Why do C4's eat alternators?
Thread Starter
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Joined: Apr 2007
Posts: 76
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From: Orlando Florida
Why do C4's eat alternators?
I have a 91 L98 with 26,000 miles on it and it is on its third alternator. This seems excessive. I would like to know if someone has experienced the same thing and if there is a long term fix for this. Both times that it has been replaced, I was 300 miles away from home when it went out. I would like to take this car on vacations but not if it keeps eating alternators. Thanks guys!
Race Director
Joined: Aug 2000
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Cruise-In II Veteran
They junk...pretty much.Been through it myself.A good upgrade is to use the CS144 unit from the later cars and a few small mods it works.
Im assuming you have the older smaller unit that wears out all the time.
About the upgrade,someone should post it.Its been done before.
Im assuming you have the older smaller unit that wears out all the time.
About the upgrade,someone should post it.Its been done before.
Race Director
Joined: Aug 2000
Posts: 14,130
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Cruise-In II Veteran
Large Impressive Member
Joined: Jul 2003
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From: Good health is merely the slowest possible rate at which one can die
St. Jude Donor '04-'05-'06-'07
What is the quality of the replacements? There's nothing wrong with a good rebuilt but they are not by far all created equal. And please don't tell me it's swell because it has a lifetime replacement guarantee.... These tend to be some of the worst junk of all. Is the battery in good shape as mentioned above? Is it of adequate capacity for the car's electrical demands? How about the cables, wiring and/or excessive resistance from them or other bad connections? Is the belt and tensioner in good shape? Is it the correct length? A slipping belt can cause an ungodly amount of heat which is transfered into the alternator through the pulley, overheating the front bearing and causing other internal problems. And you cannot always hear a belt slipping.
Last edited by Corvette Kid; Jun 16, 2007 at 10:37 PM.
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Thread Starter
Advanced
Joined: Apr 2007
Posts: 76
Likes: 1
From: Orlando Florida
Thanks guys. That CS-144 looks interesting. I have heard that this is a common problem. Not only on the early c4's but also TPI trans ams and camaros. Besides the heat, I wonder if the stock 100amp is not enough for these cars. By the way I just bought this car from my dad who bought it new. I will be putting more miles on it.
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
I own and drive every day an 87 vette with 214k miles and I am on my 3rd alternator. I don't consider that bad, but I replace them with rebuilt Delco's. Most, not all, rebuilt alternators use inferior replacement parts and those rebuilts don't last. Modern cars have so much electronics in them, the alternators supply a lot of current and this increases the alternator temp which shortens their life. My last daily driver was a 74 vette which I sold at 214k miles and it had its original 35 amp alternator.
Race Director
Joined: Aug 2000
Posts: 14,130
Likes: 7
Cruise-In II Veteran
I own and drive every day an 87 vette with 214k miles and I am on my 3rd alternator. I don't consider that bad, but I replace them with rebuilt Delco's. Most, not all, rebuilt alternators use inferior replacement parts and those rebuilts don't last. Modern cars have so much electronics in them, the alternators supply a lot of current and this increases the alternator temp which shortens their life. My last daily driver was a 74 vette which I sold at 214k miles and it had its original 35 amp alternator.
I guess sometimes you get lucky and have one that will just keep going.
I have a 95 olds Van,3800 V6 engine with the CS144 in it...it made some bearing noise one day and I had a shop install new bearings and test everything out...I had 140K on it..they fixed it,and said the internals were good and now have nearly 180K on it...Im a believer sometimes we get good parts,but also that the 144 is far superior than the 130 units.
Race Director
Joined: Nov 2000
Posts: 17,103
Likes: 39
From: stop the fun suckers
I had issues with alternators for a few years.. like 4 in 2 years.. I got frustrated and took it to my local dealer.. they put a new lifetime parts and labor unit in and it has been solid for 4 years! 
not all parts are created equal... I think most aftermarket C4 alts are JUNK!
not all parts are created equal... I think most aftermarket C4 alts are JUNK!
Safety Car
Joined: Feb 1999
Posts: 3,504
Likes: 4
From: Mexico Beach FL
There was a time, years ago, when rebuilts were quality -- most aren't today.
On my TownCar, after replacing the "Lifetime" warranty piece of junk for the 4th time in 2 years, I bought a new one and didn't replace it the remaining 5 years I owned the car.
It cost twice as much but was well worth it.
I have had good luck with local rebuilds too, where they use quality components.
But, the "chain store" "lifetime warranty" garbage has diodes made in a camel tent in the middle of the desert by a woman in conjunction with doing her laundry.
Impurities in diodes and other silicon components cause gradual degradation over time and with heat
Diodes need to be made in a "clean room" environment, and "cost cutting" demanded by the consumer today (you get what you pay for) has driven the diode production to third-world countries that couldn't care if they last -- but, you get a lifetime warranty.
You say you want a "real" alternator?
Hold onto your wallet:
http://www.mean-green.com/products/alternator.html
Notice it has a one year warranty like most quality units do.
However, I also had good luck with the Autozone Duralast Gold (brand new) alternator that does have a lifetime warranty. But, it costs twice as much as the rebuilts that Autozone sells.
Tom Piper
On my TownCar, after replacing the "Lifetime" warranty piece of junk for the 4th time in 2 years, I bought a new one and didn't replace it the remaining 5 years I owned the car.
It cost twice as much but was well worth it.
I have had good luck with local rebuilds too, where they use quality components.
But, the "chain store" "lifetime warranty" garbage has diodes made in a camel tent in the middle of the desert by a woman in conjunction with doing her laundry.
Impurities in diodes and other silicon components cause gradual degradation over time and with heat
Diodes need to be made in a "clean room" environment, and "cost cutting" demanded by the consumer today (you get what you pay for) has driven the diode production to third-world countries that couldn't care if they last -- but, you get a lifetime warranty.
You say you want a "real" alternator?
Hold onto your wallet:
http://www.mean-green.com/products/alternator.html
Notice it has a one year warranty like most quality units do.
However, I also had good luck with the Autozone Duralast Gold (brand new) alternator that does have a lifetime warranty. But, it costs twice as much as the rebuilts that Autozone sells.
Tom Piper
Last edited by Tom Piper; Jun 17, 2007 at 08:05 AM.
Burning Brakes
Joined: Mar 1999
Posts: 858
Likes: 5
From: Fl,USA
Heat is the answer. Run a cooler thermostat and turn the fans on earlier. Also remove the reinforcement bar from the exhaust manifold.
Open your hood after a drive and try to place your hand on the alternator. You will see quickly why its dying.
Do all of the above and this will end your alternator purchases.
John
Open your hood after a drive and try to place your hand on the alternator. You will see quickly why its dying.
Do all of the above and this will end your alternator purchases.
John
Drifting
Joined: Dec 2000
Posts: 1,833
Likes: 4
From: Calgary, Alberta
If you don't use the Car a lot and it sits most of the time, try a battery tender. Otherwise your making your Alternator work very hard to recharge the battery and all accesories as you are driving. I'm on my original alternator on my '88 with 165,000 kms.
Safety Car
Joined: May 2002
Posts: 4,010
Likes: 26
From: Somewhere nowhere
I have 2 GM vehicles that ate alternators.
My success has been adding ground straps in front and behind the alternator. Havn't had a problem since.
Although I may have gotten lucky with a quality rebuild, but you never know.
My success has been adding ground straps in front and behind the alternator. Havn't had a problem since.
Although I may have gotten lucky with a quality rebuild, but you never know.