87' 535i Won't STAY Started If Cold - BMW Forum

Hypnotised · 12-20-2007, 02:53 PM

My 87' 535i runs like a champ always, UNLESS IT'S COLD, then it won't even start. It was doing this a couple months ago, then it just stopped, and was starting fine, EVEN WHEN IT WAS COLD OUT. (I mean cold for Los Angeles, which is below 50.) If it's cold out, it turns over fine, and starts RIGHT UP, but only stays started for one whole second before dying! I wait a minute or two, it turns over and starts RIGHT UP, then dies immediately. I don't need to press on the accelerator when starting since it's fuel injection, so IT IS NOT FLOODED. I can assure you it's not flooded, or it would not turn over and start so quickly EVERY TIME like that. I sat in my car today after work and played that stupid game for 45 minutes. IT WOULD NOT STAY STARTED. I never know when the hell it's going to do this. It's a little maddening now. I had to leave it at work tonight and take a damn bus home. (No BMW owner should be taking a bus home from work.)
Here's a couple factors which may play into it. The temperature gauge in the car HAS NEVER WORKED. This means that the wire from the sending unit is shorted out or corroded somewhere. Could the fact that the gauge doesn't work, mean that the computer doesn't know what the engine temperature is, causing this reaction? Just a thought. Could that be effecting the DME chip somehow? If I get that temp gauge fixed, do you think it might solve this problem?
Is it something totally different?
I'd appreciate any feedback on this. I posted about this problem about six months ago, and someone suggested it's the vacuum pressure in the engine. It's not that. Someone else said a new DME chip. Those are EXPENSIVE (Rebuilt on pelicanparts.com is $497.00.). It's got to be something else.
Someone mentioned maybe a cold start valve? Hell, it's only about 50 degrees outside!
It's making my life miserable, and I really want to get to the bottom of this.

Thank you.

Tom B.

Hypnotised · 12-30-2007, 06:51 PM

Gosh, I posted this 10 days ago. Doesn't ANYONE have a clue what is causing this weird thing?
Because it is so random and so unpredictable, it seems like it has to be something electronic, or computer related.
I don't know, though.

Tom B.

AlpineSixAndSeven · 12-30-2007, 07:44 PM

sry for the slow reply but that is a complicated issue you got there.....
it could be that the tempeture gadge's sensor went out then the temp sender for the cold start valve whent bad as well i'd say replace them both there on the thremostat housing to my knowlage...

Hypnotised · 12-31-2007, 12:43 PM

Hey thanks for the reply. I know. It is a complicated problem. Thankfully it doesn't happen often, but when it DOES HAPPEN, it's a MAJOR PROBLEM for me.
I will try both of those fixes.
Thanks again.

Tom B.

Quote:

Originally Posted by AlpineSixAndSeven

sry for the slow reply but that is a complicated issue you got there.....
it could be that the tempeture gadge's sensor went out then the temp sender for the cold start valve whent bad as well i'd say replace them both there on the thremostat housing to my knowlage...

AlpineSixAndSeven · 12-31-2007, 05:35 PM

let me know how it goes.

Hypnotised · 01-08-2008, 02:47 AM

We're having a cold snap out here in California, and it's below 50 at night, and colder than usual during the day. It won't start at all, which leads me all the more to believe it may be the cold start valve. I'm just kind of broke right now, so I'll have to wait on it
I was doing some research in my 5 Series Haynes Manual, and was wondering if a Thermo-Time Switch was also necessary, or possibly the problem?

Thanks.

Tom B.

AlpineSixAndSeven · 01-08-2008, 02:53 AM

lol yeah it is cold.... i'm in the bay area......
yep this cars cost more then average... but their worth it when their running right

Hypnotised · 01-08-2008, 01:26 PM

I'm not sure if that cold start problem has manifested itself into this problem or not, but now my car will not start at all, and the battery will not hold a charge. It would just barely even turn over yesterday, as if the battery were dead. I took the battery out and walked it to my AutoZone store, and they charged it and tested it, and they said the battery is fine, and it holds a charge. Put it back in, and it still will not start. It turned over, but wouldn't start. Same problem as before. It seemed to drain power rather quickly after 4 or 5 tries. This morning it sounded like it was nearly dead again! I had to push it across the street so I wouldn't get a ticket.
What on earth is draining that battery? It is supposedly good, and this is a brand new problem. It just will not stay charged. It seems that that whole "not starting when it's cold" problem, has maybe COMBINED with some other electrical problem, that is now driving me nuts.
HELP!!

Tom B.

AlpineSixAndSeven · 01-08-2008, 05:59 PM

It takes alot to start these cars. hmm take the battery out of it and put it on a charger in your garage/house/aprt. and charge it for 24 hours...
then put it in your car but dont crank it....
Come back 24 hours later if it cranks good then batt is good and there is no electrical drain...

ldsbeaker · 01-08-2008, 08:45 PM

You could also have some fuse/relay problems.

AlpineSixAndSeven · 01-08-2008, 08:48 PM

yeah, I just want to make sure that there is now short somewere......
could be a relay maybe the main relay.....

Hypnotised · 01-09-2008, 05:47 PM

...or possibly the alternator is shot??

I got that battery totally charged, and when I put it back in, it STILL sounded like a slow turnover. With each progressive crank, it just SLOWER AND SLOWER AND SLOWER, until after about three cranks, it sounded nearly dead again! That's after the battery being totally charged! There's a drain somewhere.
So the main relay?... or maybe the alternator?
I need someone with a voltage meter to fully check that system out.

Will keep you posted.

Thanks again.
You guys are helpful.

AlpineSixAndSeven · 01-09-2008, 06:10 PM

don't think it is the alternator...... really how lonng was the battery charged for? where are you located...?

Hypnotised · 01-13-2008, 02:39 AM

I had a mobile BMW mechanic come out to diagnose. This was a difficult diagnosis. He deduced it was the Crank Position Sensors. Who knew?? Not I. You need two. I found 2 on EBay Motors for $75.00. Normally $52-57 each. He also said my battery was old and cheap. Way past time to replace it. Will rectify these two problems in the next couple days. I'm thinking that that chronic cold start problem may also be connected to that bad Crank Position Sensor. I think it just finally manifested itself to this point. I'm crossing my fingers that this will finally resolve all these maddening problems.
Will let you know.
I'm in Los Angeles.

Thanks.

Tom B.

Quote:

Originally Posted by AlpineSixAndSeven

don't think it is the alternator...... really how lonng was the battery charged for? where are you located...?

AlpineSixAndSeven · 01-13-2008, 02:53 AM

ok never thought of that....
hmm hopefully that will fix every thing! fingers crossed!