Longer crank times at startup - anyone else?

[anom3]

dont mean to throw gas on the fire, but mine doesnt sound nothing like that when cold starting. even if it sits for a week.

i have been dealing with another issue and have about 25 cold start recordings.

the average time between start-button click, and when i hear ignition is about 1.25 seconds. on cold start.

on "warm" start (eg: car been driven already today) the average is about 0.75 seconds.

also i have never had what looks like some sort of hesitation your video shows.

im no expert, but frankly, this looks like a fuel system issue.

Originally Posted by gpxl

I've observed this cold start issue with my "new to me" E90. Is this similar to what everyone else is experiencing? It's a 3-4 second crank but feels like forever.

[jaco]

Mine does it if the car has been sitting more than a day or two. Same day starts are never an issue.

Circulating oil?

[gpxl]

Originally Posted by anom3

im no expert, but frankly, this looks like a fuel system issue.

Yup, that's what I'm thinking too. I should have mentioned earlier that this only occurs during the initial start up. It'll start up immediately after that for the rest of the day. Thinking there's some pressure lost overnight.

[anom3]

Wish I could help some more but I'm pretty amateur when it comes to this stuff, but someone in one of the other threads mentioned measuring fuel pressure before and after 12+ hours.

If you do decide to go at the injectors, the Bosch part# is 0280158164.

I was just looking at those actually.

They are (visually) the same as the OEM, but about 1/2 the price (here in EU anyways...).

If they are EXACTLY the same as OEM, I do not know... Maybe the BMW are cherry picked or something?

Originally Posted by gpxl

Yup, that's what I'm thinking too. I should have mentioned earlier that this only occurs during the initial start up. It'll start up immediately after that for the rest of the day. Thinking there's some pressure lost overnight.

[gpxl]

So just to follow up, it was the rod bearings.

Just kidding! Strange thing though, I took her on a long drive then left her unused for a couple of days. Since they she's been starting right up.

I'm still going to test the battery and fuel pressure to make sure they're within spec, but otherwise I'll just have to chalk it up to finicky electronics for now.

[MisterClutch888]

ancient post, but anyone solved this?

Idle control valve? fuel breather valve?

[alfalfa]

Why is there a complain about a longer crank at a complete cold start?
Longer crank means more oil pressure before the start of the engine.
Maybe the engineers at BMW M exactly want this?
The measurements of anom3 shows this really good. ;-)

[IamFODI]

'08 6MT with 110k miles here. Bought almost 2 years ago with 80k. Daily-driven year-round since then. ICV and at least one throttle actuator were replaced by the PO, though that was a while back by now.

Always felt it took slightly too many cranks on a cold start, but not by much. Since the COVID lockdown I've been driving much less, and the car has been taking a lot longer to crank on a cold start. Warm/hot starts have been fine. Replacing spark plugs (and engine air filter) made zero difference.

Battery is several years old by now, but I'm not sure whether to suspect it because it behaves exactly the same after sitting at full charge on a battery maintainer until 1-2 minutes before starting.

Recently got codes for catalyst efficiency. They didn't come back after a reset, but who knows...

Sometimes the engine feels slightly rough when I gently raise the RPM from idle in neutral, like it's not entirely comfortable sitting at low RPM and low throttle. Can't remember noticing that before. It's not horrible but I don't know if that's normal.

I like alfalfa's hypothesis -- as in, I want to believe it even though I don't think it explains this issue. Hopefully someone informed can weigh in.

[akkando]

Originally Posted by IamFODI

'08 6MT with 110k miles here. Bought almost 2 years ago with 80k. Daily-driven year-round since then. ICV and at least one throttle actuator were replaced by the PO, though that was a while back by now.

Always felt it took slightly too many cranks on a cold start, but not by much. Since the COVID lockdown I've been driving much less, and the car has been taking a lot longer to crank on a cold start. Warm/hot starts have been fine. Replacing spark plugs (and engine air filter) made zero difference.

Battery is several years old by now, but I'm not sure whether to suspect it because it behaves exactly the same after sitting at full charge on a battery maintainer until 1-2 minutes before starting.

Recently got codes for catalyst efficiency. They didn't come back after a reset, but who knows...

Sometimes the engine feels slightly rough when I gently raise the RPM from idle in neutral, like it's not entirely comfortable sitting at low RPM and low throttle. Can't remember noticing that before. It's not horrible but I don't know if that's normal.

I like alfalfa's hypothesis -- as in, I want to believe it even though I don't think it explains this issue. Hopefully someone informed can weigh in.

my car behaves similar except I have not tried raising rpm in neutral after cold start. I feel like it's been better in the warmer weather. Any non cold start it cranks like a champ.

[MAE90M3]

Two weeks ago I started having long cranks only in the morning. The spark plugs were replaced in January, and the battery and alternator replaced in February. No rough idle or rpms bouncing around. No codes either. I am cycling through gas to see if it was bad gas. Any idea what this could be? I've searched around and couldn't find any solid answers.

[Scharbag]

Originally Posted by MAE90M3

Two weeks ago I started having long cranks only in the morning. The spark plugs were replaced in January, and the battery and alternator replaced in February. No rough idle or rpms bouncing around. No codes either. I am cycling through gas to see if it was bad gas. Any idea what this could be? I've searched around and couldn't find any solid answers.

Leaking injectors can cause this. It did on my car.

Cheers,

[Redd]

Originally Posted by MAE90M3

Two weeks ago I started having long cranks only in the morning. The spark plugs were replaced in January, and the battery and alternator replaced in February. No rough idle or rpms bouncing around. No codes either. I am cycling through gas to see if it was bad gas. Any idea what this could be? I've searched around and couldn't find any solid answers.

First and foremost, check your ground strap at the front exhaust. Might be a cheap solution if it's worn or corroded.

[IamFODI]

Originally Posted by IamFODI

'08 6MT with 110k miles here. Bought almost 2 years ago with 80k. Daily-driven year-round since then. ICV and at least one throttle actuator were replaced by the PO, though that was a while back by now.

Always felt it took slightly too many cranks on a cold start, but not by much. Since the COVID lockdown I've been driving much less, and the car has been taking a lot longer to crank on a cold start. Warm/hot starts have been fine. Replacing spark plugs (and engine air filter) made zero difference.

Battery is several years old by now, but I'm not sure whether to suspect it because it behaves exactly the same after sitting at full charge on a battery maintainer until 1-2 minutes before starting.

Recently got codes for catalyst efficiency. They didn't come back after a reset, but who knows...

Sometimes the engine feels slightly rough when I gently raise the RPM from idle in neutral, like it's not entirely comfortable sitting at low RPM and low throttle. Can't remember noticing that before. It's not horrible but I don't know if that's normal.

I like alfalfa's hypothesis -- as in, I want to believe it even though I don't think it explains this issue. Hopefully someone informed can weigh in.

As long as we're updating the thread...

Since this post I've replaced the battery and starter, and I'm back to driving the car daily. Car now has >120k miles, so >1k per month since then -- coming up on pre-lockdown driving levels.

The battery swap was mostly preventative, but it did improve cranking slightly.

The starter swap was mainly because it was showing symptoms of solenoid failure. Turns out the newer starter for cars with auto-stop-start has superseded the old one, so this was a nice upgrade. Faster and quieter.

The car still seems to take a fair number of cranks on a cold start, though those cranks are now MUCH faster. Like the startup is in fast-forward now but otherwise the same. If I weren't paying close attention, I don't think I'd care about crank times. I'm not sure I do anyway.

Interested in Scharbag 's leaky injector idea. Thanks for sharing that. My last oil analysis did show elevated fuel dilution, though that sample was pulled shortly after a track day. Might go hunting if I see other symptoms or any of this gets worse.

[Mcte92]

Fuel tank breather. When they’re old and worn they close from pressure in the gas tank and take too long to open at startup. 40 bucks. Change them do the fuel pressure sensor while you have the air box out of the way

[IamFODI]

Originally Posted by Mcte92

Fuel tank breather. When they’re old and worn they close from pressure in the gas tank and take too long to open at startup. 40 bucks. Change them do the fuel pressure sensor while you have the air box out of the way

This thing?

https://www.realoem.com/bmw/enUS/sho...44#13907838281

https://www.fcpeuro.com/products/clo...m3-13907838281

[Vuu]

Originally Posted by IamFODI

This thing?

https://www.realoem.com/bmw/enUS/sho...44#13907838281

https://www.fcpeuro.com/products/clo...m3-13907838281

Yup, and make sure you order a spare hose too. If you break the nipple off the old breather valve (most do and it happened to me), the only way to move the broken piece is to cut the hose.

You wouldn't want to do that either in case you pinch the hose when re-installing.

[acarr6]

Revisiting this one. Similar issue,

-cold start long crank/stutter
-turn off
-turn back on, cranks instantly.

Only happens on cold starts, every other start is instant. Replaced the battery, seems to have helped a little, but still stuttering. Seems like it struggling to get fuel on cold start.. no codes.

[Route 16]

I'm having a parasitic drain somewhere in my car. After market headunit, Airlift Suspension with possibly an out-going compressor. It's drawing power too much somwhere.

[Magnetic Fusion]

So I had a fuel leak in my 08 M3. I found the source of the leak at the top of the gas tank, sending unit side. The sending until plastic cover that seals to the gas tank was deteriorated. Really strange but gas was gushing out of the car. I was getting 8.9 mpg and about 190 to the tank. Replaced the send unit cover piece and leak is now gone. But, now my car takes a few seconds longer to start. Didn't di this before I replaced that top piece. I kept the old sending unit in there. takes, what appears to be 5-6 seconds to start. This is what Im guessing. I have air in the gas line since I opened the gas tank and when Im cranking not enough gas is getting to the spark. I used to notice when I got in the car I can hear the fuel pump working. Thats supposed to send fuel to the injectors. Now I dont hear that sound and Im wondering if the gas isn't getting primed right causing long starts. I know 100% it wasn't an issue until I fixed this leak. So Im thinking air in the line, car runs like new though. 183k and fixing the leak even fixed my idling issue where it was ever so slightly rough. If I do have air in the system how do I get it out? Whats the mechanism that primes the gas into the system? Maybe I need to listen a bit harder but I think Im on to something with it not getting primed or air in the system. Let me know. Experiencing long starts now. Will try some fuel system cleaner to see if that works or my next guess would be fuel filter clogged? Car was sitting for 6 months before I fixed the leak. First start after the leak was fixed was fine. Every other start now takes like 4-6 seconds

[Scharbag]

It would be interesting to see what the fuel pressure is after sitting for a night. If the system is depressurizing, that will cause long crank as it waits for the system to charge.

Use to have a Honda that would do the same. Simple fix was to tur the key on to run, listen for the fuel pump to prime, then turn the key to off then start the car.

Anyway, I had the same issue and it was fixed by changing injectors.

[chenium]

I had this issue too and have since resolved it. I had a few things replaced simultaneously so I can't pinpoint which exactly was the issue or maybe all of them combined were.

Things I had replaced:
- All fuel injectors
- Low fuel pressure sensor. The updated Bosch variant with the adapter.
- Fuel breather valve
- Spark plugs
- Fuel cap (this was replaced earlier and did not affect the issue)