BMW 524td shuts down after warmup......... - PeachParts Mercedes-Benz Forum

MotoZuki · #1 02-01-2007, 01:49 AM

I am an ex-240D and 300D owner (totaled in a not-my-faulter) who has spent vast hours rebuilding, restoring, and generally working on these fine automobiles. I note this only because I now own a BMW 524td, and my question is of a general diesel nature, but does have to do w/ the BMW (only because I know of the vast knowledge available on this site). Now down to business.

Symptoms:
1) Start car from ambient temp (first start of day) = starts great, good power, etc
2) After about 1/2 hour of opperation or idling in the driveway (enough time to warm up), the car loses all power, sounds very weak (no knocking, or hard noises), and shudders to a stall-out
3) Engine will not restart until it has cooled off again (see #1).

I've resorted to taking the car to a respected diesel mechanic and he's stumped. He's never seen a diesel car's running condition WORSTEN after it warms up.

PS. Fuel supply is in tact. The engine functions this way whether running out of a can of diesel or from the tank.
PPS. If running thicker fuel (ie, strait ATF from a bottle), the symptoms do not occur, and the car runs fine (none of the above symptoms).

Please help!

William

#2 02-01-2007, 01:53 AM

Humm. Stumping me too.

(Sorry for the useless post, I wanted to subscribe to the thread)

DeliveryValve · #3 02-01-2007, 01:58 AM

Could you have a intake manifold leak? Possibly a bad gasket that expands when hot and letting in too much air? That would be my guess at this point.

#4 02-01-2007, 02:01 AM

Quote:

Originally Posted by rmarzan

Could you have a intake manifold leak? Possibly a bad gasket that expands when hot and letting in too much air? That would be my guess at this point.

That shouldn't make a difference. I'm pretty sure there is no mass airflow sensor on that engine.

Shorebilly · #5 02-01-2007, 04:38 AM

I have to go to school today.....so I don't have a bubcha time to think about this.....but it will bug me for awhile.....

My first thought is the fuel lift/booster pump......

If your lift pump were to have an issue...like maybe in the check valves within.....a thinner fuel may not pump as well as a thicker/more viscous fuel...

Also.....check the IP return...banjo bolt....it is actually a pressure regulator, it's purpose is to keep a designed positive pressure within the IP fuel gallery....if it has a bit of trash caught inside.....it may allow the thinner fuel to pass more readily than the thicker stuff.....and not maintain the internal IP pressure......

Are all of your fuel lines in their original factory positions?? If the fuel supply line is heating up for some reason (i.e. too close to exhaust pipe) you could be getting a gassification of the fuel before the IP ....similar to vapor lock in a gasser.....

Those are my initial thoughts.....I think your problem will have a very simple answer......

SB

Ken300D · #6 02-01-2007, 07:45 AM

What does the car have in the way of fuel filters? Is it an in-line primary filter followed by a spin-on secondary filter?

If this were happening on my car, I'd start by replacing at least the secondary filter. Also, if the car stalled while running from a can of diesel under the hood, I'd pull my secondary filter to see if it was full or empty of fuel.

Also, if you have a primer pump like the MB diesels, these can stall the engine in what seems like a random pattern. In fact, it may be some seal issue on the primer pump that leaks when warm. Again, after a stall I would be pulling the secondary filter to see if it was full or empty of fuel. What this does is help divide the problem between fuel supply and injection pump issues.

Ken300D

peterhardie · #7 02-01-2007, 07:15 AM

I had similar symptoms, eventually the car wouldn't start back up.

The culprit turned out to be the purge pump, was letting air into the system. At first, tightening it (old style unscrew-and-pump) seemed to fix the problem. I ended up putting in a new one.

I would suspect the fuel system, but I don't know bimmers.

Good luck.

TX76513 · #8 02-01-2007, 08:18 AM

The EDC actuator pump will cause the symptoms you describe. This was a big problem with early '85 to mid year '86 engines. You didn't mention what year your bimmer is.

CSX293 · #9 02-01-2007, 08:26 AM

Make sure the crankcase vent isn't plugged.

retx · #10 02-01-2007, 08:29 AM

Does this happen only when driving (as it gets warm) or have you had it warm up and die while still in the driveway? Check your tank screen (if it has one). Does the engine temp increase as its stalling, im just curious on that one.

TX76513 · #11 02-01-2007, 08:33 AM

Quote:

Originally Posted by retx

Does this happen only when driving (as it gets warm) or have you had it warm up and die while still in the driveway? Check your tank screen (if it has one). Does the engine temp increase as its stalling, im just curious on that one.

I believe he has eliminated tank and filters by running engine straight from can to pump.

retx · #12 02-01-2007, 09:08 AM

Quote:

Originally Posted by TX76513

I believe he has eliminated tank and filters by running engine straight from can to pump.

woah, i missed that part. weird. well he still hasnt eliminated the filters. unless he is going straight from can to pump. hes not clear on that one.

babymog · #13 02-01-2007, 09:12 AM

I had similar symptoms on a Cat diesel. It ran great for a while, started losing power (no smoke & no top end) to the point where it wouldn't idle properly. After shut down it would restart fine, but every time it would lose power more quickly than the last.

The culprit was algae in the fuel, changing the primary filter solved it temporarily, eventually I changed the filters enough to empty the (300 gal) tank and have it cleaned.

I'd start with the filter if you haven't already. You didn't say whether sucking from a can was through the filters, I'm assuming so. The ATF is a high detergent oil, might cut through some filter crud temporarily (and burn it).

MS Fowler · #14 02-01-2007, 09:33 AM

I don't know BWM diesels, either.
Is it possible that the valve adjust is tight? I mean so tight as to cause the valves not to seat when it gets warm and things expand?
Just a shot in the dark....

retx · #15 02-01-2007, 10:09 AM

Quote:

Originally Posted by MS Fowler

I don't know BWM diesels, either.
Is it possible that the valve adjust is tight? I mean so tight as to cause the valves not to seat when it gets warm and things expand?
Just a shot in the dark....

i thought this car would have self adjusting hyraulic lifters?