M42 swap issues (crazy, maybe)

[OSAH racing]

Looking for some knowledge today. My car 91 318 had a bad M50 so I asked Jack Fuhina ( well he offered to ) supply and swap in an M42. picked it up yesterday. Its a street /track car. registered out of california and the goal is to have California plates and drive to the track. I have a good running engine based on oil and water temps on the drive back to Riverside from Van Nuys in 100 degree weather. its passed smog that jack had done for me with all the smog components in place and a passable exhaust system.

whats wrong:

vibrates like a son of a .... from idle gets worse at 2500 to 3000 and then settles down but does not seem to go away. It makes the engine feel like its missing on timing but its not. he reused my M20 single mass and clutch/pressure plate and said they were good to use. He used rubber engine bushings. the car has poly bushings everywhere else and the m50 did not do this. i was told it would vibrate but this is ridiculous, no one would ever choose this option if its the m20 flywheel.

on deceleration in gear there is a loud buzzing or zinging sound from the drive train . 240 trans is good and reused, he installed unknown drive shaft connected to my 4.10 LSD

stiff brake pedal, no stopping almost at all. car has Willwood 280 brakes, porsche 944 booster e32 M.C. these brakes were perfect when i drop of the car.

Vince

[bmwman91]

The m42 is not the smoothest engine in the world, but what you describe sounds unusual. When you say rubber engine bushings, do you mean solid rubber engine mounts (rather than the hydraulic stock ones)?

I ran an M42 with M30 solid rubber mounts and a stock M20 FW for a while and it definitely vibrated more than the stock setup, but not so much that I had a problem with it. The built 2.1L I run now has OEM hydraulic mounts and a 7.4lb FW, and it is fine, no worse than stock IMO.

It sounds like a bunch of stuff is screwed up. A common cause of bad vibrations when the car is moving is not getting the two driveshaft halves aligned properly (there are paint marks to indicate alignment, which can easily be overlooked if they are covered in dirt). As far as the engine, if it is vibrating badly just revving it in neutral, then either the engine mounts are bad or hilariously stiff, or the flywheel is somehow out of balance. If it is a poorly balanced FW (not even sure how that would happen...damaged PP?) then stop running the engine as it'll be hell on the bearings.

[OSAH racing]

The m42 is not the smoothest engine in the world, but what you describe sounds unusual. When you say rubber engine bushings, do you mean solid rubber engine mounts (rather than the hydraulic stock ones)?

I ran an M42 with M30 solid rubber mounts and a stock M20 FW for a while and it definitely vibrated more than the stock setup, but not so much that I had a problem with it. The built 2.1L I run now has OEM hydraulic mounts and a 7.4lb FW, and it is fine, no worse than stock IMO.

It sounds like a bunch of stuff is screwed up. A common cause of bad vibrations when the car is moving is not getting the two driveshaft halves aligned properly (there are paint marks to indicate alignment, which can easily be overlooked if they are covered in dirt). As far as the engine, if it is vibrating badly just revving it in neutral, then either the engine mounts are bad or hilariously stiff, or the flywheel is somehow out of balance. If it is a poorly balanced FW (not even sure how that would happen...damaged PP?) then stop running the engine as it'll be hell on the bearings.

Its parked in my Garage, tow truck is taking it back Monday. I am trying to get on top of this to direct the shop on what I want. I do not know if I have rubber or liquid filled mounts at the engine , I wasn't told they are liquid filled and Rubber was the word used. . I will find out. I would hope that checking the spec of the flywheel ( it was not a problem with the m50) , driveshaft alignment and road testing are included in the swap procedure. The workmanship looks good to me. Jacks been around a long time, has a good rep in the 2002 world and has a few m42 swap into 2002's completed so I figured this was a good choice. It appears that since I have a track ready suspension that it was assumed that the suspension is the culprit here with the flywheel.

IYO, do you think the poly suspension , trans and diff bushings mixed with what ever rubber used on the engine are adding to the vibrations. My springs are 450/550 Eibach with AST Moton shocks adjustable perches?

[OSAH racing]

update. Jack took the car back last Tuesday and got on all its issues. his items are fixed. here's what was done:

Heavy vibration from idle to high RPM. Fixed. Hydraulic M42 engine mounts and rubber trans mission mounts installed. most (90%} of the vibrations are gone and its very little at this point and livable. The trans mounts were condor speed shop delrin and the main source of the heavy buzzing when down shifting also. The M20 lightened flywheel remained as i knew this wasn't the source of the vibrations.

The correct brake check valve was installed and my brakes are awesome again.
,
My drive home from Jacks shop is 65 miles. 102 degrees yesterday. i averaged about 30 MPG at 80 mph. Engine speed is 3500 rpm's , water temp was 210 degrees, oil temp was 200 and oil pressure about 55 psi at that speed. ran smooth and was what i expected the first time.

Next up to do is the rear diff. it has had a whine since i purchased it. I am going to replace it or rebuild it. I like the ratio but wonder if a 3.91 would be the sweet spot for track and street. The condor mount is coming out too and a high quality rubber one is going in. Suggestions?

[bmwman91]

Ha, yeah Delrin mounts ANYWHERE in the drivetrain will make for a hell of a noisy ride. You had mentioned poly mounts, and while Delrin is a polymer, the term usually refers to polyurethane which is a LOT softer (while still being much stiffer than rubber).

Hold off on any diff rebuilds until you have a softer diff mount installed. When I ran a poly diff mount, a lot of whine transmitted into the car, but it was just the normal meshing of the gears.

Other than that, I am glad to hear that things are working out better now.

[OSAH racing]

Two problems currently. I was hoping that things were sorted out but not so.

Problem one. I was doing some break-in miles ( 200 apx ) this weekend. drove the car 20 miles Saturday and 30 miles yesterday. yesterday i stopped at the Fot now to sort. ntana raceway to look at the PCA AX (15 miles from home) and found oil on the driver floor. My interior is removed. Its engine oil and i suspect it is leaking when parked and being forced in the cabin through any small gap on the firewall. More evidence is a puddle on the garage floor. the skid plate must be collecting it because there is more in the car than on the floor. What gasket is the most likely source? i realize that it could be any one of them since all were replaced. i sure hope its not the RMS. i can not see the source of it. I am think the back lower side of the block.

[OSAH racing]

Problem two.

Once warmed up, the engine starts to run rough from idle after coming to a stop while driving. it sounds and feels like it is misfiring on one cylinder. I can feather it out after a few seconds with the throttle. yesterday it took about 15 seconds to correct it . I feel this issue is progressing because when the swap was completed a few weeks ago this happened a few times and corrected itself (ECU?) in about 5 seconds not i need to help it adjust. The AFM, ECU are original to the m42 and were reused . I don't know about the TPS if its new or original. The intake boot is new. Plug wires appear to be not new, coils are not new, spark plugs are new. There is a tear on one coil boot that i taped up. I have anAEM wide band AFR and the reading are 13.1 to 15.1 while driving settling in about 14 to 14.5 while cruising at 65MPH.

[bmwman91]

Wow. It sounds like whatever was done with this engine & swap was not done correctly. Oil on the driver's side floorpan...that is a first. There is an M12 bung on the back of the head which is part of the main oil gallery. Check that the plug is actually tight (I think that a 6mm allen key is the right size). The larger bung is for the coolant. If that is not obviously loose and leaking, then the next thing down would be the RMS. Being that it is inside the transmission bellhousing, I would be a little surprised if it could get oil all the way onto the firewall, but at this point who knows. If you can get the car up on some stands an look around, maybe the source will become obvious. I feel like it would need to be a high pressure leak to get all the way onto the firewall, and I certainly cannot think of a place where it would get in.

As far as the poor running, it is hard to say. If the plug wires are original, then they could be cracked and arcing/shorting to the head. Coils do go bad from time to time, and sometimes you can inspect them and see little bulges and cracks in the epoxy potting, but not always.

It sounds like the person who you had paid to do work for you needs to deliver on what they were paid for. Hopefully they will be of some help.

[Panici]

...found oil on the driver floor. My interior is removed. Its engine oil and i suspect it is leaking when parked and being forced in the cabin through any small gap on the firewall. More evidence is a puddle on the garage floor.

Bit of a long shot, but do you have a mechanical oil pressure or temperature gauge?

Whenever I hear about engine oil in an interior this is my first thought. The little Nylon tube that comes with these gauges is a common failure point.

[OSAH racing]

Bit of a long shot, but do you have a mechanical oil pressure or temperature gauge?

Whenever I hear about engine oil in an interior this is my first thought. The little Nylon tube that comes with these gauges is a common failure point.

i will check on that today. I assumed that the auxillery oil, water temp and oil pressure gauges are wired in with a sensor. If the oil pressure is mechanical it could be it.

[OSAH racing]

Update: got the 318 CS back. The oil leak was from the oil pressure sensor. Oil dropped on the skid plate ( a lot of oil) and while driving was blown onto the firewall and into a gap to the driver side cabin. Coolant was leaking at the O rings from the new heater core I had the shop replace. Drove home again in 103 degree heat. 65 miles with a midway stop for the IE open house. The IE open house was an improved experience from years past. Unfortunately I have a new issue. Actually two.

The drive home. M42, 4:10 LSD. 78 mph, 3,700 rpms. 218* water temp, 200* oil temp, 55/60 lbs oil pressure seems good. I experienced the intermitent rough running when slowing down to a stop and idling. I can feather it out with fuel. It feels like the ECU isn't reading what is happening because its a slight miss and the timing is off. while the car was at the shop I had the delrin rear diff bushing ( no way this is a bushing its a solid mount) replace with stock myle rubber and steel bushing. The LSD fluid was replaced also. I have had a noisy diff since I bought the car. Jack informed me there is axle play with the diff.

The New issue: pops out of 4th gear. with the clutch in i can engage 4th and a few times it stayed in gear but 90 percent it pops out. Could the Short shifter not line up now going from all delrin engine, trans and diff to all rubber? could during the diff removal messed up something with the shift rod alignment ? I haven't checked trans fluid level yet.

in gear letting off the throttle you can feel the diff slip. that got to be the axle play Jack informed me of. I am going to need to address the LSD. Its a small case. I love the idea of less weight. 4.10 feels good but the highway revs in 5th are up their. I will be tracking the car but it will be driven all the time on the street. What is a good ratio LSD with the M42/ 240? in the case that my 240 is bad I do have a rebuilt ZF320 5 speed. That trans would require a different driveshaft and diff ratio,?

Someday this car is going to be reliable....

[OSAH racing]

UPDATE. rough Idle and stalling issues have been mostly resolved. The Idle control valve was stuck open, cleaned it, soaked it and still stuck open. I replaced it with an eBay refurbished unit with a warranty for 92.00 that's with shipping. I got the part in 3 days. after installing it I let the m42 idle in the drive way then did a 30 minutiae stop and go street test. idled perfect. I am not ready to say its totally resolved before I put more miles on the car. But its a step in the right direction. This is the part on eBay: : BMW Idle Speed Stabilizer Python Injection 91-95 318i