E53 2003 4.4I shacking/rumbling

[break80]

I have a 2003 4.4i X5 76k that recently started acting strange.

The best way to describe it is slight rumbling at idle especially when cold. The rpms drop slightly and I feel my seat shakes intermittently. On two occasions, it started and briefly thereafter the rpms went down and the engine died out. I had to depress the accelerator to keep it going. But has only died twice and not since about two weeks ago. Also, I am not sure, but I feel that there is some delay in the pick up while driving -- hard to tell though.

There are no error messages on the OBdII, so I am thinking it is not the coils -- I had messages when a coil failed in the past.

I'm thinking of starting with the spark plugs.

Anybody had similar experience? Thanks.

[break80]

Someone suggested to add fuel injector cleaner to the gas tank before doing anything too drastic. Any thoughts?

[SlickGT1]

My 4.8 vibrated since the day I got it. About a month now. No check engine codes either.

Seems to go away after driving a while. I have just done, maf cleaning, spark plugs, new air filter, injector cleaner. It has not made a change to the vibration. Car rips off the line like a monster now though.

Going to check secondary air pump now, and exhaust return check valves. I'll keep let you know. Hopefully will get to it this weekend.

[DallasGV]

Originally Posted by SlickGT1

My 4.8 vibrated since the day I got it. About a month now. No check engine codes either.

Seems to go away after driving a while. I have just done, maf cleaning, spark plugs, new air filter, injector cleaner. It has not made a change to the vibration. Car rips off the line like a monster now though.

Going to check secondary air pump now, and exhaust return check valves. I'll keep let you know. Hopefully will get to it this weekend.

I'm putting my engine back together after a timing chain guide failure and noticed that the secondary air line - #11 in the pic

(RealOEM.com * BMW E53 X5 4.4i EMISSION CONTROL-AIR PUMP)

was heavily coated with carbon where it meets the block and the o-rings seemed to have shrunk as well allowing air to enter and exit the system. My car also has the low vibration at idle and it's just a theory but, I "think" cleaning the pipe and replacing the o-rings will smooth it out. My engine is not back together yet and I've replaced waaaaaaay too many other parts to know if this would make a difference in the idle by itself but I think it would. So, if someone who has the rough idle could try it - it might be a cure.

[SlickGT1]

Deff going to look at this. I have a part list I am putting together. Cheap stuff first. O rings a cleaner have been added. Thanks.

[SlickGT1]

Originally Posted by DallasGV

I'm putting my engine back together after a timing chain guide failure and noticed that the secondary air line - #11 in the pic

(RealOEM.com * BMW E53 X5 4.4i EMISSION CONTROL-AIR PUMP)

was heavily coated with carbon where it meets the block and the o-rings seemed to have shrunk as well allowing air to enter and exit the system. My car also has the low vibration at idle and it's just a theory but, I "think" cleaning the pipe and replacing the o-rings will smooth it out. My engine is not back together yet and I've replaced waaaaaaay too many other parts to know if this would make a difference in the idle by itself but I think it would. So, if someone who has the rough idle could try it - it might be a cure.

Damn, can't find this on RealOEM for the 4.8is

[kmagnuss]

My 05' 4.4i did this at start up also. All it was was the crank case vents. Maybe $60 and 20 minutes to fix and all good for a few months now.

[break80]

Originally Posted by kmagnuss

My 05' 4.4i did this at start up also. All it was was the crank case vents. Maybe $60 and 20 minutes to fix and all good for a few months now.

Maybe my 2003 M62 engine is different than the 2005 above, but I thought that to change the crankcase vent (oil separator) I have to pull apart half of the engine compartment. I had the dealer do that for me a couple of years ago and it charged me over $2k mainly for labor because it made it look that the oil separator is very hard to reach being located behind the bottom rear of engine block.

If such a major project, I'd like to make sure that is my problem, and I am not sure.

Last time, I get no messages on the OBD, and I remember getting them last time. My symptoms have became clearer: my engine dies out when cold -- it starts fine it does its initial rev up to over 1k rpm but when it drops it keeps on dropping and dies out, rather than stay on idle. Once it gets going, it runs fine but it sputters on every quick stop when the rpm go to idle quickly as it wants to die. Once completely, warmed up and adequately gunned a few times, all symptoms seem to disappear.

Any help?

[kmagnuss]

yeah that's a little different than my symptoms. In a previous car of mine, I had symptoms identical to those and it was the IAC (idle air controller) valve. That was maybe a $60 part on a Jeep (so I'm sure much more on a BMW... if that's even the case) but at least they're typically very easy to get at. It's a little motor or valve right on the intake plenum/manifold or throttle body.

You could look to see how much a new IAC valve is, how hard it is to replace... and if it's cheap and easy just give it a whirl and see if it helps.

I can't remeber since it's been a few days since I read your posts... but have you changed the spark plugs yet? @ 75k and 8 years old they're due.

[break80]

Sometimes you just have to laugh about these things.

After gearing up for a major repair and $, turns out the culprit was a loose clamp on the RUBBER BOOT downstream from the air filter. I am guessing, the breach was causing loss of low pressure and was correspondingly disturbing the vacuum(low pressure) in the in lines that attach to the rubber boot outlets.

Talk about sensitive -- my engine would shut down if I did not hit the accelerator shortly post ignition.

MANY THANKS to all that contributed.