jerking e30

[frigmo///325i]

Hey there, I recently bought an e30 325i...its still
pretty neat and has minor things that needs
attention. The biggest thing that's buggin' me is that the car jerks when I completely release
the clutch at cruising speed in 1st/2nd gear. The
mechanic I bought it from says it because of the
cam...what can I do to correct this?

 

[Luis Malhou]

cruise in first or second? Don't think the cam is the problem unless its got a hot cam and the idling drops too low, but not top of the list. I would start looking at the clutch assembly.. sticky release bearing.. worn clutch, worn pressure plate , if i recall they use Hydraulics to activate the clutch not a cable, good place to start? First find a new mechanic.



Can you tell more details about the problem, noises, hard gear changes etc.

 

[frigmo///325i]

Thanx for the reply louis...yep the cam was cut and indeed the idling drops too low sometimes...don't think its the clutch coz transmission is smooth...what can I do to fix the jerking

 

[Donovan2412]

Replace the cam and see if it still happens

 

[Luis Malhou]

Yip, unless its got a aftermarket ECU, someone might be able to make some adjustments

 

[frigmo///325i]

So I what type of cam do you recommend? And do I only replace the cam? Or do I have to adjust anything else for smooth running?

Thanx a lot guys I'm really appreciating ur help here

 

[Luis Malhou]

Depending who done the mods, everyone does differently, different things so its hard to say.

They could have changed rockers, cut valves, ported the head, skimmed the head, all sorts of things. Bigger bore, longer strokes. Unless you did the mods or know exactly who did it you would need to strip the motor, measure everything against standard before you could determine what has been changed, and only then you'd know the route.

Returning to a std cam could make it worse, valves might not open enough, or too much, all types of crap. A hotter cam is normally put in when you want more fuel and air in the motor, by making the valves open slightly longer by changing the duration of the lobes. The more travel and higher travel on the cam lobes the more time the engine has to suck in more fuel and air. If bigger valves were done you might land up with an unresponsive engine, heavy on fuel or loss of power... best to let a good mod place check, I can think of a few here, maybe even Budler, Peter etc on her to check.

Maybe even a over all check might find something amiss with the management system, fuel supply problem, etc.. might not even be a cam problem

 

[frigmo///325i]

Thanx luis for sharing your knowledge, I am totally horrified right now just the thought of what this all will cost if the car starts to give trouble

Damn! I spoke too soon...this morning I wanted to take it for a spin but for the first time it did not want too start up...being from a small town in WC (clanwilliam) I have to rely on a friend who is a toyota mechanic...we don't have bmw specialists here...nevertheless we managed to find the problem after doing a series of tests- spark plugs were flooded with fuel...
We managed to change the plugs bt then another problem stuck its head out...

Now it pulls away smoothly in 1st gear but as soon as I accelerate and the revs climb to about 2000 rpm the car smothers and loose power dropping the revs instantly..does the same thing in 2nd gear...I pulled the car in the yard and called it a night- for now...tomorrow we will continue...mechanic is convinced its an air problem..??? I am clueless..

 

[Donovan2412]

Thanx luis for sharing your knowledge, I am totally horrified right now just the thought of what this all will cost if the car starts to give trouble

Damn! I spoke too soon...this morning I wanted to take it for a spin but for the first time it did not want too start up...being from a small town in WC (clanwilliam) I have to rely on a friend who is a toyota mechanic...we don't have bmw specialists here...nevertheless we managed to find the problem after doing a series of tests- spark plugs were flooded with fuel...
We managed to change the plugs bt then another problem stuck its head out...

Now it pulls away smoothly in 1st gear but as soon as I accelerate and the revs climb to about 2000 rpm the car smothers and loose power dropping the revs instantly..does the same thing in 2nd gear...I pulled the car in the yard and called it a night- for now...tomorrow we will continue...mechanic is convinced its an air problem..??? I am clueless..

Maybe a vacuum pipe leak?

 

[frigmo///325i]

Twisted and turned all night tryin to figure out what the heck is wrong...so this morning the hood was open before the birdz could chirp...disconnected the afm plug, removed the cover, the pin and the 3 wires connected to it...screwed loose the nut attaching the pin to the afm to remove it completely...then I took some Q20 and a clean rug to remove all the dirt and residue on the board...finally after carefully assembling everything, I started her up and she ran perfectly...I just luv owning a e30- life would be boring without it lol!

Thanx again guys for your inputs