Author Topic: 91 M42 vs 93 M42 Questions (Read 4845 times)

1991BMWE30 · « **on:** May 22, 2012, 08:45:31 AM »

Hi fellas!

I'm finally registered! For some reason my yahoo email automatically got banned so I had to come up with a work around.

Anyways....

I'm still new here and new to BMWs. I have a 91 318is that I've been restoring to DD condition.

The current M42 has a major ticking sound. It never goes away, but it hasnt got any worst either.

I'm pretty sure its time for new lifter/ tappets, but at $400 in parts plus misc items. I'm not sure I want to go that route.

I would rather spend $1000 on a good condition 93 M42 long block and make it work with the 91 accessories etc.

My question is what will I need to make this swap work?

I've researched as much as I can but only found bits and pieces.

I think so far I got new cam sensor, new pilot bearing.

Has anyone done this? Would anyone mind pointing me in the right direction?

I have funds to purchase a long block, I just need to make sure this will work.

Thanks!

zacrl1230 · « **Reply #1 on:** May 23, 2012, 03:59:57 AM »

what???

you confuse me???
m42=m42
no?

Geoff · « **Reply #2 on:** May 23, 2012, 06:16:02 AM »

yes, a little confusing..also, most "ticking" sounds will eminate from the head and associated timing gear, the bottom end is pretty tough. I would suggest some research on your end to find out what the problem is before attempting such a transplant.
Geoff

1991BMWE30 · « **Reply #3 on:** May 23, 2012, 01:41:19 PM »

Thanks for responding guys.

Ok so let me get this straight and excuse my ignorance if I'm incorrect.

An M42 1.8 4 cylinder engine from a 1994 BMW 318ic, is exactly the same as the one found in the 91 318is?

And to answer geoff, the current motor has over 280k miles on the clock. And I agree the motor seems fine aside from the ticking so yes I believe the bottom end is tough, however the parts to rebuild the head are outrageous.

So if you were in my boat with ticking M42 you would just change the head huh? Price wise it seems cheaper to get a lower mileage M42 and just go from there rather than try and rebuild a BMW motor.

Prices for the parts are crazy and I dont have the cam tool.

Thanks for hearing me out.

Geoff · « **Reply #4 on:** May 23, 2012, 01:49:52 PM »

Yeah, I guess with 280 thou on it the whole thing should probably be done if you are going to do it. So from that standpoint a cheaper solution would be to replace the whole thing, with a lower mileage unit.
Geoff

DesktopDave · « **Reply #5 on:** May 23, 2012, 01:59:51 PM »

There are some detail differences between the M42 motors, but they all can be resolved by swapping parts. I'm pretty sure the '94 would drop right in. Hopefully you'll get the updated timing chain rails and tensioner.

I'd do the whole motor myself, if you have the gear. IMHO it's easier than doing a head. You're gambling with the new motor, but they tend to be pretty robust. I'd make sure they offered a good warranty just in case it's been overheated. Having a spare motor is good insurance regardless.

The DISA manifold, knock sensors, serpentine belts, coil packs and updated DMEs can all be "downgraded" to '91 parts from what I've heard (YMMV - I haven't done this myself). Odd you brought this up - I have a spare e36 M42 on the way. I'll update if/when it gets here.

zacrl1230 · « **Reply #6 on:** May 23, 2012, 02:01:34 PM »

Cam tool is easy enough to fake with a couple of vice grips
I think elephant motorsports had the m42 valves on sale last i checked
hydraulic lifters ain't cheap though
ticking/rattleing right noise has usually lead to a timing issue in my experience though

As to not spread misinformation I am not 100% sure because I have only owned e30's but I thought all m42's and m44's were exactly the same as far as block and head were concerned, but like I said I could be 100% WRONG

1991BMWE30 · « **Reply #7 on:** May 23, 2012, 02:31:34 PM »

Appreciate the dialog guys....desktop dave please keep me posted!

Thats exactly what I want to do.

keflaman · « **Reply #8 on:** May 23, 2012, 02:45:51 PM »

If I hadn't already blown this month's car parts budget I'd have this one for a spare: Go to post #2

http://www.r3vlimited.com/board/showthread.php?t=241620&highlight=m42%2A

mr ilia · « **Reply #9 on:** May 24, 2012, 09:25:32 PM »

Before switching engines, seafoam your current engine by adding third of the bottle to the gas tank, third to the oil and the last third of the bottle to intake. Drive for 500km and do oil change with mineral oil 10w30. This should clean up the iside of the engine for good. If this does not help then you can do whatever you have in mind.

Ryann · « **Reply #10 on:** May 24, 2012, 11:42:21 PM »

Quote from: zacrl1230;112730

As to not spread misinformation I am not 100% sure because I have only owned e30's but I thought all m42's and m44's were exactly the same as far as block and head were concerned, but like I said I could be 100% WRONG

No. e30 and e36 m42 long blocks will interchange so long as everything e30 is swapped over, but the e36 valve train differs in that the e36 uses narrower valve stems/guides and single springs vs. dual. There are other differences in the timing components that are supposedly 'better'. The m44 is a completely different animal in the bottom end.

1991BMWE30 · « **Reply #11 on:** May 26, 2012, 01:13:13 AM »

Just updating the thread...turns out more searching and I stumbled on to this bit:

To Quote C.Saenz

E36 M42 into E30.
I recently put in an E36 318ti M42 with 85,000 miles on it into my 1991 318is.
I unplugged all of the wiring so I could leave the plastic box that sets under the intake in the car. I removed the A/C compressor and power steering pump from the motor but left the hoses connected to both. I used wire to hold them up so they wouldn't be hanging from the hoses.
After removing the usual remaining stuff, I pulled the motor. The E36 motor was dated 10/95.
From 9/95 up the M42 and all of the M44's use a different type oil pan gasket. It's similar to the valve cover gasket, a rubber with circles around the bolt holes that sits in a recessed groove. The groove is machined into the block. It also goes around the problem area at oil pickup. The old type gasket works with this block. I had several people look at it and they all thought it would be OK. None the less, I turned it over with no ignition until I got oil pressure just to be safe. I put locktite on the pan bolts that are covered with the lower sump. realoem.com shows this gasket on cars with the M44.
From the front back, I had to change the balancer and pulleys, water pump pulley, alternator bracket and alternator, valve cover, and motor mount arms. Thakfully, you don't have to remove the big crankshaft nut to swap balancers and pulleys. The front temp sensor is the same but I had to reuse the rear one from the original motor. Same with the cam and crankshaft sensors. From 9/90 and up the pilot bearing is the new larger type so no change was necessary. I also swapped the complete intake assembly, using the one from the E30. The flywheel and clutch assemblies are the same part numbers also.
It was a really straightforward swap. Just nuts and bolts. I thought about going to a serpentine belt but that would have meant water pump, P/S pump, and A/C compressor pulleys. End the end I didn't want to spend any more than necessary so I didn't do any performance mods either.
It runs quieter, smoother and has a bit more power. All due to age and miles on the motor. The actual HP increase is probably not noticeable if both motors had been in top shape. The old motor had really gunked up the intake from the blow by and other stuff from the valve cover/crankshaft vent line.

Hmm...exactly what I needed!

I'm downloading the service manual, but where exactly are the cam and crank sensors?