Timing belt too short to install

[farley463]

Well, lets start out with an intro. My name is Josh, I'm a 17 year old high school automotive student who just got his first car, its a 1997 Monte Carlo z34 with the 3.4 dohc motor. While I'd like to say, this car hauls pretty good once it hits the powerband, is sure is a PAIN to work on. I just redid the head gaskets on it and got to drive it for one day, that is, until one of the bolts for my timing belt idler pulleys snapped. Luckily it somewhat kept cam timing so I don't think I smacked any valves, so I ordered a new gates timing set for 200 bucks. Anyways, these timing belts are so tight I can't install them without forcing anything! Last time, I had to pry the idler pulley down then use the bolt to force it on because the belt seems like its about an inch too short. My tensioner is fully retracted and even like that I cannot for the life of me slip it over the last camshaft sprocket. Now I know there are some variations between belts over the years, and I don't know if one of the previous owners swapped engines before, but what I do know is that the 97 belt does NOT fit at all. Has anyone had this problem before? This is really irritating, and I really need to get my car back on the road ASAP. Does anyone have any ideas? Thanks in advance by the way. I'd really appreciate some guidance...

[pocket-rocket]

Welcome to the site, Josh

Yeah, I haven't done a 97, but you are right. The belts in general on the DOHC are pretty tight. I've always had to pop the bolt out of the idler, get the belt put into place (minus the one idler), put the idler in place (which is usually a struggle) and put the bolt back in said idler and use the end of the bolt to pry the idler back into place. I myself have found no easier way to feed the belt into place. I've tried bolting idlers into place and leaving the cams for last but that was a no go due to the belt length. Even this way the idler won't just pop in place; it's still a struggle...

Yours is the first I've heard of an idler bolt breaking on these boards, but as long as you weren't winding it out the valves should be fine, the DOHC isn't an interference engine by design. Also use your finger to make sure the ball on the end of the tensioner is it's "socket" on the tensioner pulley. It's possible for that not to be seated correctly but I don't remember if that would try to remove slack from the belt or let more in off hand.

Good luck and I hope you get it taken care of.

[farley463]

Welcome to the site, Josh

Yeah, I haven't done a 97, but you are right. The belts in general on the DOHC are pretty tight. I've always had to pop the bolt out of the idler, get the belt put into place (minus the one idler), put the idler in place (which is usually a struggle) and put the bolt back in said idler and use the end of the bolt to pry the idler back into place. I myself have found no easier way to feed the belt into place. I've tried bolting idlers into place and leaving the cams for last but that was a no go due to the belt length. Even this way the idler won't just pop in place; it's still a struggle...

Yours is the first I've heard of an idler bolt breaking on these boards, but as long as you weren't winding it out the valves should be fine, the DOHC isn't an interference engine by design. Also use your finger to make sure the ball on the end of the tensioner is it's "socket" on the tensioner pulley. It's possible for that not to be seated correctly but I don't remember if that would try to remove slack from the belt or let more in off hand.

Good luck and I hope you get it taken care of.

Thanks for giving me your insight on that. The thing that has me nervous is that me being the 17 year old dumbass I am, I had the motor out to about 5 grand when it blew, lol. I don't think any of the valves are bent because I didn't hear any kind of clanking noise, it just lost power completely, idled at about a grand for a few seconds, then died. I'm gonna try putting the new belt on along with playing with the timing a little bit. I can't get my cam sprocket bolts to break loose so I'm guessing a tooth off would be about 6 degrees, right? Thanks again for your help man, I really appreciate it...

[pocket-rocket]

I want to say we figured a tooth was 12 degrees. Remember, the cams spin at half of engine rpm so 2 crank revolutions = 1 cam revolution so 6 degrees on the cam is 12 on the crank.

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[Schurkey]

I am not aware of a change to the belt based on the model year. If I'm wrong, what year is the engine? Is it original to the car, or has it been swapped?

If there's no change to the timing belt and pulleys, $200 is WAY too much to pay for a timing set. Amazon has 'em for my '92/93 Luminas for ~$120.

First Guess: The pulley bolt broke BECAUSE you levered the pulley into place with that bolt, it wound up cross-threaded and didn't tighten properly. Be very careful upon re-assembly that the female threads aren't buggered.

I don't remember having belt-length problems when I've stuffed belts/pulleys into my 92 or 93 Luminas. Sure you're routing the belts properly? Is the tensioner FULLY retracted? I'm half-assed remembering that I install the belt on all the pulleys, then install the tensionser. But it's been over a year, so maybe that's a false memory.

[pocket-rocket]

I am not aware of a change to the belt based on the model year.

If I remember right 96 and 97 has round toothed belts vs the 91-95 square tooth belts, but lengths should remain the same.

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[farley463]

If I remember right 96 and 97 has round toothed belts vs the 91-95 square tooth belts, but lengths should remain the same.

Sent from my HTC One X using Tapatalk 2

Yep, that's right. The 96-97 belt has rounded teeth. Also, Shurkey, I'm pretty sure you were right about that. I initially thought it was because the belt was too tight but that makes more sense because the bolt was wayyy to hard to turn after I got the pulley on. With the new kit, I made sure the pulley was center this time, and the bolt was much easier to tighten. Well anyways I got the car back up and running. I REALLY need a new timing belt cover, lol. I ordered one from gmpartsdirect for about 30 bucks. I'm glad to find out that I didn't bend any valves. The motor runs decent but now I have a miss at idle that I didn't have before. If I rev it or start driving it smoothes out but at idle its pretty bad. My ses light flashes and I have 4 codes, one for the tps, mass air flow, evap system, and random multiple misfire. This doesn't make sense because I never even touched anything from the air cleaner the the intake elbow when I did it. I did remove the center plenum though, and I made sure to reconnect the crankcase vent line. What do you guys think because I'm absolutely stumped, lol.

[Schurkey]

Clear all the codes, see what comes back.

Are you reading the codes with a REAL scan-tool, or some consumer-grade junk code reader, or consumer-grade junk scan tool? A junk tool may not tell you the REAL code, instead it may substitute the Generic OBD II code.

[farley463]

Clear all the codes, see what comes back.

Are you reading the codes with a REAL scan-tool, or some consumer-grade junk code reader, or consumer-grade junk scan tool? A junk tool may not tell you the REAL code, instead it may substitute the Generic OBD II code.

At the moment I'm using one of those cute little generic scanners. They suck, believe me I know, but its all I could use at my shop. We have a genesis which if you've ever used one you would know its a real badass scanner, lol, but were practicing for the AAA Ford troubleshooting competition and our teacher doesn't want it to be used on any other car. Anyways, I'm starting the think that it may have something to do with the fact that the battery was completely DEAD, because it did that when I first bought it, the alternator died while driving it home and after replacing it everything sort of smoothed out and the codes never came back until now. I'm gonna try a few things and hopefully I can get it fixed. Thanks again for your help man.

Update: Well I've been driving the car around and it seems like the more I drive it, the smoother it gets. I also erased my codes and nothing has come back yet, so that's a plus. The misfire is still there though, but I believe the computer just needs to relearn itself and it should straighten out. Ill keep you guys posted.

[ericjon262]

a buddy of mine had a VW that lost time an kissed valves, the valves got bent, but we just put a new belt on and rolled with it. the engine made lots of noise initially, but smoothed out and quieted down after the valves "self straightened" on the seats...

[farley463]

Oh damn, lol. I bet that ran great haha. I wonder if that's what happened to mine, I probably should have done a compression test before I put the plenum back on, but oh well, haha.

[ericjon262]

Oh damn, lol. I bet that ran great haha. I wonder if that's what happened to mine, I probably should have done a compression test before I put the plenum back on, but oh well, haha.

actually, it didn't run as bad as you would think. ran like crap when we first started it, but smoothed back out pretty quick. never ran perfect again, but it got him around until he finished the build on his WRX.

[dohc nut]

your random multiple misfire code is more than likely due to improper camshaft timing. If you cannot open your cam pulleys you CAN NOT properly time this engine. You could only get close. close is only good in horseshoes and hand grenades. close timing results in poor performance,lack of power/fuel economy AND RANDOM MULTIPLE MISFIRE codes which do not otherwise make sense. You must retime your engine adhering to proper timing procedure with cams locked in position and cam pulleys LOOSE from cams as detailed in any decent manual.( at least this does not require belt reinstallation but only retiming.)
Also to help install tight timing belts completely remove any hydraulic actuators they are installed at the end.when routing only put the belt on any one pulley about half way this will allow more stretch in the belt as it can pull slightly around the edge of the pulley. then bend the inside edge of the belt up while forcing over the edge of your final pulley once its on there more than a quarter inch you can very easily push the entire belt the rest of the way in.

[Schurkey]

I ran my cam timing "close" on my '93. I replaced the belt and the typical pulleys/bearings, but did NOT loosen the cam pulleys. I marked the old belt, counted teeth on the old and new belts, marked the new belt to match the old, and installed the new belt to match the old marks. Ran great for forty thousand miles, at which point I yanked the heads off to repair a blown head gasket. I did the '92 the same way, and it's still running fine, although with many fewer miles.

Close CAN work just fine.

[dohc nut]

I ran my cam timing "close" on my '93. I replaced the belt and the typical pulleys/bearings, but did NOT loosen the cam pulleys. I marked the old belt, counted teeth on the old and new belts, marked the new belt to match the old, and installed the new belt to match the old marks. Ran great for forty thousand miles, at which point I yanked the heads off to repair a blown head gasket. I did the '92 the same way, and it's still running fine, although with many fewer miles.

Close CAN work just fine.

Ok so you got lucky. Its very easy to time an engine which is still timed. however once the time is lost its a whole other story. That said you are not close but spot on, you matched the original timing exactly. he on the other hand lost the belt at 5000 rpm timing is out to lunch. While close may work for you I'm a professional licenced technician who works on p0300 (random misfire) codes every day. #1 cause of unexplained random misfires when nothing else is wrong is cam signal or you guessed it cam timing especially on pre obd 11 dis fired engines. and even more especially after doing a timing belt without following the proper procedures which are of course given for a reason------ SUCH AS THIS.