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#1
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IP timing: Valve lift method differs from cam marks???
I checked my timing chain stretch yesterday by using the cam mark method. I had about five degrees of stretch. Well, I did some more reading and noticed people saying its not really an accurate method. I figured it was probably close enough but I thought, what the heck, I'll pick up a dial indicator at Harbor Freight and do it the right way. So I did. I've got 14 degrees of stretch!!!! I performed the test multiple times to make sure I was doing it right and came up with the same result each time. With 2mm of lift my crankshaft reads 25ATDC. I've got a 616 with a #10 cam code which should be 9 degrees ATDC with a new chain or 11 degrees ATDC with a used chain. 25 - 11 gives you 14 degrees of stretch. Yikes!
LET THIS BE A LESSON TO EVERYONE WHO USES THE CAM MARK METHOD. It is NOT always "close enough." I'd be curious to know if other people have done it by both methods and had the same discrepancy I found. Scott
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Scott 1982 Mercedes 240D, 4 speed, 275,000 1988 Porsche 944 Turbo S (70,000) 1987 Porsche 911 Coupe 109,000 (sold) 1998 Mercedes E300 TurboDiesel 147,000 (sold) 1985 Mercedes 300D 227,000 (totaled by inattentive driver with no insurance!) 1997 Mercedes E300 Diesel 236,000 (sold) 1995 Ducati 900SS (sold) 1987 VW Jetta GLI 157,000 (sold) 1986 Camaro 125,000 (sold - P.O.S.) 1977 Corvette L82 125,000 (sold) 1965 Pontiac GTO 15,000 restored (sold) |
#2
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What is the part number? I should get around to doing this...
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Andrew 1989 Volvo 745- 202K |
#3
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Quote:
Dial indicator: http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=33675 Magnetic base: http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=5646
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Scott 1982 Mercedes 240D, 4 speed, 275,000 1988 Porsche 944 Turbo S (70,000) 1987 Porsche 911 Coupe 109,000 (sold) 1998 Mercedes E300 TurboDiesel 147,000 (sold) 1985 Mercedes 300D 227,000 (totaled by inattentive driver with no insurance!) 1997 Mercedes E300 Diesel 236,000 (sold) 1995 Ducati 900SS (sold) 1987 VW Jetta GLI 157,000 (sold) 1986 Camaro 125,000 (sold - P.O.S.) 1977 Corvette L82 125,000 (sold) 1965 Pontiac GTO 15,000 restored (sold) |
#4
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The two methods cannot differ by 14 degrees.
There is an error of some type in the procedure that you are using for the valve lift method. The chances of the chain having an elongation of 14 degrees are just about zero. |
#5
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Quote:
Possibilities are = Taking reading from follower finger instead of valve spring retainer.....Worn valve gear...Worn cam....worn follower...or balance pulley position migrated. Please explain the method you used. .
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[http://languageandgrammar.com/2008/01/14/youve-got-problems-not-issues/ ] "A liberal is someone who feels they owe a great debt to their fellow man, which debt he proposes to pay off with your money." |
#6
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I would be curious if someone rolled a new chain in sometime and got the cam one tooth off. The degrees off sound about right. Also there is another way to get chain stretch but you will have to hunt the archives for it. You physically measure the link pin distance over a specified distance and calculate the findings. Probably have to borrow a micrometer to do it. New chain distance is a known refference. Just my two cents worth and perhaps wrong but worth checking perhaps.
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#7
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Quote:
This is the method I used: http://www.peachparts.com/Wikka/OM617TimingChainStretch Look here for pics I posted using the cam tower method. You'll see the indicator on the 4-5 degree mark: Scuff marks on timing chain rollers Like I said, I did the valve lift method about 5 times to make sure I was getting an accurate reading to include removing the tool and reinstalling it to make sure it was on right. I removed the valve lash, put the tool on top of the flat part that sits on top of the spring (valve keeper, I think its called) and then rotated the cam until I got 2mm of lift. I don't know what I could have done wrong??? Scott
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Scott 1982 Mercedes 240D, 4 speed, 275,000 1988 Porsche 944 Turbo S (70,000) 1987 Porsche 911 Coupe 109,000 (sold) 1998 Mercedes E300 TurboDiesel 147,000 (sold) 1985 Mercedes 300D 227,000 (totaled by inattentive driver with no insurance!) 1997 Mercedes E300 Diesel 236,000 (sold) 1995 Ducati 900SS (sold) 1987 VW Jetta GLI 157,000 (sold) 1986 Camaro 125,000 (sold - P.O.S.) 1977 Corvette L82 125,000 (sold) 1965 Pontiac GTO 15,000 restored (sold) |
#8
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Hmm
FWIW, I just did both methods using the same instructions today and got the same answer using both methods.
This is the first time I tried it so Im no expert... Perhaps you had the indicator bottomed out or not fully reaching down?
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------------------------------- '85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit) '82 300D, 'Tex', 228k body / 170k engine ... summer car '83 300TD Cali Wagon 210k, wife's car |
#9
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Quote:
I really hope to find out what's going on. Scott
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Scott 1982 Mercedes 240D, 4 speed, 275,000 1988 Porsche 944 Turbo S (70,000) 1987 Porsche 911 Coupe 109,000 (sold) 1998 Mercedes E300 TurboDiesel 147,000 (sold) 1985 Mercedes 300D 227,000 (totaled by inattentive driver with no insurance!) 1997 Mercedes E300 Diesel 236,000 (sold) 1995 Ducati 900SS (sold) 1987 VW Jetta GLI 157,000 (sold) 1986 Camaro 125,000 (sold - P.O.S.) 1977 Corvette L82 125,000 (sold) 1965 Pontiac GTO 15,000 restored (sold) |
#10
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I should add that when I first start the car there is a loud noise - almost like a valve tap - until the oil pressure builds up. I had a mechanic tell me its probably the timing chain. That's what first got me interested in checking the stretch. Maybe being off 14 degrees would cause that problem?? Why is 14 degrees impossible?
Scott
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Scott 1982 Mercedes 240D, 4 speed, 275,000 1988 Porsche 944 Turbo S (70,000) 1987 Porsche 911 Coupe 109,000 (sold) 1998 Mercedes E300 TurboDiesel 147,000 (sold) 1985 Mercedes 300D 227,000 (totaled by inattentive driver with no insurance!) 1997 Mercedes E300 Diesel 236,000 (sold) 1995 Ducati 900SS (sold) 1987 VW Jetta GLI 157,000 (sold) 1986 Camaro 125,000 (sold - P.O.S.) 1977 Corvette L82 125,000 (sold) 1965 Pontiac GTO 15,000 restored (sold) |
#11
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Me thinks theres a mis calculation here
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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" |
#12
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Quote:
Thanks, Scott
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Scott 1982 Mercedes 240D, 4 speed, 275,000 1988 Porsche 944 Turbo S (70,000) 1987 Porsche 911 Coupe 109,000 (sold) 1998 Mercedes E300 TurboDiesel 147,000 (sold) 1985 Mercedes 300D 227,000 (totaled by inattentive driver with no insurance!) 1997 Mercedes E300 Diesel 236,000 (sold) 1995 Ducati 900SS (sold) 1987 VW Jetta GLI 157,000 (sold) 1986 Camaro 125,000 (sold - P.O.S.) 1977 Corvette L82 125,000 (sold) 1965 Pontiac GTO 15,000 restored (sold) |
#13
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Quote:
So, if my numbers are correct, this cannot be the culprit. |
#14
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Did you remove all valve last first? You do this by adjusting the valve past where it touches the cam lobe. This will result in a valve that is partially open so remember to readjust it when you are done.
-Tad
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1995 G320 2003 C230 Kompressor Coupe 2005 ML500 2007 ML350 |
#15
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Just how much valve lash do you remove? I loosened it up a lot.
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Scott 1982 Mercedes 240D, 4 speed, 275,000 1988 Porsche 944 Turbo S (70,000) 1987 Porsche 911 Coupe 109,000 (sold) 1998 Mercedes E300 TurboDiesel 147,000 (sold) 1985 Mercedes 300D 227,000 (totaled by inattentive driver with no insurance!) 1997 Mercedes E300 Diesel 236,000 (sold) 1995 Ducati 900SS (sold) 1987 VW Jetta GLI 157,000 (sold) 1986 Camaro 125,000 (sold - P.O.S.) 1977 Corvette L82 125,000 (sold) 1965 Pontiac GTO 15,000 restored (sold) |
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