Crank / Cam Sensor

[MotoMan]

Hi there,

I have a vibration/missfire/????? at between 2150rpm to 2800 rpm depending on whether or not the eng is cold, how many tiumes i have started it ???? yes i know sounds crazy. But from one eng run to the next i have very different "power" levels and the vibration shifs ever so little. Sometimes the eng feels dead as a door nail, others a little more lively.

I have changed the coils, had the vehicle serviced, had a vanos kit installed (BMW bulletin) to make the vanos less noisy (this also seemed to give a better spread to the torque not just a terrible sling shot effect from around 4800rpm,) and G-D knows what else.

I have had the eng on DIS to see if any faults are stored, nothing!

I am at my witts end. This damn vibration never lets up and i am sure its the cause of the lack in power in the eng. (Mabe i do need an M5 as recogmended by my mechanic.... LOL)

He suggested last night that mabe the Crank sensor is faulty and that at that rpm it is experiencing a vibration or it is not sending the correct signal just then, mabe even the cam sensor or both ???

Any ideas ????

Thanx


'94 525im (euro Spec)

[632 Regal]

I actually have no clue but I would usually think a faulty crank/cam sensor would either work or not work. Have you done a compression test? It sounds to me like one cylinder is causing havoc with you. Maybe you have a dirty fuel injector or bad plug, You didnt mention replacing either so thats where I would go from where you are.

[MotoMan]

Hey Jeff, thanx for replying.

Yeah i also considered the injectors or an injector. Plugs keep getting fouled with oil, apparently my eng keeps blowing the tappet cover seal, had it replaced one service back but it has done it again. I then said that the oil on the plugs was the prob, but my mac says that it wasn't sufficient to cause the prob.

Actually i forgot abt that, mabe there is some relation to y the gasket keeps blowing and the missfire/vibration

Any thoughts ???

Thanx again, u'r help is much appreciated.

[ryan roopnarine]

IF THE valve cover keeps blowing, i'd check the plug wells for oil, that might cause the problem you describe. it did when i detailed my engine and willed the wells up with water :) oil could do something similar.

[632 Regal]

ahhh! lots of crankcase pressure hmm... that could be from a bad cylinder. Either a bad fuel injector (cant see if their clogged inside) a bad wire/boot or plug may cause the blowby needed to pop out gaskets. Wose case scenereo is...nevermind. Try to locate the bad cylinder by comparing the plugs in order and go from there.

[Unregistered]

but if you somehow find that it is I have a brand new one that I am willing to sell to you for a lot cheaper then bmw will (its a $115 to $130 part). I had a problem that I thought was the crank sensor and I bought the part and found i was wrong. Let me know
tetsuo48@hotmail.com

tetsuo48

[MotoMan]

IF THE valve cover keeps blowing, i'd check the plug wells for oil, that might cause the problem you describe. it did when i detailed my engine and willed the wells up with water :) oil could do something similar.


Hey Ryan. Yeah 2 plugs were fouled with oil on the last service. The mac said that the amount of oil was insufficient to cause the "vibration/missfire" present though couldn't offer an explanation ??

I really do not know if its my imagination, but i do believe that the eng ran without the said vibration for abt a day or so after the service. Difficult to pinpoint though or say for sure. There are days that it is so faint almost inperceptable and then others its like the eng is gonna fall out or something.


Jeff thanx also, i concur with what u are saying. My gut also tells me something ain't quite right there. This is the 2nd time the gasket has blown and as far as i am concerned, if it had just "worn" out the first time what gives with 12000km and then it blowing again ? I will have the cylinders compression tested tomorrow and then try to get the injectors to a test bench, take it from there.

Thanx again for all the input it's really appreciated, this is a damn nucence when u know how smooth the eng is supposed to run, If i had wanted to buy a piece of crap i would have, this is infuriating!

Tetsu, i will keep u'r offer in mind thanx.

Cheers

Victor

[caqueenslace]

We are having the same problem with our 95 525i. Replaced MAF, fuel pump, plugs, couple boots, o2 sensor, new gasket, fuel filter, new cats, one was bad. Still have oil soaking the pugs and blowing the gasket and the exact same symptoms you had.

What fixed your car??????????????????