M42club.com - Home of the BMW E30/E36 318i/iS

DISCUSSION => Engine + Driveline => Topic started by: adam12hicks on September 13, 2008, 10:14:25 AM

Title: Can the cam sprockets be replaced without engine removal?
Post by: adam12hicks on September 13, 2008, 10:14:25 AM

Sorry if this is a ridiculous question... I had the valve cover off the ole M42 the other day and noticed the cam gears are very sharply pointed.  More than I expected for a 130k engine (and I'm the second owner of the car.)  I've replaced the lower oil pan seal, checked the upper pan bolts and everything is perfect.  I have never seen any hints of metal or chain guide issues.  I've also replaced the chain tensioner.

I had a wild ass dream that perhaps the chain tensioner could be pulled and maybe these cam gears could be replaced without a major overhaul.

I guess go ahead and tell me I'm nuts.  :)

Thanks!
Adam

Title: Can the cam sprockets be replaced without engine removal?
Post by: ak96ss on September 13, 2008, 10:50:14 AM

It can certainly be done, and it's not *really* a major overhaul, but it's a fair amount of work. You should also think seriously about replacing the guides and the other gears while you are in there.

(http://lh3.ggpht.com/2006TopBanana/SMveTlIZ2JI/AAAAAAAAFJM/ZuNRhjzd1D8/s800/060915%20Timing%20Chain%201.jpg)

Title: Can the cam sprockets be replaced without engine removal?
Post by: KenC on September 13, 2008, 11:18:31 AM

It's possible to change the cam gears without taking off the thermostat housing :).  Just loosen the upper timing cover and pull it back a little.

Title: Can the cam sprockets be replaced without engine removal?
Post by: adam12hicks on September 13, 2008, 11:27:55 AM

Very interesting!  So do you guys think it would be a good idea?  I would have to expect that these sharp toothed gears mean there is extra play in the chain from wear.  If this + the tensioner would buy me some miles before needing a chain replacement then I'll about it.

Another quick question since you guys were so gracious to answer quickly... can the 4 bolts on the cam gear be accessed with the valve cover off or does the crank need to be turned to position them for removal?

Now I need to go to REALOEM and see what I'm gonna need parts-wise...

Title: Can the cam sprockets be replaced without engine removal?
Post by: batsbats on September 13, 2008, 03:11:58 PM

Quote from: adam12hicks;56641

Very interesting!  So do you guys think it would be a good idea?  I would have to expect that these sharp toothed gears mean there is extra play in the chain from wear.  If this + the tensioner would buy me some miles before needing a chain replacement then I'll about it.

Another quick question since you guys were so gracious to answer quickly... can the 4 bolts on the cam gear be accessed with the valve cover off or does the crank need to be turned to position them for removal?

Now I need to go to REALOEM and see what I'm gonna need parts-wise...

brendan purcell's site has the p/n for all the necessary things for the overhaul.  it's under maintenance, timing chain, and there's a link for the writeup at the bottom with the numbers.

Title: Can the cam sprockets be replaced without engine removal?
Post by: adam12hicks on September 13, 2008, 05:21:50 PM

Thanks... is there a link to his site anywhere?

Title: Can the cam sprockets be replaced without engine removal?
Post by: Frankie on September 14, 2008, 12:47:49 AM

http://www.esatclear.ie/~bpurcell/

Title: Can the cam sprockets be replaced without engine removal?
Post by: adam12hicks on September 14, 2008, 09:02:22 AM

Thanks Frankie!