high milage m20s

[Earendil]

or he changes it weekly and knows it will NEVER break

How much more worried can you be than to be that guy that changes it every week for fear it'll break? ;)

Now, if he inadvertently won a lifetime supply of weekly timing belt changes when he was really trying to win the Alaskan cruise vacation, then I could see how he may not be worried.

[jeffnhiscars]

What???? Your timing belt breaks and you can kiss your engine good-bye. Unless you are being sarcastic...

or he changes it weekly and knows it will NEVER break

[dnguyen1963]

Im not really concerned w broken timing belts

What???? Your timing belt breaks and you can kiss your engine good-bye. Unless you are being sarcastic...

[Earendil]

Im not really concerned w broken timing belts

Then you do not drive an M20 :)

The M20 is an interference engine. Timing belt breaks and your engine is

[bastianshaw]

A retired BMW engineer in the Netherlands told me that the M20 was a 500k km (312k miles) service life design, given proper maintenance. That is, it should not need major repairs involving opening the engine, other than a major component failure repair, which was rare. However, this applied to M20s in Germany only, as records from America showed that maintenance was not 'proper', performed as specified by BMW and failures were well below 312K miles. I have witnessed this myself, having worked or consulted on 37 different 528e models, in the last several decades, all with less than 225k miles and in typically poor condition. Four of them had broken cam belts, due to excessive time and mileage, resulting in major cylinder head and piston damage. Another 8-10 had badly worn cam belts due to excessive time and mileage on them. This is not a unique problem with BMW's, as most American cars are poorly maintained too.
FWIW,
-Rod

Im not really concerned w broken timing belts

[603Racing]

Unless the engine had at least a crank scraper, the track use is probably what set the stage for the bearing failure.

I'm sure your're exactly right, which is why the first part I bought for the replacement motor was a IJ scraper.

[rodpaine]

A retired BMW engineer in the Netherlands told me that the M20 was a 500k km (312k miles) service life design, given proper maintenance. That is, it should not need major repairs involving opening the engine, other than a major component failure repair, which was rare. However, this applied to M20s in Germany only, as records from America showed that maintenance was not 'proper', performed as specified by BMW and failures were well below 312K miles. I have witnessed this myself, having worked or consulted on 37 different 528e models, in the last several decades, all with less than 225k miles and in typically poor condition. Four of them had broken cam belts, due to excessive time and mileage, resulting in major cylinder head and piston damage. Another 8-10 had badly worn cam belts due to excessive time and mileage on them. This is not a unique problem with BMW's, as most American cars are poorly maintained too.
FWIW,
-Rod

[bastianshaw]

Ive got 263 on mine...and it pulls very hard and doesnt burn a thing.

Leaks terribly but thats it. I dont know if anything has ever been done to it, but it really doesnt look like its ever been apart.

my ETA's engine had over 300k on it, I dissassembled it and nothing showed signs of severe wear anywhere.

M20s are buelletproof.

tell this to cabriolet

[TimKninja]

Ive got 263 on mine...and it pulls very hard and doesnt burn a thing.

Leaks terribly but thats it. I dont know if anything has ever been done to it, but it really doesnt look like its ever been apart.

my ETA's engine had over 300k on it, I dissassembled it and nothing showed signs of severe wear anywhere.

M20s are buelletproof.

[bastianshaw]

M20's rock

word

[ForcedFirebird]

Just puled an m20 out of a car with over 360,000 on the odo that broke 2yrs ago. Still ran like a champ, but puffed a little blue smoke. Maintenance records dating back to 30k miles.

[Earendil]

M20's rockers break

FTFY.


M20's are great until you rev too high and one of your rockers snaps in two. It's certainly one of the weakest links in the engine when trying to push the M20.

[Cabriolet]

what was compression before rebuild?

No, leakdown first. compression tests hide issues.

[ROLLingKING]

M20's rock

[jlevie]

179,000 miles on mine when the bearings went. Of course my oil light did not work and I drove around for about 3 days (200 miles) with very low oil pressure. I had no signs of problems until I started to hear engine noises. The car was used as a track/DE/AutoX car for two summers before I bought it, so that's the likely cause of the early wear.

Unless the engine had at least a crank scraper, the track use is probably what set the stage for the bearing failure.