I have a 2000 X-308 with the AJ 27 4.0 engine in it. I have owned the car since new, and now it has 41,000 miles on it. As time marches on, life keeps throwing curve balls at me (each new one more violent than the last), up to the point that, at this point in time in my life, I can only dedicate a little bit of time to the car about once a month, if I’m lucky. Which brings me to the point of this posting: Dry Starts aka timing chain rattle at start-up.
I also own a 2004 Ford Explorer Sport Trac with the 4.0-liter SOHC V6 engine that also suffers from the same dry start problem if it is not started at least once a week. Sometime ago, a friend gave me some advice on how to solve the problem: remove the fuel injector fuse (so that the engine does not fire up), crank over the engine continuously for about 15 seconds or so at a time, let the starter rest for a few seconds and repeat this “cycle” a few times until the oil pump builds up oil pressure, replace the fuel injector fuse, and you are good to go. It is amazing how well this works on my truck! In my truck’s case, I remove the fuse, turn the engine over for about 15 seconds, let the starter rest for a few seconds, and repeat… At about 8 or 9 seconds into the second cranking “cycle”, the needle in the oil pressure gauge jumps to the normal position. I replace the fuse and fire up the engine… It is a beautiful thing how this engine starts; no different than any other engine would start after a quick stop at the Mini Mart!
So…use the same procedure on my XJ8, and problem solved, Right? Not so simple! In the case of my XJ8, I remove the fuse, and I crank the engine over continuously for about 15 seconds per “cycle”, letting the starter rest for a few seconds in between “cycles”. After 8 or 9 of these cranking “cycles” (for a total of 2 minutes and 15 seconds of almost continuous cranking time), the oil pressure indicator light won’t even budge. By this point, the battery starts getting a little sluggish due to all this cranking; at which point I usually panic, and decide to fire up the engine before the battery goes completely dead. Oh Lord!… I crinch every time for the first few seconds of each one of these Dry Starts! The engine fires up, the timing chains rattle and slap for around 3 seconds (about the same amount of time it takes the oil pressure indicator light to turn off during the initial start after an oil and filter change), then the engine builds up oil pressure, the oil pressure indicator light turns off, the engine quiets down and runs smooth and silent as it always has. What really gets to me is the fact that when I do this on the Sport Trac, after 30 seconds of cranking the engine, it has built up oil pressure; whereas in the XJ8 after 2 and 1/4 minutes, the engine has not built-up oil pressure. What is it? Is the oil pump on the Sport Trac that fast, or is it the pump on the Jag that slow? Where has my thought process gone wrong? What is it that I’m not doing or that I’m doing wrong? Does anyone have any advice for me to help me out?
PS. I had the secondary chain tensioners replaced with the new aluminum ones about 14 years ago. Chains, guides, and primary tensioners are the original ones.