Robb S via CarKB.com

It would seem to me that the clicking noise would be faster with the valve
train, and slower with the bearing noise. You might even have piston slap
going on. That's wear of a cylinder and a piston is slopping around. That
stephascope will really help you pinpoint it, and also, pay attention to the
frequency of the noise.....valve train= twice as often in RPM Cransk= RPM
or a slower noise.......
Anyone else???? AM I right or just a couple toooooo many beers?

Robb S wrote:
>get yourself a stethascope, and place it in the engine compartment. Go hi,
>Go low. that'll answer your question.... ;)
>
>>Jeff DeWitt did pass the time by typing:
>>> The last few months of driving my good old Cherokee with a 4.0 engine
>[quoted text clipped - 35 lines]
>>
>>I'd still check the exhaust manifold first.


--
Message posted via CarKB.com
http://www.carkb.com/Uwe/Forums.aspx/jeep-cars/200507/1

Robb S via CarKB.com

It would seem to me that the clicking noise would be faster with the valve
train, and slower with the bearing noise. You might even have piston slap
going on. That's wear of a cylinder and a piston is slopping around. That
stephascope will really help you pinpoint it, and also, pay attention to the
frequency of the noise.....valve train= twice as often in RPM Cransk= RPM
or a slower noise.......
Anyone else???? AM I right or just a couple toooooo many beers?

Robb S wrote:
>get yourself a stethascope, and place it in the engine compartment. Go hi,
>Go low. that'll answer your question.... ;)
>
>>Jeff DeWitt did pass the time by typing:
>>> The last few months of driving my good old Cherokee with a 4.0 engine
>[quoted text clipped - 35 lines]
>>
>>I'd still check the exhaust manifold first.


--
Message posted via CarKB.com
http://www.carkb.com/Uwe/Forums.aspx/jeep-cars/200507/1

Robb S via CarKB.com

It would seem to me that the clicking noise would be faster with the valve
train, and slower with the bearing noise. You might even have piston slap
going on. That's wear of a cylinder and a piston is slopping around. That
stephascope will really help you pinpoint it, and also, pay attention to the
frequency of the noise.....valve train= twice as often in RPM Cransk= RPM
or a slower noise.......
Anyone else???? AM I right or just a couple toooooo many beers?

Robb S wrote:
>get yourself a stethascope, and place it in the engine compartment. Go hi,
>Go low. that'll answer your question.... ;)
>
>>Jeff DeWitt did pass the time by typing:
>>> The last few months of driving my good old Cherokee with a 4.0 engine
>[quoted text clipped - 35 lines]
>>
>>I'd still check the exhaust manifold first.


--
Message posted via CarKB.com
http://www.carkb.com/Uwe/Forums.aspx/jeep-cars/200507/1

Lee Ayrton

Collapsed lifter, perhaps? For a while I had an `82 Malibu with the V-6
that would make horrible loud death-coming-soon whacking noises every
once in a while, always while hot, always in hot weather -- this a few
months after my `79 CJ had spun a rod bearing on my way to work (the
motor kept turning just long enough to get off a busy interstate and
into to a commuter parking lot). As the Malibu was my only ride at the
time (and I was broke) it scared the bejeasus out of me the first couple
of times it happened. Apparently it was a gummy lifter that would come
and go at will. I got another 30K out of that motor.


Jeff DeWitt wrote:
> The last few months of driving my good old Cherokee with a 4.0 engine
> and about 300,000 miles has been making a bit of a clicking sound when
> the engine is cold. Tonight as I was driving along the clicking sound
> got a lot worse, and the engine was hot.
>
> As this engine has a BUNCH of miles on it I'm really afraid it might be
> a rod bearing letting go, but I'm hoping it might actually be a lifter.
> The noise is now always there, and it seemed to be getting worse as I
> drove, it is somewhere between a click and a clatter. The oil pressure
> is at least good enough the idiot light stays off, and of course the
> crankcase is full. Under moderate to heavy acceleration the noise goes
> away, it's always there under light acceleration and when cruising or
> idling.
>
> Is there a quick and dirty check? I seem to recall if you pull the
> spark plug wires off one by one and the problem really is a bad rod
> bearing it will quiet down when that cylinders wire is pulled, but if
> it's a lifter pulling wires won't make any difference.
>
> If it is the rod bearings what kind of luck have you guys had with used
> engines vs rebuilt. I have neither the money or the inclination to buy
> a new Jeep and plan to keep this one for as long as I can. (Well, a new
> Wrangler Unlimited with a hardtop would be really cool, but that's only
> going to happen if the Prize Patrol shows up!).
>
> Jeff DeWitt

Lee Ayrton

Collapsed lifter, perhaps? For a while I had an `82 Malibu with the V-6
that would make horrible loud death-coming-soon whacking noises every
once in a while, always while hot, always in hot weather -- this a few
months after my `79 CJ had spun a rod bearing on my way to work (the
motor kept turning just long enough to get off a busy interstate and
into to a commuter parking lot). As the Malibu was my only ride at the
time (and I was broke) it scared the bejeasus out of me the first couple
of times it happened. Apparently it was a gummy lifter that would come
and go at will. I got another 30K out of that motor.


Jeff DeWitt wrote:
> The last few months of driving my good old Cherokee with a 4.0 engine
> and about 300,000 miles has been making a bit of a clicking sound when
> the engine is cold. Tonight as I was driving along the clicking sound
> got a lot worse, and the engine was hot.
>
> As this engine has a BUNCH of miles on it I'm really afraid it might be
> a rod bearing letting go, but I'm hoping it might actually be a lifter.
> The noise is now always there, and it seemed to be getting worse as I
> drove, it is somewhere between a click and a clatter. The oil pressure
> is at least good enough the idiot light stays off, and of course the
> crankcase is full. Under moderate to heavy acceleration the noise goes
> away, it's always there under light acceleration and when cruising or
> idling.
>
> Is there a quick and dirty check? I seem to recall if you pull the
> spark plug wires off one by one and the problem really is a bad rod
> bearing it will quiet down when that cylinders wire is pulled, but if
> it's a lifter pulling wires won't make any difference.
>
> If it is the rod bearings what kind of luck have you guys had with used
> engines vs rebuilt. I have neither the money or the inclination to buy
> a new Jeep and plan to keep this one for as long as I can. (Well, a new
> Wrangler Unlimited with a hardtop would be really cool, but that's only
> going to happen if the Prize Patrol shows up!).
>
> Jeff DeWitt

Lee Ayrton

Collapsed lifter, perhaps? For a while I had an `82 Malibu with the V-6
that would make horrible loud death-coming-soon whacking noises every
once in a while, always while hot, always in hot weather -- this a few
months after my `79 CJ had spun a rod bearing on my way to work (the
motor kept turning just long enough to get off a busy interstate and
into to a commuter parking lot). As the Malibu was my only ride at the
time (and I was broke) it scared the bejeasus out of me the first couple
of times it happened. Apparently it was a gummy lifter that would come
and go at will. I got another 30K out of that motor.


Jeff DeWitt wrote:
> The last few months of driving my good old Cherokee with a 4.0 engine
> and about 300,000 miles has been making a bit of a clicking sound when
> the engine is cold. Tonight as I was driving along the clicking sound
> got a lot worse, and the engine was hot.
>
> As this engine has a BUNCH of miles on it I'm really afraid it might be
> a rod bearing letting go, but I'm hoping it might actually be a lifter.
> The noise is now always there, and it seemed to be getting worse as I
> drove, it is somewhere between a click and a clatter. The oil pressure
> is at least good enough the idiot light stays off, and of course the
> crankcase is full. Under moderate to heavy acceleration the noise goes
> away, it's always there under light acceleration and when cruising or
> idling.
>
> Is there a quick and dirty check? I seem to recall if you pull the
> spark plug wires off one by one and the problem really is a bad rod
> bearing it will quiet down when that cylinders wire is pulled, but if
> it's a lifter pulling wires won't make any difference.
>
> If it is the rod bearings what kind of luck have you guys had with used
> engines vs rebuilt. I have neither the money or the inclination to buy
> a new Jeep and plan to keep this one for as long as I can. (Well, a new
> Wrangler Unlimited with a hardtop would be really cool, but that's only
> going to happen if the Prize Patrol shows up!).
>
> Jeff DeWitt

Lee Ayrton

Collapsed lifter, perhaps? For a while I had an `82 Malibu with the V-6
that would make horrible loud death-coming-soon whacking noises every
once in a while, always while hot, always in hot weather -- this a few
months after my `79 CJ had spun a rod bearing on my way to work (the
motor kept turning just long enough to get off a busy interstate and
into to a commuter parking lot). As the Malibu was my only ride at the
time (and I was broke) it scared the bejeasus out of me the first couple
of times it happened. Apparently it was a gummy lifter that would come
and go at will. I got another 30K out of that motor.


Jeff DeWitt wrote:
> The last few months of driving my good old Cherokee with a 4.0 engine
> and about 300,000 miles has been making a bit of a clicking sound when
> the engine is cold. Tonight as I was driving along the clicking sound
> got a lot worse, and the engine was hot.
>
> As this engine has a BUNCH of miles on it I'm really afraid it might be
> a rod bearing letting go, but I'm hoping it might actually be a lifter.
> The noise is now always there, and it seemed to be getting worse as I
> drove, it is somewhere between a click and a clatter. The oil pressure
> is at least good enough the idiot light stays off, and of course the
> crankcase is full. Under moderate to heavy acceleration the noise goes
> away, it's always there under light acceleration and when cruising or
> idling.
>
> Is there a quick and dirty check? I seem to recall if you pull the
> spark plug wires off one by one and the problem really is a bad rod
> bearing it will quiet down when that cylinders wire is pulled, but if
> it's a lifter pulling wires won't make any difference.
>
> If it is the rod bearings what kind of luck have you guys had with used
> engines vs rebuilt. I have neither the money or the inclination to buy
> a new Jeep and plan to keep this one for as long as I can. (Well, a new
> Wrangler Unlimited with a hardtop would be really cool, but that's only
> going to happen if the Prize Patrol shows up!).
>
> Jeff DeWitt