Chain is so loose I'm able to lift it off the top sprocket. Also getting marks inside cam cover.
Cam sprocket looks good, side rail from what I can see has no grooves and also looks good.
Question - What else should I look at as far as sprockets and (?)

Thanks

Is this on a 1949 Chrysler?

OOPS - Gettin' old.
1981 240D, 220,000 miles. 1 quart oil every 2500 miles

My first thought is that the chain tensioner is not working.......whatsoever. If it's similar to the 617, it is pressurized via oil and keeps the chain very taut. It's a ratcheting affair that maintains tension to the nearest tooth even after the oil pressure is zero.

The other possibility is that the chain is so loose that the tensioner is no longer in range.

I wouldn't drive it under such conditions. You run the extreme risk of losing the chain and taking out the valvetrain. In such a case, you've probably trashed the engine.

I can see a 'round pushrod' where the tensioner would be. Seems to be visibly pushed out against the rail. Should I check for chain stretch prior to the tensioner or would it be a good idea just to replace both? Stopped driving it as soon as I discovered a problem. I'm old not yet senile.

It should be against the rail and the rail should be against the chain to take up all the slack.

You can roughly check the chain stretch, before you do anything else.

Set the mark on the camshaft thrust washer precisely on the tower mark (be very accurate.......make sure the mark is right smack on the center of the tower mark) and then read the number on the crankshaft.

Note, that it's not easy to get the marks to align perfectly, and, you cannot go in reverse, especially with a chain that has so much slop. Your readings will be wildly off.

There is an instruction procedure for the five cylinder engine in the DIY forum that has some photos.

http://www.peachparts.com/Wikka/OM617TimingChainStretch

The tensioner on the 616 is'nt ratcheting, dont know if that makes any diff.

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1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"

'Pushrod' is up against the rail. Not sure how much pressure it's exerting. I've seen instructions (here) on lining up cam and timing marks, I'll start there. Noticed the chain while adjusting valves (turning engine clockwise from front) and just stopped everything. Appreciate your prompt reply. I can get rolling on it after work.

So, the chain would be loose at all times when the engine is not running???

I need to get some clarification from others regarding that engine. The chain may be normally loose due to the fact that the tensioner appears to be non-ratcheting. There will be more replies to clarify this issue on the thread when you return.

Stevo - Part # on tensioner for a 1981 300D is the same. 1982 300TD and others would be different.
Engine was quite cold when I checked. As Brian Carlton mentioned 'not running and loose chain', should I start it to build up oil pressure or start off with chain stretch measurement?

Thanks Brian

The manufacturer by intent would not want a really loose chain prior to startup. The load of inertia initially is far too high to ignore. A lot of engines slip their timing on initial startup. That chain is either really stretched to the point the engine probably would have not been running well or more likely the hydralic tensioner is shot. Great you found it before it found you.

Sounds to me like the tensioner is shot.

My tensioner has a removeable spring that maintains pressure until the oil pressure comes up.
On his model there is no replacement spring. It has to be replaced as a unit.

Danny

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1984 300SD Turbo Diesel 150,000 miles

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What's the deal with the ratchet, or lack thereof, on the 616? Without a ratchet, what holds tension when the engine is shutdown?