How do I get the Distributor Cap off?

Post Mon Jun 12, 2006 6:23 am

I have a 1989 325i. I think the dizzy is on its way out, but I need to get into it to check the rotor etc. How do I go about getting the distributor cap off, and what do I look for when I'm eventualy in there?

Any help appreciated.

Post Mon Jun 12, 2006 8:58 am

Three small hex headed bolts at the front of the cap. 8mm heads, I think, and go easy, they have been known to shear off. Didn't say they'd be easy to get at!
Rotor arm is held by three small allen bolts, which are a fairly soft metal, and round off easily. Use a good quality allen key of the correct size.
When you get in there, inspect the condition of the spring loaded carbon button, check the metal for pitting and burning away, and check the plastic for cracks and tracking.

Post Mon Jun 12, 2006 9:06 am

Be very very very carefully on these bolts, i had 2 sheer of on me once. I ended up stripping out the rad and drilling out and retapping them.

What should have been a 10min job turned out to be 2-3 hours

Post Mon Jun 12, 2006 9:10 am

Combining this job with a coolant change isn't a bad idea. Takes about five minutes to whip out the radiator if its empty, and makes distributor access easy.

Post Mon Jun 12, 2006 9:44 am

I dont need to turn the engine to top dead center and pull plug 1 etc etc?

Post Mon Jun 12, 2006 11:29 am

jog5000 wrote:I dont need to turn the engine to top dead center and pull plug 1 etc etc?

no

Post Mon Jun 12, 2006 2:42 pm

dude these bolts are very, very hard to get at, im trying to do the same thing at the mo and have decided its not possible without taking out the rad hoses at least, the 2 visable bolts are possible with the right tools but the one underneath is a mare, and of course if its this hard to take out, it will be a nightmare to get back in!!

What are the symtoms dude outr of interest? misfiring?

Post Tue Jun 13, 2006 12:55 pm

Symptoms are - engine misfiring in lower rpm, then with increase of spead and rpm, runs fine....

I managed to get it off in 15 minutes, no problems. Used a 8 mm socket, stuck to a hex key. Works fine.....

Although it still hasnt fixed my problems. Still stuttering and juddering.

Post Tue Jun 13, 2006 1:22 pm

The dizzy cap will come off fine without removing the rad or hoses although the bottom bolt is the worst one to do. As Brian said, you could always combine the job with a coolant change which is a good idea on the M20.

If you dont want to do a coolant change and pull off hoses etc, you can remove the fan blades from the clutch to make things easier. I think theres enough room between the fan and rad to get at the 4 allen bolts holding it on.

Post Tue Jun 13, 2006 2:34 pm

damn it, well typically mine arnt hex bolts just regular 8mm bolts, must have been replaced it the past.

I didnt realise the fan blades come off??! How is this done? this would give me enough room to get my half inch rachet in then i think

Dude mine started as the opposite, ok low down but wa missing like hell and about 4k up, now when it plays up it does it from idle and i literally can't rev it above like 3k lol!

Have you changed your dme relay?

Post Tue Jun 13, 2006 3:16 pm

dan_emaps wrote: I didnt realise the fan blades come off??! How is this done? this would give me enough room to get my half inch rachet in then i think

Four 5mm allen bolts hold it to the clutch....

Post Tue Jun 13, 2006 3:22 pm

Gay i wasnt planning on having to take the rad off lol

Cheers dude!

Post Tue Jun 13, 2006 3:27 pm

You dont need to, or atleast you shouldnt.

That pic was taken with the engine sat on my garage floor, not in the car.

Post Tue Jun 13, 2006 5:52 pm

Sorry, scratch that idea - you cant take the fan off without removing the rad

Having just finished fitting a rad into a 325i, I now remember just how close it all is.

Sorry for being a fool

Post Tue Jun 13, 2006 7:09 pm

jmc330i wrote:Sorry, scratch that idea - you cant take the fan off without removing the rad :

Yes you can. Loosen the fan shroud, and remove it with the fan.
Don't see the point of serarating the fan from the viscous coupling.
Just spin the whole lot off. 32mm spanner and REVERSE thread.

Post Tue Jun 13, 2006 9:36 pm

Brianmoooore wrote:
jmc330i wrote:Sorry, scratch that idea - you cant take the fan off without removing the rad :
Yes you can. Loosen the fan shroud, and remove it with the fan.

Sorry, my point was that thats hardly any room infront the fan to get at the allen bolts - my hands are fairly small and I wouldnt bother trying. It would be more hassle than getting the dizzy cap off with the fan in place.

Don't see the point of serarating the fan from the viscous coupling.
Just spin the whole lot off. 32mm spanner and REVERSE thread.

I suggested taking the fan of the clutch because not many people have a spanner big enough to remove whole lot and sometimes it can be a real pain to get loose. 4 allen bolts are easy, if you could get at them that is

Post Tue Jun 13, 2006 11:37 pm

Cheers guys! i dont have a 32mm spanner unfortunately, so im gonna get a 8mm socket for my 1/4 inch rachet tomorrow, hopefully being as its alot smaller i'll be able to fit the racket between the dizzy and rad.

Post Wed Jun 14, 2006 12:53 pm

What is the DME Relay, where would I find it, and could that actually be the fault?

Post Wed Jun 14, 2006 4:08 pm

It could be dude! if you've checked the dizzy and cap then it has to be the next thing to try, out of interest whilst i was getting a price for a new dizzy cap and rotor today i asked how much DME relays are new, Ã‚£11.01 from BMW

you'll find it under a black cover bettween your afm and inner wing if yours is like mine, should be a little white relay.

Post Wed Jun 14, 2006 9:47 pm

jog5000 wrote:Symptoms are - engine misfiring in lower rpm, then with increase of spead and rpm, runs fine....

I managed to get it off in 15 minutes, no problems. Used a 8 mm socket, stuck to a hex key. Works fine.....

Although it still hasnt fixed my problems. Still stuttering and juddering.

Missfire at idle, improving when throttle opened is a symptom of a dud inlet manifold or throttle body gasket.