Anyone Have a Dead/Low battery affect LT4 Performance?
Thread Starter
Race Director
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From: Santa Ana, Costa Rica
Anyone Have a Dead/Low battery affect LT4 Performance?
I have noticed my LT4 would make a noise, like a spark knock, just after I let off of the key when it starts, I also have noticed a slight knock, scary like a bearing or something, but quiet enough that I alone noticed it...........Last night my battery died (I didn't know it was sick), and I just got it replaced....when I started the car, the valves clattered like hell, and then finally settled down.....I guess my question is,..... Although the gauge always showed it was charging just right, would a dying battery cause all of this?
I have never heard of anyone else with an LT4 that made ANY noise, except for a slight injector tick or something, got any thoughts anyone?
Thanks!
:cheers: ........... :seeya
I have never heard of anyone else with an LT4 that made ANY noise, except for a slight injector tick or something, got any thoughts anyone?
Thanks!
:cheers: ........... :seeya
Team Owner
Joined: Aug 1999
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From: Bagpipes put the "fun" in "funeral"
Re: Anyone Have a Dead/Low battery affect LT4 Performance? (DCTC)
My 93 vette (and my old 90) occasionally make that "spark knock" noise just when the engine catches. My friend's 94 does the same.
I don't think it's anything to worry about.
The other faint knock you hear could just be the flywheel. A bearing knock starts off sounding bad, and gets worse right before your engine dies.
Other causes of knocking.... a worn belt, one of the accessory pulleys, etc.
Valves clattering... they settle down when oil starts getting pump to them. Are you sure you're not just becoming overly aware of sounds now that you had a problem elsewhere in the car? The battery wouldn't cause any of this.
[Modified by Thud, 9:47 AM 5/11/2002]
I don't think it's anything to worry about.
The other faint knock you hear could just be the flywheel. A bearing knock starts off sounding bad, and gets worse right before your engine dies.
Other causes of knocking.... a worn belt, one of the accessory pulleys, etc.
Valves clattering... they settle down when oil starts getting pump to them. Are you sure you're not just becoming overly aware of sounds now that you had a problem elsewhere in the car? The battery wouldn't cause any of this.
[Modified by Thud, 9:47 AM 5/11/2002]
Thread Starter
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From: Santa Ana, Costa Rica
Re: Anyone Have a Dead/Low battery affect LT4 Performance? (Thud)
Hi Thud.....Thanks for the feed back....I ran in to a GM mechanic, who is a member of the local Corvette club I am about to join and I described this to him....... He said that if the battery is weak, regardless of the alternator's charge, the computer receives lower voltage, and all the values can be thrown off, which made that start-up knock, that has now gone away, and the low knocking and valve clattering are all products of the low-volt problem.
I drove the car alst night for a while and it's running just fine, in fact, probably better than before....the second gear grab produced a great LONG chirp at 50 mph, so I'd guess he was right.
I always thought that a low battery didn't affect the computer, unless it was right at start-up, but apparently it has an effect during all operation.....go figure......... :crazy:
Thanks for the feed-back on this one...this car only has just a little over 15k miles on it and I just knew it was too young to be having any serious problems, nevertheless, it had me worried...Murphy's Law says that if there is an oddball, screwed up car, I would be the one to get it...
Best to you!
:cheers: :seeya
[Modified by DCTC, 3:49 PM 5/11/2002]
[Modified by DCTC, 3:50 PM 5/11/2002]
[Modified by DCTC, 3:51 PM 5/11/2002]
[Modified by DCTC, 3:51 PM 5/11/2002]
I drove the car alst night for a while and it's running just fine, in fact, probably better than before....the second gear grab produced a great LONG chirp at 50 mph, so I'd guess he was right.
I always thought that a low battery didn't affect the computer, unless it was right at start-up, but apparently it has an effect during all operation.....go figure......... :crazy:
Thanks for the feed-back on this one...this car only has just a little over 15k miles on it and I just knew it was too young to be having any serious problems, nevertheless, it had me worried...Murphy's Law says that if there is an oddball, screwed up car, I would be the one to get it...
Best to you!
:cheers: :seeya
[Modified by DCTC, 3:49 PM 5/11/2002]
[Modified by DCTC, 3:50 PM 5/11/2002]
[Modified by DCTC, 3:51 PM 5/11/2002]
[Modified by DCTC, 3:51 PM 5/11/2002]
Melting Slicks
Joined: Jun 2001
Posts: 2,525
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From: Sarasota, FL
Re: Anyone Have a Dead/Low battery affect LT4 Performance? (DCTC)
Low voltage can and does affect the fuel injector pulse width, which can lead to a lean condition. Low voltage = leaner fuel ratio
Le Mans Master
Joined: May 2000
Posts: 6,694
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From: Gurnee IL
Cruise-In II Veteran
Re: Anyone Have a Dead/Low battery affect LT4 Performance? (DCTC)
I have noticed my LT4 would make a noise, like a spark knock, just after I let off of the key when it starts, I also have noticed a slight knock, scary like a bearing or something, but quiet enough that I alone noticed it...........Last night my battery died (I didn't know it was sick), and I just got it replaced....when I started the car, the valves clattered like hell, and then finally settled down.....I guess my question is,..... Although the gauge always showed it was charging just right, would a dying battery cause all of this?
I have never heard of anyone else with an LT4 that made ANY noise, except for a slight injector tick or something, got any thoughts anyone?
Thanks!
:cheers: ........... :seeya
I have never heard of anyone else with an LT4 that made ANY noise, except for a slight injector tick or something, got any thoughts anyone?
Thanks!
:cheers: ........... :seeya
Someone told me that when the LT4 starts it briefly checks the knock sensor. I'll be curious to see if your car ever does this again.
Keep us informed....
Thread Starter
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Joined: Apr 2002
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From: Santa Ana, Costa Rica
Re: Anyone Have a Dead/Low battery affect LT4 Performance? (Patrick96LT4)
Hi Patrick.....
It's been a few days and I've had a chance to drive the car a bit, and sure enuff....that spark knock is there, but not NEARLY as pronounced as before, it does it dead cold, and at operating temp, so I don't see any pattern there. also, I HAVE noticed that the car runs a bit stronger (May just be me.), and although I have made sure the oil is right, I still get a lot of valve noise occasionally, when I first start it...this is bugging me, and I plan to ask that GM Tech I mentioned in my earlier post....I'll keep you posted!!
Dan.
[Modified by DCTC, 3:47 AM 5/17/2002]
It's been a few days and I've had a chance to drive the car a bit, and sure enuff....that spark knock is there, but not NEARLY as pronounced as before, it does it dead cold, and at operating temp, so I don't see any pattern there. also, I HAVE noticed that the car runs a bit stronger (May just be me.), and although I have made sure the oil is right, I still get a lot of valve noise occasionally, when I first start it...this is bugging me, and I plan to ask that GM Tech I mentioned in my earlier post....I'll keep you posted!!
Dan.
[Modified by DCTC, 3:47 AM 5/17/2002]
Le Mans Master
Joined: May 2000
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From: Gurnee IL
Cruise-In II Veteran
Re: Anyone Have a Dead/Low battery affect LT4 Performance? (DCTC)
It's back! I almost ran out and got a new battery! :crazy:
Both my LT4 cars were "noisy" from the valve covers. It could be my imagination, but right when I was due for an oil change it'd be a bit tickier.
Both my cars had low miles (around 20k).
My solution? I cut off the mufflers and just stopped listening to all the interior squeeks and engine ticks. He11, I can't hear anything! :lol:
Both my LT4 cars were "noisy" from the valve covers. It could be my imagination, but right when I was due for an oil change it'd be a bit tickier.
Both my cars had low miles (around 20k).
My solution? I cut off the mufflers and just stopped listening to all the interior squeeks and engine ticks. He11, I can't hear anything! :lol:
