The 'knocking' noise is more like a rattle....

That is the pistons flopping around.

A carbon buildup will cause that.

To find out, run a tank of high test through it. If the noise goes
away, it is carbon making the compression too high so it ignites the gas
from compression before the spark hits it.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

Bob wrote:
>
> Year: 1997
> Model: Wrangler (TJ)
> Tranny: AX15? (I think that's the 5-speed manual tranny found on the
> 97 TJ...)
>
> I was wondering if it could have anything to do with the throwout
> bearing. I had read something about that making noise somewhere, too.
> I hope its none of these bearings you're talking about, though. They
> don't sound easy to replace! :(
>
> Do you actually know the sound I'm talking about? It's not a very
> difficult sound to reproduce on any standard transmission vehicle by
> simply hitting the gas when going to slow for the present gear... I'm
> just asking because people have so far seemed certain it is "knocking"
> sound I'm hearing, but it just doesn't seem like that to me. I don't
> have first-hand experience hearing what true engine "knocking" sounds
> like, though, so I don't have a very good basis for comparison...
>
> Roy <spamless@microsoft.net> wrote in message news:<uQxsb.646$WF2.43264@news.uswest.net>...
> > Could be loose cat converter internals. Could be pinging. Could
> > be loose input shaft bearing. Could be throwout bearing. Etc.
> > Year/model/tranny?
> >
> > Bob wrote:
> > > I have a question for you more auto-mechanic inclined than me (which
> > > is probably most everyone who posts here often).
> > >
> > > You know that noise the engine makes when it lugs down? Kind of a
> > > clicking/rattling noise, especially prevalent when you shift into the
> > > next gear too early, right when you release the clutch and put
> > > pressure on the gas again? What specific part is making this noise.
> > > Does anyone know? I have been hearing it more lately, when I'm just
> > > driving normally, and there is no reason for the engine to be lugging
> > > down (I'm not shifting too early, etc.), and I'm wondering if
> > > something in my tranny or clutch is about to go bad that would cause
> > > this noise to occur more often. I still only hear it pretty close to
> > > when I first get back on the gas after changing gears. I'd like to
> > > catch any potential problem before it strands me.
> > >
> > > Thanks
> > > /Bob

 

I asked a mechanic, he said to also have your spark plugs checked.

"Bob" <magicclaw@mac.com> wrote in message
news:47b769ae.0311131546.58b507f@posting.google.co m...
> Year: 1997
> Model: Wrangler (TJ)
> Tranny: AX15? (I think that's the 5-speed manual tranny found on the
> 97 TJ...)
>
> I was wondering if it could have anything to do with the throwout
> bearing. I had read something about that making noise somewhere, too.
> I hope its none of these bearings you're talking about, though. They
> don't sound easy to replace! :(
>
> Do you actually know the sound I'm talking about? It's not a very
> difficult sound to reproduce on any standard transmission vehicle by
> simply hitting the gas when going to slow for the present gear... I'm
> just asking because people have so far seemed certain it is "knocking"
> sound I'm hearing, but it just doesn't seem like that to me. I don't
> have first-hand experience hearing what true engine "knocking" sounds
> like, though, so I don't have a very good basis for comparison...
>
>
> Roy <spamless@microsoft.net> wrote in message
news:<uQxsb.646$WF2.43264@news.uswest.net>...
> > Could be loose cat converter internals. Could be pinging. Could
> > be loose input shaft bearing. Could be throwout bearing. Etc.
> > Year/model/tranny?
> >
> > Bob wrote:
> > > I have a question for you more auto-mechanic inclined than me (which
> > > is probably most everyone who posts here often).
> > >
> > > You know that noise the engine makes when it lugs down? Kind of a
> > > clicking/rattling noise, especially prevalent when you shift into the
> > > next gear too early, right when you release the clutch and put
> > > pressure on the gas again? What specific part is making this noise.
> > > Does anyone know? I have been hearing it more lately, when I'm just
> > > driving normally, and there is no reason for the engine to be lugging
> > > down (I'm not shifting too early, etc.), and I'm wondering if
> > > something in my tranny or clutch is about to go bad that would cause
> > > this noise to occur more often. I still only hear it pretty close to
> > > when I first get back on the gas after changing gears. I'd like to
> > > catch any potential problem before it strands me.
> > >
> > > Thanks
> > > /Bob

 

I asked a mechanic, he said to also have your spark plugs checked.

"Bob" <magicclaw@mac.com> wrote in message
news:47b769ae.0311131546.58b507f@posting.google.co m...
> Year: 1997
> Model: Wrangler (TJ)
> Tranny: AX15? (I think that's the 5-speed manual tranny found on the
> 97 TJ...)
>
> I was wondering if it could have anything to do with the throwout
> bearing. I had read something about that making noise somewhere, too.
> I hope its none of these bearings you're talking about, though. They
> don't sound easy to replace! :(
>
> Do you actually know the sound I'm talking about? It's not a very
> difficult sound to reproduce on any standard transmission vehicle by
> simply hitting the gas when going to slow for the present gear... I'm
> just asking because people have so far seemed certain it is "knocking"
> sound I'm hearing, but it just doesn't seem like that to me. I don't
> have first-hand experience hearing what true engine "knocking" sounds
> like, though, so I don't have a very good basis for comparison...
>
>
> Roy <spamless@microsoft.net> wrote in message
news:<uQxsb.646$WF2.43264@news.uswest.net>...
> > Could be loose cat converter internals. Could be pinging. Could
> > be loose input shaft bearing. Could be throwout bearing. Etc.
> > Year/model/tranny?
> >
> > Bob wrote:
> > > I have a question for you more auto-mechanic inclined than me (which
> > > is probably most everyone who posts here often).
> > >
> > > You know that noise the engine makes when it lugs down? Kind of a
> > > clicking/rattling noise, especially prevalent when you shift into the
> > > next gear too early, right when you release the clutch and put
> > > pressure on the gas again? What specific part is making this noise.
> > > Does anyone know? I have been hearing it more lately, when I'm just
> > > driving normally, and there is no reason for the engine to be lugging
> > > down (I'm not shifting too early, etc.), and I'm wondering if
> > > something in my tranny or clutch is about to go bad that would cause
> > > this noise to occur more often. I still only hear it pretty close to
> > > when I first get back on the gas after changing gears. I'd like to
> > > catch any potential problem before it strands me.
> > >
> > > Thanks
> > > /Bob

 

I asked a mechanic, he said to also have your spark plugs checked.

"Bob" <magicclaw@mac.com> wrote in message
news:47b769ae.0311131546.58b507f@posting.google.co m...
> Year: 1997
> Model: Wrangler (TJ)
> Tranny: AX15? (I think that's the 5-speed manual tranny found on the
> 97 TJ...)
>
> I was wondering if it could have anything to do with the throwout
> bearing. I had read something about that making noise somewhere, too.
> I hope its none of these bearings you're talking about, though. They
> don't sound easy to replace! :(
>
> Do you actually know the sound I'm talking about? It's not a very
> difficult sound to reproduce on any standard transmission vehicle by
> simply hitting the gas when going to slow for the present gear... I'm
> just asking because people have so far seemed certain it is "knocking"
> sound I'm hearing, but it just doesn't seem like that to me. I don't
> have first-hand experience hearing what true engine "knocking" sounds
> like, though, so I don't have a very good basis for comparison...
>
>
> Roy <spamless@microsoft.net> wrote in message
news:<uQxsb.646$WF2.43264@news.uswest.net>...
> > Could be loose cat converter internals. Could be pinging. Could
> > be loose input shaft bearing. Could be throwout bearing. Etc.
> > Year/model/tranny?
> >
> > Bob wrote:
> > > I have a question for you more auto-mechanic inclined than me (which
> > > is probably most everyone who posts here often).
> > >
> > > You know that noise the engine makes when it lugs down? Kind of a
> > > clicking/rattling noise, especially prevalent when you shift into the
> > > next gear too early, right when you release the clutch and put
> > > pressure on the gas again? What specific part is making this noise.
> > > Does anyone know? I have been hearing it more lately, when I'm just
> > > driving normally, and there is no reason for the engine to be lugging
> > > down (I'm not shifting too early, etc.), and I'm wondering if
> > > something in my tranny or clutch is about to go bad that would cause
> > > this noise to occur more often. I still only hear it pretty close to
> > > when I first get back on the gas after changing gears. I'd like to
> > > catch any potential problem before it strands me.
> > >
> > > Thanks
> > > /Bob

 

Thanks guys.

I will try the higher octane fuel on my next fill up. I'm driving an
eight hour drive from Denver to far east Nebraska for Thanksgiving, so
I'll have plenty of opportunity to run the engine at a good RPM for a
little while and let it try to burn off any deposits.

I think I'll also go ahead and just replace the spark plugs this
weekend. They're cheap, and if that makes a difference, great! If not,
it can't hurt; they're most likely still the original plugs anyway!

I'll let you guys know if what I did if I manage to get it to go away.


"SteveG" <sg@hotmail.com> wrote in message news:<cZBtb.107$s81.423@newscontent-01.sprint.ca>...
> I asked a mechanic, he said to also have your spark plugs checked.
>
> "Bob" <magicclaw@mac.com> wrote in message
> news:47b769ae.0311131546.58b507f@posting.google.co m...
> > Year: 1997
> > Model: Wrangler (TJ)
> > Tranny: AX15? (I think that's the 5-speed manual tranny found on the
> > 97 TJ...)
> >
> > I was wondering if it could have anything to do with the throwout
> > bearing. I had read something about that making noise somewhere, too.
> > I hope its none of these bearings you're talking about, though. They
> > don't sound easy to replace! :(
> >
> > Do you actually know the sound I'm talking about? It's not a very
> > difficult sound to reproduce on any standard transmission vehicle by
> > simply hitting the gas when going to slow for the present gear... I'm
> > just asking because people have so far seemed certain it is "knocking"
> > sound I'm hearing, but it just doesn't seem like that to me. I don't
> > have first-hand experience hearing what true engine "knocking" sounds
> > like, though, so I don't have a very good basis for comparison...
> >
> >
> > Roy <spamless@microsoft.net> wrote in message
> news:<uQxsb.646$WF2.43264@news.uswest.net>...
> > > Could be loose cat converter internals. Could be pinging. Could
> > > be loose input shaft bearing. Could be throwout bearing. Etc.
> > > Year/model/tranny?
> > >
> > > Bob wrote:
> > > > I have a question for you more auto-mechanic inclined than me (which
> > > > is probably most everyone who posts here often).
> > > >
> > > > You know that noise the engine makes when it lugs down? Kind of a
> > > > clicking/rattling noise, especially prevalent when you shift into the
> > > > next gear too early, right when you release the clutch and put
> > > > pressure on the gas again? What specific part is making this noise.
> > > > Does anyone know? I have been hearing it more lately, when I'm just
> > > > driving normally, and there is no reason for the engine to be lugging
> > > > down (I'm not shifting too early, etc.), and I'm wondering if
> > > > something in my tranny or clutch is about to go bad that would cause
> > > > this noise to occur more often. I still only hear it pretty close to
> > > > when I first get back on the gas after changing gears. I'd like to
> > > > catch any potential problem before it strands me.
> > > >
> > > > Thanks
> > > > /Bob

 

Thanks guys.

I will try the higher octane fuel on my next fill up. I'm driving an
eight hour drive from Denver to far east Nebraska for Thanksgiving, so
I'll have plenty of opportunity to run the engine at a good RPM for a
little while and let it try to burn off any deposits.

I think I'll also go ahead and just replace the spark plugs this
weekend. They're cheap, and if that makes a difference, great! If not,
it can't hurt; they're most likely still the original plugs anyway!

I'll let you guys know if what I did if I manage to get it to go away.


"SteveG" <sg@hotmail.com> wrote in message news:<cZBtb.107$s81.423@newscontent-01.sprint.ca>...
> I asked a mechanic, he said to also have your spark plugs checked.
>
> "Bob" <magicclaw@mac.com> wrote in message
> news:47b769ae.0311131546.58b507f@posting.google.co m...
> > Year: 1997
> > Model: Wrangler (TJ)
> > Tranny: AX15? (I think that's the 5-speed manual tranny found on the
> > 97 TJ...)
> >
> > I was wondering if it could have anything to do with the throwout
> > bearing. I had read something about that making noise somewhere, too.
> > I hope its none of these bearings you're talking about, though. They
> > don't sound easy to replace! :(
> >
> > Do you actually know the sound I'm talking about? It's not a very
> > difficult sound to reproduce on any standard transmission vehicle by
> > simply hitting the gas when going to slow for the present gear... I'm
> > just asking because people have so far seemed certain it is "knocking"
> > sound I'm hearing, but it just doesn't seem like that to me. I don't
> > have first-hand experience hearing what true engine "knocking" sounds
> > like, though, so I don't have a very good basis for comparison...
> >
> >
> > Roy <spamless@microsoft.net> wrote in message
> news:<uQxsb.646$WF2.43264@news.uswest.net>...
> > > Could be loose cat converter internals. Could be pinging. Could
> > > be loose input shaft bearing. Could be throwout bearing. Etc.
> > > Year/model/tranny?
> > >
> > > Bob wrote:
> > > > I have a question for you more auto-mechanic inclined than me (which
> > > > is probably most everyone who posts here often).
> > > >
> > > > You know that noise the engine makes when it lugs down? Kind of a
> > > > clicking/rattling noise, especially prevalent when you shift into the
> > > > next gear too early, right when you release the clutch and put
> > > > pressure on the gas again? What specific part is making this noise.
> > > > Does anyone know? I have been hearing it more lately, when I'm just
> > > > driving normally, and there is no reason for the engine to be lugging
> > > > down (I'm not shifting too early, etc.), and I'm wondering if
> > > > something in my tranny or clutch is about to go bad that would cause
> > > > this noise to occur more often. I still only hear it pretty close to
> > > > when I first get back on the gas after changing gears. I'd like to
> > > > catch any potential problem before it strands me.
> > > >
> > > > Thanks
> > > > /Bob

 

Thanks guys.

I will try the higher octane fuel on my next fill up. I'm driving an
eight hour drive from Denver to far east Nebraska for Thanksgiving, so
I'll have plenty of opportunity to run the engine at a good RPM for a
little while and let it try to burn off any deposits.

I think I'll also go ahead and just replace the spark plugs this
weekend. They're cheap, and if that makes a difference, great! If not,
it can't hurt; they're most likely still the original plugs anyway!

I'll let you guys know if what I did if I manage to get it to go away.


"SteveG" <sg@hotmail.com> wrote in message news:<cZBtb.107$s81.423@newscontent-01.sprint.ca>...
> I asked a mechanic, he said to also have your spark plugs checked.
>
> "Bob" <magicclaw@mac.com> wrote in message
> news:47b769ae.0311131546.58b507f@posting.google.co m...
> > Year: 1997
> > Model: Wrangler (TJ)
> > Tranny: AX15? (I think that's the 5-speed manual tranny found on the
> > 97 TJ...)
> >
> > I was wondering if it could have anything to do with the throwout
> > bearing. I had read something about that making noise somewhere, too.
> > I hope its none of these bearings you're talking about, though. They
> > don't sound easy to replace! :(
> >
> > Do you actually know the sound I'm talking about? It's not a very
> > difficult sound to reproduce on any standard transmission vehicle by
> > simply hitting the gas when going to slow for the present gear... I'm
> > just asking because people have so far seemed certain it is "knocking"
> > sound I'm hearing, but it just doesn't seem like that to me. I don't
> > have first-hand experience hearing what true engine "knocking" sounds
> > like, though, so I don't have a very good basis for comparison...
> >
> >
> > Roy <spamless@microsoft.net> wrote in message
> news:<uQxsb.646$WF2.43264@news.uswest.net>...
> > > Could be loose cat converter internals. Could be pinging. Could
> > > be loose input shaft bearing. Could be throwout bearing. Etc.
> > > Year/model/tranny?
> > >
> > > Bob wrote:
> > > > I have a question for you more auto-mechanic inclined than me (which
> > > > is probably most everyone who posts here often).
> > > >
> > > > You know that noise the engine makes when it lugs down? Kind of a
> > > > clicking/rattling noise, especially prevalent when you shift into the
> > > > next gear too early, right when you release the clutch and put
> > > > pressure on the gas again? What specific part is making this noise.
> > > > Does anyone know? I have been hearing it more lately, when I'm just
> > > > driving normally, and there is no reason for the engine to be lugging
> > > > down (I'm not shifting too early, etc.), and I'm wondering if
> > > > something in my tranny or clutch is about to go bad that would cause
> > > > this noise to occur more often. I still only hear it pretty close to
> > > > when I first get back on the gas after changing gears. I'd like to
> > > > catch any potential problem before it strands me.
> > > >
> > > > Thanks
> > > > /Bob