey all, just wondering if anyone has a vacuum gage on their car, and can tell me what the stock vacuum is. If I remember from auto shop class, a normal engine runs at about 20 or 21 HG. Right now the car is at 16-17 HG. Not really enough for a vacuum leak, more like late valve timing. So the question is, is the timing retarded, or is this just the way a DOHC engine runs ?? If it's not normal, how do I fix it ? The timing should be controlled by the DME correct ? any advice would be appreciated. | | | 07-24-2008, 07:51 PM | #2 | Senior Member Join Date: Jan 2008 Location: New Orleans Posts: 970 | timing is controlled both by the dme and the position the camshafts are in with the timing chain. im not sure what they should run at though, so if you find that out, your next step may be checking the timing on the chain with the cams. __________________ ^being rebuilt^ until then: daily car: 96' Blue DASC'd ti with koni coilovers slowly progressing... weekend car: 85 1/2' 944 Porsche no a/c, p/s, gutted cat, loud as hell exhaust, loud as hell sound system | | | 07-24-2008, 08:05 PM | #3 | Senior Member Join Date: Jan 2008 Location: New Orleans Posts: 970 | also, check for ripped/broken/hard hoses, pretty common on bmws __________________ ^being rebuilt^ until then: daily car: 96' Blue DASC'd ti with koni coilovers slowly progressing... weekend car: 85 1/2' 944 Porsche no a/c, p/s, gutted cat, loud as hell exhaust, loud as hell sound system | | | 07-24-2008, 08:52 PM | #4 | Member Join Date: Jun 2008 Location: Chicago Posts: 96 | I have checked every hose I can get near. I did remove the upper intake to check the Fuel injector hoses (the air shroud spider). The only other thing I can think of would be a bad PCV valve, or the cam timing is off. God I hope it's not the cams, or timing chain. I'm wondering if the timing chain has stretched, if it would cause the cams to be off from each other, or if the timing chain tensioner needs to be replaced. thanks for the input guys........... anyone else ? | | | 07-24-2008, 09:05 PM | #5 | Senior Member Join Date: Jan 2008 Location: New Orleans Posts: 970 | chains usually dont stretch, they made them pretty well, your more likely to just be off a notch or two just from someone not adjusting it right or tensioner is a possibility too, if it goes weak, it could make the chain skip a tooth or something. may be pcv valve, easiest way to check for vaccum leaks is to take a propane tortch, open it just enough to get a little flow, and stick it around areas where it might be, and listen to the idle for changes. if it changes, the area your in is where the leak is. and i hope im helping you, lemme know how it turns out. __________________ ^being rebuilt^ until then: daily car: 96' Blue DASC'd ti with koni coilovers slowly progressing... weekend car: 85 1/2' 944 Porsche no a/c, p/s, gutted cat, loud as hell exhaust, loud as hell sound system | | | | Currently Active Users Viewing This Thread: 1 (0 members and 1 guests) | | Posting Rules | You may not post new threads You may not post replies You may not post attachments You may not edit your posts HTML code is Off | | | |