Couple problems with my 325e

[Steevo]

Hey guys I'm not only new to the R3vlimited forums, but I'm also new to the BMW world. I've owned my 325e for about 2 weeks now and I'm already getting frustrated with it, because it's sucked my bank dry and it still isn't running properly.

If anyone could help me out with some info to fix the issues I'm having, I would be very very grateful.
I have a 1986 Arctic Blue 325e with black and white/cream leather interior.

The car won't start on some mornings, and if I turn it over while pushing the gas pedal up and down repeatedly and let it sit for roughly 30 minutes, it'll fire right up. Almost like I have to prime the fuel myself. So I figured fuel pump. I bought a fuel pump (the in-tank one, under the seat) and it wasn't the correct fit. We messed with it and eventually got it to sit in far enough that I could attempt to prime the fuel system, and it's still not priming with the newer pump. Does anyone have any idea? Did I replace the wrong pump? Do I need to order a correct fit one for it to work properly?

Also when I'm driving, the car bogs very heavily below 2k rpms, strong powerband from 2k-3k, then starts breaking up after 3k rpms. I also thought this was the fuel pump but I also have a feeling it needs plugs and wires, along with a full tune-up.

Neither of my passenger windows work. I haven't been able to test the motors yet, but I was just wondering if it is a common problem for these motors to go out? Or the switches?

My temperature gauge is always reading cold. I replaced the thermostat and the temperature sending unit (there was 3 sensors ontop of the thermostat housing?) and it still reads cold. Any idea?

The rear of the car shakes violently when I take off in 1st and 2nd. Feels almost like it's doing a really grippy burnout. lol


Like I said, I'm new to the BMW world and I really would like to keep this car but if I can't figure out the problems then she's gotta go. I'm also not a super skilled mechanic, so if you could answer in derp-terminology I'd be grateful. Thank you guys.:)

[Andy.B]

The car won't start on some mornings, and if I turn it over while pushing the gas pedal up and down repeatedly and let it sit for roughly 30 minutes, it'll fire right up. Almost like I have to prime the fuel myself. So I figured fuel pump. I bought a fuel pump (the in-tank one, under the seat) and it wasn't the correct fit. We messed with it and eventually got it to sit in far enough that I could attempt to prime the fuel system, and it's still not priming with the newer pump. Does anyone have any idea? Did I replace the wrong pump? Do I need to order a correct fit one for it to work properly?

You car came with two fuel pumps, a low pressure supply pump in the tank, and a high pressure pump in front of the driver rear wheel. What pump did you replace the in tank pump with? Did you convert it to a single high pressure pump? I can't imagine why the correct replacement pump wouldn't fit, unless a prior owner converted it in the past...

Before you spend more money replacing parts, I highly recommend getting a volt meter and fuel pressure gauge, and spend a few hours going through all of the checks in the fuel management section of the Bentley manual. You will find most, if not all, of your problems right there. Also, you will see over and over again that an intake leak test (smoke test) is critical on these cars. Vacuum leaks can cause lots of problems, but if you don't have access to a smoke tester, it is (in my opinion) more cost effective to simply replace all of the gaskets and seals as preventative maintenance, than it is to pay someone to do a smoke test and tell you you need to replace all the gaskets and seals because they leak. You can source all of the parts for about $150, and replace them with standard tools in an afternoon (including a new intake boot and crankcase vent hose) to ensure you don't have any vacuum leaks, and won't for a long time.

Keep in mind that old dme's can collect moisture and corrode internally, so it may actually be caused by a bad dme. Don't just assume that and spend money on one, however... rule out the other problems first.

Also when I'm driving, the car bogs very heavily below 2k rpms, strong powerband from 2k-3k, then starts breaking up after 3k rpms. I also thought this was the fuel pump but I also have a feeling it needs plugs and wires, along with a full tune-up.

What have you done so far? If it needs a tune up, it's worth doing, but don't just start throwing parts at it. That could be caused by a faulty afm, incorrect fuel pressure, etc. Properly checking everything as per the Bentley manual will point out what is wrong.

Neither of my passenger windows work. I haven't been able to test the motors yet, but I was just wondering if it is a common problem for these motors to go out? Or the switches?

It is common for the motors to get gummed up and seize. It is possible to disassemble the motor to clean and lubricate, and have it work again. If you search, there are pictoral diy guides around the internet.

My temperature gauge is always reading cold. I replaced the thermostat and the temperature sending unit (there was 3 sensors ontop of the thermostat housing?) and it still reads cold. Any idea?

On a 325e there are 4 sensors screwed into the thermostat housing. Did you replace all 4 sensors? The big/tall one with the plastic connector provides a ground for the cold start valve, the one with the plastic connector and one pole provides a signal to the cluster, the one with a plastic connector and two poles provides the temp to the dme, the one with two spade connectors acts as a temperature switch to the idle control module. Which one(s) did you replace so far? Did you make sure the correct connector is plugged in to the correct sensor? (one pole vs two poles?)

The Bentley tells you what resistance you should see at each of these sensors at different temperatures to test them.

The rear of the car shakes violently when I take off in 1st and 2nd. Feels almost like it's doing a really grippy burnout. lol

Have you lifted it off the ground to check for any loose/worn components? There are lots of rubber bushings in the rear suspension, and if they start failing, they can cause all sorts of problems. I would start looking things over in the suspension and drivetrain to see if anything is visibly worn or damaged. A drive shaft that is out of balance can cause some intense vibrations at low speeds/rpms.

If you want to avoid draining your bank account on the car, start investing in some basic tools and equipment, and learn to track down problems instead of spending money on solutions. Lots of r3v'rs have made that journey, and everyone here is willing to chime in and help if you get stuck. A Bentley manual will walk you through nearly every major diagnosis and repair on these cars, and were it doesn't, there is a wealth of DIY guides here, and elsewhere. Good luck!

[Gary Horneck]

Sounds like the inline pump is weak, and can't keep up with demands. Just get rid of the inline, and replace the in tank pump with a TRE 255 LPH Fuel Pump. I've never had a fuel problem since making the change. Cheap too. http://trefuelpumps.com/i-88969-bmw-...fuel-pump.html

No idea on the window motors, mine are all pulled.

Center support bearing shot will make it shake.

[tonerrrr]

First: Do not replace parts without at least diagnosing things first. Why did you replace the fuel pump? Did you check if it was turning on with ignition?

For the windows again, the simple thing to do is try a working switch in the plug for the window that isn't working. My sunroof "died" one day so I put the window switch where the sunroof switch was and it worked. It turned out my switch for the sunroof died.

If you throw parts at a car this old you're going to have a bad time.

Always troubleshoot first. One thing to do first is a normal tune up or even check all your fuses! Get some oem plugs, inspect all your suspension bits, inspect your spark plug wires, take off your distributor, etc.

For me, I wanted to start fresh so I replaced a lot of my suspension stuff and ignition stuff. These are things that have a maintenance interval anyway so I figured the PO probably didn't do it anyway. Get another O2 sensor, more than likely yours hasn't ever been changed. This is all preventative stuff but if you just want to get the car going, troubleshoot the simple things first!

[Steevo]

You car came with two fuel pumps, a low pressure supply pump in the tank, and a high pressure pump in front of the driver rear wheel. What pump did you replace the in tank pump with? Did you convert it to a single high pressure pump? I can't imagine why the correct replacement pump wouldn't fit, unless a prior owner converted it in the past...

Before you spend more money replacing parts, I highly recommend getting a volt meter and fuel pressure gauge, and spend a few hours going through all of the checks in the fuel management section of the Bentley manual. You will find most, if not all, of your problems right there. Also, you will see over and over again that an intake leak test (smoke test) is critical on these cars. Vacuum leaks can cause lots of problems, but if you don't have access to a smoke tester, it is (in my opinion) more cost effective to simply replace all of the gaskets and seals as preventative maintenance, than it is to pay someone to do a smoke test and tell you you need to replace all the gaskets and seals because they leak. You can source all of the parts for about $150, and replace them with standard tools in an afternoon (including a new intake boot and crankcase vent hose) to ensure you don't have any vacuum leaks, and won't for a long time.

Keep in mind that old dme's can collect moisture and corrode internally, so it may actually be caused by a bad dme. Don't just assume that and spend money on one, however... rule out the other problems first.



What have you done so far? If it needs a tune up, it's worth doing, but don't just start throwing parts at it. That could be caused by a faulty afm, incorrect fuel pressure, etc. Properly checking everything as per the Bentley manual will point out what is wrong.



It is common for the motors to get gummed up and seize. It is possible to disassemble the motor to clean and lubricate, and have it work again. If you search, there are pictoral diy guides around the internet.



On a 325e there are 4 sensors screwed into the thermostat housing. Did you replace all 4 sensors? The big/tall one with the plastic connector provides a ground for the cold start valve, the one with the plastic connector and one pole provides a signal to the cluster, the one with a plastic connector and two poles provides the temp to the dme, the one with two spade connectors acts as a temperature switch to the idle control module. Which one(s) did you replace so far? Did you make sure the correct connector is plugged in to the correct sensor? (one pole vs two poles?)

The Bentley tells you what resistance you should see at each of these sensors at different temperatures to test them.



Have you lifted it off the ground to check for any loose/worn components? There are lots of rubber bushings in the rear suspension, and if they start failing, they can cause all sorts of problems. I would start looking things over in the suspension and drivetrain to see if anything is visibly worn or damaged. A drive shaft that is out of balance can cause some intense vibrations at low speeds/rpms.

If you want to avoid draining your bank account on the car, start investing in some basic tools and equipment, and learn to track down problems instead of spending money on solutions. Lots of r3v'rs have made that journey, and everyone here is willing to chime in and help if you get stuck. A Bentley manual will walk you through nearly every major diagnosis and repair on these cars, and were it doesn't, there is a wealth of DIY guides here, and elsewhere. Good luck!

This is the most helpful post I've ever received on any forum I've ever been a part of, and miata forums (I'm also a miata owner) are typically extremely good. Thank you very much haha.
As far as what I've done so far: I have only replaced the clutch for the clutch fan, that temp sending unit (all the P/O said was wrong with the temp gauge ), the thermostat, and I'm going to replace the odo gears whenever I find the time to.
I was going to track down the problems a little more in-depth but when the car was acting like it does, I instantly assumed fuel pump. The pump I bought was a factory replacement from autozone but it did not match the one in the car.

In the second photo, there is 2 hoses running out of the one inside the car; however the replacement only has 1 hose spot. The other is welded closed? I believe it is the return hose?
Is this bentley manual sold at any autoparts store or do I need to order one? It seems like this manual will be extremely helpful haha.
I have jacked up the underside of the car, and all of the suspension bushings look relatively new. Everyone that has ridden in the car has said driveshaft instantly.
I will look into the smoke-tester, I have a few friends who are certified BMW techs and I'm sure I can get a hold of one somewhere around here haha.
Thank you again for all the answers!

[NoM54me]

The driveshaft center support bearing can absolutely cause that rear-end shaking, and you can't visually inspect it easily without moving some things around first. Luckily, it's relatively easy to replace, and cheap. Buy the Bentley manual on Amazon, but a Haynes manual will keep the car on the road...it's all I've ever used. Your no-start condition could be caused by a number of things. If the engine turns over rapidly, one of the two sensors on the transmission bellhousing-ignition speed and reference sensors-could be bad. Search for test procedures. Do you have the 13-button OBC? If so, the "code" function might also be causing your no-starts via a faulty relay. The ignition switch circuit goes through the relay. The OBC relay is a black box by the hood release. You'll find a green wire snd a green and red wire. Cut them, and connect them. Voila! OBC bypassed.The OBC and temp gauge share a harness, which plugs in to the cluster right behind the temp gauge. If the OBC doesn't work, the harness connection might be wonky, which might also cause the temp gauge needle to be wrong. If you remove the knee bolster under the steering wheel, you can reach the harness connector. Wiggle it around some, see if that wakes the needle up. When cars go bad after nearly 30 years, you have to begin to look beyond the obvious.