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Car cut out while driving - wont restart! Help!

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weejangus
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Car cut out while driving - wont restart! Help!

Post by weejangus » Fri Apr 05, 2019 6:55 pm

Hi all,

This morning was a day I'd been looking forward to for the past 25+ years... the day I finally took ownership of a BMW E24 635 CSi!

Have loved this car since I was a kid and I now have one!

It started and drove fine for the first 10 / 15 minutes but all of a sudden it lost power and cut out. It rolled to a stop and now doesn't even try to start.

I turn the key, all the instrument lights come on, turn further and... nothing.

It doesn't crank or anything.

I've checked the battery, hooked up a Jump Starter pack and it's still the same. I'd have guessed that the starter motor isn't working but that doesn't explain why it cut out in the first place.

As I'm new to this car, I was wondering if there is anything obvious I can check. Hoping it's something simple!

Any help would be very much appreciated.

Jay

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tschultz
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Re: Car cut out while driving - wont restart! Help!

Post by tschultz » Fri Apr 05, 2019 8:00 pm

What year and is it an automatic?

weejangus
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Re: Car cut out while driving - wont restart! Help!

Post by weejangus » Fri Apr 05, 2019 8:01 pm

It's a 1987 automatic.

Don't know if it's related or relevant but I've noticed that the fuel pump appears to be buzzing away when I put the ignition on.

I don't think it was making that noise when the car was delivered this morning but it's quite noticeable now.

Having done some research, it looks like the fuel pump isn't supposed to function until you actually try to start the car. I confirmed that the noise is definitely the fuel pump by removing Fuse 11 under the bonnet - the noise stopped.

Any ideas?

Pod
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Re: Car cut out while driving - wont restart! Help!

Post by Pod » Sat Apr 06, 2019 11:09 pm

Read the thread "M635 not starting". This should give you some pointers.

I'm wondering if the previous owner had similar issues? Why not contact them and see what they did to get it running?

Good luck.

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miklilmag
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Re: Car cut out while driving - wont restart! Help!

Post by miklilmag » Sun Apr 07, 2019 12:14 am

Hello,
Whatever happened sucks!
BIG time!
points to a faulty main relay!
Good luck!
Franke

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miklilmag
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Re: Car cut out while driving - wont restart! Help!

Post by miklilmag » Sun Apr 07, 2019 12:21 am

Hello
The whole not cranking thing throws things off,
If you have it in park, on rock the whole car back and forth, still no cranking afterwards?

Franke

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tschultz
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Re: Car cut out while driving - wont restart! Help!

Post by tschultz » Sun Apr 07, 2019 9:00 pm

Could be the automatic neutral safety switch relay that is preventing the starter circuit from being completed.

weejangus
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Re: Car cut out while driving - wont restart! Help!

Post by weejangus » Mon Apr 08, 2019 7:29 pm

Thanks all for the responses so far.

I did contact the previous owner. He is very apologetic and I genuinely don’t think this happened in his ownership. He’s in his 60’s and had owned the car for 26 years. He did however phone the garage that knows the car well. The only thing they could think of is a bad starter (but that doesn’t explain the cutting out).

Tried rocking it in Park and still no luck (but thanks for the suggestion).

Had a mechanic look at it briefly and he thinks it’s definitely an electrical issue. So relays and the starter motor will be his first port of call. He did see a black / yellow connector that looks like it should have been attached to the starter but wasn’t connected. Reconnected and still no crank.

Took the cover off under the steering wheel and found 4 more black / yellow wires not plugged in so I think someone’s rewired the starter at some point.

Should be getting collected tomorrow and taken to his garage for a proper inspection and diagnosis (Limited with what he could check on the driveway).

Please keep throwing ideas out there and I’ll pass them on.

I’m not even angry at the car, it still looks amazing! Haha!

Thanks all

J

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Hefeweizen
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Re: Car cut out while driving - wont restart! Help!

Post by Hefeweizen » Mon Apr 08, 2019 11:33 pm

Do you get power to the starter? Tried going straight from the battery to the starter? Checked all the fuses and relays?
Rainer
03 330Xi (DD)
85 635CSi (RIP 3 May 19)
80 633CSi (Red Euro, Project)

"If you think a good European mechanic is expensive, try a bad one!"

weejangus
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Re: Car cut out while driving - wont restart! Help!

Post by weejangus » Tue Apr 09, 2019 10:31 am

Thanks for the suggestion. Tried that this morning. Nothing.

Got recovery out and the chap reckons the starter is gubbed. He also tried sending power right to the starter and got nothing. He expected even a clunk but nothing happened.

Cars been taken to a local trusted mechanic so I’ll update when I know anything.

Thanks again for the replies. This looks like its a great forum. I look forward to getting to know you all.

Jordan

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Hefeweizen
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Re: Car cut out while driving - wont restart! Help!

Post by Hefeweizen » Tue Apr 09, 2019 11:00 am

Freaky things do happen with this car. Your two problems may not even be related. The cutout may just be the fuel relay.
Rainer
03 330Xi (DD)
85 635CSi (RIP 3 May 19)
80 633CSi (Red Euro, Project)

"If you think a good European mechanic is expensive, try a bad one!"

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panthercity
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Re: Car cut out while driving - wont restart! Help!

Post by panthercity » Sat Apr 13, 2019 6:19 pm

I had this happen to me a few years back. An inline battery cutoff switch was installed at the battery terminal at the time. It was failing.

-I'd check for loose and corroded ground connections and a good & tight positive circuit from the battery.
-My Main relay got wet once and the entire electrical system was out until it dried up. I now carry an extra one in the trunk since you are dead on the road without it.
'85 635CSi Euro
Image

weejangus
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Re: Car cut out while driving - wont restart! Help!

Post by weejangus » Mon May 20, 2019 5:03 pm

UPDATE

So after getting the car running very briefly today, it was very clear that something wasn’t well within the engine itself. Very loud knocking noise. My mechanics face confirmed that the engine was no more!

He believes that there may have been a blockage or failing oil pump that resulted in the big end bearings being damaged (but he’s not opened the engine to check).

I’ve managed to source another engine and this is being shipped up. The old engine will be swapped out for the second hand unit.

Is there anything that NEEDS to be done while the engine is out? I’m thinking replace the head gasket, water pump, oil pump while the engine is easily accessible.

Any other advice would be greatly appreciated. Might as well deal with these costs now. Haha!

bpoliakoff
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Re: Car cut out while driving - wont restart! Help!

Post by bpoliakoff » Mon May 20, 2019 6:09 pm

If you are going to pull the head and the pan you may as well double check the cylinder bores and all bearings as you can do a cheap rebuild without any machine work or at least make sure all is up to spec. You might even consider a 5 speed swap while the motor is out. I guess it just depends on how thick your wallet is.
81 Euro 635 M90 with motronic. Currently under a complete nut and bolt restoration. Pictures at
flickr.com/photos/bertsphotos.

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mdkohler
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Re: Car cut out while driving - wont restart! Help!

Post by mdkohler » Sun Oct 27, 2019 11:13 pm

Weejangus, I have a new head gasket and 5 valve cover gaskets if needed.
Marc
Austin, Tx
1985 635CSi Euro

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Brucey
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Re: Car cut out while driving - wont restart! Help!

Post by Brucey » Tue Oct 29, 2019 8:41 am

word of warning; 1987 is a changeover year. If your car has chrome bumpers and was built before 6/87 then you need a M30B34 motor and if it is an aluminium -bumpered car (highline) you need an M30B35 engine. They are quite different from one another and whilst it is possible to swap between the two it only adds complications.

cheers
~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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