M10 Engine Checkup

[tfortmuller]

Just purchased a 1974 2002 with the original M10 in it sight unseen. Apparently it runs smoothly but I'm a fan of trusting but verifying. Never worked on an M10 engine before and I'm wondering what a good set of bullet points to check on this engine would be for safe and reliable use. Any gotchas or commonly fading components I should be aware of? I appreciate the help.  

[Dudeland]

There is extensive information about the challenges of the 02's.  Read through the "Articles" section and then ask questions.  They are pretty simple machines,  like a VW beetle, but with A/C and a rad (and all the awesome BMW stuff as well) . 

 

Take lots of pics.  Pictures will get you an answer or response 50 times faster. 

 

Take a look at the peoples profile and look at number of posts.  There are a couple of folks there in the 10K's, so it is a great forum.  If you can't get an answer here, then somebody knows someone who does. 

 

Take the vin and run it though BMW, ( I can't find the link right now).   They will tell you when it was built,  which in some cases helps. 

 

Congrats  and  Welcome. 

[TobyB]

Skip the bullet points and go straight to the test equipment:

 

compression tester

leakdown tester

wideband o2 meter

fuel pressure gauge

eyeballs

jack (lift the engine, see if the engine mounting system has failed)

10 mm socket and ratchet and wrench, and 2 mm allen wrench (check under the valve cover, then lash the valves)

mechanic's stethoscope

 

heavy right foot.

 

that'll do it

 

t

to verify is not to trust

['76mintgrün'02]

 

Skip the bullet points and go straight to the test equipment:

 

Insert -- variable timing light right here

 

compression tester

leakdown tester

wideband o2 meter

fuel pressure gauge

eyeballs

jack (lift the engine, see if the engine mounting system has failed)

10 mm socket and ratchet and wrench, and 2 mm allen wrench (check under the valve cover, then lash the valves)

mechanic's stethoscope

 

 

you forgot one, Toby!

(assuming the light has a built in dwell meter)

[Conserv]

 

 

... Take the vin and run it though BMW, ( I can't find the link right now).   They will tell you when it was built,  which in some cases helps....

 

Send an email with the car’s VIN (if the engine number is not the same as the VIN, send that as well, to find out it’s source) and request their data. No charge. Two business days or less for a reply, generally.

 

info,grouparchiv@bmwgroup.com

 

Congratulations and welcome!

 

Regards,

 

Steve

 

 

[Son of Marty]

Check the engine mounts and the left side mounting arm for cracks.

[TobyB]

 

 

Insert -- variable timing light right here

 

you forgot one, Toby!

(assuming the light has a built in dwell meter)

I did!

 

Thanks, Tom!

 

t

 

['76mintgrün'02]

You're welcome! I couldn't resist.

 

I just searched-up INNOVA 5568 and got 54 hits.  I was 38 of them. 

 

Tom

 

 

[Dudeland]

FYI these cars are very sensitive to timing, so you will likely need to set it (a bit of an art) the innova 5568 is one of those essential tools to do this. 

[Mike Self]

Take a look at the carburetor--all 74's had a two barrel carb, but is it a Solex (OEM equipment) or a Weber (aftermarket).  And if the latter, is it a manual choke (cable running from the carb through the firewall to the left side of the steering column surround), electric choke (wire and terminal on the choke body) or water (two small diameter hoses running to the choke body)?

 

If it's a Solex, they're problematic--both choke and the secondary barrel, which is vacuum operated.  Most have been replaced by Webers--if the choke is automatic, make sure it's operating properly.  

 

And welcome to the '02 fraternity/sorority--lotsa good info and nice folks here on the FAQ.  And depending on what part of the country is your home, there are more than a few 2002 gatherings--East Coast, West Coast and in between.  You should come.

 

mike

 

PS--just remember...as my late and much missed father-in-law, who taught me how to work on cars from his experience going back to Model T days, used to say, "Mike, if it ain't broke, don't fix it." and "90% of your carburetor problems are in your ignition.  Keep your hands off the carburetor until you know the ignition system is OK."   ?

[TobyB]

...and along those same lines, the distributor wears out.  It's a 50,000 mile part on the earlier cars, and not that much

longer on the later ones.

They can be refreshed, rebuilt, replaced or substituted for something else entirely.  

 

But if they're old, floppy, sticky and worn out, you won't get decent idle AND good power from the same settings.

 

t

Tom was right. 

[114TYP]

 

...and along those same lines, the distributor wears out.  It's a 50,000 mile part on the earlier cars, and not that much

longer on the later ones.

They can be refreshed, rebuilt, replaced or substituted for something else entirely.  

 

But if they're old, floppy, sticky and worn out, you won't get decent idle AND good power from the same settings.

 

t

Tom was right. 

 

What parts of the distributor should be checked after every 50 000 miles?

['76mintgrün'02]

 

What parts of the distributor should be checked after every 50 000 miles?

 

the moving parts

 

 

It is sort of a thick topic.  The main thing is to keep it clean and lubricated and shimmed to eliminate extra axial play.  They are a maintenance item that is typically neglected. 

 

Drilling the pin out of the gear, to slide it off of the shaft is not very difficult.  The pin is very soft.  I replace the pin with a 5/32" x 3/4" roll pin, to make it easier to get in there in the future.

 

Here is a(n obnoxiously long) thread, where I have taken some apart and taken a lot of photos.

Tom

 

[Conserv]

 

 

What parts of the distributor should be checked after every 50 000 miles?

Tom would like you to really understand your distributor, you know, become best buds. I don’t have near Tom’s patience. Allow me to sum up your distributor’s needs in two words: Advanced Distributors

 

http://advanceddistributors.com/wordpress1/

They will rebuild your distributor and return it to its original specs.

 

Regards,

 

Steve

 

 

 

Edited January 9, 2020 by Conserv

[NickVyse]

 

Take a look at the carburetor--all 74's had a two barrel carb, but is it a Solex (OEM equipment) or a Weber (aftermarket).

 

Just in case the original poster isn't in North America - the rest of the world continued with single barrel carbs except late model automatics.