Intermittent Starting Grinding noise

[Hokie]

Only when the truck has sat for atleast 1.5 days, I will get an abrupt noise at start up. Its kind of a grinding, but more of a crunch. The closest I can come to describing the noise is a missed shift on a manual transmission (or when the synchro's don't align properly) but less metalic (less of a gear on gear grinding, more of a crunch).

The noise seems to come from directly underneath me so in the vicinity of the trans/xfer case.

This only happens if i haven't driven the truck in a while (letting it sit overnight is not long enough). I never use AC so i know its not a bad compressor, and it doesn't do it everytime, so I know its not something rubbing as a result of my body lift.

Oh, I have the SOHC and the 5R trans.

Any opinions on what to troubleshoot? My searching has revealed lots of starter problems, but the truck starts fine when you drive it daily.

thanks!

-brett

 

[Hokie]

Oh, and 8XXX miles ago, we had the 60k mile service done which included a replacement of all major fluids.

 

[Hokie]

anybody?

 

[Alec]

My initial thought would be flywheel or flexplate, or maybe starter. I'd have it checked out.

 

[Hokie]

So I guess i would drop it off and tell em not to drive it for 1.5 days and pray they hear the noise on the first time?

 

[Alec]

I had a similar problem and a few weeks later my flywheel blew up

 

[Hokie]

I'm going to have it checked out, but my question is... if the flywheel, flex plate, or starter is going bad, why doesn't this happen at every start up? I just think its wierd that it happens with 24+ hours of rest between start ups.

 

[Nate1]

Because after that long, fluids drain down to the bottoms of the pan, and there is a breif delay before the pump gets fluids back to the tops of the parts and lubricating again... at least, that is my take.

 

[MonsterTrac]

Sounds to me like the bendix on your starter is sticking, Had that problem on my 01 Trac. It woudl start right up, make a horrible noise for a second or two, then sound normal. After removing the starter I found lots of build up or dirt. I pulled the starter and threw it in a bench clamp. Took over a spare battery and set the starter up so that I could make it engage with a screwdriver ( ill explain later). I then made the starter engage then doused it with WD40, then held the starter upside down to let it drain, I repeated this a few times, problem fixed. Its been like 6 months and a few desert trips later and still no noise. The starter has three wires going to it. A ground, a 12v hot, and a 12v acc. If you hook the ground on the starter to a good ground. And the 12v hot to the positive terminal on a battery. You can make the starter engage by using a screwdriver to connect the 12v hot terminal with the 12v acc terminal. Make shure you use a screwdriver with a rubber/plastic handle. Also, dont let the starter motor engage for more than a few seconds, It was not designed to run constantly.

 

[Hokie]

I'm definately going to try that... Thanks MonsterTrac. I'm thinking it is more a starter problem now. I heard it again and it sounds like its coming more from around my feet during start up. When I get more time i'll pull the starter and see how the teeth in the starter look.

 

[Mbrooks420]

I had a similar problem and a few weeks later my flywheel blew up

I also had an intermittant grinding and in a few weeks the flexplate cracked out. It broke after 2 days of sitting, which my truck never sees. I would pull the starter and check out what MosterTrac posted for sure.

 

[MonsterTrac]

Good luck, hope you jsut had the same problem I did, it was an easy fix. feel free to re-post or e-mail me if you have any further questions. Lates.