So FWIW, and maybe it's good for nothing other than reassuring my fellow shadetree mechanics that you are not alone in the confusing world of 70 series, here is my most recent adventure with Marilyn, my wife's 1998 V70 GLT with 312,000 miles.
A couple of weeks ago the timing belt broke while going about 50. The car died abruptly and she had it towed home. Just to see what would happen (and because miracles happen every day) I put on a new belt and cranked, only to hear that dreaded sound of zero compression. Oh well, no surprise there. I pulled the head, and counted 16 bent valves, ordered 20 new valves, sent everything out to be prepped and assembled, and a week later I was ready to start reassembly. Everything was going great, although slow, since I'm super busy with work and just had evenings to spare, but I chipped away and when it came time to start it, NOTHING. No compression, no spark, just that awful whirring sound, same as the night it came back on the flatbed. I realized that I hadn't soaked the cam followers, so they must have collapsed, and proceeded to crank and crank to try to build up some oil and get some better valve action. No good. But no spark either, so I tested the crank sensor (good), and since the cam sensor plug crumbled when I unplugged it, I replaced it. No spark still. Hmmmmm....and here's where I show my boneheadedness......When I set the timing I used number 5 cylinder, not number one. My thought was that while the head was off I would just eyeball TDC by lining up the top of the piston flush with the block surface (I realize now that was at least 2 mistakes right there). my Chilton book illustration shows a misleading diagram depicting firing order where the distributor is closest to #1, but is actually just a representative drawing. I learned later that number one is always closest to the timing belt, and timing is set on these cars not at TDC but slightly BTDC. OH CRAP WHAT HAVE I DONE. Off comes the cam cover, reset to number 1 cylinder (oh there are those marks I keep seeing in pictures), cams in, cover on, get right with Jesus, and hope for the best. Before I cranked, I did have the sense to rotate the motor by hand, and it felt fine. By the way, I rotated it by hand the first time, and didn't feel like it hit anything then either. It sort of started, but didn't want to run. Backfires, no idle, barely revved. Rechecked all the vacuum lines, firing order (wasn't ever disturbed but i was desperate), tested TPS, new orings on the injectors, found a rotten vac line on the FPR tube, still no change. I did notice that unplugging the MAF made it run a tad longer, but not acceptable at all. Finally found the problem: the little flap of metal on the driver side of the intake manifold that retains the PCV tubing was placed between the manifold and the head, instead of on the outside, which was causing a massive air leak. After I corrected it, Marilyn started and ran like the champ she always was. Whew. Drove it around today, everything seems good. Whew.
Since the completion of this project (ordeal) the following thoughts occurred to me:
1. Follow instructions!!!!!!!!
2. How on Earth did I not wreck valves when I cranked the motor with the timing set so wrong? When I corrected it, I did check compression and all the numbers were in spec, and less than 10% different from each other. I really debated pulling the head after I realized my blunder, but I figured it was worth the extra time to try to reset the timing correctly and try it again instead of assuming the worst and doing another headgasket job. I was banking on the hope that since I was able to turn the motor by hand with it set up wrong, that no interference happened, and maybe the collapsed lifters helped me. At any rate, my gamble paid off and I avoided having to pull the head (again) and replace valves (again).
3. The internet is truly awesome.
4. I think I want a Chewbacca mask like the crazy lady on Facebook.
153k
