SlickDizzy
SlickDizzy SuperDork
8/21/11 2:46 p.m.

As part of my resto-mod effort, I want to refresh the 240k mile M30B28 in my euro 528i. I know that I want to do the usual seals (front & rear main, cam, etc) and put a streetable cam in while I have everything apart, but I'm not sure what else to do. I figured a timing chain and/or tensioner would be a good idea. Should I go so far as pulling the head and doing the head gasket, or is it better left alone if it still seals alright? I also seem to recall hearing that these engines can break rocker arms at higher miles, should I look at replacing those? I figured a water pump wouldn't be a bad idea either.

Any/all advice is appreciated - I've only ever had old Subaru engines down to the block before and those are a bit of a different beast.

Taiden
Taiden HalfDork
8/21/11 3:02 p.m.

Give it to me and I will give you an ej22e to work on instead.

mad_machine
mad_machine SuperDork
8/21/11 3:06 p.m.

HG can't hurt. Not sure about the Rocker Arms.. but the oilpump is always good insurance

02Pilot
02Pilot Reader
8/21/11 3:11 p.m.

M10 and M30 engines share the same basic architecture (the M30 just has an extra couple of cylinders), so much of what follows comes straight from the 2002 world, but is generally applicable to your M30.

The M30 is about the most stout, long-lived engine BMW ever built. Even at 240k miles, there's no particular reason to open it up unless it is exhibiting specific problems.

The head is the weak point in the engine, inasmuch as it has a weak point. Most everything in the head can cause problems: the occasional broken rocker (more likely if you run at high RPM a lot), worn adjusters that allow clearances to creep easily out of whack, leaky valve seals, valve springs that go soft with age (again, lots of high-revving will make this more of an issue), oil spray bar bolts that work loose and starve the cam lobes of oil, and a general tendency to warp quickly if overheated. Note that the head bolts are reusable and should be checked and retorqued as necessary before each valve adjustment.

The timing chain will stretch with time, and the spring in the tensioner will get weak. The water pump and thermostat will eventually fail (though less frequently than on newer models). The ignition components are usually good for 60k miles or so if you use the factory parts.

The electrical stuff - switches, relays, solenoids - can be flaky as they get old. You might preemptively replace all those on the engine just to remove the possibility of an inconvenient failure. The thermo-time switch, the cold start injector, and the main relay are the biggest culprits; I'd replace all those at the very least.

The bottom end is so strong that there's no reason to touch it. The only thing I'd even consider doing down there is the oil pump, and only if I was seeing marginal pressures.

In short, aside from a few wear items, I would inspect carefully but not do any more than was necessary. If you do go as far as installing a cam, you should then completely overhaul the head; it doesn't make sense to do all that disassembly and not refresh everything.

wjones
wjones New Reader
8/22/11 12:44 a.m.

Why would you refresh an M30 with only 240k?

AngryCorvair
AngryCorvair SuperDork
8/22/11 8:49 a.m.
wjones wrote: Why would you refresh an M30 with only 240k?

beat me to it...

Giant Purple Snorklewacker
Giant Purple Snorklewacker SuperDork
8/22/11 8:56 a.m.
AngryCorvair wrote:
wjones wrote: Why would you refresh an M30 with only 240k?

beat me to it...

Seriously... those kms are a tiny scale not really suited for use measuring the life of the M30. You refresh those motors at 400k MILES.

RossD
RossD SuperDork
8/22/11 9:01 a.m.

He said 240k miles, not kilometers.

Giant Purple Snorklewacker
Giant Purple Snorklewacker SuperDork
8/22/11 9:08 a.m.
RossD wrote: He said 240k miles, not kilometers.

Right you are sir. I read the title which begins the mileage with 240km... the trailing 'i' escaped my less than spectacular attention to detail.

SlickDizzy
SlickDizzy SuperDork
8/22/11 9:29 a.m.

The other thing is that this car hit a deer hard enough to snap the distributor off the front of the engine and crack the front upper cover...so I'm going to be mucking around with E36 M3 in there anyways.

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