Hey guys! I'm Nate, this is my first post to the website. I came here because I'm at a loss, and maybe some of you would know better than I (since i'm only 18 and an aspiring mechanic.) I recently got interested in reviving my great grandmother's 1992 G20 Coachman van. It sat for 12 years, and I figured it would have literal tons of problems. As it turned out, it only needed a new battery and some carb cleaner to get it going! It started up great, and idled wonderfully (better than my Jeep!) After letting it warm up, I was able to rev it up to around 5,000RPM, and it has absolutely no knocks or pings or rattles. Once I got the brake lines fixed (separate issue), I went to take it for a test drive. Once I got on the road, and I hit about 15MPH, I noticed a ticking or tapping sound that sounds like it is coming from the bell housing. As I accelerate more, it seems to increase with RPM. I don't feel any power loss at all. Honestly, it hauls ***. I've had some people tell me it's the main bearing, I've also been told it's the flex plate, and torque converter, etc. Nobody is able to give me a straight answer on it, and I'm hoping to maybe find a clue here. I'll link a video of the sound below. You can hear the ticking/tapping very loud here. And, of course, I'll post a picture of it and my Jeep.
Any help would be greatly appreciated! (Sorry if the post is too long!)

 

Wow. Good job reviving it.

So you get the sound in Park and in Drive right? The oil might have gotten gummed up from sitting so long and it's blocking the flow to some moving parts. It might just need a good hard drive to get the engine nice and hot to burn off the varnish.

This sounds like a job for a mechanic's stethoscope.

 

take a piece of 3/4 (or what ever you have lying around)heater hose about 2-3 foot in length and put one end to your ear and the other try to pin point where the noise is coming from. the noise could be very well from the flex plate or like joe mentioned something didnt get enough oil while driving. take the dust cover off the transmission bell housing and inspect the flex plate. cracks will sometimes be hard to see while other times they may stand right out. but put a wrench on each flex plate bolt and try to tighten it. if they move see if the noise goes away. if it does remove the bolts and add some thread locker to prevent them from backing out again

 

I forgot to mention, I did both of those things! I took off the flex plate inspection cover and couldn't see any cracking, but I haven't unbolted anything else. I'm wondering if maybe it's cracked farther in? I also did do an oil change, and I used some brand new 15w-40 I had laying around, hoping maybe that would help. I don't think it did help. The noise is only while the vehicle is under load in drive. I tried running it in overdrive and in normal drive but they both still had the noise. When the car is in park or neutral, it has no noise. Like I said, it revs up and down very smoothly.

 

If you only get the noise under load, then I would suspect the engine.

An oil change won't help oil sludge because it stays behind. Like I said it needs to be pushed hard on hills and highways for a while.

 

I'll try out the flexplate tightening and I'll get some motor medic sludge cleaner, and I'll take it for a drive after that. Thanks for the advice!!

 

The tech at my work is experienced with these vans, ran it by him. He said flex plate is common, go deeper to inspect though. He recommends unbolting as cracks develop from bolt-to-bolt. Good luck and update when you can.

 

did you try to tighten the bolt?

 

Amsoil makes an engine flush. Pour it in run it for 20 minutes then change the oil.