1989 BMW engine knocking - PeachParts Mercedes-Benz Forum

JohninFla · #1 01-27-2003, 12:08 PM

A posting on my recent addition, a 1989 325IC BMW, 122K+ miles, automatic. Light beige with cream interior, dark brown top.

I bought the car from a friend, after sitting for a year or so. His wife had run the car out of oil, and the cam locked, broke the cam gear off the cam. He took the head off, found out it cost $$ to repair it, tried to find a replacement and gave up.

When I bought the car, it was in boxes, covered in dust. I put it back together with a "refreshed" head, (new valve job, valve seals, valve guides and springs. The car started and ran good, for about 500 miles. I recently started getting a noise upon start up, and after the car is hot. The noise sounds like a "knocking" or "clunking". I also noticed upon start up, the oil light takes more than a moment to go out.

I have noticed a relief valve repair o ring and snap ring kit for sale, and of course also the oil pump. I just don't like the idea of throwing parts at it without a clear direction. Has anyone heard this problem before? Offer any ideas? Thanks in advance for any help

jsmith · #2 01-27-2003, 12:12 PM

if it was run out of oil you are probably hearing connecting rod knock...

blackmercedes · #3 01-27-2003, 12:35 PM

I agree. During the oil-free run time, the bearings were probably starved. I'd suggest a main bearing has been spun. Looks like you're in for a bottom end too.

JohninFla · #4 02-11-2003, 12:25 PM

Well, I agree with the others, this is most likely a rod knocking.

I am getting my things together to pull the engine/transmission this weekend. Any hints would be appreciated. Items such as:

Where to attach the lifting chains to the engine, to lift the engine and transmission as one unit? I am considering wrapping a chain around the rear exhaust manifold, near the head, and another around the intake manifold, to lift the engine. Has anyone done this? Or is there a better way? The one hook mounted behind the timing belt to the head does not look strong enough to hold the entire assembly.

Is lifting the engine and transmission possible on this car? Things look tight, regarding clearance between the radiator support and the base of the engine, when lifting the assembly out of the car.

I intend to remove the radiator and acessories from the front of the engine, drain all fluids of course, and leave the intake and exhaust manifolds attached to the head.

Thanks for any help or advice.

JohninFla · #5 03-03-2003, 12:05 PM

Productive weekend, which led to another question.

I removed the oil pan, dropping the steering gear but not removing it. It also requires sneaking your hands in and removing the oil pump, while the oil pan is halfway out. Big fun.

I found #1 cylinder rod bearing spun, and all others actually looked really good, but I replaced all of them. Got the lower end back together, removed the cap for the oil pump drive at the top of the engine, spun the oil pump drive shaft with an electric drill to build pressure. Replaced everything and it started right up. I cruised around last evening, top down, enjoyed the Florida weather, no problems.

This morning, upon start up, I noticed that it seemed to take a while before the oil pressure light went out. Longer than I was comforatble with. I shut it down, checked the oil level, which was fine. I then started engine again, and no delay in the oil pressure light this time.

Is there a check valve, or some part in the system that holds fluid to prevent starving for oil on starting up? Perhaps something that can be repaired/replaced? I am thinking something to prevent "leaking down" after long periods.

I appreciate the help on this it. Thanks!

#6 03-03-2003, 10:18 PM

Damn I wish I read this thread before you ripped it apart because I have a brand new oil pump for the baby six in my garage. PRIME REASON TO CHECK YOUR OIL! you can also develop a bad thrust bearing with neglecting oil as I found because a PO.
go to www.roadfly.org you may have a little more luck.

#7 03-03-2003, 10:19 PM

JohninFla

Send me an email with your vin and I will get you some info of the ETK about the factory filter. I also have a fram out in the garage if you need the number. It's just a standard spin on filter as far as I know

JohninFla · #8 03-04-2003, 12:28 PM

I went to my local Foreign parts house here in Orlando last night, and bought a Knecht brand filter. I noted inside the hole for the filter threads, a spring and small plate. Must be some sort of check valve.

With this filter, in place of the Fram, the first start this morning had no delay in oil pressure light going out. Worked out well.

I will be tearing apart the bottom end again though. I believe I hear a small noise when I first start, and again at high RPM's. I believe I need to look at the rod bearings, again, and probably replace the oil pump.

Dan - you still have the new pump, in the box? Are you interested in unloading it on me? I will be up at Bike Week Friday afternoon/evening this week, (Feb 7, 2003). Let me know if we can hook up, via e mail.