Electrical Issue.....Maybe
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Elder User
Joined: Nov 2003
Posts: 723
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From: Spring, Texas
Electrical Issue.....Maybe
About a year ago my motor RPMs began fluctuating at idle. It is very slight. The Tach hardly moves at all. I ruled out the IRP, IPC, and filters. The truck has been running fine for the last year except for this idle fluctuation.
Recently I have noticed that as the idle fluctuates so does the brightness of my headlights. Again, it is a very slight fluctuation and a very slight dimming of the headlights but it is there.
It almost feels like something is bogging down my motor breifley and then stops. Then comes again and stops. Again and stops.
I also noticed when I have the high idle switched on the my motor has a vibration in a similar pattern. It will shake the truck slightly then stop, shake and stop, shake and stop.
Could this be electrical? Hpop? Injectors? Im just under 148,000 miles. Mods listed below.
Thanks in advance.
Recently I have noticed that as the idle fluctuates so does the brightness of my headlights. Again, it is a very slight fluctuation and a very slight dimming of the headlights but it is there.
It almost feels like something is bogging down my motor breifley and then stops. Then comes again and stops. Again and stops.
I also noticed when I have the high idle switched on the my motor has a vibration in a similar pattern. It will shake the truck slightly then stop, shake and stop, shake and stop.
Could this be electrical? Hpop? Injectors? Im just under 148,000 miles. Mods listed below.
Thanks in advance.
Smokin
Joined: Jun 2006
Posts: 8,849
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I read on another thread a few days back that a bad alternator can result in some pretty strange ill effects, including those that affect how the motor runs and overall power.
I, too, have a slight uneven idle..but only sometimes, and its not enough to post that there is an issue. Like you, its only at idle, and the second I hit the throttle it goes away.
Curious to see what you find out.
I, too, have a slight uneven idle..but only sometimes, and its not enough to post that there is an issue. Like you, its only at idle, and the second I hit the throttle it goes away.
Curious to see what you find out.
Postmaster
Joined: Oct 2005
Posts: 2,956
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From: Northeast TN
Ron has been experiencing fluctuating idle since he changed HPOP's. Have you checked the voltage with the batts disconnected(with a VOM)? Also you might want check your grounds. Someone with a lot more knowledge will be along shortly. Good Luck
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Elder User
Joined: Nov 2003
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From: Spring, Texas
You know, I have been experiencing alot of build up on my batterie terminals in the last year or so. I have been cleaning them with baking soda and water. Wuld a bad ground cause the build up? If not what does? How can I stop that? I'm cleaning the terminals every three months or so.
Hotshot
Joined: Jan 2002
Posts: 17,988
Likes: 207
From: La La Land
My first guess would have been the HPOP pressure regulation, too.
The corrosion buildup is because acid is seeping past the lead post seals on the battery. This is likely the result of the batteries getting over-charged by the alternator.
What voltage are you reading across the battery terminals at idle, and if it varies, is it in sync with your vibration?
Pop
The corrosion buildup is because acid is seeping past the lead post seals on the battery. This is likely the result of the batteries getting over-charged by the alternator.
What voltage are you reading across the battery terminals at idle, and if it varies, is it in sync with your vibration?
Pop
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Elder User
Joined: Nov 2003
Posts: 723
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From: Spring, Texas
My first guess would have been the HPOP pressure regulation, too.
The corrosion buildup is because acid is seeping past the lead post seals on the battery. This is likely the result of the batteries getting over-charged by the alternator.
What voltage are you reading across the battery terminals at idle, and if it varies, is it in sync with your vibration?
Pop
The corrosion buildup is because acid is seeping past the lead post seals on the battery. This is likely the result of the batteries getting over-charged by the alternator.
What voltage are you reading across the battery terminals at idle, and if it varies, is it in sync with your vibration?
Pop
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Lead Driver
Joined: Jan 2007
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From: Kiowa CO
Now that I think of it, my alternator just went south last week but my idle did fluctuate ~50rpm at idle until I swapped it out. Now it's smooth again. Even with my DP set at high idle, (1100 rpm setting) it fluctuated.
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Hotshot
Joined: Jan 2008
Posts: 13,144
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From: Rochdale MA
To help stop and prevent corrosion in the future clean the battery terminals and the clamps well. There is a product called Noalox it is avaliable at Home Depot or Lowes. It is an oxide inhibiting compound that is electrically conductive. Coat both the terminals and the clamps with this stuff and as an added measure put a thin coat on the outside of the clamps after tightening. I swear by this stuff.
Hotshot
Joined: Jan 2002
Posts: 17,988
Likes: 207
From: La La Land
Jim,
It never occurred to me to use Noalox on battery terminals. I coat breaker box buss bars with it (as well as the occasional aluminum conductor I encounter, yea, still.....).
For my battery terminals, I use a butter-colored NLGI 1-1/2 synthetic bearing grease, being sure to liberally coat the surface of the battery between the post and top (where the seal is). I used to use clear RTV to augment the seal, but found the grease just as effective, and easier to use.
I virtually NEVER have any "acid nastys".
I'd have rep'd you for the Noalox, but the rep police still have me contained.
Pop
Pop
It never occurred to me to use Noalox on battery terminals. I coat breaker box buss bars with it (as well as the occasional aluminum conductor I encounter, yea, still.....).
For my battery terminals, I use a butter-colored NLGI 1-1/2 synthetic bearing grease, being sure to liberally coat the surface of the battery between the post and top (where the seal is). I used to use clear RTV to augment the seal, but found the grease just as effective, and easier to use.
I virtually NEVER have any "acid nastys".
I'd have rep'd you for the Noalox, but the rep police still have me contained.
Pop
Pop
Hotshot
Joined: Jan 2008
Posts: 13,144
Likes: 11
From: Rochdale MA
Jim,
It never occurred to me to use Noalox on battery terminals. I coat breaker box buss bars with it (as well as the occasional aluminum conductor I encounter, yea, still.....).
For my battery terminals, I use a butter-colored NLGI 1-1/2 synthetic bearing grease, being sure to liberally coat the surface of the battery between the post and top (where the seal is). I used to use clear RTV to augment the seal, but found the grease just as effective, and easier to use.
I virtually NEVER have any "acid nastys".
Pop
It never occurred to me to use Noalox on battery terminals. I coat breaker box buss bars with it (as well as the occasional aluminum conductor I encounter, yea, still.....).
For my battery terminals, I use a butter-colored NLGI 1-1/2 synthetic bearing grease, being sure to liberally coat the surface of the battery between the post and top (where the seal is). I used to use clear RTV to augment the seal, but found the grease just as effective, and easier to use.
I virtually NEVER have any "acid nastys".
Pop
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Elder User
Joined: Nov 2003
Posts: 723
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From: Spring, Texas
Thanks for the Suggestion Mega.
Over the weekend I went to check the voltage as Pop suggested. My multi meter was broken so I went to AZ for a replacement. While there I picked up a new belt as mine is old and cracking. I changed the belt and went to check the voltage.
The symptoms were gone. No more fluctuation. I throw the multi meter one it anyway. 13-13.5 volts at idle. I drove the truck around thinking it might start after getting it up to temp. No flucuation. Drove to work this morning. No fluctuations. No dimming headlights.
Could my old belt have been the problem? Seems unlikely to me.
Over the weekend I went to check the voltage as Pop suggested. My multi meter was broken so I went to AZ for a replacement. While there I picked up a new belt as mine is old and cracking. I changed the belt and went to check the voltage.
The symptoms were gone. No more fluctuation. I throw the multi meter one it anyway. 13-13.5 volts at idle. I drove the truck around thinking it might start after getting it up to temp. No flucuation. Drove to work this morning. No fluctuations. No dimming headlights.
Could my old belt have been the problem? Seems unlikely to me.
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Elder User
Joined: Nov 2003
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From: Spring, Texas
The flucuations returned. I checked the voltage and it was surging from 12 vlt- 15 vlts with the flucuattions. I took the alternator back to AZ were it failed the test. They replaced it under the warranty.
No more flucuations but my new belt has a lot of vibration. It is flapping enought to create a audible noise that I can hear inthe cab when at idle. I can see the belt flapping more than normal between the alternator and power steering pump. When I push on it with handle of a screw driver the noise and vibration go away.
Do you think it is time to replace the belt tensioner?
I have no idea how old it is.
No more flucuations but my new belt has a lot of vibration. It is flapping enought to create a audible noise that I can hear inthe cab when at idle. I can see the belt flapping more than normal between the alternator and power steering pump. When I push on it with handle of a screw driver the noise and vibration go away.
Do you think it is time to replace the belt tensioner?
I have no idea how old it is.
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