I have a 1995 740iL (E38?) with 125k miles. For some time now, it has
idled irregularly -- sometimes fine, sometimes with a distinct
vibration, sometimes seeming to lope. This does not seem to vary with
environmental conditions, although, to be honest, it may worsen in
cold weather.

Over the last year, I have had a tuneup and an "injector flush" at the
BMW dealer and had the intake manifold gaskets checked for leakage -
none found.

My local mechanic says that the problem is endemic to high-mileage BMW
8-cylinder engines and that he has tried for years and found no
solution.

Thoughts? Ideas?

my 85' 735 is the same too. mechanic solved the problem by replacing the
gasket and also suggested using high octane gasoline.

its an annoying problem especially when youre in a stop light and your cheek
starts to wiggle =).


"Douglas Moffitt" <dougmoffitt (AT) drum-fife (DOT) com> wrote

In article <nl1unvc65rb57crljvat32868an11sclv1 (AT) 4ax (DOT) com>,
Douglas Moffitt <dougmoffitt (AT) drum-fife (DOT) com> wrote:

No offense intended, but that's a pitiful answer from the mechanic. 125K
on one of those engines isn't anything. Maybe opt for a different
dealership and see what they say.

I had a cruise control problem once and took the car (525i) in to the
dealer, under warranty, five times without resolution! Went to another
dealership and it was fixed first time.

Nate
--
Why is it all the sensors seeking intelligent
life are pointed away from earth?

Have you had a leakdown? Is that an alusil engine or nikasil. Nikasil was
original and they often failed. Alusil is the replacement.

--
Gary Derian
"Douglas Moffitt" <dougmoffitt (AT) drum-fife (DOT) com> wrote

On Thu, 06 Nov 2003 23:41:32 GMT, "Gary Derian"
<gaderian (AT) ameritech (DOT) net> wrote:

Gary,

Help me a bit here:

What do you mean by "leakdown"? The waterpump was replaced quite a
while ago. Other than that, there have been no fluid system problems.
The engine seems to use some coolant, but I have had it pressure
checked and it passed that. I believe that the computer's coolant
level sensor is failing and requiring the level to be maintained too
high to keep the warning silenced. This, of course, leads to 'blow
off' due to overfilling. That is, I'm unsure whether the coolant loss
is leakage or simply overfilling.

The terms "alusil" and "nikasil" are also completely unknown to me.
The engine is the original. I would not term the current problem
'failure'. It runs beautifully and seems to provide most of the
original power level. It's just that part of the time it idles like a
chainsaw.

D

"Gary Derian" <gaderian (AT) ameritech (DOT) net> wrote

That 95 engine has to be already Alusil.

I have a 09.92 530i with the 3.0 litre V8 (M60) engine with 149k.
For me the actions that helped to smoothen the idle were:
- cleaning the idle control valve with carb cleaner
- injector cleaning (made the most difference for me)
- running a thicker (15W60 full synth.) oil.
but it still doesn't idle as smooth as one would expect from an engine with
so many cylinders.
PS the plugs are also important. I use the standard NGK BKR6EK-s. BMW has
also issued
a service note that recommends (then) new High-Power plugs (NGK BKR6EQUP)
plugs as
poor idle remedy. Nowadays these are installed from factory to all (at least
european) engines.
But for one EQUP plug you get three EK-s. I doubt the result would be three
times better idle!


On geman groups there is often also mentioned that because this engine uses
very long timing chain, it
tends to lenghten with mileage. And the only reasonable solution would be
the replacement of the complete chain
together with the cog-wheels, would it only not be so labour-intensive. The
chain itself is not expensive,
should be under $100.

Regards,
Priit

I don't think the change to alusil was made until 1996. See
www.koalamotorsport.com for casting numbers.
--
Gary Derian

"PV" <priit.varik (AT) mail (DOT) punkt.ee> wrote

Just a thought, often times an injector flush doesn't include cleaning the
entire fuel delivery system. If you haven't tried BG 44K then I would try it
first, before doing much else. Also BG's air intake cleaner. Both are fairly
inexpensive and we find in our shop it eliminates the symptoms you have more
often than not. you can buy it on-line at
http://www.storesonline.com/site/598452/ at a very competitive price.


"Gary Derian" <gaderian (AT) ameritech (DOT) net> wrote

Get a compression check done on each cylinder. This car in n the batch
where the cylinder bore liners are prone to failure.

In message <jdDwb.298041$Tr4.954149@attbi_s03>, paddington
<paddington (AT) insightbb (DOT) com> writes
--
Larry

On Sat, 04 Oct 2003 13:49:34 -0400, Douglas Moffitt wrote:


Same issue with 99 328i
changed gas
changed spark plugs
checked gaskets
reprogrammed computer
added fuel line cleaner/ injector cleaner
Multiple emails to BMW Canada .... followed by car in shop for 21 days...
Still no solution.

But after an extensive search I found a person with the same problem that
had the poblem fixed. The dealer changed the "idle control valve". My
BMW dealership refused to change it because the "computer" said it was
fine. But it was so dirty it did not operate properly. The policy not to
guess what is the problem is only what the computer told them what was
wrong made me live with it for over 2 years. I ordered the part online
from some BMW oem place($120). I planned to put it in myself but...could not
find where. I brought it to the dealership and paid them $114 to put it
in. When they put it in they said the hose that feeds it was broken and
also needed replacing...(sounded like a scam to me but told them to go
ahead) WOW it runs smooth now. Who would have guessed...an "IDLE CONTROL
VALVE" could control the idle.... not the dealership. So for the risk of
a couple of hundred bucks I fixed the problem. Previously my idle would
fluctuate as high as 1500 and down to 500... now steady at 700 except when
a.c. comes on and dips 100 or so. Good luck