timing belt jumped

[kpaske]

IndianaVX - I concur with Merlin, I think it was more than likely a worn tensioner that allowed the belt to skip in the first place, so you should most definitely replace it. However, if you're going to take everything apart, you might as well replace the belt (and possibly the water pump also). I personally did NOT replace my water pump because I couldn't really spare the extra $150 at the time, but normally I prefer to err on the side of caution. Either way, replace the belt and tensioner and you're good to go for another 75-100k miles. Replace only the tensioner and you'll just have to tear it down again in 36k miles.

A word of warning - Mark is 100% correct about NOT rotating the cam shafts once the belt has been removed. Much of the published information is incorrect, and if you follow the CD manual letter for letter, you'll screw up your timing and the cam shafts will need to be reindexed. I know because I made that mistake myself and wound up having to have a shop complete the job for me. There is a TSB that explains the issues, and the correct way to reindex your cam shafts. The shop that does the work should have access to this TSB, but I also have a copy somewhere. If you need it I'll dig it up for you (please PM me). In all likelihood they will need to do this reindexing, since your belt skipped and the timing is probably off now.

FWIW, I also concur with Tone - I am under the understanding that this motor is, in fact, NON-INTERFERENCE.

[Ldub]

kpaske,

If you do find the TSB on cam timing, how about forwarding it to Moncha to add to the download section.

That right there could be some handy information to have.

[Tobert]

Weird. I totally had my cams & stuff all out of whack and I don't remember having any particular trouble getting it all lined up. It was mostly a pain in the butt because the cams wanted to snap out of place due to valve spring pressure.

I followed the CD manual's procedure. Maybe I got lucky?

[kpaske]

Weird. I totally had my cams & stuff all out of whack and I don't remember having any particular trouble getting it all lined up. It was mostly a pain in the butt because the cams wanted to snap out of place due to valve spring pressure.

I followed the CD manual's procedure. Maybe I got lucky?

You must have. I did the job TWICE myself, using the CD manual, to the letter, and my timing was all screwed up. I took it to a nearby shop, and it took them THREE tries before finding that TSB and correcting the problem.

I'll try to find that TSB and get it posted here. It's a little oily, but it should scan OK to be readable.

[Tobert]

I've been trying to remember what I did to get it right. I am not a professional mechanic, so don't be afraid to correct me ...

* check #1 TDC on the crank by probing the #1 cylinder with a long screwdriver (don't rotate the engine with the screwdriver in the spark plug hole as you risk gouging or worse, breaking pieces off in your cylinder chamber -- it's probably safe if rotating with a wrench, but don't blame me if something goes wrong)
* work with the valve covers off so you can see which valves are open
* use only a wrench to rotate the engine to protect your parts and yourself
* take your time and wrap your brain around the process of how the cams and crank are synchronized, then it'll become clear how it should be

With that information, it's pretty easy to figure out if you're on the right revolutions from there. For example, you know when you're on #1 compression stroke when both valves are closed and you're at TDC. Then you can forward through the firing order and figure out where everything else should be when the cams and crank are set at the default marks.

Once you put the belt on, rotate it around a bunch of times by hand and follow the firing process in your head. If the firing order is 123456 (I don't think that's right for the VX), you should see compression stroke on #1 with both valves closed, then the same on #2 and so on ... simultaneously, the next upstroke on #1 should be exhaust ... you get it.

Save yourself some time and go buy a few of those metal office clips suggested in the service manual. They really help a TON. It would probably also be a lot easier with two people, but I did it myself.

When I put a new timing belt on my wife's Subaru, I actually started it up while the timing cover was still off to make sure I got it right. Don't run it more than a second or two as the engine will burn up without coolant around the cylinders and in the heads. The temperature gauge is useless without coolant, so don't rely on it

[IndianaVX]

Okay,
heres the update.
My mechanic put a new timing belt on today. said the vx ran like new!!!!! it ran so well, that he didnt even feel that its necissary to do a compression check.
so i called merlin, ordered a water pump, and a belt tensioner rod. im going ahead and paying for these parts for peace of mind. so i should have my truck by middle of next week!!! I CANT WAIT!
this brings up a couple of things to my mind though. did i just get lucky that the valves didnt kiss the pistons in this interferance engine? or is this a sign that it is a non interferance? who knows, and at this point, i dont really care, im getting my truck back!!!

cant wait to shine er up, and smile again.

david

[volume311]

The engine is a non-interference engine, you'll be fine.

[biju]

excellent news.

-biju.