Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here XJ (84-01)
All OEM related XJ specific tech. Examples, no start, general maintenance or anything that's stock.

motor knocking

Thread Tools
 
Search this Thread
 
Old Dec 27, 2011 | 12:50 AM
  #1  
94cherokeeman's Avatar
Thread Starter
CF Veteran
 
Joined: May 2011
Posts: 3,380
Likes: 0
From: Partlow, va
Year: 1994
Model: Cherokee
Engine: 4.0 i6, 307 injectors
Default motor knocking

My motor has had a knock for a little bit now I here it more now what can I do? Also how long will it take to pull it out and a new one put in
Reply
Old Dec 27, 2011 | 12:53 AM
  #2  
1991Jeep_Man's Avatar
CF Veteran
 
Joined: Oct 2009
Posts: 2,867
Likes: 16
From: Fauquier County, Virginia
Year: 1991
Model: Cherokee
Engine: I-6 4.0 HO
Default

Try running a heavier oil. I run 5w40. Didn't really have knock, but there was little noises that the heavier oil cleared up. I ran the 5w because of winter. If you're knocking, I'd suggest sticking with a 10w40.
Reply
Old Dec 27, 2011 | 01:03 AM
  #3  
94cherokeeman's Avatar
Thread Starter
CF Veteran
 
Joined: May 2011
Posts: 3,380
Likes: 0
From: Partlow, va
Year: 1994
Model: Cherokee
Engine: 4.0 i6, 307 injectors
Default

I have 10w-30 with Lucas in it
Reply
Old Dec 27, 2011 | 01:13 AM
  #4  
1991Jeep_Man's Avatar
CF Veteran
 
Joined: Oct 2009
Posts: 2,867
Likes: 16
From: Fauquier County, Virginia
Year: 1991
Model: Cherokee
Engine: I-6 4.0 HO
Default

Originally Posted by 94cherokeeman
I have 10w-30 with Lucas in it
...oh. Then if you're running lucas with a 10w30, Idk what else to offer. Lucas itself is already nothing but a thickener.
Reply
Old Dec 27, 2011 | 01:19 AM
  #5  
94cherokeeman's Avatar
Thread Starter
CF Veteran
 
Joined: May 2011
Posts: 3,380
Likes: 0
From: Partlow, va
Year: 1994
Model: Cherokee
Engine: 4.0 i6, 307 injectors
Default

Thanks anyway
Reply
Old Dec 27, 2011 | 01:26 AM
  #6  
Firestorm500's Avatar
CF Veteran
 
Joined: Apr 2009
Posts: 4,734
Likes: 12
Year: 2015, 2012
Model: Grand Cherokee (WK2)
Engine: 3.6L
Default

Don't use Lucas. Drain the oil, change the filter using a good brand, and put good 10W-30 in it with no additives.

A thicker oil strains your oil pump and doesn't lubricate the bearings as well.

Thicker oil doesn't prevent or cure engine wear. It actually accelerates it.
Reply
Old Dec 27, 2011 | 02:05 AM
  #7  
DFlintstone's Avatar
CF Veteran
 
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
Default

Did you check the torque converter bolts? They are known to loosen and knock like hell. And Amen ^...my pump must be REALLY strained, pushing that 30W for 263,000 miles. (OK only the last 120K for sure!)
Reply
Old Dec 27, 2011 | 02:47 AM
  #8  
pulltabmike's Avatar
CF Veteran
 
Joined: Jul 2011
Posts: 3,235
Likes: 2
From: Elkton, Maryland
Year: 1998
Model: Grand Cherokee
Engine: 4.0
Default

Originally Posted by 94cherokeeman
My motor has had a knock for a little bit now I here it more now what can I do? Also how long will it take to pull it out and a new one put in
A little more info please....Mileage, oil pressure, last tuneup. Is the knock coming from the bottom of the motor or higher up? Could be a couple of reasons that do NOT require a rebuild or new motor.
PM Bohnett and see how far he is from you, he may be able to stop by and help you idenify the problem.
Reply
Old Dec 27, 2011 | 05:03 AM
  #9  
cruiser54's Avatar
::CF Moderator::
 
Joined: Aug 2011
Posts: 43,971
Likes: 1,578
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Default

What brand of oil filter are you using?

And the torque converter to flexplate bolts, if you have an auto trans, and has already been suggested, is where I would start.
Reply
Old Dec 27, 2011 | 08:59 AM
  #10  
94cherokeeman's Avatar
Thread Starter
CF Veteran
 
Joined: May 2011
Posts: 3,380
Likes: 0
From: Partlow, va
Year: 1994
Model: Cherokee
Engine: 4.0 i6, 307 injectors
Default

Originally Posted by pulltabmike

A little more info please....Mileage, oil pressure, last tuneup. Is the knock coming from the bottom of the motor or higher up? Could be a couple of reasons that do NOT require a rebuild or new motor.
PM Bohnett and see how far he is from you, he may be able to stop by and help you idenify the problem.
Ok its a out 230,000 miles index at running temperature going 55mph the oil pressure is at 40psi, and the knocking is hard to tell if you r under the hood it sounds like it is on top but if u are going into the cab with the door open it sounds like its coming from the bottom, and I am using mobile1 oil and frame oil filter
Reply
Old Dec 27, 2011 | 09:50 AM
  #11  
1991Jeep_Man's Avatar
CF Veteran
 
Joined: Oct 2009
Posts: 2,867
Likes: 16
From: Fauquier County, Virginia
Year: 1991
Model: Cherokee
Engine: I-6 4.0 HO
Default

Originally Posted by Firestorm500
Don't use Lucas. Drain the oil, change the filter using a good brand, and put good 10W-30 in it with no additives.

A thicker oil strains your oil pump and doesn't lubricate the bearings as well.

Thicker oil doesn't prevent or cure engine wear. It actually accelerates it.
Not entirely true. Going overboard with 20w50 or what not will do harm, but Xw40 oils have been proven to show lower wear numbers in UOA's.
Reply
Old Dec 27, 2011 | 10:05 AM
  #12  
xjsnake's Avatar
CF Veteran
 
Joined: Aug 2010
Posts: 1,150
Likes: 1
From: Nashville, TN
Year: 1997, 1993
Model: Cherokee
Engine: 4.0L
Default

Originally Posted by 94cherokeeman
Ok its a out 230,000 miles index at running temperature going 55mph the oil pressure is at 40psi, and the knocking is hard to tell if you r under the hood it sounds like it is on top but if u are going into the cab with the door open it sounds like its coming from the bottom, and I am using mobile1 oil and frame oil filter

Get rid of the fram filter. I know some people say they run them and are fine but I've used them in the past and my engine runs quieter now that I've switched brands. Go with Napa Gold (made by wix), wix, mopar, Mobil 1 or Motorcraft oil filters.
Reply
Old Dec 27, 2011 | 10:14 AM
  #13  
94cherokeeman's Avatar
Thread Starter
CF Veteran
 
Joined: May 2011
Posts: 3,380
Likes: 0
From: Partlow, va
Year: 1994
Model: Cherokee
Engine: 4.0 i6, 307 injectors
Default

Originally Posted by pulltabmike

A little more info please....Mileage, oil pressure, last tuneup. Is the knock coming from the bottom of the motor or higher up? Could be a couple of reasons that do NOT require a rebuild or new motor.
PM Bohnett and see how far he is from you, he may be able to stop by and help you idenify the problem.
How do I find bohnett? Im on a moble app
Reply
Old Dec 27, 2011 | 10:19 AM
  #14  
Firestorm500's Avatar
CF Veteran
 
Joined: Apr 2009
Posts: 4,734
Likes: 12
Year: 2015, 2012
Model: Grand Cherokee (WK2)
Engine: 3.6L
Default

Originally Posted by xjsnake
Get rid of the fram filter. I know some people say they run them and are fine but I've used them in the past and my engine runs quieter now that I've switched brands. Go with Napa Gold (made by wix), wix, mopar, Mobil 1 or Motorcraft oil filters.
As I have said before, the salvage yard is full of vehicles with Fram oil filters.

The Orange Can Of Death.
Reply
Old Dec 27, 2011 | 02:52 PM
  #15  
cruiser54's Avatar
::CF Moderator::
 
Joined: Aug 2011
Posts: 43,971
Likes: 1,578
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Default

The old OCODs. More than likely the singlemost cause of bearing failure in our beloved 4.0s.

That said, it sounds like the OP may have loose TC to flexplate bolts since he has good oil pressure. Have we determined he has an auto trans?
Reply



All times are GMT -5. The time now is 04:36 PM.