M42club.com - Home of the BMW E30/E36 318i/iS
DISCUSSION => Engine + Driveline => Topic started by: AFARR on October 29, 2007, 07:09:10 PM
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Original problem...vibration on acceleration and on turning right, worse when cold...
So, I go to fix it.
CSB changed--no change to the problem (drove as it always did--no increased vibration after the attempt at repair).
OK, figure I'll look at the tranny mounts...sheared off at the top.
Figure that is it...so, I decided to order those (got a pair for the E21), a missing rear turn light (side) lens, etc.
While I'm at it (suggested from the the projects here), I figured I'd swap out the hoses under the intake manifold (so I bought the gaskets), and re-route the coolant (and remove the throttle body heaters) due to a slow leak.
Got E21 trans mounts (more solid) and put them in place with no problems.
Work on the intake...get to the bottom of all the hoses, etc...
Turns out one part was bad (had to order 11531714738--plastic piping connector to engine block). It was cracked through at all 4 junction points--this was the likely source of the leak.
Wait 3 days for the dealer to get the part in.
Put it back together on Wed. PM (because it was going to rain most of the week). Didn't drive it, just filled the radiator completely, and vented any air from the vent screw.
Got a chance to run it yesterday (for a mile or two) and it did fine.
Took the spark plugs out, checked them (they did look like it was getting to be time to replace them, but no major issues like cracked insulators, gunk, etc.)--two of them had oil in the spark plug hole--need new Valve Cover gasket (source of the leak). That will need done soon, along with the helicoils (feels like 5 are partially/totally stripped)
Put everything back together.
Go for a drive today---the car starts vibrating something fierce...
More related to load (at higher RPMs becomes more pronounced), however, I do get some Vibration even when the clutch is pushed in and I rev the engine.
Engine is running rough (lower idle), small backfires once or twice), and while the vibration was going on, it seemed to severely lack power..push on the gas, get more vibration, not a real significant increase in speed...
I tried to check the routing of the plug wires--seems to match the coil numbers 1-->1, 2-->2, etc.
Any ideas on what to look at first? I checked the Guibo (a few cracks around where the bolts are, but not destroyed. I checked the Diff. Bushing...there is a 4mm gap between the center part (where the bolt goes, and the lower rubber piece. Otherwise it appears OK.
Since I messed with the intake (and vacuum lines), the Trans mounts, and the plugs...I pretty much Left the issue WIDE open as to what I did...
put new plugs in tonight...scrubbed (with a shotgun cleaning brush) the plug holes completely free of any oil, cleaned the wires and put new plugs in place.
It did smooth out a bit....
HOWEVER, when test driving afterwards, I rested my hand on the gearshift--almost no "vibration" through it. I can get it to 'vibrate' while gunning the engine with the clutch pedal pushed in...
I think I was feeling the rough running/hesitation of the engine as a vibration...there is still a minor vibration on turning right, but the main issue is a separate, new problem.
I did get some minor backfires (pops that sounded like they came from the resonance chamber area) while driving.
Idle actually drops to about 600rpm and is rough...pushing the gas pedal slightly raises it to 1000rpm and it seems to smooth out. Low RPMs while driving aren't too bad, but when you try to accelerate, you can feel the hesitation and roughness in the engine.
Could a Vacuum leak cause this?
I did use 2 new intake manifold gaskets while doing the work.
replaced a couple of worn vacuum hoses (checked those tonight)--including the thin line from the throttle body to the FPR.
Didn't think to get the throttle body to intake gasket--just reused the flat metal plate gasket (saved the other one--there was one on each side of the heater plate, if I recall properly).
I tried to check all the connections--don't see any loose. Vacuum hoses look OK--the one to the ICV from the intake, I had to put a narrower piece of hose inside the first (the larger diameter one would collapse under stronger vacuum).
Any thoughts!
Thanks!!
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did you check your valve cover gasket? there could be a vacuum leak there.
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Couple of the threads (front 3 and two near the intake manifold) are gone (bolts are loose, and cannot hand tighten them anymore). Figured it was going to take a helicoil repair at some point.
AFARR
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Couple of the threads (front 3 and two near the intake manifold) are gone (bolts are loose, and cannot hand tighten them anymore). Figured it was going to take a helicoil repair at some point.
AFARR
Ouch! Ya i was super careful when i took my valve cover off. That's too bad bro. You get any estimates on what the helcoil is going to cost?
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I should be able to handle it myself when I get a chance...., so just the parts cost (looks like--after a brief search--it will be around $30 following the instructions here).
I'd guess that is not the likely source of the problem, since I didn't take it off while fixing the intake, etc. Probably will get around to it at some point in the near future.
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I should be able to handle it myself when I get a chance...., so just the parts cost (looks like--after a brief search--it will be around $30 following the instructions here).
I'd guess that is not the likely source of the problem, since I didn't take it off while fixing the intake, etc. Probably will get around to it at some point in the near future.
I believe that if you are leaking out of the side of the valve cover its going to cause your car to shake. Not that i've ever tried it but I have forgot to put the oil cap back on and that caused a little bit of shakyness when i tried to drive it.
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When the M42 runs at rpms below factory idle it vibrates a bit, so i bet you have a vacuum leak. The valve cover would not cause this problem, and it would be leaking oil all over the place if it wasn't installed correctly. Less likely is an engine mount failure, causing the upper oil pan to rest on the steering rack, transmitting the engine's vibrations to the chassis through direct contact. It's easy to check, as the two shouldn't be anywhere near touching.
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Between the oil pan and steering rack. Engine mounts..appear to have some minor cracking at the "folds" of the rubber, nothing leaking.
No major oil leaks around the valve cover.