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    Camshaft Wear

    For those who'd rather avoid the rambling backstory, is it normal to see lines on the parts of the camshaft that ride on the bearing surfaces?

    While progressing towards my presumably inevitable timing chain tensioner work on my 2000 MGM, I went to work on a 2001 MGM at my favourite U-pull. The intake manifold had a plastic crossover, so I wasn't about to take that home. I made a point of getting the timing cover as a spare (for less than $14 all in) so I don't have to leave my timing stuff exposed when I work on it outdoors.

    The passenger side tensioner arm was worn to the point where the chain was just starting to eat into the tensioner. The driver's side arm was obviously worn along most of its length, though the tip had about half of the plastic left.

    I got the valve covers off without having to mess around with the engine mounts, though I doubt I could've gotten the one on the passenger side off without removing the intake manifold. (I thought maybe the heater pipe might be worth taking, but it was too corroded.) I got one camshaft out to see if they would be worth swapping. I could see lines on the parts that ride on the bearing surfaces, though there wasn't any obvious roughness when feeling them or dragging a fingernail across them. I didn't have too close of a look at the cam retainers, but I could see at least one line on each of two of the bearing surfaces on one of them.

    Are the lines a normal wear pattern? The cam surfaces were nice and smooth, and that's what I was expecting on all contact surfaces. My first guess was that some aluminum from the passenger side tensioner arm had been floating around in the oil. (AFAIK, the oil filter does not provide 100% protection.) Another consideration was that the various timing parts had a dark glaze, so I guess the owner had not been diligent about oil changes. The odometer had only five whole digits, so I don't know if the reading 37k was 137k or 237k (presumably kilometers). Overall, I had no problem holding out for something better, though I'd appreciate some input regarding what to look for. Thanks in advance.

    2000 Grand Marquis LS HPP, a hand-me-down in 2008 with 128,000 km; 175,000 km as of July 2014
    mods: air filter box 'tuba', headlight relay harness, J-mod (around 186,350 km), 70mm throttle body, KYB Gas-A-Just shocks, aluminum driveshaft, ARA3 PCM

    #2
    I would think lines indicate scoring and are not normal. Lack of oil changes, cheap oil filters and low grade oil are most likely what's causing that. That and running the thing hot too.
    1985 LTD Crown Victoria - SOLD
    1988 Town Car Signature - Current Party Barge

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      #3
      You will see some wear just because there has been contact, but if you can't feel it with a fingernail, for all practical purposes it does not exist.
      86 Lincoln Town Car (Galactica).
      5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley

      91 Lincoln Mark VII LSC grandpa spec white and cranberry

      1984 Lincoln Continental TurboDiesel - rolls coal

      Originally posted by phayzer5
      I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers

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        #4
        Originally posted by IPreferDIY View Post
        ... The odometer had only five whole digits, so I don't know if the reading 37k was 137k or 237k (presumably kilometers). ...
        I had a closer look today. I had mistaken the odometer for one with five whole digits plus a fractional digit when in fact it has six whole digits with the first one (from the right) half-way through a change. The mileage was therefore over 371,000km, which is over 230,000 miles. I brought a magnifying glass this time, and the wear was pretty bad. I could indeed feel some unevenness in some spots. At least I know I can take a camshaft out and put it back in.

        I was figuring maybe F-150s and Exploders would have more space in the engine bay to make messing around with valve covers easier, but I was dead wrong. I can't imagine having to work on them.

        I should note that the camshaft retainer bolt on the passenger side bottom corner near the firewall on the 2001 MGM was about as bad as the valve cover bolt in that location. I couldn't get the bolt out on its own. I had to take it out with the retainer. And it looks like I wouldn't be able to fit a torque wrench in there. At least it won't be a last-minute surprise.
        Last edited by IPreferDIY; 07-31-2017, 11:32 PM.

        2000 Grand Marquis LS HPP, a hand-me-down in 2008 with 128,000 km; 175,000 km as of July 2014
        mods: air filter box 'tuba', headlight relay harness, J-mod (around 186,350 km), 70mm throttle body, KYB Gas-A-Just shocks, aluminum driveshaft, ARA3 PCM

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