Hey Bill R. and Jr, no recurrence of the noise.

[billb]

I think the heat shield licked it. I romped through the country Sunday afternoon and could not recreate the noise. My bet's on the crack in the heatshield. Thank goodness for JB Weld.

http://i34.photobucket.com/albums/d106/tarheelbimmer/heatshield.jpg

Thanks again for hearing me out! If nothing else, it forced me to take a look at those pristine timing components!!

Thanks again.

[Jr ///M5]

Glad to hear it Bill...now you can quit worrying and start to enjoy that car the way you were supposed to. Now get those silly ideas out of your head about selling it and keep it between the lines.

[ScottyWM]

Bill, thought I had a buyer for Junior, but get this... he wants an AUTOMATIC because his wife might need to drive it!!! I told him to get the manual so she WON'T drive it... but he won't listen.

[billb]

...but went away when I cut the A/C belt off! I'm pretty sure the tensioner pulley is getting hot and doing some funky harmonics, or something of that nature. After cutting that belt off, and running the motor on up and getting her hot on a drive this afternoon, the noise didn't recur.

I do not think it is timing chain related anymore. It's definitely an accessory drive item. Will keep you posted on the final resolution!

Oh, and fyi, the car is not for sale any longer!:) :D :p

[billb]

...but went away when I cut the A/C belt off! I'm pretty sure the tensioner pulley is getting hot and doing some funky harmonics, or something of that nature. After cutting that belt off, and running the motor on up and getting her hot on a drive this afternoon, the noise didn't recur.

I do not think it is timing chain related anymore. It's definitely an accessory drive item. Will keep you posted on the final resolution!

Oh, and fyi, the car is not for sale any longer!:) :D :p


This morning, I was heading up to my local dealer again, hotfooting it around the same left exit ramp. About 3-4 miles later, after a couple of quick departures from stop lights, the rattle came back. It is timing chain related. If it were directly related to the left-hand sweeper, wouldn't the noise come about sooner, instead of 5 or so minutes later? Oil pressure is still showing 15-20 at idle, 40-60 at speed.

I'm going to switch back to 15W50 tomorrow and see if I can reproduce it. I have a new tensioner to install, but hate to install it if I don't need it.

At this point, I welcome any and all suggestions...:(

[billb]

This morning, I was heading up to my local dealer again, hotfooting it around the same left exit ramp. About 3-4 miles later, after a couple of quick departures from stop lights, the rattle came back. It is timing chain related. If it were directly related to the left-hand sweeper, wouldn't the noise come about sooner, instead of 5 or so minutes later? Oil pressure is still showing 15-20 at idle, 40-60 at speed.

I'm going to switch back to 15W50 tomorrow and see if I can reproduce it. I have a new tensioner to install, but hate to install it if I don't need it.

At this point, I welcome any and all suggestions...:(

Think I'll drop the pan tonight for some inspection. This has got to stop!

Thanks

[billb]

Think I'll drop the pan tonight for some inspection. This has got to stop!

Thanks


remove/replace oil filter housing gasket and o-ring (I suspected a leak there, but it turned out to be my oil pressure sending unit wasn't quite tight enough in my distribution block; running a o/p gauge too)
dropped lower oil pan, removed oil pump pickup tube and checked that gasket was intact, which it was
changed oil back with 0W40...local Advance was out of 15W50...4.5 total qts.
did NOT change chain tensioner...want to wait this out a few days


I think the common thread here has been hard left-hand turns under acceleration. But I can't see why this wasn't occurring during my driving school at VIR last July going through Nascar turn (turn 3), which is a pretty high speed left-hand sweeper. And why was it showing up so much farther up the road this Sunday 4-5 miles after the lefthand sweeper, and after some quick starts from stoplights. And never has the op light flickered, or have I observed idle op below 18-20. At speed, op is right at 60 warm.

Grasping at straws...

[billb]

...last week after 75-mph on the interstate, exiting onto a sweeper right offramp. I installed a new tensioner piston the other day, and changed back to 15W50 on 4/8. Haven't really had the car in a position to recreate the noise yet, but I have noticed warm idle oil pressure is back up over 20psi, where it was around 15 or so with the 0W40.

Will keep you posted. By the way, I just love how easy it is to change the oil on a M42 (or M50 for that matter). Took me right at 9 minutes from start to finish, including a minute or so to find my torque wrench...

[billb]

15W50 and the new tensioner must've licked it. No rattles at all. Just a slightly lumpy idle now, but I'm suspecting fuel injectors.

[Bill R.]

searching on the internet... in the back of my mind i kept remembering something about 318's and oil starvation.
when you mentioned sweepers a lightbulb lit up. I'm almost positive that you experienced oil starvation and the oil is getting aerated. Its more obvious on the 0w40 since its a slightly lower viscosity when warmed up than 20w50 but i can almost guarantee that the starvation is still taking place with the 20w50 even though you don't hear it.
When you had the oil pan off, how well designed did the factory windage tray look?
I think on that long sweeper the g forces are slinging all the oil in the pan to one side away from the oil pickup, a few seconds later and you're sucking air for a very short period but long enough to encourage aeration of the oil.
I also seem to recall that a number of people had to keep their oil topped off right to the max and some even as much as one quart overfull in racing conditions to keep this from happening... Of course a well designed windage tray and better oil pickups like the dual pickup that the m3 uses would help more.




15W50 and the new tensioner must've licked it. No rattles at all. Just a slightly lumpy idle now, but I'm suspecting fuel injectors.

[billb]

Here's the upper:

http://69.0.158.19/live/A606072186OES.JPG

I don't think the lower has a windage tray at all.

[Bill R.]

91 e36 version.... Also the pic here of the oil pickup doesn't seem to jibe with starvation on lefthanders,I was thinking right hand which would make the oil rush away from the pickup here




Here's the upper:



I don't think the lower has a windage tray at all.