Somebody please help before I replace everything in the car.

[SimonEnochs]

Hello! So, I have a 1995 BMW 540i, automatic transmission with the V8 M60 engine, and I have a problem. The car starts and idles amazingly, runs great... except after it's about halfway to operating temperature. When I drive off a cold start, it revs high before changing gears. If I take it straight up to 55 on my way to the freeway and come to a stop at a stoplight, it idles extremely low, almost stalling, for about 15-20 seconds before it fixes itself and drives as if there was never an issue. Sometimes, when I'm accelerating from a stop, it will hesitate and jerk forward, but it won't do that when accelerating at a high speed. Any suggestions? I have replaced the fuel pump, the fuel filter, and my air intake hose. I have spark plugs and a FPR on standby waiting to be installed, but do you have any suggestions that will help me figure out this 10 month old issue?

[alexisonfire]

How are your throttle bushings?

[moroza]

Hello and welcome!

Can't help you with the shifting issue, except to note that most automatic E34 I've driven seem to shift a bit sluggishly until warmed up.

Sparkplugs shall be NGK BKR6EK.

Low/rough idle is usually vacuum leaks. The M60 has a PCV diaphragm plate on the back of the intake manifold that can cause similar issues. Recommend 1. replace that plate outright, and 2. smoke-test the intake to see if you have intake leaks elsewhere (the manifold gaskets can also get leaky).

Why'd you replace the fuel pump and have an FPR on order? Did you test fuel pressure?

[bimmer@15]

Yeah thats what i was thinking, vaccume leak or a dirty icv.

Sent from my LG-US998 using Tapatalk

[SimonEnochs]

I'm new to cars, but I have been putting in the time and effort to a car that I loved the second I saw it. My fuel pump failed about six months ago, so it wouldn't start at all. I used to have an issue where if I ran it for a little bit, then parked it for an hour or two and tried to start it, I'd have to crank it about three times before it finally turned over, very sluggishly and slow to build up in RPMs. That issue went away after the fuel pump replacement and a bit of upper cylinder lubricant and fuel injector cleaner. I'm still learning, but I want to take the best care of this car as I can.

- - - Updated - - -

I should also add that I have no CEL.

- - - Updated - - -

If it's a dirty ICV, do you think I should take it out and clean it or replace it altogether?

- - - Updated - - -

I have no idea how the throttle bushings are. I'm still learning about this engine.

[fo3]

Clean the IAC. And check it (40ohms between pin 1 and 3, and 20ohm between 1-2 and 2-3)

[moroza]

Pre-OBD2 check engine lights are slightly useless. False negatives and false positives can both happen.

There are bushings at the gas pedal, and at the throttle cable near the throttle body. They can cause jerky acceleration, but not a rough idle.

That does sound like a failing (and repaired) fuel pump issue. I wouldn't throw any more fuel parts at it before testing fuel pressure, however.

Sounds like you're on the right track with taking care of your car and learning about it.

[SimonEnochs]

What's the best way for me to test my fuel pressure? And ill definitely clean the ICV and update you!

- - - Updated - - -

I have also noticed recently that sometimes it feels as if its in a higher gear than it should be until I depress the pedal pretty deep. If I push it to the floor and hit the button, it'll spike to 5,000 RPM from 2,500.

[moroza]

BMW slushboxes aren't the most responsive. Perfectly healthy ones behave as you describe.

AutoZone will rent (for free, just a fully-refundable deposit) a fuel pressure test kit.

[SimonEnochs]

That makes me feel a bit better knowing that I don't need to start having a headache over my tranny. Do you know the best place to put the pressure tester in? I'm pretty sure the m60 doesn't have the valve on the fuel rail

[moroza]

Yup, just tee in to the supply hose near the back of the engine, inboard of the fuse box. Recommend running the engine with fuse 23 pulled until it stalls, otherwise you'll get a 50+psi spray when removing that line. An easy way to test fuel pressure then is to use a coat hanger or similar object, touching one end to the B+ terminal, and the other to the top of (reinstalled) F23.

[SimonEnochs]

New update! I started her up for the first time today, drove half a mile to the gas station (with no issues on startup or the drive), turned it off, went in and out of the store after about 10 minutes, then came back out to my car. I started it up, and it felt like it started unevenly, if that makes sense, and idled at about 1200. I put it in drive once it died back down to the normal 700-800 rpm, and as soon as I did, it dropped RPM so bad it almost stalled. Then it rose to 400 for a couple seconds before dipping down again and again. I put it back in park, let it chill out, then put it back in drive and it idled fine. When I started driving back to my house, it started jerking when I accelerated, unless I accelerated VERY lightly.

- - - Updated - - -

I should add that once it warms up, there is no problem whatsoever.

[SimonEnochs]

Please help haha

[moroza]

What were the results of fuel pressure and smoke tests?

[SimonEnochs]

I'm going to have to perform the smoke test and fuel pressure test around November 4th. I'll get back to you once I'm able to do so!

[SimonEnochs]

Update: my ICV was FILTHY. Sprayed it down with Gumout and it's opening beautifully. Bad news is that when I went to replace the spark plugs, there's a nice little pool of oil under the cover on BOTH sides. I have brand new valve cover gaskets coming in tomorrow morning, I'll update you when they're on! Any suggestions on how to clean out this old oil hanging out in my spark plug wells?

[moroza]

Paper towels, brake cleaner, and elbow grease.

[SimonEnochs]

Sounds good! I'll have it cleaned up with brand new gaskets and some nicely cleaned and detailed valve covers come 8 in the morning tomorrow! I'll post some pictures and give you an update.

[SimonEnochs]

Please help me. I snapped two of the bolts to the valve cover. What size bolt can I buy at Home Depot or Lowe's or an auto parts store that can match? I'm going to tap out the old broken bolts and perhaps replace all of them.

- - - Updated - - -

20201106_134133.jpg20201106_134141.jpg

[fo3]

They're studs aren't they? Don't bother with hardware stores, and auto parts stores are probably more expensive than a dealer. Use realoem for things like this and try a dealer or BMW parts supplier first.
https://www.realoem.com/bmw/enUS/par...BMW-540i&mg=11

Get the part number from there and google for ecs/fcp/pelican/turner/bmw atlanta, autohauaz etc. Or if you can't wait for mail and there's no dealers near by, then at least realoem tells you bolt size, thread pitch, lengths, list price etc.
When you have all the bolt/stud info then try a specialist. Here in Australia we have fastener specilists (nut and bolt shops basically and the USA must have them too) that can usually help you out much better than a hardware store (mainly construction fasteners)or auto parts stores (small range and high prices).

[moroza]

M6x1.0, grade 8.8 or higher (10.9, 12.9), which any hardware or auto parts store will have, but note that these are not just bolts or studs - they have a hexagonal center portion as well. You might get away with generic hardware, at least long enough until you source good used (or new) replacements.

[SimonEnochs]

I came up with a plan: I bought M6x40 stainless-steel bolts, just a bit longer than the 30mm long OE studs, and screwed in from the outside of the valve cover with an extra grommet to fit the extra length of the bolt. Screwed in, it's making a beautiful seal and everything else is installed and ready to go. Im letting the gasket sealant on those recommended areas sit until tomorrow morning, then I'll fire her up and let you know how she runs. With a wonderfully clean ICV and new valve cover gaskets, I expect her to purr. I'll let you know!

[moroza]

Don't use stainless in aluminum. Galvanic corrosion.

[bimmer@15]

+1 at a minimum use anti seize

Sent from my LG-US998 using Tapatalk

[SimonEnochs]

Just a quick update, I've never heard her start or run better.