1995 325i won't start, was running great. new to site
 

I was googling around and trying to figure out where to start trouble shooting my '95 325i I found some good information at this site and decided to join. I drove it one night then parked it. moved it to another spot on property and parked it, went 2 days later in the morning to start it up and go and it turns over and just barely sputters. It's not catching and starting. I checked the battery and it tests ok.
Does anyone have any ideas as to what the problem might be.

If it cranks okay but won't catch, my guess (and I do mean "guess") is your fuel pump, fuel pump relay, possibly fuel filter.

I admit I'm a novice at best when it come to working on cars. I bought this car in july 2008. It was always dependable until the cooler weather set in, around October. at that time it all of a sudden one morning upon starting, started up but it was chugging and blowing blue exhaust. I figured it was a sensor. so I said to heck with it and let it sit for about 2 or three weeks. Then one morning I felt lucky and went to crank it over and bingo! Started up like a charm and ran great. I just intuitively thought it was a sensor and figured maybe the cars computer system would catch up to the climate change. Now, here it is December, I drove it 40-50 miles one night, seat warmers on, heater on, lights on, cd player on. I was on the highway though for some of this. two days later I moved it to park it in a better spot. It was a cold day. It sat for about 4 days. Early in the morning and it was one of those frozen frosty cold mornings, I went to start it and it just cranked and tried to catch a couple of times. I turned it over 5 or 6 times in 20 second intervals. the cranking just kept getting weaker.
So, I figured it's the battery. I removed the battery and took it to auto zone and it was at 75% charge. they charged it up for me and tested it under a heavy load and told me they were sure the battery is good. The battery is an interstate but it's an '02.
I tried starting it some more, same result. Today it was 2 degrees. So I figured I'd put the battery to the test and see if it peatered out under the extreme cold. After 5 attempts at starting with 20 second intervals and different throttle positions it stopped wanting to turn over. I'm thinking the autozone dudes are not familiar with the extra demands these cars put on batteries. It could be the fuel pump though because was sputtering a little bit at times for like 2 seconds like it wanted to start, yet it never really fired up at all. I kept wanting to use starter fluid, I refrained from doing so. I don't know. fuel pump, battery, sensors, timing? I need help. Thank you!

Hey, Thank You 3050RPM!

With this car I've always had to crank it over for around 2 seconds or maybe a little more; Especially upon the the 1st start of the day. Does this further indicate a failing fuel pump? In other words, does the fuel pump slowly deteriorate and then finally kaput? Again thank you, I really do appreciate the help.

Other Problems Too. Trunk won't open, "coolant level low/check owners manual", the ambient temp is reading -37 f Yet the coolant level is not low and the outside temperature is not minus 37. Where are the sensors? Quick fix for the trunk? Will these sensor issues affect the vehicle operations? Any information and experience is greatly appeciated.

As to the trunk not opening, you're probably not aware that the trunk lock button has a couple of different positions tied into the central locking system. Just insert the key and rotate 90 or 180 degrees or whatever and that should take care of that.

The "check coolant level" message is a rather common anomaly, having to do with surface corrosion on the prongs of the sending unit, located I think at the base of the expansion tank. I think you pinch the two clips on the side and remove it for cleaning, but I can't fully remember. In any event, it's a false reading.

Your ambient temperature sensor is either missing or broken. I think it's located by one of the fog lights, but not sure. Won't affect driving.

As to warning signs from a failing fuel pump, you might hear a whirring sound upon starting the car indicating it's on its way out. Generally though, I think they just fail without notice.

If the car requires some prolonged cranking to get started, it could be plugs, injectors, I'm not sure perhaps even crankshaft position sensor, and perhaps a lot of other things. It would help if you had service records or somehow knew what was last done on the car and when, it sounds as if it might need a thorough going through of the basics.

I now have irrefutable evidence that Santa Clause is real, furthermore he is a bmw enthusiast and goes around fixing peoples BMW's while their sleeping. Skeptical? Quantum physics accounts for the fact that the same matter (Santa) can exist in many places at the same time, this renders the theory that only the "spirit" of Santa exists obsolete and explains how Santa can cover the entire globe in just one night. Joking, yet overwhelmed with gratitude.

Here's why I say this, the morning of Dec. 24th the car started!

Santa is real! I think, but just to be on the safe side I'm going to change my spark plugs.

THANK YOU 3050RPM

3050RPM, here's what I think happened: For the last few months I've been driving in automatic mode and driving short distances around town.

Then that one cold morning I moved the car to a more favorable position about 10 or 20 feet while the engine was cold. After parking I let it sit for about 4 days as the weather got increasingly colder.

I'm reasonably confident that my spark plugs fowled as a result of two things; 1. Not driving in manual mode and just kind of "dogging" it around town hence the accumilation of carbon on the plugs and possibly elsewhere. 2. moving the car 15 feet while cold and parking did the rest.

After getting it started I switched it into manual mode and went for an elated joy ride deliberately keeping up the RPM's with the intention of incinerating any residual accumilation. THANK YOU 3050!

Perhaps somewhat related to your experience, I had something very weird happen to me a few winters ago. It was a particularly cold spell we were having, and I was only driving the car for short distances to run errands and such, and then leaving it parked outside until repeating the routine the next day.

One morning the car just wouldn't start, despite cranking strongly. After several attempts, and before I wore the battery down, I had it towed to my mechanic.

What he found was quite surprising, the O2 sensor was useless because it was wet with water, which came about because the catalytic converter had filled with water, and when he drilled a small hole in the converter he out came about a quart of water. New O2 sensor and a check of the diagnostics to make sure nothing else was awry and I was on my way.

The explanation is still elusive, but somehow it seems that when the car was being driven those short distances, water vapor was generated in the exhaust but not fully expelled. When the car was shut off, and with the cold weather, whatever water was in there froze. Repeat this a few cycles and voila, ice and water buildup, inoperative exhaust, inoperative O2 sensor, inoperative car.

I'm not sure if that explanation makes sense, but it could mimic your experience.

Very likely yes. The weather conditions were exactly conducive for this to happen. We went through a spell of rains during the day and then eventually freezings at night preceding the won't start episode.

Immediately prior to and during the actual refusing to start, the weather was bitterly cold and freezing. Again, it had rained consistantly for days at just barely above freezing point and almost certainly dipping into freezing temperatures at certain points. Then everything froze solid.

I anticipated problems knowing only that water could potentially have found it's way into the engine compartment and cabin and then froze.

The day it finally started, yesterday, the air temperature was about 47 degrees and it was raining. I just thought, well it's thawed, so I gave it try. This is sort of funny but I thought maybe there was a saftey sensor in the seat to be sure passenger side kids could not start the car if there was no one in the driver seat; so I bounced up and down in the seat knowing the leather was cold and taunt and could possibly prevent the sensor if present from being activated. I also adjusted the seat to further ensure this. Then I pressed the peddle to floor and released it five times and then repeated this.

The car cranked over and did not start, I waited 30 seconds, cranked it over and it sputtered and started.

Early this morning while still very cold about 10 degrees, started right up. I'm leaning towards the frozen oxygen sensor theory.

Could well be water/ice in the catalytic converter, but just to give you something else to worry about, fuel pressure regulator. Since you mention all that rain, your ECM (I think that means Electronic Control Monitor, or something like that) could have gotten wet.

3050rpm, I drove the car 1600 miles round trip all interstate. Ran great there and back and have had no starting issues since. Interesting car to say the least. I did have moderate weather and no precipitation and am still having good weather.

As for the trunk not opening; I tried the different key positions with the master key and no luck. The tumbler turns and pushes in or out and unlocks all four doors from the trunk yet the trunk is not opening. Is there a safety theft code or something I'm overlooking? Or perhaps a button somewhere. Is there a trunk open lever inside? I'm not sure if it's a mechanical issue or an electronic issue?

Okay, maybe the extended trip frightened away the evil spirits. There is no security code for the trunk, nor am I aware of any release mechanism. It could be that somehow a tight seating has developed between the trunk lid and the rubber seals (cold, wet weather), so you might try putting the key in various positions, pushing in on the trunk button, and just giving a mighty heave on the trunk lid. Also, if you have fold-down rear seats, that would let you get into the trunk that way and poke around with the locking mechanism, it doesn't seem like an electrical problem.

3050rpm I tried various key positions and lifted heavily on trunk lid, still no luck. The rear seats do fold down and I looked around in there and have ruled out the rubber seal theory.

I'm wondering if a previous owner slammed the trunk and jammed some metal together or something?

The owners manual says some confusing things about the trunk, master key, and the inter-relation between the cars anti-theft system. However I'm not sure my particular car has an anti-theft system.

I'm thinking the old WD-40 in the key mechanism. My other thought is that perhaps there is seperate fuse for the trunk?

I'm going to re-read the trunk and anti theft paragraghs in the owners manual. I'm optomistic and still thinking it's something simple.

Your ambient air temp sensor DOES affect your COLD START enrichment map program running inside the Motronic ECU (Engine Control Unit). If its reading -37 degrees that means it is either missing or has a broken/disconnected wire or in other words infinite resistance. Fix it you will have fewer problems, they're cheap.

The Trunk issue is not electrical if it fires all the door locks when you rotate the key in it. Are you pushing the button in while the key is turned? My 87 if freaky that way while my 86 is not. DO NOT spray WD in the lock mechanism unless you want all the electricals to fail.

Sensors on these cars, and ANY vehicle with a computer, are VERY important since that is how EVERYTHING from your fuel maps, dwell timming and on and on and on are controlled. Without the proper information from ALL of the sensors the computer will simply hunt and peck to get it to kind of work if at all. Hence the long cranking sputtering and crappy start up quality. In fact when starting one of these cars its best to turn the key on hit the brake, push the check button on the overhead and then crank, giving the computer a few seconds to get the sensor data and set the start up map before you try to start it. Your car will actually start faster and run better if you do that.

As far as the crank sensor is concerned, if while cranking the engine, the check engine light stays on, then the vehicle is not getting a signal from it and will not start at all. If it loses the signal while driving it will stop running. If the car starts and runs and doesn't simply sputter out intermittently then there is nothing wrong with that sensor/wiring.

Other critical sensors are you mass air flow wich includes your baro sensor, and your throttle posistion sensor. They are both mechanical sensors and do wear out. Also make sure there are no leaks in the vacuum system or the rubber elbow boot between the maf and the throttle plate, it should be tight and fully intact. AutohauseAZ for like 27 bucks or something for it for a new one.

Make sure ALL the sensors read and the hookups are secure and tight in the vac and intake system, most of your problems should disappear. As far as water getting into a cat and freezing especially a quart!? that sounds like a head gasket issue as any water in front of the converter would HAVE to go through the engine, and that you would notice. Good Luck