Timing chain interval
- Thread starter mez
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Exactly. If you ignore the belt it's gonna break at the worst possible time. Yes, your engine might be ok but you will be stranded.
Well, it's not like you're some little boy lost in the woods. I'm sure that we're big boys by now and any number of items can leave you "stranded" and you can't do a darn thing about it. Are you going to replace all your operational essential sensors "just in case"? I just don't like "compound" jobs. It's one of the "Horn-a-Plenty" things. While you're there do all this other stuff. In a non-interference engine .. I just don't see the odds being in favor of one of the proposed replacement parts "while you're there" as being any more or less likely than the other for failure.
All kidding aside, I've just seen too many t-belts with advanced mileage that looked as good as the new ones that replaced them. Keep in mind that a Kia recommends a 60k t-belt change ..except in California ..where it's 90k (or figures of that proportion).
Otherwise, I'm all for doing something like this in a planned manner if the alternatives are more expensive. My son has a 96 Neon that he commutes 75+ miles a day. His other vehicle is a Jeep Cherokee. If it gets taken out by a bad timing belt ...it goes to the junkyard and he's stuck driving a gas hog. OTOH, he can probably get another NEON for less than the price of a t-belt job.
Exactly. If you ignore the belt it's gonna break at the worst possible time. Yes, your engine might be ok but you will be stranded.
Well, it's not like you're some little boy lost in the woods. I'm sure that we're big boys by now and any number of items can leave you "stranded" and you can't do a darn thing about it. Are you going to replace all your operational essential sensors "just in case"? I just don't like "compound" jobs. It's one of the "Horn-a-Plenty" things. While you're there do all this other stuff. In a non-interference engine .. I just don't see the odds being in favor of one of the proposed replacement parts "while you're there" as being any more or less likely than the other for failure.
All kidding aside, I've just seen too many t-belts with advanced mileage that looked as good as the new ones that replaced them. Keep in mind that a Kia recommends a 60k t-belt change ..except in California ..where it's 90k (or figures of that proportion).
Otherwise, I'm all for doing something like this in a planned manner if the alternatives are more expensive. My son has a 96 Neon that he commutes 75+ miles a day. His other vehicle is a Jeep Cherokee. If it gets taken out by a bad timing belt ...it goes to the junkyard and he's stuck driving a gas hog. OTOH, he can probably get another NEON for less than the price of a t-belt job.
JHZR2
Staff member
Originally Posted By: Shannow
JMH, interesting, and useful for degreeing cams, but if you are so far into the engine, why not replace the chain while you're there ?
You do the measurement when adjusting the valves. Youre only into the engine as far as taking the valve cover off. MB provides a methd of determining "stretch" via lineup of the chain sprocket to a mark on the cam tower, and reading an indicator inscribed into the harmonic balancer. It really is quite easy.
If I had 6-8 degrees of "stretch", I'd not be thinking about an offset key, Id be replacing the chain... what others do is not up to me...
JMH
JMH, interesting, and useful for degreeing cams, but if you are so far into the engine, why not replace the chain while you're there ?
You do the measurement when adjusting the valves. Youre only into the engine as far as taking the valve cover off. MB provides a methd of determining "stretch" via lineup of the chain sprocket to a mark on the cam tower, and reading an indicator inscribed into the harmonic balancer. It really is quite easy.
If I had 6-8 degrees of "stretch", I'd not be thinking about an offset key, Id be replacing the chain... what others do is not up to me...
JMH
Originally Posted By: Chris142
Originally Posted By: Kestas
I have a 91 Mercury with the 302 V8 engine. I'm pretty sure this engine has the nylon-coated timing chain gears. How does one know when the timing chain needs service?
If that 302 has over 60K it's due. Those realy stretch fast and the plastic teeth jam the oil pump which spins the oil pump shaft like a Candy Cane. But it will still run.............A few minutes.
The gear tooth would have a hard time getting past the oil pump pick-up screen, though.
However, I did see this happen once to a poorly maintained Lincoln Zephyr. The engine was so sludged up that the oil pump pick-up screen got clogged with sludge. The oil pump had enough suction to suck the screen away from the intake tube. I thought at the time that perhaps this is by design to prevent total oil starvation.
Sometime later, the plastic on the cam sprocket get's old and starts to chip away. With an open oil pump pick-up, the tooth gets sucked into the pump and locks it up. Twisted the oil pump drive shaft pretty good too.
Installed a rebuilt engine along with a lecture on regular oil changes.
Even this new engine had its oil starvation problems. A few months later when it came into the shop behind a tow truck, I thought my Dad was going to go into vapor lock.
Checking the dipstick, the engine was way overfilled. I find out that the owner would put in an extra two quarts of oil when he'd go on long trips. Loss of oil pressure due to foaming. Changed the oil and filter. Luckily, the engine didn't exhibit any strange noises.
Another stern lecture soon followed.
Originally Posted By: Kestas
I have a 91 Mercury with the 302 V8 engine. I'm pretty sure this engine has the nylon-coated timing chain gears. How does one know when the timing chain needs service?
If that 302 has over 60K it's due. Those realy stretch fast and the plastic teeth jam the oil pump which spins the oil pump shaft like a Candy Cane. But it will still run.............A few minutes.
The gear tooth would have a hard time getting past the oil pump pick-up screen, though.
However, I did see this happen once to a poorly maintained Lincoln Zephyr. The engine was so sludged up that the oil pump pick-up screen got clogged with sludge. The oil pump had enough suction to suck the screen away from the intake tube. I thought at the time that perhaps this is by design to prevent total oil starvation.
Sometime later, the plastic on the cam sprocket get's old and starts to chip away. With an open oil pump pick-up, the tooth gets sucked into the pump and locks it up. Twisted the oil pump drive shaft pretty good too.
Installed a rebuilt engine along with a lecture on regular oil changes.
Another stern lecture soon followed.
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Originally Posted By: JHZR2
You do the measurement when adjusting the valves. Youre only into the engine as far as taking the valve cover off. MB provides a methd of determining "stretch" via lineup of the chain sprocket to a mark on the cam tower, and reading an indicator inscribed into the harmonic balancer. It really is quite easy.
Ah, OHC...sorry, I wasn't thinking OHC
You do the measurement when adjusting the valves. Youre only into the engine as far as taking the valve cover off. MB provides a methd of determining "stretch" via lineup of the chain sprocket to a mark on the cam tower, and reading an indicator inscribed into the harmonic balancer. It really is quite easy.
Ah, OHC...sorry, I wasn't thinking OHC
[/quote]
The gear tooth would have a hard time getting past the oil pump pick-up screen, though.
[/quote] His screen has a valve built into it that allows oil to bypass the screen if it's cold or the screen is plugged, much like a bypass in a oil pump. The 302/351w Ford is the only one I know of that uses this.
The gear tooth would have a hard time getting past the oil pump pick-up screen, though.
[/quote] His screen has a valve built into it that allows oil to bypass the screen if it's cold or the screen is plugged, much like a bypass in a oil pump. The 302/351w Ford is the only one I know of that uses this.
Kestas
Staff member
Originally Posted By: Chris142
Originally Posted By: Kestas
I have a 91 Mercury with the 302 V8 engine. I'm pretty sure this engine has the nylon-coated timing chain gears. How does one know when the timing chain needs service?
If that 302 has over 60K it's due. Those realy stretch fast...
My Mercury has 80K on it. I may entertain the thought of replacing the timing chain setup this summer (it's my winter car). Is there an upgrade I can do? I'd hate to replace the gears with a similar nylon design.
Originally Posted By: Kestas
I have a 91 Mercury with the 302 V8 engine. I'm pretty sure this engine has the nylon-coated timing chain gears. How does one know when the timing chain needs service?
If that 302 has over 60K it's due. Those realy stretch fast...
My Mercury has 80K on it. I may entertain the thought of replacing the timing chain setup this summer (it's my winter car). Is there an upgrade I can do? I'd hate to replace the gears with a similar nylon design.
Ya most aftermarket sets are all steel.
I've never seen a nylon gear in a replacement set. The OEMs did that to keep noise down. Then again, I've never listened to a new car and thought Wow, what a loud timing chain.
My very first car was a 69 Charger with a 383. It had a nylon gear on the cam gear. When I pulled it apart to install a bigger cam, the car had about 68,000 miles on it. The nylon gear was missing 11 teeth. They were all in the oil pan.
My very first car was a 69 Charger with a 383. It had a nylon gear on the cam gear. When I pulled it apart to install a bigger cam, the car had about 68,000 miles on it. The nylon gear was missing 11 teeth. They were all in the oil pan.
I always thought that chains were good for the life of the vehicle, hmmm.
Anyone know if stretched timing chain could be picked up by oil analysis, there should be more wear on the sprocket teeth as the chain links are no longer lign up, resulting in greater wear numbers, IMO.
Anyone know if stretched timing chain could be picked up by oil analysis, there should be more wear on the sprocket teeth as the chain links are no longer lign up, resulting in greater wear numbers, IMO.
Kestas
Staff member
Even chains need to be replaced with high miles. My 71 olds rocket motor had 10° stretch at 165K. I think 120K is a good interval for a non-tensioner design if the car is still worth it at that point.
The 91 ranger I currently own as a winter car, got the timing chain replaced in it last year when I bought it. Friend who I bought it from thought the reason it wouldn't start was the timing chain snapped. I figured since he builds 10 sec mustangs, to trust his assessment. (turns out roof let water leak down the a-pillar all over the ECU)
I spent the whole day tearing it down. Timing Cover comes off and the chain wasn't broken :\. Chain had some slop, but for all I know stock chain could have been just loose. Replacement Cloyes chain wasn't that much tighter. The engine is guesstimated (according to the last carfax report in 94-averaging miles) to have 230,000+ Miles on it. 3.0L Vulcan V6.
My 1995 Roadmaster has 170K and original timing chain also.
Matt
I spent the whole day tearing it down. Timing Cover comes off and the chain wasn't broken :\. Chain had some slop, but for all I know stock chain could have been just loose. Replacement Cloyes chain wasn't that much tighter. The engine is guesstimated (according to the last carfax report in 94-averaging miles) to have 230,000+ Miles on it. 3.0L Vulcan V6.
My 1995 Roadmaster has 170K and original timing chain also.
Matt
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The engines with roller cams are much easier on chains and gears than the old slide across the cam lifters were.
Kestas
Staff member
I remember the resistance to roller cams from Chrysler back in the early 80s. It would have added $70 to the cost of manufacturing an engine. Relatively speaking, $70 was big money to spend on a design upgrade.
Originally Posted By: Buffman
The 91 ranger I currently own as a winter car, got the timing chain replaced in it last year when I bought it. Friend who I bought it from thought the reason it wouldn't start was the timing chain snapped. I figured since he builds 10 sec mustangs, to trust his assessment. (turns out roof let water leak down the a-pillar all over the ECU)
I spent the whole day tearing it down. Timing Cover comes off and the chain wasn't broken :\. Chain had some slop, but for all I know stock chain could have been just loose. Replacement Cloyes chain wasn't that much tighter. The engine is guesstimated (according to the last carfax report in 94-averaging miles) to have 230,000+ Miles on it. 3.0L Vulcan V6.
My 1995 Roadmaster has 170K and original timing chain also.
Matt
I though Vulcan V6 was pushrod, is that different in a Ranger from a Taurus?
The 91 ranger I currently own as a winter car, got the timing chain replaced in it last year when I bought it. Friend who I bought it from thought the reason it wouldn't start was the timing chain snapped. I figured since he builds 10 sec mustangs, to trust his assessment. (turns out roof let water leak down the a-pillar all over the ECU)
I spent the whole day tearing it down. Timing Cover comes off and the chain wasn't broken :\. Chain had some slop, but for all I know stock chain could have been just loose. Replacement Cloyes chain wasn't that much tighter. The engine is guesstimated (according to the last carfax report in 94-averaging miles) to have 230,000+ Miles on it. 3.0L Vulcan V6.
My 1995 Roadmaster has 170K and original timing chain also.
Matt
I though Vulcan V6 was pushrod, is that different in a Ranger from a Taurus?
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