The Saga Continues/Timing Woes

This post continues from: EGR Defeat

Finally got some time to take a look at the damper. Took awhile as all of the cap screws accept one was rounded. Had to Dremel the heads off and grind them all down. Really like broken cut-off wheels zipping by my head.

Got the damper off and took a close look at it. In the balancer is a stud which refrences the damper. Only one way to place it on. The damper shows no stress fractures or fatigue of the vulcanized rubber ring. So am to back scratching my head once again.

Is it possible the PO had the timing chain replaced and it was improperly installed, skipping a tooth or two? Don’t know just grabbing at straws once again. Would appreciate your advice once again.

[ctaylor738]

At this point, I think you have only the option of bringing #1 up to TDC with a dial guage and making sure the cam marks are lined up. Use the offset keys if you need to compensate for chain stretch, or replace the chain. Put the damper back on and mark your NEW TDC with paint and time the engine around 8 BTDC using your new mark as a reference.

I still subscribe to the "wrong pointer" theory. Can you check the year of the block from the serial number below the head?

[leathermang]

OK,, how do you use a dial indicator to find tdc without taking off the head ? Do you let a valve drop, measure it at its top , then reattach it to the valve train ? Can you reach the piston through the injector hole without pulling the precombustion chamber ?

Thanks for the replies.

The engine number is 110 922 12034747. Checked the pointer and it is below the lower right hand bolt of the thermostat housing. Can see no other place a pointer could be placed.

I think replacing the chain would be the answer, then to align everything up to were it is sapposed to be. Just beat the H out of me how the timing could have gotten off by 30 degrees BTDC. A real head scratcher to say the least. Talked to one mechanic and he thought I was kidding him as he has never heard of such a thing. Something about muffler bearings I guess. :p

[psfred]

Gympie:

Almost has to be the balancer rotating on the hub, can't be anything else if there is a locating stud.

Best bet is to get new bolts (duh!), double check installation, and if it is still off with the piston, remark the crank and see what happens. Worst case will be it slips again, and that will answer the question definitively.

There is only one pointer for the M110 engine, I've been told, so there goes that theory.

Make sure the valve timing is OK with the crank, measure for the timing mark, and have at it.

Check to make sure the PO didn't modify the hub to "fit", too, anything is possible.

Leatherman:

The M110 is the DOHC engine, spark plugs are dead center on the combustion chambers in the middle of the head. Easy to stick something down a spark plug hole to check for TDC. Not true on any other MB engine that I know of.

Peter

Thanks for the reply.

You know had the same idea about the balancer rotating on the hub. Went to a bone yard today to compare my damper with others. Out of three dampers my damper matches each of them in respect to degree numbers and screw holes. So unless all have slipped the same amount, mine is OK.

Have not taken off the balancer as yet. According to the manual and othe posts it too has reference studs, to the left and right. There are 4 washers between the bolt and balancer which cover the hole, so I can't see if has knocked off the studs or not.

Thanks again.

[psfred]

Gympie:

The bolt goes in before the pins, so the pins (or the holes they are supposed to be in) are visible with the bolt in place. Not possible to put them in before running the bolt down.

Dollar to a doughnut, they aren't there and that is why the timing marks are wrong.

Peter

Thanks for the reply Peter.

In the 110 service manual 03-340 Removal and installation of pulley, it has a diagram of the assembly. The pins are to the sides of the screw hole under cup springs. Later in the job pictures it shows the balancer without the screw and only then the pins are visable.

Same/same on mine. Can't see the pins. Wish they were visible it would make things much more simple to diagnose a problem.

Appreciate your help and time Peter. A real stumper, no?

[ctaylor738]

My beloved Haynes manual has an excellent picture of the front end of the crank with the balancer off. Half of the holes for the pins are in the crank, and half are in the balancer. They are 180 degrees apart. You would line up the hole halves, insert the pins, and the bolt/washers would hold them in.

I suppose that someone could have put the balancer back on without the pins. We are really coming to the end of the line here. When you get the bolt out, we will know!

I am still hanging on to the two-pointer theory because of the 280 water pump housing I bought that would not work with my pointer.

But you have an early engine, so that kind of blows the theory in your case.

Thanks Chuck for your response. Appreciate the steadfast help you and Peter have given in this situation.

Will give a go at removing the crank bolt. One question although, how is the crank blocked from turning while using an impact wrench on it? Also in torque(ing) down once removed?

As to the pointer theory don’t know. If the thermostat housing is incorrect with the wrong pointer, for my TDC to be correct, the pointer would have to be 4 inches to the right longer as the damper indicates 30 BTDC.

Have a feeling the PO had a chain replaced and they botched the job, like the reaming of the cap socket screws. But when turning the chain I see no master link installed, so there goes that theory.

As you are, I am nearing my wits end on this. Starting to think it is a bad dream. If Stu Ritters shop wouldn’t charge 600 clams to do the job, I’d have him think it out. But guess you have to pay for fame and glory.

Gympie

[ctaylor738]

I have usually wedged a screwdriver into a tooth on the ring gear on the flywheel or against one of the bolts on the torque converter.

But I have always thought about putting a socket and breaker bar on the bolt, positioning the breaker bar on the floor, and bumping the starter - not for the faint of heart.

Not to complicate matters, but this would be a good time to do the front oil seal if it is leaking!

Thanks Chuck for the reply.

Well got the crank bolt off. Logged a screwdriver through a hole in the balancer to the block. It did not take 400 Nm to get it off at all, but with little effort. Must have been pretty loose. Happy I checked it now. Have a vision of the darn thing flying off and the damage it would have caused. The cup springs are about flattened, lost their cup(ness).

The bottom line is the balancer has its pins and are in the correct place. Looks like someone used a slege to get them in as they are pretty flat and gouged.

Well guess this has gone full circle now. Back to the timing chain.

[psfred]

Gympie:

Proper procedure is to use a crimp link on a replacement chain. If you use the MB tool, it will be impossible to tell which one was the open link. The "master link" is for pulling the chain through, not for actual use. There are some out there, buy the factory discontinued the practice some time ago.

I still think that it is possible to have the balancer "one hole off" -- wouldn't this be about correct? Besides, the reading on the balancer doesn't match the position of the crank, right?

And lack of adhesion between the damper and rubber may not be visible from the outside -- the only way to check would be to attempt to rotate the damper on the rubber.

Peter

Well it is a happy ending. Like to put an end to this thread and tell all I thank you for your time and help. To recap, the timing on the damper was 20+ degrees retarded. Unbeliveable I know and even stumped Stu Ridder. But is is possible that a chain can stretch so far on a M110 and not damage the valves.

Took two days of part-time work and aggrivation to remove the tensioner. Could not get the damn thing out! Was to the point of blowing the 116.020 up. Decided to have it towed to a shop and they had problems getting the tensioner out due to "crud" built up. Cost me a couple hours of labour, but have the chain in and it runs like never before. Alas I know a chain can stretch to the maximum limit of 20 degrees ATDC on a M110, but I would not recommend anyone waiting so long to do it although.

Thanks again all for your help and support.

May God Bless,

Gympie