Noise for the first minute of start up when cold.

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

So I went out, and started it after leaving the battery on the trickle charger for the day.
The battery had more of a charge.
Starting it the noise was much shorter. Maybe for 5 seconds if that. Then idled normally.
I also put a rod to the alternator and starter, nothing sounded odd. But it also wasn't making the noise by the time I grabbed it and put it to my ear.
I'm tempted to go buy a battery, start it in the morning after it's completely cooled and see what happens.
If it does the same, then it's not that. Regardless it's looking like I'll have to get one.
 
After sitting for about two plus weeks my battery was absolutely dead. Not a volt to be found. Brought it in to the Zone, they ran a charge test on it and confirmed it was indeed dead. The battery was two years old, bottom shelf with lots of heat cycles and short trips. I bought a Duralast ( Die Hard or so I hear ) and threw it in. First start and zero noise. I'm going to start it every morning to see if it comes back at all. Might have a chance to drive it later int he week as well.
 
Dullyouth: the voltmeter needle dips in sequence with the noise in your video,
(and the OP mentioned his lights dimmed with the noise).

Did either of you have your alternators checked?
 
I didn't bring it anywhere to get tested. Just simply checking the output at the battery when running. It was 14.7.
I do need to check the charging system somewhere though. Just to double check.
 
I just listened to the video you posted in post #4.
That thump is mechanical.
Is the fan hitting the shroud?
Do you have a frayed belt?
A thump that pronounced should be easy to pinpoint. Something is flogging around in there.
 
89325iturbo said:
I didn't bring it anywhere to get tested. Just simply checking the output at the battery when running. It was 14.7.
I do need to check the charging system somewhere though. Just to double check.
Click to expand...
Alternator is holding steady at 14.5. Should there be a fluctuation in charging, idle vs 2k rpm etc etc? Its possible the Alt is on the fritz as well, intermittently.


jonheld said:
I just listened to the video you posted in post #4.
That thump is mechanical.
Is the fan hitting the shroud?
Do you have a frayed belt?
A thump that pronounced should be easy to pinpoint. Something is flogging around in there.
Click to expand...

Fan is not hitting the shroud ( my initial thought when this started ). I replaced my broken shroud in process of tracking this noise down but no change resulted. Checked out the water pump and fan clutch while I was there ( blue hub fan ), other pulleys and everything was good.
Belts are all looking good. I could not find anything loose or flog-able in the engine compartment.
This noise only happens about 2-4 times in that initial minute or so before the engine idles down.



BILT4ME said:
Got a cat that climbed into the engine bay to hang out where it was warmer? :rofl: ;)
Click to expand...

Hahahah, All cats accounted for. Although If I ever need to make one disappear I now know to put it into the magic disappearing box and close the hood and start it up...



edit: left out a word
 
Last edited:
Dullyouth said:
This noise only happens about 2-4 times in that initial minute or so before the engine idles down.
Click to expand...
Something that pronounced should be apparent. You're going to have to get your hands dirty. Remove the engine underskirt (4 bolts). Have someone sit in the driver's seat while you lay on your back under the truck.
 
I also couldn't figure find anything mechanical making the noise. Which is why I don't think it is.
Specially since I left the battery on a trickle charger for a couple days, and the duration of the noise was much less. For a handful of seconds compared to a minute. Also quieter.
Also the dimming of dash lights or headlights if on, for that minute.
Could be an intermittent fault in the alternator or just from the battery being weak.
 
A couple more WAGS after watching the video again. If it is electrical Have you checked your ground wires? I had a bad ground wire burn up my alternator. The other thing I thought was the starter could it be staying engaged or loose. It sounds like something is banging against the oil pan to me.
 
89325iturbo said:
I also couldn't figure find anything mechanical making the noise. Which is why I don't think it is.
Click to expand...
You're telling me that the almost rhythmic banging noise is not mechanical. Vehicle electronics don't bang together.
This can't possibly be that difficult to localize.
 
I have not checked grounds. But is that something that would change if it was cold or warm? Doesn't seem like it would.
Doesn't help that the quality of the phone video isn't the best. So could be hard to hear the sound clear.
 
I'm not saying the noise isn't mechanical but I just think it's based from the electrical system.
I don't think the noise is very rhythmic at all. starts off the same. Then goes twice in a row and then it's a bigger Gap in between when it makes the noise, ect.
 
Alternator belts? That would also work into the fan clutch theory. Since the fan roars on startup, it's obviously putting more load on the belts, which could be causing them to slip. At the same time, the alternator is running hard, trying to charge the battery. If the belt slips because of the stiff fan load, the alternator will drop out momentarily, then recover when the belt grabs again.
Are your belts hard and shiny? Are they a matched set from Mr. T?
Do you have the typical "fan roar on startup"? Did you used to?
 
I'm gonna try to get back to this over the weekend. My belts I should change anyway, I haven't changed them. So not sure how long they have been on there.
 
89325iturbo said:
I'm not saying the noise isn't mechanical but I just think it's based from the electrical system.
I don't think the noise is very rhythmic at all. starts off the same. Then goes twice in a row and then it's a bigger Gap in between when it makes the noise, ect.
Click to expand...
Since this happens right after start, my second move would be to pull the starter and inspect.
My FIRST move would be to lay under the truck and have someone start it while I try to localize the sound.
 
^^ I agree another hand so I can listen when it's started would be ideal.
As a side note if I start it and immediately bring the revs up to say 1500 rpms. Then the noise isn't present. Another reason why I think it's part of the charging system. Maybe the extra revs get the alternator going or take up the slack in a slightly slipping belt?
 
89325iturbo said:
^^ I agree another hand so I can listen when it's started would be ideal.
As a side note if I start it and immediately bring the revs up to say 1500 rpms. Then the noise isn't present. Another reason why I think it's part of the charging system. Maybe the extra revs get the alternator going or take up the slack in a slightly slipping belt?
Click to expand...
Continued speculation is pointless.
 
You must log in or register to reply here.

Share this page

Back
Top Bottom