Newbie with 96 Monte Carlo Z34

[cmanningjr]

I just thought I'd introduce myself. I live in Alabama and bought a 96 Monte Carlo Z34 about a year ago. I love/loved this car. It's a cool looking blue color. Ran great till my timing belt disaster about 2 months after I got it. The tensioner leaked down and caused the car to jump time. I've never worked on one of these engines before so I called a "Mechanic" that works for our company to see what was wrong with it. (He discovered that the timing belt had slipped) After about two weekends of him trying to get it in time I gave up and had it towed to a shop. (My 2nd mistake) I told the guy at the shop that I was in no big hurry to get it back and to take his time. After 2 weeks the guy called and said the motor was shot and i need to to find another engine. (I found this hard to believe, but then again I didn't know anything about these engines either) So, after a couple of days I told him that I wanted to take it somewhere else to get a second opinion. THEN he tells me he had backed over the car with the wrecker when he took it to his shop. (I hadn't been to the shop just over the phone dealings) To make a long story short. The car got towed back to my house(bent hood,crushed headlight and bumper pad) We fussed back and fourth for about a month, then he paid for me a trip to the body shop.

In the mean time, I got a cheasey manual and somewhat got the car in time and it's running. (Not great but driveable) So I know the engine is not shot.

Note, I didn't have the cam holding tools or anything line that, Just some makeshift type tool.

After reading the "How to" on this forum, I know I was close and can do it correctly. This Spring when it warms up, it'll be my project.

BTW the car has 97,000 miles on it and has been taken very good care of.

What would the experts advise on this endevor? All help is appreciated....

[grandprixgtp_91]

Welcome to the board, first off make sure you have a new belt, dont get oil on it, and make sure you replace that tensioner, and the 2 plasitc idler pulleys , make sure you replace those its important. then you will need the cam timing hold down tools, they are easy to make or have someone make. and follow the instructions on the site carefully. any questions and ask.

Jake

[Carlspike]

Did your timing belt slip while you were driving? If it did then I would make sure the valves aren't bent. I think that 1996 was interference.

[cmanningjr]

Yep, it slipped while driving. I was planning on going ahead and taking the heads off and having them worked. I've been told all diffrent kinds of stories about it being an interference engine or not....

[z34phoenix]

yeah there is nothing that i remember that said the 96-97 were deff interference. only thing i have heard is that at higher rpm valve float will cause it to be interference.

sappy... a word to put this subject to rest?

[SappySE107]

I don't think it is any more interference than 91-95. I haven't clayed one to see what it would be clearance wise at TDC with the valves at peak lift. Valve float, rod stretch can cause it to be interference, but that requires high RPM and probably an overrev issue.

[Carlspike]

I had heard before only the 96 and 97's were interference. Something about either no valve reliefs in the pistons or a slightly higher compression ratio. Can anybody confirm this? Gradprixgt91 probably would know.

Here is a thread that it appears somebody with a 96 bent their valves (I think it said his engine was at like 5k though)

http://60degreev6.com/showthread.php?t=34325&page=2&highlight=lq1+interference

[cmanningjr]

My wife was driving the car at the time, (No High RPM's) I was thinking just to be on the safe side to pull the heads anyway. Does anyone know a good source for parts?(Gasket set, Pulleys ect??)

[96MonteZ34]

Re:newbie

I have worked on these engines quite a bit and from my past experience the 91-93 motors are the only ones that are NOT interference motors. After that you kinda take a risk on that whole subject and ride with it. I have the exact same car and i am doing intake manifold gaskets right now but it will be a sweet free car when i am done. once you replace that belt you should be good for another 50-60k until you have to do it again. Another common thing if you take the heads off make sure to replace the oil pump drive seal (distributor shaft) they are really common to leak and can be a royal pain in the ass and leak about a quart every couple days.

[cmanningjr]

Thanks for the tip on the oil pump seal. (I'm making notes)

This is prob a stupid question but, when you change the belt and you set the flats of the first set of cams, you rotate the engine 360'. OK. My question is if it is an interference engine, will the valves on his on the side that is not set when rotating the crank 360'?

Just a thought.

[napatiger]

rockauto.com has good prices on parts, do a search for discount code (I just posted another).

I don't think the cam hold down tool is much better than a flat metal straitedge.

You can not trust the hold down tool to actually hold it's bolt in the aluminum head, I stripped the threads once.

Good luck.

[grandprixgtp_91]

as far as i know 96-97 motors are NOT interference motors, according to gm they only build interference motors that are chain driven cams, not belts due to the fact that they can break easy. anyways from personal experience i have a friend who has a 96 gtp and blew his belt while at 6000rpm , and he did not bend the valves, we changed the belt and it ran perfect. so there is first hand experience with a belt breaking on a 96-97 motor. i guess it all depends on the milage and whatnot, because ive heard of valves bending in a 91-95 motor before, but i can clearly remeber reading something printed from gm at the dealer about , if its belt driven then its NON- interference. i guess you just have to look and see.

Jake