ok! Timing Belt Overload!....3.4 DOHC

[brandon293]

Ok...I just tackled a Timing belt replacement on my 3.4 DOHC Cutlass supreme Convertible....I should finish it tomorrow....We will see....My car so torn apart and I have had a blast so far.....so far so good.....my car has 195,000 mi. so with a new timing belt it will be good to go for a long time of riding and enjoying.....

Comments please!

[bszopi]

Well, first off, welcome to the site! Did you use any of the site articles to help you out with the replacement?

[Smittro]

Well, first off, welcome to the site! Did you use any of the site articles to help you out with the replacement?

Good idea there's so much help on this site It would be foolish not to use the knowledge..imho

To the OP. How are you setting and holding the cams? If that belt is original or has'nt been replaced since early in it's life the timing will most likely be off a bit.. More so on the back cams.. I would definetly reset the cams to be certain. One tooth with timing already off could easily cost you a set of valves or even possibly a head/pistons..

[brandon293]

Good idea there's so much help on this site It would be foolish not to use the knowledge..imho

To the OP. How are you setting and holding the cams? If that belt is original or has'nt been replaced since early in it's life the timing will most likely be off a bit.. More so on the back cams.. I would definetly reset the cams to be certain. One tooth with timing already off could easily cost you a set of valves or even possibly a head/pistons..

Good morning, I am waiting on the belt and pulley kit from napa now. Should be in today. I have clamps holding the cams still. It was very hard to see them but I did find the factory marks on the cams and crankshaft and painted them red. The back cam does look slightly off. I hope to fix that. I got the tension piston out and it looks in good shape. (no oil leak) The belt is still on but loose. I was not going take it off untill I had the new one in hand. I have been reading the "paperclip" procedure in the service manual..any pointers? I just found this site yesterday so I have not had much time to browse around. So glad I did find it! Looks like a great site!

Brandon

[bszopi]

In case you didn't see them, here are the site articles addressing changing the belt...

http://60degreev6.com/content.php/31-Cam-timing-text-walkthrough

http://60degreev6.com/content.php/30...re-Walkthrough (still need to fix that one)

I'm not a DOHC guy, but if I remember correctly, I wouldn't trust the "factory markings" you are talking about.

[Smittro]

Good morning, I am waiting on the belt and pulley kit from napa now. Should be in today. I have clamps holding the cams still. It was very hard to see them but I did find the factory marks on the cams and crankshaft and painted them red. The back cam does look slightly off. I hope to fix that. I got the tension piston out and it looks in good shape. (no oil leak) The belt is still on but loose. I was not going take it off untill I had the new one in hand. I have been reading the "paperclip" procedure in the service manual..any pointers? I just found this site yesterday so I have not had much time to browse around. So glad I did find it! Looks like a great site!

Brandon

Follow the links provided in #5.. SHould help greatly..

Okay here's mine with a clear view of what your working with..
First this is the mount for the belt tensioner.

After the tensioner is removed you'll need to pull out the little rubber cap @ the back of the tensioner and the one strait up from that. Look inside the hole there will be a slotted screw down inside.. Insert a small regular screw driver and rotate the screw to draw up the piston..

After the piston is drawn up as far as it can go insert a paper clip or in this case I used a strait pin.. *NOTE: You will have to hold both the tensioner and the screw driver together in one hand to be able to insert the pin/clip.. As the srew is spring loaded and will snap back to the extened possition if not held securely..

Install the tensioner with pin/clip left inserted.

Make sure the ball or the tensioner is inserted correctly into the pivot groove as seen here.. Then install the outer support.

Once everything is where it should be simply remove the pin by pulling it out..
You're done! now you can go on to resetting your timming.. Again follow the instructions in the links previously provided and you should be golden..
This pic shows the finished project with pin pulled and belt in place.. Cam covers pulled in prep for setting timing..


Good luck!

[walterdude]

Man, you NEED to do some homework!! You don't mention a year on your LQ1, older ones require you to break loose or remove the lock rings on the cam gears. Often you must remove the cam carrier to do it. Also you say you have the clamps across the flats of the camshafts,,, do NOT rely on these to break loose the nuts on the cam gears. They will bend or worse case rip the threads out of the cam carrier. There is a tool to hold the cam gears while removing/loosening the nut, they are easily made. You really should follow the guide to set timing,,, many people have found those marks to be inaccurate.. As confusing as it may seem it's worth it to take the time and do it right.... Oh and the reccomended life of a timing belt is 60,000 miles... I like to follow it as much as possible,,, those 4 cam-shafts put a LOT of strain on the belt...
Read those links that Brad posted,,, THOROUGHLY!!! Then ask questions, you're likely to have a few!!
Hope this helps and GOOD LUCK!!!!
Tom....

[Smittro]

Man, you NEED to do some homework!! You don't mention a year on your LQ1, older ones require you to break loose or remove the lock rings on the cam gears. Often you must remove the cam carrier to do it. Also you say you have the clamps across the flats of the camshafts,,, do NOT rely on these to break loose the nuts on the cam gears. They will bend or worse case rip the threads out of the cam carrier. There is a tool to hold the cam gears while removing/loosening the nut, they are easily made. You really should follow the guide to set timing,,, many people have found those marks to be inaccurate.. As confusing as it may seem it's worth it to take the time and do it right.... Oh and the reccomended life of a timing belt is 60,000 miles... I like to follow it as much as possible,,, those 4 cam-shafts put a LOT of strain on the belt...
Read those links that Brad posted,,, THOROUGHLY!!! Then ask questions, you're likely to have a few!!
Hope this helps and GOOD LUCK!!!!
Tom....

I believe you're reffering to these tools..


There are companies that have begun to make these again.. Depending on your means they are not expensive and worth every dime imho.. A simple google search will locate them.. My LQ1 in the photos is a virgin gen 1 with newer style cam pullies..

[brandon293]

car is a 1994 cutty convertible. Shop manual says to line up the marks as I have done. I have used the paperclip procedure and installed new pullys that came with the kit from napa. Belt is so damn tight i cant get on! I am going to remove the hydrolic tensioner again and make sure I have it fully retracted! I will post again after belt is on and before I start it. Thanks All

[brandon293]

oK..Happy thanksgiving to all. I did get the belt back on. Per the shop manual (pic) I did rotate engine three times before cranking it. Bad news is the timing is out. I guess the good news is that it cannot be by much because the engine did run and idle. (tap, tap, tap, tap, tap, tap) I have herd several cars over the years sound like this when the hood was up. So at this point I am assuming that the timing is slightly out. On Friday morning I hope to pull the belt slightly off and adjust the rear cams again. That appears to be where the sound is coming from and the marks dont look quite right. I know most of you think I a fool for trying this...but this my toy car and I have plenty of time to tinker on it. Guys please keep checking this thread for me.....Your information has been so reassuring!!! Thank you!

[bszopi]

Again, I am just pulling this from memory, but I think the Service Manual is actually wrong...

[Smittro]

Again, I am just pulling this from memory, but I think the Service Manual is actually wrong...

I believe you're correct.. The service manual if I recall also states that the marks are "stamped" on the sprockets.. I've never seen one timing mark on the sprockets on the couple LQ1's I have layin' right here.. I also have the 2 different types of sprockets that came on them. The solids and the spoked.. Non of which has markings as the book suggests..

The marks being painted on leads me to believe that each engine had it's timing specially set by hand. Possibly with a degreeing wheel prior to installation.. But who knows.. @ the time of the first gens these things were "state of the art".. Would'nt surprise me if each engine got LT5 type treatment for the first couple of years..

[brandon293]

The book said to look for "painted on marks" They were BARLEY VISIBLE. Now they are fire engine red courtesy of my wifes nail polish. The one on the Crank shaft was factory scored at "two o'clock" and the one on the intermediate cog was very visible. The belt is back on for the second time and the engine is running with a slight tap tap tap ( F*&K) anyhow i will be posting a link to a youtube video for you guys to listen to the engine run. I am considering removing the belt again and trying to tweak it. Once again thanks for all the help!
Brandon

[brandon293]

Ok Posting pics this post...

Right side cams (re-painted factory marks) aligned per manual


Left side cams (re-painted factory marks) aligned per manual


Original Factory intermediate sproket mark vertical with notc mark at bottom of engine


"two O'clock Factory mark" re-painted red on crankshaft


Now, after rotating the crankshaft 360"0" you can see that my "two O'clock" factory mark is about "one 30" while the intermediate sproket mark aligns well with the lower notch in the engine......and that difference shows up in the cam pics


Right hand cams after a 360"0" rotation of the crankshaft


Left hand cams after a 60"0" rotation of the crankshaft


I know that they are off and that is why I can hear the slight tap tap tap....So I am gonna try to tweak them some more.... Like I said before this is my toy car and I dont plan on drag racing it or nothing but hey...I want it to be dependable and I want to be confident in the car enough to put the pedal to the floor every once in a while. Engine builder I am not...Afraid to get my hands dirty....nope...saving $1100 at the GM place to do this will make me smile bigger than you can imagine!

Below is the link to the youtube video of how it sounds right now...

http://www.youtube.com/watch?v=5okRdmG34TU

Thanks to all...Comments please!
Brandon

[Teardrop]

I have yet to do this job, and boy do I dread it worse than I dread having my lower wisdoms pulled.

You will come across something about loosening the cam sprocket bolts and turning the cams to align, as well as setting the intermmediate shaft sprocket, then tightening the cam bolts.
It is a mess for sure but since you are dealing with four cams, knocking them out of alignment is very easy, almost like destroying a house of cards.

I myself am not quite sure why "just lining up marks" doesn't qork well but supposedly it just doesn't.

Most engines timing belts are cake. I thought the zetec was a pain until I saw what THIS engine entails.
You can do this,