|10-03-2012 04:42 PM|
Timing belt is the 'colonoscopy' of engine work
Fear of the procedure was way worse than the actual procedure itself!
So, last weekend I replaced the timing belt on my daughter's '02 SE wagon's Zetec engine. The car has 156k miles on it & the belt looked like the original.
I used this thread as the basis for my plan of attack. I also relied on this How-To as my work instructions. (There were a few differences on my '02's job, which I'll list.) Thanks to mikebontoft for the explanation & reasoning behind the method he uses for this job! It made things relatively quick & easy for a 'first-timer'!
I replaced the timing belt, water pump, serpentine belt, serp idler & tensioner pullies, hydraulic (passenger) motor mount, transmission torque mount (dogbone), & attempted a 'fix' for a leaking p/s pressure switch. (I did not replace the serp tensioner itself, just the pulley.) The whole thing took me about 7 hrs, not counting setup/cleanup time & the time I spent running to the parts store for the 2 pullies & the dogbone.
Her p/s pressure switch started leaking the day before I was doing the belt change, & I didn't know (at that time) what it was going to take to fix it. I tried one of the fixes mentioned in another post, of threading a screw into the center hole of the switch. That worked for about a day. So the next day I went over to Ace Hardware & bought a 12x1.75 hex head bolt & a copper sealing washer (about $1.50). The 20mm long bolt was the same length as the switch, so I knew it was short enough to clear all of the pump's internals. The only thing I didn't do was use Teflon pipe tape on the threads, which I should've done. It's still leaking just a few drops, but nothing like the constant stream from the failed switch. The new switch just arrived at the dealer, so that will go in this weekend.
Changes from lhc's How-To:
1) I didn't remove the valve cover
2) I didn't disconnect the coolant tank
3) I'd recommend removing the engine mount's three 15mm bracket bolts before removing the two 18mm stud nuts. Why? Because if you don't get the engine jacked up exactly level to this mount, then the mount's cast metal housing is going to side-load those studs. Removing the 15mm bolts first allows you to easily tell if you need to raise the engine a bit more, or will unload the studs if you've already raised it a bit too high.
4) I didn't have a Torx E10 socket to remove the studs, but a standard 8mm socket worked perfectly.
5) I used the 'engine bump' method of removing the crank bolt. If you do this, snug the breaker bar up against the underside of the suspension arm that runs to the wheel (sorry, I don't know the official name of this piece).
6) After I removed the crank pulley, I carefully used a large slip-joint pliers to rotate the crank so that the key was pointing up. Don't gouge the surface of the crank that the pulley slips onto!
7) I painted my marks onto the two cam pullies & engine block, then also on the pullies & belt. This gave me two different methods of clocking the cams. The crank was stiff enough to turn that I didn't bother marking it to the block. (In retrospect, this might've been a mistake. My belt replacement went flawlessly, so I don't know if it's possible that the crank might rotate slightly on its own with the plugs pulled & the belt off.)
8) When I replaced the belt, I hung it over the two cam sprockets first, then threaded it between the idler & tensioner. This left a slack loop down at the crank. I visually verified that my cam locations hadn't changed (I checked both the block (horizontal) paint marks and counted teeth between belt (vertical) paint marks), then easily slipped the slack loop over the crank. One last verification of marks & I tightened up the tensioner.
9) When reinstalling the crank pulley bolt (to 88 ft/lbs?), I actually snapped the rubber strap wrench I was using to hold it in place. I only got up to 75-80 ft/lbs when the strap broke. So instead, I used a large center punch as a 'pulley stop.' I placed the nose of the punch into one of the two holes in the face of the pulley, then wedged the shank of the punch against the welded-together sheet metal of the wheel well. I pushed the punch hard into the pulley with one hand, & torqued the crank bolt up to 88-90 ft/lbs.
On a scale of 1-10 (10 being hardest), I'd give this job a 3. lhc gave this job a 4 in his How-To write-up, but he also had to reset his timing. The most frustrating part of the entire job was rubik's-ing the water pump out between the engine & frame. Except for the unexpected p/s pressure switch failure, the rest of it was all pretty normal (for me) maintenance stuff.
There was a brief moment of panic when we took the car for a test drive. Power output was reduced, exhaust sound was poopy, & ATX shifting was very delayed. This is the point where I thought, "Crap! I didn't paint mark the crank & it must've rotated a tooth!" It wasn't a huge deal, since I knew my cams wouldn't need changing & I'd only have to remove about 1/3 of the stuff (hydro mount, top belt cover, serp belt, & crank pulley) to gain access to the crank to change the belt/tooth setting. In actuality, I lucked out even more than that. The problems were caused by one of the spark plug boots not fully seating onto its plug. All I had to do was push the plug wire farther into the boot for it to snap in place onto the plug, & everything returned to normal.
As I said at the beginning, the fear of this procedure was much worse than the procedure itself. If you take your time, follow the written procedures & make your (redundant) paint marks, you should have no troubles R&R'ing a timing belt that's still set properly.