could it be the camshaft ?

[JDY]

Hi,need some help... there are a few problems with my e30m40 1.engine always dies when idles(e.g stopping at traffic light..etc) 2.rev cuts off at 5000rpm 3.petrol consumption is very highI was advised by a fellow forummer that it is definately the camshaft that needs to be replaced..but when took to my regular mechanic,he insists its not the camshaft but he still cant figure out wht it is (esp number 2) .. tried replacing afm but problems still persist...i just wanted to know if all of the problems above could be related to the camshaft ? not a very technical person so all input would be appreciated thx..

 

[absidian]

Checked the crankshaft position sensor?

This causes all those symptoms you mentioned. They do fail from wear and tear... what mileage on yours?

When this fails, the engine won't know accurately "where" and "what" is happening from the feedback loop, so it goes into "safe" mode. Hence limited revs, default/inaccurate fuelling/timing and will die when idling (especiallt when hot in traffic).

Hope this helps... good luck.

 

[JDY]

i see..okay then i will ask my mech to check the crankshaft sensor then..thanks

 

[Zoggee]

same simptoms as our friend Nelsone30.

 

[JDY]

Has he solved his problem ?.. what was it ?

 

[Jules]

me not so technical too but sounds electrical system....coil n the lot!

good luck keep us posted!

 

[Zoggee]

as usual la...yada..yada..yada...cam shaft bengkek la,fan clutch casuing the camshaft to bent la...its actually down to proper maintenance.

I still believe its the in Nelson case. It's his engine oil pump that caused it all...its a chain reaction.

He is a happy man right now...change to M42 liao.

 

[fabianyee]

Check your fan clutch whether it's fully locked now...

one way of checking is try stopping the fan with the engine running using a rolled up newspaper. I read this somewhere online and have tested it myself. but please apply common sense when doing this. The objective is not to stop the fan with immediate effect but to slow it down progressively.

Anyway, I don't think it's the fan clutch but I'll never know based solely on your diagnosis. it's a simple test anyway..

 

[JDY]

Update: Sent it to a different mechanic.. He says that it could be the camshaft. I will be sending it to him this weekend for him to open it up and check it.. btw is it advisable to replace the camshaft with a secondhand one or should i just get a new one ? (thats if the problem is the camshaft lah...

 

[Zoggee]

If you want to keep ur stock M40,the best option is to do total engine overhaul. Dun do bit by bits....it'll even get worse.

 

[selespeed]

If you want to keep ur stock M40,the best option is to do total engine overhaul. Dun do bit by bits....it'll even get worse.

yes, absolutely correct. i had mine top-overhauled last year and it couldn't be better! new valves new camshaft, new distributor cap, new tps, new hoses...many other new things.

i think at least a top overhaul would justify.

 

[anaksarawak]

yes, absolutely correct. i had mine top-overhauled last year and it couldn't be better! new valves new camshaft, new distributor cap, new tps, new hoses...many other new things.

i think at least a top overhaul would justify.

Care to share how much you have spend on that??

 

[selespeed]

Care to share how much you have spend on that??

ok, i just cut from my notepad... done in 2006

2/4 - timing belt broken @215,161km)
2/8 - $897 (new camshaft, gaskets, all valves, rocker arms, distributor cap, timing belt&tensioners, aux belts, hydraulic tappets, hose)
RM877.9 (labor for top overhaul + oil change-castrol magnatec + towing)

 

[JDY]

Update : Just checked the camshaft and also crankshaft sensor..all seems to be in good condition and wroking fine.however after replacing the afm with another second hand one , replacing the timing belt and setting the timing now the cut off is at 6000rpm instead of 5000rpm (still not at the normal cut off ) , engine does not die off anymore , petrol consumption seems to be better.

So basically the engine still cuts off before it's suppose to ...anybody got any other ideas as to why this is happening ?! Am seriously considering a top overhaul !!!... hehe

 

[Zoggee]

Update : Just checked the camshaft and also crankshaft sensor..all seems to be in good condition and wroking fine.however after replacing the afm with another second hand one , replacing the timing belt and setting the timing now the cut off is at 6000rpm instead of 5000rpm (still not at the normal cut off ) , engine does not die off anymore , petrol consumption seems to be better.

So basically the engine still cuts off before it's suppose to ...anybody got any other ideas as to why this is happening ?! Am seriously considering a top overhaul !!!... hehe

Dude...try check ur Oil Pressure. Issit the right pressure.??? If its not..then No harm spending money for the top overhaul. But pls...DO, run in( Prime,break in...what ever terminologies la) Dun simply whack after that.

 

[fabianyee]

Update : Just checked the camshaft and also crankshaft sensor..all seems to be in good condition and wroking fine.however after replacing the afm with another second hand one , replacing the timing belt and setting the timing now the cut off is at 6000rpm instead of 5000rpm (still not at the normal cut off ) , engine does not die off anymore , petrol consumption seems to be better.

So basically the engine still cuts off before it's suppose to ...anybody got any other ideas as to why this is happening ?! Am seriously considering a top overhaul !!!... hehe

What was the cut-off for your car then if not 6000rpm?? I think the stock M40 engine cut off at about there...

 

[absidian]

Was your engine warmed-up enough before you tested the rev limit?

If I'm not mistaken, the ECU won't let the car redline until it senses the engine is warmed up. Usually the oil temperature too, which will usually take much longer than the water temp.

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[python_dev]

I have a similar problem... was cutting off at 4000rpm, checked every last electrical (fuel pumps, sensors, plugs, leads, distributor etc etc etc..) changed the lifters and tappets improved it but still slumping at 4000 but able to rev to 6000 (318i E36 1992) although I noticed when the cam was out it had about a 0.5 mm grove in it So pondering new cam or full overhaul of the head. compression @ 200 psi/cyl good.
Have tried many things so far and waiting for some sugestions