M1009 Engine Noise

[toomuchjosh]

Hi, I am trying to diagnose an engine noise that I discovered on my recently acquired M1009.

1, When I first started driving it, the noise was intermittent. One minute there, gone the next. This week it has been persistent.
2, The pitch of the noise escalates when the engine revs higher.
3, the noise seems louder when you listen from under the engine.

See the YouTube video below for the noise. Any assistance would be appreciated.

[media]http://www.youtube.com/watch?v=4FgpFmKnO-Y[/media]

 

[Kid Kodiak]

recorded engine noises are too difficult to analyze. But I'd say maybe an exhaust leak from a loose manifold or maybe fan clutch, alternator pulleys.

i'm not the expert, but that's where I'd start.

 

[Barrman]

Do the CUCV standard bolt check. Flywheel and torque converter bolts. I really couldn't tell much from the video either.

 

[toomuchjosh]

UPDATE August 7 evening

It turns out the small gear on the starter motor is not staying retracted after starting the engine. It is slipping back into the way of the flywheel and barely touches it. That is the source of the noise.

So, my questions is: What is the next step I need to take to fix this?, replace entire starter?

 

[Barrman]

For sure, pull the starter and pull/push on the Bendix gear to figure out where the slop is. If there is no slop in any of the connections, pull the solenoid and verify a spring is in there. Could just be a busted return spring. Or a missing spring.

 

[SGT Estum]

How on earth did you figure out that was the source of the sound? I don't know if I would have ever thought to check that.

I've got a similar sound, but I haven't gotten around to diagnosing it yet -- more pressing matters need fixing. I would describe my sound as there being an elf inside your muffler with a set of drumsticks tapping away. Not sure if that's the sound you were working with or another one.

 

[toomuchjosh]

UPDATE Aug 9 Morning.

I found a new (used) starter motor on craigslist. I'm going to replace my starter so I can have a working truck and more time to troubleshoot the broken one.

@Barrman, Thanks for the heads up on the bendix gear/spring, I will report back my findings here probably tomorrow.

@SGT Estum, I have a friend that used to be real big on Mazda RX7's. He helped me localize the sound. We decided to take off the lower bell housing to investigate further. We had one guy under the truck while the other guy started it. You could actually see the bendix gear moving toward the flywheel, hit and make noise, then the impact pushed it back a bit. As far as describing my sound... I posted the video because I couldn't properly describe it with words.

Also, @Kid Kodiak, Barrman, thank you for posting possible trouble spots, part of the reason I was able to find the problem is because of the info you guys posted. Thank you.

 

[firecontrol86]

That's lucky you had someone to help with that toomuchjosh, I wouldn't have thought to check that either. I had a similar sound once, mine was a lot more at idle though. Turned out to be the starter heat shield had completely came off the mount and was bouncing on the starter. Might be something for you to look at SGT Estum.

 

[toomuchjosh]

UPDATE Aug 10.

I was able to get to take apart the original starter motor yesterday evening. The problem turned out to be the spring inside of the solenoid. The spring was hooked on the plate that it was supposed to push against. This caused the spring to retract and push the Bendix toward the flywheel. I unhooked the spring from the plate and the starter works great now!

PS.... Forget P90X, installing these starter motors will give you a better workout!

 

[mistaken1]

Thanks for the followup. It adds to the knowledge-base.