E39 540 M62tu Idle issue, gear issue

[rusteee 52]

Hi Guys

Sorry I know there has been many threads on this sort of subject, but I thought I'd ask before taking it into Bm Workshop.

I have an issue with extremely rough cold idle, and agresively changing down to 2nd whilst coming to a stop, only when fully up to temp. She fires into life no problem, and will idle away doing its cold start process, then about 30 seconds it will begin to surge up and down slightly in the revs (roughly + or - 600rpm). After the process stops, it dies down to around 500rpm and sounds as if its missing on a couple of cylinders,and shaking the whole car. Reving it slightly (around 1100rpm) it dissapears. After about 10 minutes of driving the problem will dissappear. However, once up to temp and driven around for a while, the gearbox gets very aggresive whilst changing down, coming to a stop. At take off again, it will shudder off slightly instead of coast like normal when letting your foot off the brake without gas. It recenty had a new torque converter, another gearbox etc installed so I'm doubtful it is the gearbox. Could the problems be related? I have had the car scanned, which came up with 1 of the pre-cat o2 sensors open circuit. I had all 4 changed to eliminate. There has since been no codes, and it does not throw the CEL on. Is this more likely a sign of vacuum leak, or coil pack issues? The spark plugs looked very good so did not change them. I did have a leak test done when the gearbox was done, and it came back with only a very minor leak on the manifold.

Any pointers on where I should be looking? Don't use the car as a daily too much anymore so don't mind having to pull things apart slowly to have a look.

Cheers

[jeffbebe 1559]

All the usuals: plugs, coils, vac leaks, etc. Would be good to identify which cylinder/s are misfiring as it will help pinpoint the issue. I had a big leak from a worn intake manifold gasket on my 540. Completely eliminated rough idle when replaced. Ray did double vanos for me too which helped immeasurably but yours don't sound like bad vanos symptoms. I'd start by unplugging coil packs to see if any are at fault... If you unplug one and it makes no difference to idle it's probably bad. Think I've got a spare pack you can have if needed and have a full set of new plugs should you decide to replace. Sort the rough idle and see if gearing issue goes away.

[rusteee 52]

Cheers Julian. Just done the test pulling the coils off, all seemed to make a difference to idle so don't think its that, although 6 of them are dated 01, I think its had 2 replaced back in 2013 looking at the service history. Wasn't too bad this morning I suppose as its not that cold. A good example of what its doing, is like the oil cap has been left off when the engine is cold. I know the vanos is a wee bit noisey, but I'm not going to bother going down that road. I havn't actually looked, but whats involved in changing the intake manifold gasket?

[BreakMyWindow 1870]

Pretty easy access to the throttle body gasket but a manifold off job to get all the intake port gaskets sealing. A smoke tester will be your best bet for checking if indeed you have a vac. Leak.

[jeffbebe 1559]

As Martin says, intake manifold gasket is an easy fix but definitely do a smoke test first as the leak could be from a number of other places and you don't want to throw cash at parts until you know exactly what's wrong.

Could also be PCV for example. Good write up on symptoms and tests for PCV here: http://www.bimmerfest.com/forums/showthread.php?t=534005

[Dn540 67]

This is the exact problem I'm having right now. Seems to be getting worse and worse.

Sluggish acceleration, mild-lumpy idle, weird trans shifting including sometimes shifting into 2nd when braking on a hill, surging/bogging down when in 5th, shudder/vibration intermittently (mainly in 4th/5th).

Also just read the PCV link you put up Julian and I'm getting the whistling on acceleration symptom. Thought it was the engine fan combined with dodgy door seals but it's definitely a whistling/wind noise coming from near the firewall.

Have been trying to get INPA running, but doesn't want to work for me!

[rusteee 52]

Hmm yea does have that same noise symptom on acceleration on the motorway. It's not that bad, but stitch in time... Ray had done a smoke test on it and said the intake gasket does have a slight leak but that was about all. Given the age and k's of the car, I'd say some of these things are getting pretty perished and worn out.

[BreakMyWindow 1870]

This is the exact problem I'm having right now. Seems to be getting worse and worse.

Sluggish acceleration, mild-lumpy idle, weird trans shifting including sometimes shifting into 2nd when braking on a hill, surging/bogging down when in 5th, shudder/vibration intermittently (mainly in 4th/5th).

Also just read the PCV link you put up Julian and I'm getting the whistling on acceleration symptom. Thought it was the engine fan combined with dodgy door seals but it's definitely a whistling/wind noise coming from near the firewall.

Have been trying to get INPA running, but doesn't want to work for me!

Some of those symptoms sound like Torque converter issues - The bogging down in 4th/5th part, shudder and vibrations. You can usually hear a muffled grinding sound also.

[Dn540 67]

Some of those symptoms sound like Torque converter issues - The bogging down in 4th/5th part, shudder and vibrations. You can usually hear a muffled grinding sound also.

Hmmm, that's what i feared at the start. Had a quick look under the car today while I was checking what fluid/filter to buy and noticed a leak under the bellhousing. Thinking either trans fluid or rear main has gone. Also has a leak from somewhere around the selector linkage (or whatever it is).

Also on the topic of CCV, I had a look today and noticed it's missing a vacuum line, any idea what hose is meant to be plugged in here? I searched all around the engine bay and couldn't find a hose or fitting.

Sorry to hijack your thread Russell, just thought it easier than starting a new one for the same thing.

[rusteee 52]

Thats all good mate. Oil leaks are a pain in the tits on these arent they. Have most of mine sorted, just the power steering one to go.

That sounds like the issues I had with the torque converter, before that and the box decided to die. I think I might just be taking mine to BM Workshop and have them check it over with the right tools to save guessing, as it seems theres too much it could be.

[BreakMyWindow 1870]

Valley pan plates also weep coolant out. Good idea to get a new one while the inlet mani is off. They can be a pig as they tend to start weeping soon after. Oil leaks, coolant leaks, torque converter failure and timing chain guides are common issues on the m62tu. Once you over come those you have a very reliable and sweet car!

[westy 614]

These things ooze fluids like a cheap hooker.

[rusteee 52]

These things ooze fluids like a cheap hooker.

HAHAHA brilliant

[jeffbebe 1559]

Tony is familiar with both...

[westy 614]

Im on the night train...

[rusteee 52]

On an off note. Almost jizzed when I came across an immaculate 95 850i in what I think was montreal blue. Stunner!! You must be stoked to own a car like that Julian.

Maybe one day lol get rid of the cheap hooker

[jeffbebe 1559]

I am stoked and will be really really stoked when mine is 'immaculate'. Some way to go yet but it's still pretty sexy. Amazing the attention it gets (compared to the invisibility cloak a 540i wears) and the amount of people that think it's a new(ish) car. Timeless design.

[rusteee 52]

Just thought I'd update. Got the car back from BM Workshop yesterday, happy as with the results. Just as suspected, fixed the vacuum leak, and rough idle is gone completely. Replaced idlers, tesioner and belts while they had it, so nice and quiet. My heart sunk though when they confirmed the transmission problem is due to the torque converter being faulty =( will it ever end, only had it replaced 2 and a half months ago. At least I've got the car for the meet on Sunday!!

Edited August 22, 2014 by rusteee