My free E30 has some issues (surprise!). A little help E30 people?

So I am again a BMW owner after my father-in-law gave us 1991 325i convertible as a wedding present. You guys said to take it, so I did.

It's actually been really good, for a free BMW. Two long road trips with only minor issues. Got 30 mpgs even. Engine seems strong, transmission feels like rowing a wooden spoon through a bag of pretzels compared to my Miata. Ergonomics are great for me (it's definitely built for tall people, my wife can hardly drive it.), pedals are perfectly spaced, even if they seem bathed in molasses. The steering has a ton of feel, but is slooooow (needs a Z3 rack), and it just has a sort of unhurried feel, especially compared to the Miata. The car sort of grows on you. At first it feels like a grumpy old man, but it's charms become apparent after driving it a bit.

The issues I'd like to address:

1. Wiring. There is a drain from the OBC, and perhaps a few other things in the dash. I pulled that fuse (I think it was 17), and my multimeter shows there is no longer a drain. There are some wires sticking out of the dash. Great! The windows also stopped working randomly the other day. All of them. Then they started working two days later. Great! Any ideas on why that would happen?

2. Random no start. After I pulled that fuse, the parasitic drain seemed to go away. It started every time for a month. But then the other day my wife started it, stalled it because it hates to be cold, and then it wouldn't start. Nothing would turn on, the battery seemed to be stone dead. How could that be?

3. It leaks a ton of oil. Mainly, because it has a Home Depot bolt in the oil drain hole, which doesn't seal. For some reason, my dad in law's mechanic put some cheapo bolt in there. I noticed this when I tried to tighten it, and it was not the correct size and looked like something out of a piece of furniture. When I asked the oil change guy to put in the right bolt, he said it didn't fit. I'm thinking the mechanic rethreaded the hole or something just to fit this stupid bolt. So I am going to try to retap the hole. Hopefully that goes well.

4. It runs really rough when it's cold. Really wants to stall. It was especially bad the other day when it rained. Gulp.

Alright, thanks for any help.

Check both ends of both battery cables for looseness or corrosion

Pull the ECM and take the connector off. I'll bet you find a bunch of silver flakes. The pins are plated and the plating comes off making random intermittent non-continuity which can make a host of issues. Blast it out with air and that usually keeps things good for a little while. The real solution is a $50 junkyard ECM that is still in good shape.

Same thing for the relays under the hood. That could explain the no-start and the windows.

The main relay is notorious for failing. I carry a jumper wire with spade terminals in my old Bimmers, and put 3 dots of paint on the relay socket where it goes. That because a lot of the spare relays were junkyard pulls and they're often bad after not getting worked out regularly.

Vacuum leaks are a problem...Neglected Bimmers have rotty intake boots. They rot early and often.

Your idle air control valve may be sticky, or depending on the year, the cold start injector could be clogged or leaky.

What you have is a car that needs a good baseline: replace the intake boots, clean the terminals on the ECM, relays, fuses and sockets. Clean and tighten the grounds and battery cables. Clean the IACV. Replace the rubber fuel hoses and clamps. Valve lash adjustment and make sure the valve train spray bar banjo bolt is tight.

The oil pan isn't going to be fun. After all that, it will run okay and then you can attack the bushings.

Welcome to Bimmer ownership!

If a guy doesn't buy my two m20s tomorrow I might be able to pull an oil pan for you if that helps.

curtis73 wrote: Pull the ECM and take the connector off. I'll bet you find a bunch of silver flakes. The pins are plated and the plating comes off making random intermittent non-continuity which can make a host of issues. Blast it out with air and that usually keeps things good for a little while. The real solution is a $50 junkyard ECM that is still in good shape. Same thing for the relays under the hood. That could explain the no-start and the windows.

Thanks! I'll check the ECM. For the relays under the hood, you're saying the silver plating comes off and I need to sand them clean?

Tyler H wrote: The main relay is notorious for failing. I carry a jumper wire with spade terminals in my old Bimmers, and put 3 dots of paint on the relay socket where it goes. That because a lot of the spare relays were junkyard pulls and they're often bad after not getting worked out regularly. Vacuum leaks are a problem...Neglected Bimmers have rotty intake boots. They rot early and often. Your idle air control valve may be sticky, or depending on the year, the cold start injector could be clogged or leaky. What you have is a car that needs a good baseline: replace the intake boots, clean the terminals on the ECM, relays, fuses and sockets. Clean and tighten the grounds and battery cables. Clean the IACV. Replace the rubber fuel hoses and clamps. Valve lash adjustment and make sure the valve train spray bar banjo bolt is tight. The oil pan isn't going to be fun. After all that, it will run okay and then you can attack the bushings. Welcome to Bimmer ownership!

Thanks! Is the oil pan a pain the retap? Because it's aluminum?

In reply to Stampie:

Thanks!

Window switches sometimes need disassembled and cleaned, really easy to do.

You might want to regrease the window tracks, they gum up pretty bad. I just did that on the daughter's e30, windows roll up and down real nice now.

There is a main breaker button in the middle of the dash (looks like the hazard button and defrost button, but has a red line around the inside). If this breaker tripped, the windows will all shut off. Press that button and see if it will reset.

irish44j wrote: There is a main breaker button in the middle of the dash (looks like the hazard button and defrost button, but has a red line around the inside). If this breaker tripped, the windows will all shut off. Press that button and see if it will reset.

I came here to say this and was beaten by 2 minutes.

If it has an oil cooler, there is thermostat up on the side of the block. It's leaking a lot of oil most likely as well.

That drain plug is a vacuum leak. Everything that leaks oil on a BMW is a vacuum leak. It makes them run rough. Also, the idle control motor gets gummed up and when it's cold it fails to regulate well. Clean it with gumout. Check every single rubber hose connected to the underside of the intake and the boot itself for cracks while you are fishing around in there.

Check the cap/rotor/wires. Many a damp E30 has misfired due to problems there as well.

CLEAN the GROUNDS. All of them.

irish44j wrote: There is a main breaker button in the middle of the dash (looks like the hazard button and defrost button, but has a red line around the inside). If this breaker tripped, the windows will all shut off. Press that button and see if it will reset.

I've heard about this button, but my dash doesn't seem to have one. There is some weird little red indicator light next to the hazards above the stereo, looks like a part of a crappy alarm system. I'm wondering if some smart fella took that button out to put some indicator light in.

Thanks for the info Huckleberry.

CyberEric wrote: Thanks! Is the oil pan a pain the retap? Because it's aluminum?

No, It's because the subframe, steering rack, and swaybar are in the way to get it off the car. Given the low price of admission, you may consider tapping it in place?

Another main factor for a rough running M20 is a failed ECU coolant temp sensor. I don't have all the docs anymore, you should be able to find the spec on R3Vlimited.com, and be able to test the resistant on the sensor to see if it's done.

Here is an online database of the electrical troubleshooting manuals: http://wedophones.com/Manuals/BMW/ With luck the advice above will cure your drain problem because if it doesn't, you have to start tracking things down circuit by circuit.

Don't sand the ECU contacts. Just blow out both sides of the connector to get rid of any crud that might be shorting things out. The ECU that goes with that motor is pretty tough and in my experience, it doesn't develop internal problems.

Plenty of good advice above. For the rough idle issues I would start with cleaning the ICV, then start replacing the rubber intake boot and the vac lines. Once I got a vac leak when the intake manifold gasket gave up the ghost but that's not common unless the manifold has been off the car at least once.

Then I would move on to test the sensors that feed engine condition data to the ECU, starting with engine coolant, then crank position sensor, then O2, then maybe the air flow meter. Not likely the throttle position sensor, but it doesn't hurt to test that too. Google the resistance or voltage values you're looking for.

Then I would be looking at ignition. It's never the coil but it's easy to test the resistance so I would. It's almost never the plugs but again, it's easy to check. I once had a distributor cap that I couldn't see a single thing wrong with, but it would cause no-start conditions that all went away when I replaced it. Might be old plug/coil wires, but a replacement set for the car isn't that cheap, so I would leave that towards the end of my list.

I think the probability of fuel pressure interruptions is low based on your symptoms, so I wouldn't hit it with a pressure gauge. Same for injector problems. I might pull the back seat cushion off and see if the electrical connections to the pump are okay; it's not hard. I most definitely WOULD inspect the crap out of the rubber fuel lines in the engine bay. On a car this old, I'm worried they could suddenly develop a pinhole leak that would spray gas on a hot motor part and catch fire. I don't worry too much about the rubber lines back by the tank, because when they start to leak, it smells like gas in the cabin. Even with the top down, sometimes.

For the oil pan, just do the best you can. It is damn hard to get off the motor unless the motor is out or suspended in place with the front subframe removed. The motor is even harder to pull than it is to suspend, unless you're willing to pull the transmission out with it. Getting the transmission off the motor with them in the chassis is a legendary battle. I have never tried to re-tap the pan installed because I worry I might leave some metal behind in the pan, and the oil system might ingest it with bad effects. But who knows for sure. I would be more likely to try to jam a bigger bolt in there one time to plug the leak, and then use my cheapo oil extractor to pull the oil out through the dipstick tube ever after.

You have replaced the timing belt, right? Because if it breaks, you have a strong chance of killing at least a couple pistons and valves. If I get one of these that I want to keep for a while, I just pull the radiator, then the motor and transmission out whole. Then I replace the oil pan gasket, do the clutch, fork pivot, throwout bearing, rear main seal, and bolt that all back together. Also the shifter bushings. Then I do the water pump, thermostat, timing belt and accessory belt. Then I put it back in the car and lash the valves. Having done that, I can take them to the track and run them at 6,000 rpms for multiple stints, no problem.

Thanks for all of the info.

I was planning to retap the drain hole with the pan on the car, then run some oil through it to try and clear any metal shavings.

The engine has a newer timing belt, supposedly. This was done when the engine was rebuilt. I have my questions about how good of a job was done. My father-in-law doesn't take good care of his cars and his mechanic is some guy working out of his yard. Yeah, you get the idea. This car has a lot of other smaller issues that I haven't even mentioned (blown rear shocks, broken glovebox handle, leaking top). But hey, it's free!

I'll use that electric trouble shooting manual, thank you!

Oh, to retap that hole... drain oil thru a panty hose into a clean bucket. Shoot some shaving creme into the opening to catch the shavings. Do your work. Stick a shopvac up to the hole. Dump a quart or two of cheap ATF thru it to wash any remaining creme and shavings out. Put the old oil back in. Run car for a bit. Change oil and filter.

CyberEric wrote:

curtis73 wrote: Pull the ECM and take the connector off. I'll bet you find a bunch of silver flakes. The pins are plated and the plating comes off making random intermittent non-continuity which can make a host of issues. Blast it out with air and that usually keeps things good for a little while. The real solution is a $50 junkyard ECM that is still in good shape. Same thing for the relays under the hood. That could explain the no-start and the windows.

Thanks! I'll check the ECM. For the relays under the hood, you're saying the silver plating comes off and I need to sand them clean?

Yes. For the relays its pretty easy to scuff up the pins. For the ECM, its a a bit tricky. You can't really get in to sand the pins and they're a bit delicate. I blow them off with air. Some folks are concerned with blowing flakes into the ECM beside the pins, so they blow across the connector. I didn't know that and blew directly into the connector and didn't have any issues. But, if you have flakes, expect the problem to come back frequently as more flakes come off. Mine needed attention every 5k miles or so until I just bought a good, low-mileage ECM from a BMW yard in L.A.

So the car has been running well. No more starting issues since I pulled the fuse for the stereo etc.

I found the oil leak from the drain bolt was due to the PO installing a bad helicoil (too short and threads too wide). I put in a deeper/longer helicoil with tighter threads and that fixed it. One day I'll just replace the pan, but this is a free car.

Now that there's no GIANT oil leak under the car, I have noticed a smaller one. About dime sized. Looks like the head gasket, ugh. It's wet under the exhaust manifold on the pass side about half way down. Seems common, no?

There's an oil pressure switch over there somewhere but I think it's lower down and it should be obvious if that's the culprit.

I have heard of them getting a head gasket leak in the place you describe, and that there weren't any other symptoms of HG problems.

Haven't done the HG on an M20B25 myself. Supposedly it's not a nasty job on these, just a long one. Good opportunity to throw on a new timing belt too.

I suspect the motor will depart this earth at some point if you don't fix it, but I have no idea how long it would hold up.

HG issues usually get worse over time, not better. But if you don't have coolant in the oil or other symptoms, it's not desperate yet. Plenty of guys have played the lottery on these motors for a couple years with just a small leak.

external oil seeping out the head gasket isn't super uncommon with these, but a head gasket is pretty easy to do. Newer fasteners are torque to yield, the originals are not. I did a head gasket at the track in about 2.5 hours for whatever that's worth. Do timing belt and water pump at the same time if you don't know the history. These cars have manual valve adjustment requirements - if it's noisy or runs a little funny, it's not a hard job. Your leak could also be the valve cover gasket leaking down the side of the engine. Shifter feel can be vastly improved with new stock parts - replace everything, including the T on the transmission. If it doesn't already have it, change the fluid for Redline MTL and enjoy better synchro performance.

You have an i car - the ecm is not typically problematic on those.

Cold starting issue sounds like either vacuum leaks or the ECM coolant sender. I don't remember which is which, but both are located next to the thermostat housing at the front of the engine.

Radiators are notorious for failing the plastic end tanks and nipples. If you have the thing apart and it looks suspect at all, there are $150 aluminum radiators on Ebay that are actually pretty decent. You need the 'late' style radiator.

Thanks for the tips guys.

No oil in the coolant, so I think I'm gonna roll the dice for a while before I have more time to do the HG.

The car is growing on me. I love the open greenhouse, the steering is super feelsome (even though it's terribly slow), and the engine is strong. Also, the E30 styling looks great. I regularly have people giving me the thumbs up.

as for the oil under the exhaust manifold, don't the lower manifold studs screw into the oil galleys, or is that an M42/44 thing?