96 GC Engine Noise
 

I have a high milage (150K) 96 Grand Cherokee 4.0 that has developed a
pronounced rapping noise. It exists at all engine speeds but is most
noticable at low RPM as the engine revs down. It does not seem to be load
sensitive and does not vary much with engine temp. I have tried
sequentially killing the spark to each cylinder with no change in noise.
Anyone have any ideas on cause or diagnosis tips? Thanks...Jim Z

Re: 96 GC Engine Noise
 

Jim Z did pass the time by typing:
> I have a high milage (150K) 96 Grand Cherokee 4.0 that has developed a
> pronounced rapping noise. It exists at all engine speeds but is most
> noticable at low RPM as the engine revs down. It does not seem to be load
> sensitive and does not vary much with engine temp. I have tried
> sequentially killing the spark to each cylinder with no change in noise.
> Anyone have any ideas on cause or diagnosis tips? Thanks...Jim Z

Probably a cracked exhaust manifold. Read the Exhaust Manifold Fixed thread.

--
DougW

Re: 96 GC Engine Noise
 

Jim Z did pass the time by typing:
> I have a high milage (150K) 96 Grand Cherokee 4.0 that has developed a
> pronounced rapping noise. It exists at all engine speeds but is most
> noticable at low RPM as the engine revs down. It does not seem to be load
> sensitive and does not vary much with engine temp. I have tried
> sequentially killing the spark to each cylinder with no change in noise.
> Anyone have any ideas on cause or diagnosis tips? Thanks...Jim Z

Probably a cracked exhaust manifold. Read the Exhaust Manifold Fixed thread.

--
DougW

Re: 96 GC Engine Noise
 

Jim Z did pass the time by typing:
> I have a high milage (150K) 96 Grand Cherokee 4.0 that has developed a
> pronounced rapping noise. It exists at all engine speeds but is most
> noticable at low RPM as the engine revs down. It does not seem to be load
> sensitive and does not vary much with engine temp. I have tried
> sequentially killing the spark to each cylinder with no change in noise.
> Anyone have any ideas on cause or diagnosis tips? Thanks...Jim Z

Probably a cracked exhaust manifold. Read the Exhaust Manifold Fixed thread.

--
DougW

Re: 96 GC Engine Noise
 

Jim Z did pass the time by typing:
> I have a high milage (150K) 96 Grand Cherokee 4.0 that has developed a
> pronounced rapping noise. It exists at all engine speeds but is most
> noticable at low RPM as the engine revs down. It does not seem to be load
> sensitive and does not vary much with engine temp. I have tried
> sequentially killing the spark to each cylinder with no change in noise.
> Anyone have any ideas on cause or diagnosis tips? Thanks...Jim Z

Probably a cracked exhaust manifold. Read the Exhaust Manifold Fixed thread.

--
DougW

Re: 96 GC Engine Noise
 

Hi Jim,
Maybe a collapsed valve lifter, changing the oil may clean it up.
Then get back on a three thousand mile oil and filter change.
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/

Jim Z wrote:
>
> I have a high milage (150K) 96 Grand Cherokee 4.0 that has developed a
> pronounced rapping noise. It exists at all engine speeds but is most
> noticable at low RPM as the engine revs down. It does not seem to be load
> sensitive and does not vary much with engine temp. I have tried
> sequentially killing the spark to each cylinder with no change in noise.
> Anyone have any ideas on cause or diagnosis tips? Thanks...Jim Z

Re: 96 GC Engine Noise
 

Hi Jim,
Maybe a collapsed valve lifter, changing the oil may clean it up.
Then get back on a three thousand mile oil and filter change.
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/

Jim Z wrote:
>
> I have a high milage (150K) 96 Grand Cherokee 4.0 that has developed a
> pronounced rapping noise. It exists at all engine speeds but is most
> noticable at low RPM as the engine revs down. It does not seem to be load
> sensitive and does not vary much with engine temp. I have tried
> sequentially killing the spark to each cylinder with no change in noise.
> Anyone have any ideas on cause or diagnosis tips? Thanks...Jim Z

Re: 96 GC Engine Noise
 

Hi Jim,
Maybe a collapsed valve lifter, changing the oil may clean it up.
Then get back on a three thousand mile oil and filter change.
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/

Jim Z wrote:
>
> I have a high milage (150K) 96 Grand Cherokee 4.0 that has developed a
> pronounced rapping noise. It exists at all engine speeds but is most
> noticable at low RPM as the engine revs down. It does not seem to be load
> sensitive and does not vary much with engine temp. I have tried
> sequentially killing the spark to each cylinder with no change in noise.
> Anyone have any ideas on cause or diagnosis tips? Thanks...Jim Z

Re: 96 GC Engine Noise
 

Hi Jim,
Maybe a collapsed valve lifter, changing the oil may clean it up.
Then get back on a three thousand mile oil and filter change.
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/

Jim Z wrote:
>
> I have a high milage (150K) 96 Grand Cherokee 4.0 that has developed a
> pronounced rapping noise. It exists at all engine speeds but is most
> noticable at low RPM as the engine revs down. It does not seem to be load
> sensitive and does not vary much with engine temp. I have tried
> sequentially killing the spark to each cylinder with no change in noise.
> Anyone have any ideas on cause or diagnosis tips? Thanks...Jim Z