Chevy Impala SS Forum banner

1 - 20 of 25 Posts

·
Registered
Joined
·
11,051 Posts
Sometimes you can not tell. The timing can be off, or jump around. You need a timing light to check it, and then it may not tell you what you need to know, because the computer controls timing, and can vary it at any time.

How many miles are on the car?
 

·
Registered
Joined
·
5,243 Posts
It will break... which never happens.

Nab
 

·
Registered
Joined
·
26 Posts
I saw my mechanic one time to take the belt in two places and try to force to move from one side to other. he explaines me that the only moment in which you can move it is when the chain is loose and need to be replaced.

He turn car off, dismount the upper side of the radiator fan cover and took belt with both hands, left between air compressor and exhaust compressor and right between alt and hidraulic pump... then tried to make it move in both directions. the belt moved a bit and stopped and the same for the other side. He dissasembled and replace the chain and tooth wheels.
 

·
Registered
Joined
·
11,051 Posts
The only way you can check for a worn timing set is to remove the timing cover, and see if the chain is slack. Once you have it open, you might as well replace it anyway. The timing set is cheap, and relatively easy to replace after removing all the stuff to get the timing cover off. Do not replace just the chain, or just the cam gear and chain. You have to replace all of it, or it will wear out quickly.
 

·
Registered
Joined
·
5,243 Posts
Your mechanic knows how to make money from you.
The car will still run fine with a loose timing chain.
Timing CHAINS are good for at least 400k miles.

Nab
 

·
Registered
Joined
·
7,986 Posts
I am not a mechanic but I am sure no lack must be allowed in this parts due it will affect the sincronization between vlaves and piston positions. It must be as firm as possible
If what you were saying is "No "Slack" must be allowed" then this is not true. I only say this due to what I saw on my factory chain, there was a good amount of Slack in it.

Back when I had the Front Cover off the engine I decided to replace the Stock chain with one from Cloyes. The car ran fine before the swap, I just decided to replace the Chain and Sprockets anyway. As Nab had mentioned, its highly unlikely that these go bad unless the chain Breaks (unlikely) or the teeth on sprockets wear. So your mechanic may not have been truthful or just didn't know any better....either one of those is not good in a mechanic.

There was definitely more slack in the Stock Chain as the Cloyes setup had less slack in it when new. Keep in mind that if I was to pull the cover today and recheck it, it's highly possible that the Cloyes chain could have opened up a bit after running and have a little more Slack then when new.

EDIT - There is Slack. Here are some pics to prove it at the bottom of this thread.

http://www.impalassforum.com/vBulletin/showthread.php?t=269999&highlight=cloyes+timing+chain
 

·
Registered
Joined
·
26 Posts
If what you were saying is "No "Slack" must be allowed" then this is not true. I only say this due to what I saw on my factory chain, there was a good amount of Slack in it.

Back when I had the Front Cover off the engine I decided to replace the Stock chain with one from Cloyes. The car ran fine before the swap, I just decided to replace the Chain and Sprockets anyway. As Nab had mentioned, its highly unlikely that these go bad unless the chain Breaks (unlikely) or the teeth on sprockets wear. So your mechanic may not have been truthful or just didn't know any better....either one of those is not good in a mechanic.

There was definitely more slack in the Stock Chain as the Cloyes setup had less slack in it when new. Keep in mind that if I was to pull the cover today and recheck it, it's highly possible that the Cloyes chain could have opened up a bit after running and have a little more Slack then when new.

EDIT - There is Slack. Here are some pics to prove it at the bottom of this thread.

http://www.impalassforum.com/vBulletin/showthread.php?t=269999&highlight=cloyes+timing+chain

Dear friends... as I said, I am not a mechanic but work with precise machines (CT's) and perhaps the problem is my bad manegement of the english languajes. of course CAN be some slack and it doesn't mean you need to change chain. There is a tolerance range, but when I replace it. The total assesembly must look like the bycicle chain... not tigh but not holding just with the movement inherent to the chain parts itself.
I don´t say that a car doesn´t work with a slack chain, I say it can fail and jump a tooth in one of the pulleys with a elonged one. To adjust and keep the 0° calibrations before reconnect the calibration plug is easy but after connect it the ECM will over work to maintain it without detonate.

From another stand point, I want to be clear with something. I want to learn, and, if I make a mistake or say a wrong thing . I will no problem to apologize about.

Best regards
 

·
Registered
Joined
·
5,243 Posts
A timing CHAIN cannot jump a tooth. That is a myth.
As I mentioned earlier timing chains last up to 400k miles.
There's no need to replace it unless you want to waste money.

Nab
 

·
Registered
Joined
·
8,056 Posts
I Just HAD To Look-

I can't count on one finger the threads I've seen about the timing set since joining the forum. I've had to replace several on other cars, but that's been decades ago. The last was an '80 Riv with nylon teeth. And well there was the neighbor's Escort. But, he didn't even know how to change oil.

Cliffs: just not the issue it may have been with materials/design/motors in the past. Certainly not an LT's weak link.

For the OP, what exactly prompted you to ask? What are the symptoms of whatever problem you're having?
 

·
Registered
Joined
·
7,986 Posts
Dear friends... as I said, I am not a mechanic but work with precise machines (CT's) and perhaps the problem is my bad manegement of the english languajes. of course CAN be some slack and it doesn't mean you need to change chain. There is a tolerance range, but when I replace it. The total assesembly must look like the bycicle chain... not tigh but not holding just with the movement inherent to the chain parts itself.
I don´t say that a car doesn´t work with a slack chain, I say it can fail and jump a tooth in one of the pulleys with a elonged one. To adjust and keep the 0° calibrations before reconnect the calibration plug is easy but after connect it the ECM will over work to maintain it without detonate.

From another stand point, I want to be clear with something. I want to learn, and, if I make a mistake or say a wrong thing . I will no problem to apologize about.

Best regards
I understand there may be some language barriers going on here and didn't intend to make it sound like you were doing anything wrong with your posts. It was just from what I was reading it sounded like your mechanic was giving you some bad info and maybe I misread that. Just sharing what I know and what I've read and sorry if you interpreted this any other way.

As others have said, problems with the timing components on these engines is very small unless we are talking the Opti. Any slack or tolerance issues in the chain from normal wear is not going to pose any problems with engine timing.

You are just trying to learn and we are just trying to help and offer opions based on what we've seen and dealt with over the years. This Forum is full of lots of useful info that can be searched. If you ever come up with a problem topic feel free to post and also be sure to check the Stickies in each section of the forum along with the Qaloss Handbook which will have lots of useful info. Good luck with your car.
 

·
Registered
Joined
·
8,056 Posts
Dear friends... as I said, I am not a mechanic...
I have never professed to be one either. The best of us are merely tenacious wrenchers.

.....perhaps the problem is my bad management of the english languajes.
Your English is one helluvalot better than my Spanish. You're doing fine. You already put a capital for each new sentence. Hell, you actually use sentences! Just be mindful of your/you're, there/their/they're, its/it's and a little respect for the past perfect tense and you'll be better than most guys posting.

... I want to learn, and, if I make a mistake or say a wrong thing . I will no problem to apologize about.
No need. We're American. We don't apologize much either. cwm2

Welcome to the jungle. We've got fun 'n' games.
 

·
Registered
Joined
·
1,002 Posts
My car is a myth!

A timing CHAIN cannot jump a tooth. That is a myth.
My 73 Polara 318 ci jumped the teeth between shut down and the next start when I stopped for groceries. If I remember correctly it too had nylon sprockets that were very worn at 120 K miles.

My 76 Cutlass Rocket 350 chain was loose enough to produce a rough idle and I had to "fudge" the base timing and turn up the idle.(250 K miles)

I think the LT1 PCM will compensate for a loose chain but there must be a point (400 K ?) that it would be smart to replace when doing other work.(opti?)
 

·
Registered
Joined
·
6,802 Posts
Replacing the timing chain is a lot of additional work. Especially,to do correctly. If the motor's out,and being completely tore down,I'd say yes. Otherwise,I wouldn't mess with it. What do two 40+ year old motors that are totally different have to do with these motors anyway?
 

·
Registered
Joined
·
26 Posts
A timing CHAIN cannot jump a tooth. That is a myth.
As I mentioned earlier timing chains last up to 400k miles.
There's no need to replace it unless you want to waste money.

Nab
I confess when I read 400K I suposed a mistake and a "0" added for error.
I really remember 20 years ago a Ford 82 LTD I had stop to start... A good samaritant told me chain was jumped a tooth and moved the distribuitor. my car started again and when mechanic retired covers, chain looked like my grandpa underwear.... perhaps it had more than 400K , we will never know

But, if you are sure that is a myth, there is a lot of mechanics here being rich with this myth and a lot of people like me believeing in the same myth.

Do you can supply me some professional literature about it. I would like to glue the exact page to a cutting table and slam it to him face next time he suggest to change chain....

best regards and thanks for de.myth it
 

·
Registered
Joined
·
1,002 Posts
Trying to learn from the forum's experience.

What do two 40+ year old motors that are totally different have to do with these motors anyway?
First off these motors were not 40+ years old when they had problems. Some of us are older and our daily drivers are now collector cars.

The point is that new car belts are replaced to maintain warranty and chains do get loose. I was hoping to get other experienced answers like Blue Wail's.

May be a longer explanation why a LT1's chain is not a item to worry about when I have had personal experience with belts and chains leaving me at the side of the road.
 

·
Registered
Joined
·
3,505 Posts
Well many LT-1's have gone 600,000mi in civilian, police, taxi duty on original timing chains.
The many people on this board and some of the ones dedicated to 9c1's have never been left by the side of the road with timing chain failure. We don't care what problems people have had with Mopar 318's and Ford engines. No further literature is necessary to support what Blue Wail and others have told you. If you want to spend money on something that is not a problem, have at it, but people who know what they are talking about and know more about LT-1's than any of those "mechanics" you hold in such high esteem have told you it is not necessary. How much more do you want to drag this out?
 
1 - 20 of 25 Posts
Top