524td hard start and other issues

[CoyoteStarfish]

Hi there,


I just got my first 524td. I'm no newcomer to diesels but this is only my second experience with a 524td -- and the first one was running perfectly.

Unfortunately this one came with some problems, maybe someone here can help out?

Problems:
-Does not like to start when cold, takes a good amount of cranking (30-45sec.) to get it to fire up.
-Nails really hard when it does start.
-Will NOT start when hot.
-"START" position on the key does not work often - will not crank roughly 4 out of 5 tries.
-VERY hard breaking.

What I do know:

-Glowplugs seem to work, but someone has replaced the strip fuse in the glowplug relay with a 10 gauge wire. The reason I say they "seem" to work is that the wire gets pretty darn hot.

What the previous owner claims:

-Injection pump and injectors have recently been rebuilt.
-Possible timing problem.
-Possible vacuum pump problem.

The car is not in my possession just yet, but will be soon.

That all aside it's a great vehicle. I have some experience with the E28 having driven and worked on a 528e and wrecked 524td which was purchased for the powertrain.

I also have quite extensive diesel experience, so I have a pretty good understanding of what is going on with these engines -- But this one just has me confused at the time being.

Thanks!

[instg8r]

hello, the nailing i think would be from old dirty injector nozzles.
i dont have a 524td yet but i am in the market for one, so im no expert yet.

That being said, im guessing that there is a temp sensor that is causing the hot start issue.

the 10 gooahj wire could be a problem, maybe the glow plugs dont have full juice???

and the not cranking 4 out 5 times would tell me that the starter soliniod inst working....which would rebuild the starter or find a used one.

hope this helps

[CoyoteStarfish]

Thanks!

I can try replacing the strip fuse when the vehicle is delivered.

The wrecked 524 I worked on would start after 30 seconds of cranking with no glow plugs at all, but would smoke up all to heck before it cought.

This one does not smoke while cranking, takes longer and then nails.

When I try to start it hot, there is no smoke discharge either. And what really concerned was when the guy who was selling it gave it a shot of ether it even then it didn't fire up.

Yes, I know how bad ether is for diesels -- no lecture needed. But it usually does work as a last ditch effort.

The ether was predetonating, forcing the pistons backward, causing a huge strain on the starter. Maybe the valve timing is a little too advanced?

Good luck finding one, instg8r. I've been looking for 2+ years and just now got one

[bibaboon]

where you based starfish?

[CoyoteStarfish]

Based in Miami, FL.

[bibaboon]

ok
thx for reply
u seem like you will do well with a bmw
good luck with yours

[Kyle in NO]

The 524td cars can have a hard time starting if the in-tank fuel pump is dead. The main pump won't prime well and the crank time will be excessive.

Also note that the glow plugs don't stay hot when you are cranking. They only light initially and switch off when the timer tells them to. If your pump isn't primed, and you don't get any fuel to the engine until after the glow plugs are already cold, you will have a REALLY long crank time if it starts at all...

[bibaboon]

Also note that the glow plugs don't stay hot when you are cranking. They only light initially and switch off when the timer tells them to. If your pump isn't primed, and you don't get any fuel to the engine until after the glow plugs are already cold, you will have a REALLY long crank time if it starts at all...

kyle
so what are you saying? that its best to crank when green light comes on and not as good to wait until it switches on and then off?

[Kyle in NO]

You have two glow plug lights, one yellow and one green. The yellow one lights up when you turn the key and tells you to "wait" until the green one comes on. The green one means its ready to start. I always waited 2-3 seconds after the green light lit up to crank the engine, and it usually started almost instantly.

[bibaboon]

You have two glow plug lights, one yellow and one green. The yellow one lights up when you turn the key and tells you to "wait" until the green one comes on. The green one means its ready to start. I always waited 2-3 seconds after the green light lit up to crank the engine, and it usually started almost instantly.

yes...mine cranks up instantly then too...lovely sound it is



but a few times I also waited a few more seconds until the green goes out also and then I crank. The PO told me that was fine to do also but I seem to sometimes hear a slight thud then and worry if its a bad idea to wait until the green goes out also?

[CoyoteStarfish]

The electric fuel pump is working just fine. I bled all the injectors and filter housing thinking there might be air in the lines or no fuel delivery. Plenty of pressure.

I suppose my big question here is, if the cam or injection pump were timed incorrectly - would it have this affect on starting?

[wkohler]

The electric fuel pump is working just fine. I bled all the injectors and filter housing thinking there might be air in the lines or no fuel delivery. Plenty of pressure.

I suppose my big question here is, if the cam or injection pump were timed incorrectly - would it have this affect on starting?

There's another pump in the fuel tank. That's the one Kyle is talking about. Underneath the trunk carpet, there's a black access panel. the pump is under that.

[CoyoteStarfish]

Confirm:

There are 2 (two) electric fuel pumps?

[Kyle in NO]

but a few times I also waited a few more seconds until the green goes out also and then I crank. The PO told me that was fine to do also but I seem to sometimes hear a slight thud then and worry if its a bad idea to wait until the green goes out also?

Doing that pretty much defeats the purpose of having the glow plugs heat up and I wouldn't do it. Why wait? When the green light goes out the plugs are basically cold and you are placing unnecessary strain on the starter. Unless its like 100 degrees outside it makes no sense.

[altus22]

The electric fuel pump is working just fine. I bled all the injectors and filter housing thinking there might be air in the lines or no fuel delivery. Plenty of pressure.

I suppose my big question here is, if the cam or injection pump were timed incorrectly - would it have this affect on starting?

There's another pump in the fuel tank. That's the one Kyle is talking about. Underneath the trunk carpet, there's a black access panel. the pump is under that.

His electric pump is working since he was able to bleed the fuel filter housing. No, there is only 1 electric pump.

The ether detonating in the combustion chamber and forcing the pistons backwards is exactly why ether should never be used on diesels. This tells you that the engine has decent compression and valve timing.

The problem with not cranking 80% of the time, I would guess is the ignition switch, but could also be a sticky solenoid as mentioned earlier.

Once you get the car, I suggest redoing the timing from scratch so that you know you are starting from a good place there. I'd bet your hot start problem is related to the timing issue. Redo the timing belt timing and the static injection pump timing. Test the vacuum pump with your finger or a vacuum gauge once running.

The "nailing" I assume is an engine sound you're referring to. I'd guess that's also due to the timing being off. My engine has terrible piston slap when cold so part of your sound could also be that. Hope this helps.

[wkohler]

Well, I blame the Bush Administration for my not knowing that. I was under the impression that every E28 had two pumps.

[Kyle in NO]

The 524td has two pumps as well, the giant mechanical injection pump bolted to the engine block, and the electric one in the tank.

[bibaboon]

but a few times I also waited a few more seconds until the green goes out also and then I crank. The PO told me that was fine to do also but I seem to sometimes hear a slight thud then and worry if its a bad idea to wait until the green goes out also?

Doing that pretty much defeats the purpose of having the glow plugs heat up and I wouldn't do it. Why wait? When the green light goes out the plugs are basically cold and you are placing unnecessary strain on the starter. Unless its like 100 degrees outside it makes no sense.

Thanks Kyle...I agree to all you said

Im finally bringing in the 524td to my mechanic in the morning..thanksk goodness as Im curious now as all of a sudden with the weather getting colder and all whenever I crank in the morning after sitting it starts and then idles kind of noisy like its missing, popping or maybe even "nailing" as this thread orginally alluded to. who knows?

This piston clanking or whatever goes away after a few minutes when the car warms up which is good I guess but it has got me little concerned..I asked my mechanic on the phone if he thought it was missing on cold starts because of the timing belt about to go but he didnt think it had anything to do with the timing belt. Hopefully find out tomorrow thats its nothing to worry about much...

[bibaboon]

actually just started it tonight after sitting as Im driving it to the garage so my mechanic can see how it reacts in morning on starting...seems more like an ocassional thud or miss until it warms up..maybe its just bad diesel or as coyote said earlier
clogged injector or something..filter..? well see what mechanic says...hes my friend for 30 years but cant say hes an expert on diesels...

[Biomanco]

You have two glow plug lights, one yellow and one green. The yellow one lights up when you turn the key and tells you to "wait" until the green one comes on. The green one means its ready to start. I always waited 2-3 seconds after the green light lit up to crank the engine, and it usually started almost instantly.

What if my green light isint coming on at all ?

[Corner Carver]

You have two glow plug lights, one yellow and one green. The yellow one lights up when you turn the key and tells you to "wait" until the green one comes on. The green one means its ready to start. I always waited 2-3 seconds after the green light lit up to crank the engine, and it usually started almost instantly.

What if my green light isint coming on at all ?

Then at least one of your glow plugs is bad. Good time to replace all of them.

[Biomanco]

You have two glow plug lights, one yellow and one green. The yellow one lights up when you turn the key and tells you to "wait" until the green one comes on. The green one means its ready to start. I always waited 2-3 seconds after the green light lit up to crank the engine, and it usually started almost instantly.

What if my green light isint coming on at all ?

Then at least one of your glow plugs is bad. Good time to replace all of them.

Thanks a lot man got an idea if I have to go with Bosch or ngk the autolites are a bit different ??