Have you had a timing chain break!? - Page 7 - PeachParts Mercedes-Benz Forum

#91 10-08-2001, 08:23 AM

PsFred has some very good insight into the cleanliness of the job using towels. I am not much help with the specific engine you are working on but another thought for the shop towels would be the use of paper towels. Paper fibers will degrade and get purged from the engine upon the oil change.

How long do you have to wait for the black belt upon recommendation in that discipline of martial arts? I am not that famililiar with that one.

mplafleur · #92 10-08-2001, 08:58 AM

Pete,

The use of a comealong, and a heavy chain have been very helpful to me. If I didn't, the block would still be in the car! I'm not big: 5'10" and 165 lbs and of slight build.

I rebuilt a '75 300D about a dozen years ago. I know I had the block re-bored because I remember my brother shipped me 5 new pistons at about $100 each. Back then I didn't think anything could be that expensive. I remember that I had to give them to the machine shop as each was stamped with its' size. I recall transporting the block in the back of my Escort, but I don't remember having any help getting it out of the trunk. I was doing the work at my moms farm and I'm sure no one was there to help me. I do remember it was d*** heavy!

Southern_son,

I don't like shop towels, they have very poor absorbtion properties. I usually use good cloth towels (my wife hates that!) and paper towels. I like that suggestion.

Koei-kan is an Okinowan based karate. I've been learning for about 5 years now. The belt promotions at our dojo goes from white, yellow, blue, 1st green, 2nd green, 3rd green, 1st brown. 2nd brown, 3rd brown, then black. I'm currently at 2nd brown and should be testing for 3rd brown this winter. Tests usually come every 4-6 months for those green and under. At the brown belt level, I would be suprised to have a test in less than a years time since the previous. The work on the car has me going to class only once a week at present.

Larry,

I actually spent about 4 years writing engine control software for the Formula One race car that Ford sponsered in the mid-late 80's. That was for the Benneton team. I then moved to work on the Service Bay Diagnostics tool used by the Ford dealers. For the past 4 years I've been working on the system used to test engine control modules. I was contract for 14 years at Ford. I finally hired in and got 1 Ford paycheck before we got spun off into Visteon April of last year.

psfred · #93 10-08-2001, 08:28 PM

Michael:

I finally got down to the shop (and ordered more parts....): there is no part like the screw you found in the oil pan in the 190 engine. Hans thinks (like I do) that it is a temporary link to draw the chain through that is supposed to be replaced with a crimp link. Probably why the chain broke.

Yeah, one guy can move that 617 block, but what a pain! Weighs a ton (we figure the 617 is about the same weight, all decked out and ready to go in, as a Chrylser Hemi). All that cast iron....!

My dad was an electical engineer, did automated control systems for assembly machines -- alternator winders for Chyrlser, oil cooler machines for Chrylser, horn testers for Ford (that one was in the basement, spent days punching holes in electical panel boxes), etc. Pretty spiff stuff for the late 60's. I heard a rumor he worked on the control system for the Patriot missle, too, which would explain why he took FORTRAN classes about 1972. Cool stuff.

I can't do math worth crap, so I'm a plant physiologist working as a chemist.....

Peter

mplafleur · #94 10-09-2001, 12:05 AM

Well, I got word today that my head is done. But I'm not done with the block yet. I have to get it cleaned up and do those crank and rod bearings. I am also replacing both front and rear seals. I would like to wait for the UK manual that got shipped to me today to get here first. I have a big test on Wednesday evening so I can't work on it anyway.

I had heard that my dad had worked on the Mercury (Redstone?)program while with Chrysler. (That's pretty far removed from the Patriot!)

DJNEWK2 · #95 10-09-2001, 11:47 AM

I'm wondering if it may be an aftermarket equivalent type chain from someone like AMG,Braubus or Renntech,etc that one could assume would be a higher performance chain and therefore more resistant to breakage?I'm going to replace my chain on my 560 SEL (215k) that was changed at 158k and wanted to go that route if it is available...anyone here know if this is even offered to install on MB? Otherwise I'll just go with factory MB chain.

#96 10-10-2001, 07:31 AM

I'm not thoroughly familiar with which of these V8 models have the double row chain, and which don't. But, if you do not have the double row chain, it can be upgraded to the double row chain to add durability. If yours is already a double row, the important thing is to replace the chain AND guides periodically. The chain itself is usually not the cause of the problem. Once a guide gets brittle and breaks, it typically jams the chain causing it to break. If there is such a thing as a stronger chain, it probably would not prevent breakage in the event of a broken guide.

The safe thing with the V8 is to replace the guides and chain if there is any doubt at all. The sixes and fours are expensive enough to correct chain failure damage, the V8's have astronomical repair bills when this happens. If there is ANY MB engine that warrants timing chain and associated component replacement for preventive maintenance reasons, it is the V8's.

Best of luck,

#97 01-16-2002, 09:24 AM

my 92 500sl lost both on startup at 90000 also bent intake valves on number one

mplafleur · #98 01-16-2002, 11:55 AM

So your cam broke too? I though they were pretty tough to break. MB cams are even tougher. Could this be a metallurgical failure?

Benzmac · #99 01-16-2002, 10:11 PM

Cam breakage is due to the valves being rammed against it when the cam stops because the chain breaks....The valves are open, the piston comes up and BAM, the cam pops.

mplafleur · #**100** 01-17-2002, 10:23 AM

Right, but I thought that the torsional strength of the cam would be far greater than that of the valves. The valves should bend first as they are already makeing contact with the piston at an angle so that they are not at their strongest.

I just didn't think it could happen that the cam would give first, unless faulty.

blackmercedes · #**101** 01-17-2002, 10:42 AM

Sometimes when it comes to an engine destroying itself, the laws of physics seem almost as "guidlines..."

#**102** 01-31-2002, 08:28 AM

my 92 500sl ate chain rails bent two valvec broke the left intake cam destroyed two front gears, all on a warm startup. sven

bobjohnston · #**103** 01-31-2002, 11:25 AM

Geez, these are scary stories as my E420 reaches 100,000 miles. I was contemplating replacing the chain, upper guides and tensioner, maybe the check valve in the oil filter housing. Do I need to consider having the front end completely torn apart and replace the lower guides, as well?

Techs: What are you recommending?

DIY-er's: Is it tough to thread in a new chain without it skipping a tooth?

thanks,
Bob Johnston

#**104** 01-31-2002, 01:32 PM

Bob,
Had I replaced the chain guides in the head and chain oilers between both cam shafts and chain my catastrophic failure never would have happened I believe. Working on mine with the timing case cover off has given me a good idea of what could happen. You dont want to take the cover off. Always remember this, mine happened on start up, if I were you, disconnect the battery when you recieve this info, even if it means flat bedding it somewhere. Dont even think you can start it, if your engine is similar to the 119 we have the perfect tool to remove chain rail pins and also banana rail. GET A CHAIN NOW. Sven

Benzmac · #**105** 01-31-2002, 04:28 PM

If you have regular oil changes, the 100k interval is fine for the upper rails and the chain and tensioner. If you don't change your oil often, I would boroscope the lower rails to check for damage. Any damage will indicate a need for lower rails......
Good luck with this all!

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