I have a problem installing the timing chain tensioner after I installed the new timing chain. When I screwed the tensioner to the block it broke the new timing chain guide rail (the aluminium part) in two . I got a new guide rail which I installed but I'm afraid that if I screw the tensioner into the block all the way (if I don't oil leaks out) it will break the guide rail also. The tensioner is ok, when I press it at the front it retracts. I also unscrewed the hex bolt and took the spring out but even screwed like this (for a test) it looks like the tension on the guide rail is very high (with the front of the tensioner retracted all the way). What am I doing wrong ? What is the correct procedure for intalling the tensioner ?

thanks,
George


P.S. the new timing chain is exactly the same as the old one, there is no difference.

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190E 3.0-24v (M104 980) turbo @ 0.8 bar
1/4 mile: 2.483 / 13.540 / 175.17 km/h (street tires)

I am not familiar with any significant changes between the 2.5-16 and 2.3-16 engines in this particular area. I believe you should be able to reset the tensioner by disassembling it.

As I understand them, at some point they were changed to be a ratcheting type to avoid chain slap and other potential ills caused running, even if for only a few seconds, without any real tension on the chain while oil pressure builds during start up. If you have such a tensioner, it is feasible that when you took it out it was set to an extension needed to keep the old chain tight. With the new chain, you might have a tighter chain to start with and the tensioner was too far extended to work correctly. I believe it would have to be disassembled and then reassembled to reset the tensioner length to the "starting" position.

Others with more specific knowledge should pipe up. But if the chain fits, the tensioner should also fit. Jim

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Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

JimSmith, thanks for the reply. My next question is how is the tensioner reset ?

__________________
190E 3.0-24v (M104 980) turbo @ 0.8 bar
1/4 mile: 2.483 / 13.540 / 175.17 km/h (street tires)

I am not certain of this, but I believe you have to disassemble the unit. If you have one that is not the newer, ratcheting type, this is not your problem as they collapse when oil pressure is removed. Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

Reset the tensioner by pushing the piston through the body and reinserting it from the front to the first indent.

If your chain rails were original, I wouldn't be surprised they cracked. They become brittle due to the mileage and heat.

Tinker

Tinker, the guid rail that cracked was brand new, maybe it was a defective cast. I'll try to reset the tensioner tomorrow, thank for your help guys

__________________
190E 3.0-24v (M104 980) turbo @ 0.8 bar
1/4 mile: 2.483 / 13.540 / 175.17 km/h (street tires)

Did the tensioner go in ok? Just curious. Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

Check out my post at the following on this site: http://www.peachparts.com/shopforum/showthread.php?t=124206

What I describe relates to the upgraded timing chaining tensioner. If you can push in the end of your current tensioner and it retracts, I don't think you have the latest type.

Good Luck--Jim

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Jim Herold--Current: 1987 190E 16V, 1999 ML 430--Past: 1971 280 SL, 1972 250