M42 Timing Change Swap with M44?

[Steve Corbett]

I have a 92 318 with a cracked head. I bought what I thought was a M42 from a E36 to use the head from. It has the cam position sensor on the aft side so it is a M44? I noticed my M42 cam timing gears are severely worn also. I thought I read about an upgrade to use the M44 Timing Gear Components?

[roguetoaster]

Yes, you can take the lower timing case/components off of the M44 and install it on the M42. Haven't done it myself, but you shouldn't have any issues finding info on the change over.

Now is the ideal time to do it as head removal makes it easier. If I recall, you might have to make a bracket to hold the crank angle sensor.

[Steve Corbett]

I've only been able to find vague references to it. Yes, I have seen mention about the crank position sensor not having a mount on the M44 Timing case. But if I retain my rear case with the CPS Boss, and only swap the Gears, Guides and Chain. Then I can reuse my M42 Rear case and swap my lower front case with the M44. It has a bump for the bolt that replaces the stud with a snap clip.

[e30sh]

M44 uses a larger oil pump so u need that lower case. 92 has idler sprocket, 94 up uses slider rail. Your best option is the 94/95 case with all the bits so you don't have to fool with the sensor mount.

[Steve Corbett]

Doing this setup seems to keep the CPS sensor mount but retains the original oil pump size. Car will just be a daily driver for a student.

[e30sh]

Doing this setup seems to keep the CPS sensor mount but retains the original oil pump size. Car will just be a daily driver for a student.

94-95 lower case is different than 90-93 with idler sprocket. Check out RealOEM for all the part #'s and interchanges.

If you want to spend ~$500 for all new parts, ECS sells an OEM timing rebuild kit and you can keep everything the same year as your original engine.

[bmwman91]

You want the late-model M42 timing case since it gets rid of the awful idler sprocket, which is a time-bomb. You'll need the later model M42 case and the updated gaskets (case-to-block and covers-to-case) and guide rail (which replaces the sprocket).

The M44 timing case does not really confer any additional advantages other than having a thicker oil pump rotor which provides a higher oil flow rate. On a stock engine that will be used on the street, there's no point in this upgrade, and as noted above the M44 case does not have the CPS bracket so you would need to have one made (Metric Mechanic can sell you one I think).

[gespinal0301]

You want the late-model M42 timing case since it gets rid of the awful idler sprocket, which is a time-bomb. You'll need the later model M42 case and the updated gaskets (case-to-block and covers-to-case) and guide rail (which replaces the sprocket).

The M44 timing case does not really confer any additional advantages other than having a thicker oil pump rotor which provides a higher oil flow rate. On a stock engine that will be used on the street, there's no point in this upgrade, and as noted above the M44 case does not have the CPS bracket so you would need to have one made (Metric Mechanic can sell you one I think).

What years are considered the late m42's? I have a 1991 318is with around 190k so I'm starting to get worried about this lol

[e30sh]

What years are considered the late m42's? I have a 1991 318is with around 190k so I'm starting to get worried about this lol

93 got the good head (6mm) but not the updated chain slider. 94-95 got all the good stuff.

[roguetoaster]

What years are considered the late m42's? I have a 1991 318is with around 190k so I'm starting to get worried about this lol

Late M42s are in E36s. I believe the cut off year is some time in 1993 for early version M42s, with M44s taking over in the latter part of 1996.

In theory, the way to ID the change is the location of the PCV vent pipe off of the valve cover, with earlys having it on the front, and lates on the rear of the VC. All M44s will have a MAF instead of an AFM, so that's how you'd differentiate readily between late M42 and M44 in a junkyard setting. If the air flow device is missing I believe all M44s have a plastic thermostat housing.