Timing Chain Guides shattered. What to do? Why would they break apart?

verde2002

verde2002

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Just was told by my mechanic the plastic timing chain guides have broken into pieces and rattling under chain when car is on. Question is how difficult is it to replace them and what should it cost? I was given a figure of 10 labor hours which seems extreme to me. Any easy fix? How many hours labor is reasonable? How much needs to be removed to gain access and replace them?
 
It is a bit of a time consuming job, you will have to remove the rad, remove both upper and lower timing covers. It takes awhile 10 hours doesn't sound that unreasonable
You will need a frt timing cover gasket kit, plastic guide rail and maybe a new chain and chain tensioner Good question as to why, won't really know until it all comes apart
 
You have to remove the radiator and the harmonic balancer on crank to access the lower cover. Not as easy as it might appear.
 
...and depending how strongly adhered the lower cover is to the oil pan gasket and both covers to the head gasket the job might get even larger if any of those two gaskets need replacing.
 
Ten hours for a trained mechanic? I'm not buying it. Granted I've had my E3 engine and engine bay apart a BAZZILLION times recently, I took the radiator, fan/pulley, dist and upper timing cover off the other night in about ten minutes. Yeah, that's the easy part but if you have the right tools and experience there's no way it should take ten hours.
 
Y'all may be missing the most difficult part... the Jesus Nut has to come off (this isn't political or religious commentary or a dig at DeQ). Sometimes not so bad, other times a real tear-out-your-hair project. I've had to do it once on an M30, once on M10. You can't have too much leverage. Why d'yall think it has that name?

Big jobs are easy until you have to do them. Ten hours for the entire job might be a little high, but has anyone quoted the labor charge straight from the factory? And let's skip the commentary about whether that's appropriate.

Dang, c'mon, ten minutes? Really?
 
As to why the guide broke, blame the bean counters. Plastic is a light cheap temporary material. Many B30s last for impressive miles, but the plastic guides don’t survive wear or heat forever. They get brittle and grenade. BMW is currently replacing thousands of engines or chains and tensioners on four cylinder turbo engines made before 2015. Luckily for me, they extended the warranty to 70,000 miles in the US. I think they did a recall in Europe. I caught mine at 68,000 miles because I happened to watch a YouTube video warning of the problem which is preceded by a friction whining sound at 3,000 rpms. After 70K they tell you sorry and ask $20K for a new engine because it’s an interference design.
 
dang said:
We're talking M30 right? I'm sure @sfdon would know but it seems like the job could be done in half that time. Flat rate allows for problems and in Don's case, a break for wine.
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5 hours should do it.
 
Jesus’ nut (feels weird saying it)
Would one of the new super compact impact wrenches fit into the avail space?

I bought one that is 4” long and rated for 450ftlbs in reverse. It removed the crank nut on an Alfa Nord motor instantly. I could have cut down the socket if needed but instead I lifted the motor a tad (motor was coming out anyway).

I personally think 10hrs is a fair estimate given the fact that he’s got to get it done perfectly, needs to clean out the sump, and probably doesn’t do this job every month (not likea Jiffy lube job). Hopefully the guy is being conservative, finishes in less time, and charges you actual time.
 
There is a crank holding tool that bolts to the front of the crank and is positioned under the frame rail. With a 3/4 ” breaker bar and the right amount of extension pipe you can easily apply the force you need.

www.tooldiscounter.com

SIR Tools BMW3034-2 Crank Pulley Securing Bar | ToolDiscounter

BMW3034-2 Crank Pulley Securing Bar. Shop Crankshaft Tools from SIR Tools at ToolDiscounter
www.tooldiscounter.com www.tooldiscounter.com
 
sfdon said:
There is a crank holding tool that bolts to the front of the crank and is positioned under the frame rail. With a 3/4 ” breaker bar and the right amount of extension pipe you can easily apply the force you need.

www.tooldiscounter.com

SIR Tools BMW3034-2 Crank Pulley Securing Bar | ToolDiscounter

BMW3034-2 Crank Pulley Securing Bar. Shop Crankshaft Tools from SIR Tools at ToolDiscounter
www.tooldiscounter.com www.tooldiscounter.com
Click to expand...
In my younger years I would've put a big socket and breaker bar on the bolt and positioned it about six inches from the frame rail and cranked the motor with the starter. Yee haa!
 
I’ve done that and I’ve held a screw driver blade in the flywheel and cranked.
i posted that video 20 years ago and called that nut the Jesus nut in the video.

dont try the screwdriver trick- it will break your hand....
 
I’ve broken a number of breaker bars and screwdrivers doing this, the balancer tool Don mentions is great. If your tranny is exposed, you can use the “claw” to hold the flywheel but the former is more solid. I ended up with a 3/4 breaker bar and about 3 feet of pipe. And a torch.
 
And after 10 hours of work one has to put another plastic guide? Cannot a metal one be made?


stphers said:
It is a bit of a time consuming job, you will have to remove the rad, remove both upper and lower timing covers. It takes awhile 10 hours doesn't sound that unreasonable
You will need a frt timing cover gasket kit, plastic guide rail and maybe a new chain and chain tensioner Good question as to why, won't really know until it all comes apart
Click to expand...
 
I am surprised the factory did not come up with a metal variant just like they did with plastic coolant impellers in some models after getting failure experience.
Mostly surprised Stan did not craft an aftermarket group buy for metal guides...

HB Chris said:
They were always plastic, just a better quality of plastic!
Click to expand...
 
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