Blew my M42 Motor on the highway today...

[Alpine003]

Tis a sad day as I blew my M42 Motor on the highway today. It isn't official as I hadn't had the time to really have it checked out thoroughly yet.

Ever hear a backfire coming out of the intake, thru the throttle body and practically destroying your air filter? Yup, that's how bad it is as it tries to start unsuccessfully.

I'm going back to the shop tommorow to get further diagnosis

The sad part is that I just spent a bunch of $$ on maintenance lately.

Stay tuned, but for now 1 M42 down. :( :( :(

[doucy2]

but look on the bright side now you can do something like a m50 swap, woot

[bmwaddict]

Really weird, sounds like the timing is severly off, ignition related. Sorry to hear, post results.

[kylebes1]

I have a head if you need it...

[e30tom]

Timing belt maybe?

[1991 318is]

You can get a M42 out of an E36 and just use the long block. Engines are $750 to $1250 depending on mileage. I know an E30 owner that bought an entire totaled E36 for $500. Used the motor with the serpentine belt accessories and the E30 intake and electricals and sold the car for $100 to a salvage yard. Back on the road for $500 with hoses, coolant,and all that sort of stuff.
Or you can go to the M50 or S50 if you want to use the opportunity to up the horsepower.

[golde30]

Timing belt maybe?

except 318is have an m42 which has a timing chain...

[parkerbink]

Sorry. Hope it's not a catastrophic failure.

This is why I just spent 1k to have the timing belt, waterpump, tensioners and accessory belts done on the Acura 3.0cs.

[Alpine003]

Thanks for the info guys. I really hope it's a timing issue only as it sounds like it's missing a tooth or two when cranking. I plan on going back to the lot that it's at and taking the covers apart to do an inspection. It is suppose to be 45 degrees and raining all day too. :(

Unfortunatly, I don't have the garage space to work on this car so I had it towed to a lot close by.

If it was next summer, I would seriously entertain a different engine swap but funds are really tight this year.

I'll be headed out once my gf gets back in a couple hours. Wish me luck.

[Alpine003]

You guys are going to like this one.

Went back to the lot and dissassembled the valve cover and started to manually rotate the engine. It took a few turns to check over everything because I was looking in the wrong spots. Turned out to be this:

I was fearing the worst and bent valves for sure I thought. Luckily the lot I got it towed to was a local BMW mechanic friend that had all the right tools. He got out his $130 BMW fancy suction tool to hold all the tappets while we removed the guide. Then we checked with a feeler gauge for the valve clearances which indicated no valves were bent. Great news.

The guy I bought the car from had recently replaced the cylinder head due to a crack and gave me the old one. I was just going to use is as a display piece or something but I'm glad I didn't throw it away as that had the donor cam that I needed. Went back towards downtown Chicago fighting the weekend traffic to pickup my spare head.

After getting the cam out of it, I'm also glad we had the right alignment tools to put everything back together. In less than an afternoon, I was back on the road. The car's idle note does indicated that there might be possibly a couple slightly bent valves though.

The only thing I can attribute to this failure is the fact that we found the cam caps to not have been torqued properly to specs which eventually threw off the cam timing and broke the cam. I'm assuming the po did a rush job or took it to a non-BMW mechanic. I'm sort of glad the M42 have hollow cams as a solid cam probably would have done more damage.

The car runs a little smoother than before and I'm just glad I didn't have to swap in an s50 this year since I'll be low on funds for the rest of the year.

[Alpine003]

Cliff's Notes:

1. Blew motor last friday during the Friday evening rush hour.
2. Got into a confrontation with a State Trooper.
3. State trooper made me use his towing company which came to $150.
4. Went to look at the car in the afternoon on Saturday.
5. Replaced broken cam and installed new thermostat in an afternoon.
6. Rain that was projected for the whole day held off until I just got done repairing the car.
7. Drove home with a big smile knowing I didn't have to replace the whole motor.

:)

[golde30]

Cliff's Notes:

1. Blew motor last friday during the Friday evening rush hour.
2. Got into a confrontation with a State Trooper.
3. State trooper made me use his towing company which came to $150.
4. Went to look at the car in the afternoon on Saturday.
5. Replaced broken cam and installed new thermostat in an afternoon.
6. Rain that was projected for the whole day held off until I just got done repairing the car.
7. Drove home with a big smile knowing I didn't have to replace the whole motor.

:)

this is what you call a best case scenario. the PO of my 318is had something very similar happen, only with his car the timing chain guide rail snapped and the engine blew up like a grenade...

[SchnellerVert]

Lodge a complaint against trooper, can't hurt.

[Alpine003]

Lodge a complaint against trooper, can't hurt.

That's what people told me but he's not worth the ink in a pen and no harm was done except a bruised ego so I'll let this one go to the pigs.