535i rough idle...
Bryan
normal for the 535i. Is this true? Thanks
Mark D'Sylva
Bryan wrote:
> My idle seems to be a little rough but the mechanic said that is
> normal for the 535i. Is this true? Thanks
Hello Bryan,
many BMW's with the - 261 200 059 ECU (like
yours, also in 735i and some 635i, and M3, M5) have a similar problem
which may progress to intermittent cut-out and stalling. Very few
people know that there is a manufacturing defect in the ECU which causes
this. This is quite likely the cause in your car also. (I repair
this problem quite often, and often in the early stages I catch it
before the stalling)
It's unfortunate that thousands of cars have had the ECU's replaced,
often at the owner's expense, due to this defect.
Mark D'Sylva
Mark D'Sylva
Bryan wrote:
> My idle seems to be a little rough but the mechanic said that is
> normal for the 535i. Is this true? Thanks
Bryan wrote:
> My idle seems to be a little rough but the mechanic said that is
> normal for the 535i. Is this true? Thanks
Hello Bryan,
many BMW's with the - 261 200 059 ECU (like
yours, also in 735i and some 635i), the -071 and -075 ( M3, M5) have
conrad g flowers
I caught the tail end of this. Would you be kind enough to restate
the problem and solution as my ruff idle is "normal" too.
Thanks
Mark D'Sylva <mds...@interlog.com> wrote:
>
>
>Bryan wrote:
>
>> My idle seems to be a little rough but the mechanic said that is
>> normal for the 535i. Is this true? Thanks
>
>Hello Bryan,
> many BMW's with the - 261 200 059 ECU (like
>yours, also in 735i and some 635i, and M3, M5) have a similar problem
Mark D'Sylva
conrad g flowers wrote:
> Mark,
>
> I caught the tail end of this. Would you be kind enough to restate
> the problem and solution as my ruff idle is "normal" too.
>
> Thanks
The problem is that a connnection in the ECU which usually fails slowly first
causes rough idling, then mis-firing, and intermittent stalling. You may be
able to notice a weak spark if you look at the end of one of the spark plug
wires when holding it close to the car chassis.
The best test is to open the ECU and look for a the bad connection, you have
to remove the PCB from the flat metal base and inspect the 3 connections to
the ignition driver transistor. (that's the big steel cased one on the
heatsink) Look really carefully at the 3 connections to this transistor.
You may not be able to see the problem without a magnifying glass, but almost
every ECU of the type I mentioned earlier has the problem. Look for a broken
solder connection, which appears like a very thin circle around the solder
pad. (could be on any one or all 3 pads)
This is a simple fix which I don't think you will find in any BMW 'repair
tips' site on the net.
It only applies to the following BMW ECU's:
0 261 200 059 (3.5 L)
0 261 200 071 , 075 ( E30 M3 and 88 M5)
Email me if you need more details.
Mark D'Sylva
Paul R. Hunt
>My idle seems to be a little rough but the mechanic said that is
>normal for the 535i. Is this true? Thanks
Apart from the possible ECU problems mentioned elsewhere, the M30B35
engine can also be a little rough due to the timing of the camshaft.
Paul.
autotrend
You know roughness is a relative thing. These 3.5 litre engines were known
for some roughness. The only thing that smoothens out this engine is to
adjust the valves as loose as posible(14 THOU HOT). Make sure that the co is
.2% above a normal oxygen sensor reading and that the hydrocarbon content in
the exhaust is below 200 ppm
Don
Mark D'Sylva wrote in message <37CBCAA5...@interlog.com>...
>
>
>Bryan wrote:
>
>> My idle seems to be a little rough but the mechanic said that is
>> normal for the 535i. Is this true? Thanks
>
>
>> My idle seems to be a little rough but the mechanic said that is
>> normal for the 535i. Is this true? Thanks
>
> many BMW's with the - 261 200 059 ECU (like