Funny new sound

I guess this might be considered a tow rig question as I use it tow my CJ around...

I have a 87 motorhome with a chevy 454 and 92k miles. I take good care of it changing the oil etc... I was coming back from the coast tonight pulling a pretty good hill, with no trailer or anything, when it felt like it started to lose a little power. I dropped it down a gear got back up to 55 and it started getting warm, it didn't overheat. I just thought, wow, that was weird. The temp dropped right back down once I went over the top and it ran perfect the rest of the way home with plenty of power. When I pulled in the driveway there was a nasty sound coming from the engine. It's not real loud but I can't tell where the noise is coming from, valves or bottom end. I don't know if it spun a bearin, burned a valve etc... What's puzzling is it still has plenty of power and runs fine.

Anybody have a guess?

Probably time to sell it!

check clutch fan and water pump.

Exhaust leak?

It's not an exhaust leak, it doesn't sound or act like the fan. It ran normal temp the rest of the time. The real bitch of it is it's a class A and a real PIA to get to the motor. You can pull the top of the dog house off but your pretty much limited to just the top of the motor. The noise does sound like it could be a rod. It doesn't realy knock though. I would think I would loose power if it was a rod. I think the first thing to do is a compression check. Like I said, time to sell!

I've seen push rods poke through the rockers before and they tap the valve cover on a 454.

ain'tstuckjustresting said:

I've seen push rods poke through the rockers before and they tap the valve cover on a 454.

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That could explain the noise, but why would it heat up then run good afterwards??????? Suppose I should pull the vavle covers.

Some one said maybe a collasped lifter? I don't know much about BB, can you check the lifters without pulling the intake?

Collapsed lifter would show a loose rocker most likely.

North Plains Drifter said:

I guess this might be considered a tow rig question as I use it tow my CJ around...

I have a 87 motorhome with a chevy 454 and 92k miles. I take good care of it changing the oil etc... I was coming back from the coast tonight pulling a pretty good hill, with no trailer or anything, when it felt like it started to lose a little power. I dropped it down a gear got back up to 55 and it started getting warm, it didn't overheat. I just thought, wow, that was weird. The temp dropped right back down once I went over the top and it ran perfect the rest of the way home with plenty of power. When I pulled in the driveway there was a nasty sound coming from the engine. It's not real loud but I can't tell where the noise is coming from, valves or bottom end. I don't know if it spun a bearin, burned a valve etc... What's puzzling is it still has plenty of power and runs fine.

Anybody have a guess?

Probably time to sell it!

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North Plains Drifter said:

It's not an exhaust leak, it doesn't sound or act like the fan. It ran normal temp the rest of the time. The real bitch of it is it's a class A and a real PIA to get to the motor. You can pull the top of the dog house off but your pretty much limited to just the top of the motor. The noise does sound like it could be a rod. It doesn't realy knock though. I would think I would loose power if it was a rod. I think the first thing to do is a compression check. Like I said, time to sell!

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I cannot believe I am about to ask this question, as I HATE pulling motors in class A's (if that is what it is), but what kinda shape is it in otherwise? Size? And how cheap are you willing to part with it?:hello: :redneck:

Is it a suncrest?

I had a noise like that once turned out to be a hole in a piston Mine heated up and quit running though :booo: At 90,000 your motor has probably reached the end of its life hauling all that weight around.

It is a class A, I think the only way to pull the motor is through the drivers door, I hope I don't have to do that. It's a Southwind, it's in relatively good shape, everything works good, except the motor. I keep hearing all these different scenario's as to what it could be. I just haven't had time to look at it as I don't park it at home. I was thinking of selling it for around $6000 before the noise started. I really don't know what it's worth now. I'm still hoping it could be something fixable as it still runs good, just with a slight noise.

North Plains Drifter said:

It is a class A, I think the only way to pull the motor is through the drivers door, I hope I don't have to do that. It's a Southwind, it's in relatively good shape, everything works good, except the motor. I keep hearing all these different scenario's as to what it could be. I just haven't had time to look at it as I don't park it at home. I was thinking of selling it for around $6000 before the noise started. I really don't know what it's worth now. I'm still hoping it could be something fixable as it still runs good, just with a slight noise.

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If only it were that easy:;...every one I have done ended up coming out thru the house door....cleared the living area, laid down a sheet of 3/4" plywood, and brought the picker in...then use a second picker to transfer the motor thru the door...it sucks!!! Oh I take that back, dropped one down thru the front once....ONCE!!! That sucks even worse!!!!
Is it injected or still carbed?

Carbed. If the motor has to come through the center of the house, f it. It gets sold as is.

I'm hoping to look at it later this week. I have a stethoscope type thing and I will try and pin point the noise. That should help me determine what the problem is.

North Plains Drifter said:

Carbed. If the motor has to come through the center of the house, f it. It gets sold as is.

I'm hoping to look at it later this week. I have a stethoscope type thing and I will try and pin point the noise. That should help me determine what the problem is.

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That tool will help a bunch......

Also try removing the drive belt to help elimenate that noise..

X2---remove the belt(s) to eliminate any other noises other than the motor itself running...just remember to keep an eye on the engine temp as there will be no water pump turning!!! Probably have about 5 minutes or so to poke around for the noise with no water pump....

I wish it was that easy to take all the belts off, remember, it's a class A! :booo: I can't even get a timing light on it!

hows the oil pressure ? is the needle on the gauge bouncing around ?

The oil pressure is fine, so I don't thinks it's a main bearing. It's possible that a rod bearing spun then fell back into place... Then I could throw in some bearings and sell it!

compression check :awesomework:

North Plains Drifter said:

I wish it was that easy to take all the belts off, remember, it's a class A! :booo: I can't even get a timing light on it!

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Yes, I know it's a Class A; Never once said it was gonna be easy!:haha: But IMO might worth the time to hump the motor and pull the belts and have a listen---:awesomework: