How long will my M20 last??

[aTron12]

Hey all. I have just done a major overhaul on my '89 325is. I bought it for $1000 with a blown head gasket, had it towed to my mechanic who got to work right away. He had the head rebuilt, transmission seals, oil pan gasket, clutch, short shifter, lightened/resurfaced flywheel, mostly all new hoses, all new cooling system, timing belt,suspension, eibach springs.. the list goes on.

My question is about the life of the bottom end. It has 200K on the motor. He told me that it should be good for a good chunk of time partly because the scoring on the cylinder walls was immaculate & the compression is still great. He also didn't notice anything that set red flags off. His estimate was another 7 (maybe squeeze 80k) or so years before it starts really wearing out. I don't race it or push it too hard. Keep my rpms below 6K. If and when it starts failing, what would people recommend?

Any advice on the subject would be greatly appreciated!

[bmwstephen]

I'm pretty sure with proper maintanence, I wouldn't be surprised if it can last another 200k. Inline design and sturdy attributes of the m20 engine made it one of the most reliable BMW engines of all time.

I'm pretty much in the same position as you. rebuilt head, presteine block (within OEM tolerance). Doesn't drink oil and compression is within stock specs.

[aTron12]

Cool! So you would say that I'm good for road trips here and there beyond my "spirited" daily driver back and forth from work?

If it does end up going out on me after awhile, would it be worth it to find an ETA bottom end? Pretty much everything has been redone on this motor short of a rebuild.

[bmwstephen]

i'm not quite sure. but to give you a general sense. Walter, owner of Valley Motorworks, has a 300k e30 for the spec e30 league. His car sees a lot of abuse.. in fact its all abuse since he just races his car.

He mention how frequently he has to resurface the head after a couple a races but he has never mention about having to rebuild the block. Actually, I was confident in owning an e30 since that conversation.

My current mechanic is impressed when he was helping me rebuild this engine. This is coming from a mechanic who specializes in Lexus cars. he definitely sees a very long life with this engine provided I care and keep up with the maintanence.

[16v of E30]

the bottom end is bomb proof. it will push 400k with propper fluid changes

[JoeP]

My '87 e just turned 315,000 and gets 32 MPG on the highway. It doesn't smoke and runs strong. I wish the rest of the car was as good as the engine.

[StereoInstaller1]

My '87 e just turned 315,000 and gets 32 MPG on the highway. It doesn't smoke and runs strong. I wish the rest of the car was as good as the engine.

Man, I hear ya there!

How do you get better mileage than the EPA estimate by nearly 20%?

[dashboardmonkey]

Man, I hear ya there!

How do you get better mileage than the EPA estimate by nearly 20%?

It's just that slow

[Aptyp]

over 500k miles, and just recently I fell below 30mpg. Pisses me off.

[JoeP]

Cruise control!! I'm not sure what gears are in it, but it won't keep up with my '86 from a stop. The gas mileage was great when I drove 120mi a day though.

[blocke]

I just carfaxed my car the other day, and discovered that the odometer stopped at 205,183 miles..IN 2007! PO said he didn't know when it broke.
So Ive got to have around 260-270k on it if I had to guess, still runs like a champ, no smoke, no burnt oil, and still loves to R3V.

[E30bavarian]

m20 rules

I have a 1987 325 with 370,000 abbot still runs stong if you maintain these motors they will last forever

[nando]

most M20s will continue to run well after the odometer breaks at ~250k. more than a few people don't even know how many miles are on their motors, only that they're somewhere north of that range.

[SkiFree]

To reiterate they are very tough, HOWEVER your mechanic should at least take a look at the main and rod bearings (especially those furthest from the oil pickup).

[not_a_kiwi]

Have you not watched the mobil million Mile bmw 325i video? It's pretty amazing actually. It's all in the maintenance