m42 engine guru advice needed :)

[wanganstyle]

hey experienced people, please give me advice:

This is in regards to my 1991 318is M42.

Ignition system is healty, car is bone stock.

its noisy as usual and the HLA's need replacing, but im courious to know if there are any other bearings beside rod/main in the assembly.

it also leaks oil only when hot (burns alot of it too) from under the intake manifold area - is that head gasket or profile?

when you WOT it though, and carry up the RPMs,s the clicking noise does not increase, otherwise i would assume spun rod bearing for sure (i have spun rod bearing on other cars before, i dont see why M42 would be differnt)

I changed the oil yesterday and it looked terrible, no chunks but alot of metal, so i was leaning towards a bearing failure and rebuild this weekend. oil pan was replaced be previous owner, do you guys think my pickup could be loose inside and causing things not to get oil?

I dont mind rebuilding or replacing the full longmotor, my 318is is destined for heavy duty useage and I've already got a new clutch to put in. Also have a set of good HLA avail to me locally, I just need to pull the cams to confirm they need replacement.


to recap:

Timing set -  looks good from pulling valvecover. sprokets look good, no wear or slop.

Oil - nothing chunky in it, but lots of metal upon draining, almost like spun rod bearing

After driving for 20 minutes or so, if it gets really hot it will smoke a bit (from oil burning). I parked at auto parts store and drove home 20 minutes later, did not smoke.

sound: Ticks on startup, sometimes goes away, sometimes stays. never gets louder than moderate, does not change with RPM.




Sounds to me like i need (at minimum) for this weekends service:

- HLA set
- Head gasket and profile gasket
- rod and main bearings
- intake manifold gaskets
- exhaust manifold gaskets
- new timing tensioner? Motor is coming out of the car, at minimal for a clutch change - i hate pulling trans/guibo, etc

Anything else that could be at fault?

Engine crane/stand are showing up in my garage this weekend, and surgery will happen!

[RouteZeroDesign]

The oil leak on the side of your engine, is it coming off the engine block or just that area?
It could possibly be the crankcase breather system which famously gets clogged on the m42/m44.
I took mine off a few weeks ago, cleaned it in a parts washer and cleaned all the oily gunk out of the intake manifold and then put it back together.
This completely transformed the car and makes it soo much smoother and with allot more torque.
However i think that an oil leak is the least of your problems.

Metal in the oil is like finding blood in your urine.....you know that something is seriously wrong!!
Do you still have any of these metal particles? if so you should clean them up and see if they are a cooper shade of metal, and if you find particles that are burnt cooper (starting to sound like an ad for hair dye ) then you know that youve spun a bearing.
The spun bearing theory would also match your problem of it over heating and burning oil, as with a spun bearing the clearances on the bearing would have changed and now the oil that is getting into the bearing is getting heated up and burnt rapidly.

The list you have is good in terms of maintenance but i would add : "clean the breather system" to the list

My advice would be either
strip the engine and take the block to an engine builders who could advise you on the machining required to fit oversized bearings.
or
Take off the sump and inspect the damage yourself
or
Dissassemble the engine, check for the spun bearing and then buy a new short block to replace your damaged one.
(this may actually work out cheaper then having your old block machined)

While rebuilding the engine you might be able to justify some modifications aswell if money allows

[wanganstyle]

nice sig poster, seen those on many a DC2R JDM side.

No need to performance modify this one, as i have a 6mt M62 V8 in my other car for high speed pursuit

the metal was very fine, a bit coppery actually yes.

the burning of oil actually happens external- it leaks out the side of the head underneath the intake manifold and dripps, its not terrible but not at all proper. combustion actually remains clean, no smoke out of tailpipe, oil burned is from hot engine and slow drips down the side, enought to collect a slight film on rear bumper after driving around the city half an hour.

crankcase breather, i will find and clean it today.

I usually take things 1 step @ a time, are there any other things i should inspect?

side note, my motor just passed smog, legit and easily a few days ago.

[wanganstyle]

what are the charecteristics of a blown profile gasket in this senario- does it even matter to me?

first concern is metal in oil, the car still drives, idles, etc perfect- Do you think i need to prepare for oversized bearings

I dont want to do oversized, no machine shop i like here that is within budget for a M42.  
if i was building a S62.......differnt story

basically, I'd like to order all my parts for rebuild from pelican parts today, how much risk am i taking if i order standard sized bearings - i have good rep @ pelican, so return is not an issue if the plastiguage says so-

[Cobra Jet]

Usually if the profile gasket is blown, you're going to experience coolant mixing in with the oil or visa versa...  The profile gasket failure is the cause of some M42 engine head failures, as if ignored, the engine will eventually overheat and the head will crack (most common symptons).

If you are experiencing an oil leak, have you checked the valve cover out?  Have you looked at the engine from a view point from being under the car?  Sometimes when the car is on a lift, on jack stands or if on ramps, if you can get a view point from looking up at the engine from under the engine itself, you can usually spot some oil leaks and pinpoint where they may be coming from.

Some common areas to look for possible oil leaks:

Valve cover will leak oil

Timing cover will leak oil

The CPM (camshaft sensor on front of head) will leak oil if the rubber O-ring has deteriorated

The oil "can" can also leak oil from the lid or from the gasket where the can assembly attaches to the side of the block

Headgasket (where head meets block) - sometimes it's hard to tell IF the headgasket is actually leaking oil, because if the valve cover was leaking oil and has saturated the sides of the block, you would have to clean up the stauration first, then let the engine run and see if it is a headgasket leak or valve cover (or both).

how old is the oil pump?  If opening up the M42, I would check out the condition of your oil pump as well and if it's scored or has never been replaced, I would consider replacing it while the engine is opened up.

Does the car smoke @ WOT or idle?

Have you pulled the oil pan yet - or ever pulled it?  Another common M42 issue is the internal bolts coming loose and falling down into the pan (there's a few threads about this too), so I would check that out as well.

[RouteZeroDesign]

Well my roots are in civics so thats probably where it comes from....
....and its Paul, not poster

If the oil is being burnt externally then id check under the intake manifold for any perished pipes and loose plugs.

Have you been loosing coolant? If you have then its most likely the profile gasket that is gone, as in infamously does on these engines.

Changing the head gasket may solve your problem.
Have you found any mayonnaise in the coolant? as this is a sure sign of head gasket failure.

If the oil leak is only external and you dont get any blue smoke from your exhaust then there isnt many clues for me to tell whats wrong.
Id swap over all the gaskets and things that youve listed as well as cleaning the vacuum system (there is a thread called "mess under the intake" which explains how) and then report back to us.
I would however be concerned with the cooper in the oil, so maybe even an inspection of the main bearings would be a good idea.

Profile gasket leak generally consists of loosing loads of coolant and it ending up all over your engine bay (in not sure as its never happened to me)

[wanganstyle]

hmm

ok.

so:

no coolant and oil mix. Oil is not burnt inside the engine as it just passed california emissions SMOG test a few days ago.

I checked the tensioner, it is the e36 style and good. Oil pan is newly replaced

What gaskets could be leaking on the side- We are pulling the engine to do the clutch and refresh, so I was thinking about doing a full headgasket timing cover gasket swap, anyone have a reason why this would not be needed?

compression is good, car idles and drives great still.

slight metal flake in oil, so we are going to change the rod and main bearings as well, while the engine is out.

Are there any other things i should do?