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Strange Timing Chain Going Ons...
Ok, I believe this is more solid info than my Myth of the Town and Country Horn.
I made the slight error of buying a 4.5 car on ebay. However, whats done is done and since it is in far better shape than my last MB project - I'm gonna go with it. So I've got my mechanic on a campaign of Putting Things Right. My experience with my last MB is there are a lot of ways to fix things wrong. In the process of adjusting valves, he discovers that when the crank and right cam are at TDC, the left cam is off significantly. Like 13 degrees. I'm assuming its stretched, has somehow jumped a tooth OR - was somehow installed incorrectly when someone did this before. Its not the original chain or rails. Has anyone ever heard of this before? Obviously (banging head on desk) thats the next major job! Then maybe we can address the injectors. Oh and the AC. And the suspension. And then after that is all put to rights, I'm sure it will need a top end. Oh well, at least my kid only has 1.5 years of college left to go. Ann |
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Hmmm. 1.5 years for the first degree, 4.7 for the Master's and then another 2-6 for their Doctorate.........
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For starters, was this car running when you dropped it off with your mechanic?
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I am assuming that this is a US car, and the by the right side, you mean the passenger side. If that's the case, then it sounds like a replacement chain was not installed correctly - like it is off one tooth on the left side. I don't see how the chain could have that much stretch in the short chain distance between the sprockets.
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Chuck Taylor Falls Church VA '66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe |
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Are any of the valves bent?
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With best regards Al |
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And the answer is...
It was off a tooth.
Apparently it made my mechanic crazy enough that he stayed late to pull the tensioner off and put it to rights. And yes, the car was running, but not too well at idle, which was a little, err, high, to compensate. It ran ok at freeway speeds... And oddly enough Al - no bent valves. Compression is ok. It was the cam on the passenger side. Do people use an anatomical left and right when talking about cars? According to my mechanic it runs much better, and we can get to the injectors now... I'm just really, really happy I get to drive her this weekend. We have a formal dinner on Saturday night and I am so looking forwards to pulling up to this private club in my stately lady. Much cooler than my husband's ubiquitus black pickup truck or my screaming orange ford focus. Ann |
#7
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Your lucky that the valves aren't bent, I think I'm getting very close to getting another car in that body style. I need to get more aggressive about selling my current 280SEL.
I have way too many cars. If you don't know already Tomguy (the vintage group moderator) is quite the authority on W108's.
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With best regards Al |
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Al, too bad your 108 is in Texas. It's really quite nice...
Ann: Sounds like whoever put in the new chain was in a hurry and skipped a tooth. Fortunately, it sounds like the resulting timing offset wasn't bad enough to cause valves to kiss the pistons. Fortunately, on the 4.5, the pistons dont go all the way to the top of the deck, or it very well may have. I think this is why more m116s suffer fatal valve train damage than m117's - small interference from stretch causes massive strain on the rails and chain, causing it to skip time. Regardless, you're safe, and you WILL notice off-idle performance increases! Al, the only reason I know so much about them is because I've taken so much stuff apart on mine It's easy to do, and easy to remember.
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Current: 2021 Charger Scat Pack Widebody "Sinabee" 2018 Durango R/T Previous: 1972 280SE 4.5 2014 Jeep Grand Cherokee Limited "Hefe", 1992 Jeep Cherokee Laredo "Jeepy", 2006 Charger R/T "Hemi" 1999 Chrysler 300M - RIP @ 221k |
#9
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I have the same problem on my 420SEL.
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Regards Warren Currently 1965 220Sb, 2002 FORD Crown Vic Police Interceptor Had 1965 220SEb, 1967 230S, 280SE 4.5, 300SE (W126), 420SEL ENTER > = (HP RPN) Not part of the in-crowd since 1952. Last edited by wbain5280; 04-25-2007 at 04:34 AM. Reason: Fix spelling error |
#10
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Car "sides" are given from sitting in the driver's seat. Much easier than driver's side or passenger side when you consider this is an international board.
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#11
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Is that stretch, or are you 1 tooth off?
If it's the latter, you probably have a master link. Take it off, roll the cam clockwise exactly 1 link, and then reattach the link!
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Current: 2021 Charger Scat Pack Widebody "Sinabee" 2018 Durango R/T Previous: 1972 280SE 4.5 2014 Jeep Grand Cherokee Limited "Hefe", 1992 Jeep Cherokee Laredo "Jeepy", 2006 Charger R/T "Hemi" 1999 Chrysler 300M - RIP @ 221k |
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I'll find out in the morning when I rotate the engine to align everything. Then I'll rotate the cam one tooth if indicated.
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Regards Warren Currently 1965 220Sb, 2002 FORD Crown Vic Police Interceptor Had 1965 220SEb, 1967 230S, 280SE 4.5, 300SE (W126), 420SEL ENTER > = (HP RPN) Not part of the in-crowd since 1952. |
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Quote:
I'm totally thanking the car gods the valves aren't bent. I think that just goes to show how bullet proof (and well designed!) these cars are - even in light of some of the creative wrenching that gets done on them. I've yet to go through the pile of receipts that came with the car (based on how badly every was done, I'm not sure if I want to) but I suspect it ran like this a long time. As for Tomguy - I got that impression from reading his other posts! I wish there had been some sort of internet community when I got my first 108 - I was on my own about a lot of things. Ann |
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Quote:
I'm reminded of my old housemate who had an early escort and was told repeatedly by all of us, and his mechanic, that replacing the timing belt was very, very, important on that motor... Anyway, I'm barely going to be able to sit through classes this AM. Its a beginning to look a lovely day and I just want to go drive my car. Too bad I've got a final Thursday night... Ann |
#15
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I think I need a new chain
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Regards Warren Currently 1965 220Sb, 2002 FORD Crown Vic Police Interceptor Had 1965 220SEb, 1967 230S, 280SE 4.5, 300SE (W126), 420SEL ENTER > = (HP RPN) Not part of the in-crowd since 1952. |
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