Bueno, el otro dia le puse una bobina de encendido nueva, marca Bosch ( que me parece que es la original que lleva e casa) y noto que el coche va un poco mas fino pero sigue haciendo lo mismo, de todas maneras al z3 le venia bien cambiarle la bobina ya que el coche tiene ya sus años y tarde o temprano hubiera cascado. He estado mirando por internet y creo haber encontrado la solución, resulta que bmw en septiembre de 1998 saco una nota de reparación para vehículos con motor como el mio que hacen esta anomalía, yo llevo un m44 pero también están afectados los modelos
Z3 1.9, 318i/4
318i/2, 318iC
318 ti.
Aquí os dejo la nota que esta en ingles:
GROUP 11
Engine
B 11 07 98 Woodcliff Lake, N.J.
Product Engineering
September 1998
SUBJECT: Rough Idle
MODEL: All with M44 engines
Situation: A rough idle may be observed with the engine at operating temperature
due to unfavorable valve timing tolerances during the valve overlap
phase.
Note: The engine idle quality should not be evaluated before a mileage
of approximately 3000 miles is accumulated thus assuring complete
engine break in.
Correction: If a customer complaint of a rough idle with the engine at operating
temperature is received and all engine parameters meet BMW
specifications (no ignition problems, no unmetered air leaks, no fuel
supply problems, cylinder leak down is less than 15%, etc.) readjust the
camshaft timing using the new intake camshaft alignment tool Part
Number 90 88 6 119 110.
Note:
The modified intake camshaft timing is only intended as a customer
complaint field fix and will not be phased into production.
Procedure: Readjust the camshaft timing as outlined in the E36 M44 repair manual,
section 11 31 005 using the new camshaft alignment tool on the intake
camshafts shown in the illustration below.
The new tool has been designed to retard the intake camshaft timing by
6( and will not lead to any perceptible drop in engine torque or power
output.
Parts
Information:
The new intake camshaft alignment tool Part Number 90 88 6 119 110
has been sent to all BMW Centers via automatic tool shipment.
Refer to Service Information bulletin 04 07 98 for further information.
Warranty
Information:
Covered under the terms of the BMW New Car Limited Warranty.
Defect Code: 10 32 91 57 00
Readjust intake camshaft timing.
Labor Operation: 00 51 383
Labor Allowance:
Model FRU
Z3 1.9, 318i/4 35
318i/2, 318iC 34
318ti 37
[Copyright (c) BMW of North America, Inc. ]
y aquí abajo os dejo el link con la imagen del procedimiento a seguir:
http://www.google.es/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CC0QFjAB&url=http://tech.bentleypublishers.com/servlet/JiveServlet/download/68-22658-219629-2956/SI199.pdf&ei=rmtoVPOQBJPSaKbFgegD&usg=AFQjCNFnQ4pRg6f_k5mbuX7l1tuA7wClSg