Normal engine sound? Maybe timing chain related?

[Night Wolf]

'92 318iC, I've also got a '90 325iC, but this is my first M42. Previous maintenance is not well known and the odo stopped at 150k.

It had the cold start knock, but then around 3,000 RPM there seems to be a ticking, however I do not know if this is normal from the M42. The car has a Turner Motorsports chip and revs smooth to 7,000 RPM, above 3.5k or so, the noise seems to go away.

I first replaced the timing chain tensioner, the cold start knock seemed to be lessened, but it is still there for a few seconds. However the ~3k noise is still there.

I dropped the lower oil pan to check the upper oil pan bolts, upon pulling the pan, the pan had black pieces of plastic, and the oil pump pickup was basically packed with them too - I imagine they are pieces from the nylon timing chain guides? I cleaned it all up and put it back together - engine runs fine. I may pull the pan again in a while and see if there is anything new in there. It may have been old, timing problem fixed, but pan never dropped.

I then figured the timing system was shot and pulled the valve cover - but much to my surprise, the cam sprocket gears do not look "pointy" at all, the chain looks fine and all the nylon guides I can see look fine.

What do the M42 gurus think? First, does this sound like a normal M42? How does the timing system look? Should I tear into it more to inspect the lower guides? If I did go to replace what is bad - well would that just be any possible broken guides and a new chain? If the cam sprockets look good, the tensioner is new and atleast the upper guide look ok.

I haven't been driving the car much due to not knowing if it is normal or not, but I'd like to be able to spend more time behind the wheel!





http://www.youtube.com/watch?v=tHGLG4KgVug

http://www.youtube.com/watch?v=tezcq09r2dI

[DesktopDave]

I wonder if the PO changed the guides but didn't clean up the pan?  Sounds odd, but I don't know anything else plastic in the motor.  Those cam bolts have definitely been out at least once.

[Night Wolf]

Thanks for the reply!

It appears that the profile gasket was changed at some point in the cars life. Would the cam sprocket bolts need to be removed for that?

As for the plastic in the pan, I'm not sure, I should have taken a picture of it. There was alot. My oil pressure light dosen't work (faulty sender or wiring), so I never knew if oil pressure dropped, however there were no odd sounds. The engine dosen't consume oil, smoke or burn oil - it actually runs pretty darn strong.

To me, there is a sround from 2,500-3,500RPM that possibly shouldn't be there, and I can hear it in the video. If ya'll that are more familer with this engine watch the videos, and it sounds fine to you, then I will be able to relax a bit about nothing being wrong with the timing system. So far I have put about 600-miles on the car.

I was expecting to see pointy gears and broken guides when I removed the valve cover, but everything I can see looks pretty darn good, and I replaced the tensioner.

[1991 E30 M42]

I have an engine in one that has been making noise in the 2500-3000 rpm range for 3 years and it is not the first one that I have seen do it. If you looked the valve train over and everything looks goo then you should be fine. Yes the cam sprocket need to be removed, to replace the profile gasket the head must also be removed.

[Night Wolf]

Thanks That is good to hear. From what I can see, the valvetrain looks fine and the tensioner is new. Next oil change I'll drop the pan and see if there is any new plastic/nylon pieces in there. If so, I'll have to dig deeper, but if not, I'll take it as normal higher mileage/older age M42 noise. Other then an intermittent stumble she runs good though, dosen't complain shifting at 7,000RPM or anything.

1991 E30 M42 - the noise you described that you have heard - is that the same/similar sound my M42 is making in those two videos, and if you have heard an M42 with a bad timing system, does it sound different then those videos of my M42?

[2761377]

just replaced the original water pump in my '91 318iS and was surprised to find that a suspicious sound is gone. i had been worried about valve train trouble, it seemed to be that kind of sound.

apparently, it was the steel impellor rattling around in there, or maybe that's what a bad m42 water pump bearing sounds like. whatever, this very scary noise that i only noticed the previous month is now gone.

if you don't know the status of your existing pump, you may want to replace it before it leaves you stranded. my car had 165xxx miles at the catastrophic failure- thanks auto club for 100 miles free tow.

hth

robert w.

[1991 E30 M42]

The sound is similar to what mine does, and if it was something major with the valve train, trust me, you would know, I have heard every noise that these engines make as I have blown up 4 of them.

[Night Wolf]

Thanks! That is really good to hear, now I can use the car without worry. I bought it needing work, but have been hesistant to drive it alot.

I don't know if the waterpump has been replaced or not. It seems to be ok, I replaced radiator hoses and flushed the coolant system. I was thinking about replacing the waterpump, but I'll wait for now. I am still only using the car locally until I get some more miles on it, but so far it is doing great. The guy I bought it from only had it a short time and put about 20 miles on it, he said the guy he bought it from said it was sitting about a year and a half. The car is rust free and in overall good shape, was in a couple accidents early on in it's life. Actually has one of the best condition interiors I've seen, but it's blue (nearly crack free dash) It is going to be a daily driver, I've taken some parts from the red car to get the white one in better shape, LCA, rear shock mounts, sway bar links, tires. It has new shocks - Sensatracs on all 4 corners, nothing fancy but got it useable again. It already had new front and rear brakes when I bought it. The red one is my baby, she is undergoing heavy maintenace and getting performance parts in place of all the robbed parts.

Just today I swapped tops. The white cars top (blue) was in sorta bad shape, rear window fogged up and stitching shot, leaking etc... The black top is about 3yrs old, and did leak on the red car, but seals much better on the white car, hoping for no leaks! (why I get annoyed at using either e30 as a daily driver) Once the red car is driving again, she'll get a brand new top. At some point, the cars are going to get a bumper swap, the red car is my baby, the white one will be a daily driver.

The white car is in overall good shape, some stuff is worn but I replaced alot of stuff too, it's just a driver tho so I am not going for perfection - a very fun driver that gets 30+ mpg. The Jeep gets 15-16mpg, all the time (unless off-road when it got as low as 3.8 - 12 hours at 5mph or less does that) The M42 is a really fun engine for putting around town, rev-happy (chipped) + manual trans + 4.27 gears makes it fun to dart around in.

red car is an early (no airbag) 1990 325i named Noelle, white car is the 1992 318i named Ashleigh, the Jeep is just...Jeep.

Here she was the night she came to a good home. The TJ was loaded twice it's rated towing capacity (due to wheelbase, not mechanics, aftermarket bumper w/ receiver is rated for it tho) but made the 2hr trip home on the interstate, thru downtown ATL traffic fine.



Before top swap:



After:



Noelle got a new heavy duty tarp to go over the full car cover to keep her dry. It'll be a while til shes done. As crazy as it sounds, part of the reason why I bought Ashleigh was because I was itching to drive an e30 again and it would have been quicker to buy another one then Noelle would be driving again. Shes been down since April! I wanted an M42 daily driver tho, but preferably 2 or 4 door hardtop and not another ragtop, but this one came along at such a good price.

Thank yous very much for the advice! That was bugging the heck outta me since I got the car, atleast I don't have to worry about it anymore.

[Night Wolf]

Another, older video of the sound too. (cluster is from the red car)

http://www.youtube.com/watch?v=bA1yCQ3uoXc