EXTREME rough idle at R and D gear, but ok in P & N.

[mikeyb74]

I have read a bunch of rough idle threads and talked to alot of BMW enthusiasts. If there's a vaccuum leak the car will have rough idle regardless of which gear it is in. However, for me, it's very smooth when in P or N. But when I stop in R or D, the whole car literally shutters. But smooths out when I give it gas. Already replaced the CCV, Spark plugs, Fuel filter, DISA, ICV, VC gasket, intake boots, and even replaced the fuel pump. Which was not really related. I tried a different set of ignition coils.

And it has nothing to do with it missing the third pedal. :)

Thoughts?

[gr330zhp]

Check tranny mounts. My dads E32 used to do the same, on his it ended up being a cracked spark plug. But tranny mounts also seemed likely :dunno

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[mikeyb74]

Check tranny mounts. My dads E32 used to do the same, on his it ended up being a cracked spark plug. But tranny mounts also seemed likely :dunno

I was thinking tranny mounts or motor mounts. I do know the t-case mount is cracked.

[danewilson77]

Codes?

[mikeyb74]

No codes...

I've been trying to figure this issue out since November.

[danewilson77]

OK....tranny mounts make sense here. What about engine mounts?

[mikeyb74]

OK....tranny mounts make sense here. What about engine mounts?

I'll have to check them. Wouldn't surprise me since the car has 170K on it.

[Mtnman]

When a landscaping block decided to jump into the middle of the road in front of me a few months back, and after i drove over it (ouch, and large thump!) the car drove fine but when i stopped a half mile later to check it out, it shook like hell at idle. I thought I had busted an engine mount. After it went into the shop (insurance repair) i discussed this with the my indi shop. Scott, the owner, told me it probably was not an engine mount as bmw mounts were pretty stout and he hardly ever sees them come in damaged. What was damaged was oil pan busted, tranny case (auto) dented, metal skid plate major dent/replaced, engine oil level sensor replaced.

I dont know what it was about these items that caused that shake in the car, but one of them obviously did. Maybe that helps. I crushed a damn landscaping block that dented my skid plate enough to cruch my oil pan and damage the tranny case, and it did not break an engine mount. On the bright side, the tranny cover was only $500 bucks. :facepalm yeah, all that with an oil and tranny fluid change was 3,000 bucks. luckily covered by comp insurance.

[gr330zhp]

I'll have to check them. Wouldn't surprise me since the car has 170K on it.

Daaaang already??/ Thats awesome!

[Johnmadd]

I have similar characteristics in my e30, have you seen my guibo pic? It only does it sometimes and only when in gear and on the brake. I got the owner of the european car place that is on rochambeau dr and he said driveshaft, and I normally don't need answers but I will do a swap this weekend and see if it works.

[billschusteriv]

I have read a bunch of rough idle threads and talked to alot of BMW enthusiasts. If there's a vaccuum leak the car will have rough idle regardless of which gear it is in. However, for me, it's very smooth when in P or N. But when I stop in R or D, the whole car literally shutters. But smooths out when I give it gas. Already replaced the CCV, Spark plugs, Fuel filter, DISA, ICV, VC gasket, intake boots, and even replaced the fuel pump. Which was not really related. I tried a different set of ignition coils.

And it has nothing to do with it missing the third pedal. :)

Thoughts?

Above you indicated you get the shake when you come to a stop in gear. What about when you shift through the gears while parked before driving (from P to/through R to/through N to D)?

[mikeyb74]

Above you indicated you get the shake when you come to a stop in gear. What about when you shift through the gears while parked before driving (from P to/through R to/through N to D)?

Tried that. Which it still shakes.

[MisterMotorist]

I had a broken motor mount in my E36 - same vibration symptoms as you are describing. I replaced it and a couple of years later the vibration returned, this time the same motor mount was broken but on the "opposite side" - torn close to engine block - hard to see. All this happened with less than 100k miles.

[mikeyb74]

Apparently this is a very common issue on xi models. Most owners replace everything I have and motor, trans, and transfer case mounts. Which will smooth the viberation out but it is still there. The problem is from the rubber joint for the steering.