Motor questions guys...Facts not opinions..
Honorary Moderator
Joined: Mar 2010
Posts: 8,135
Likes: 16
From: Gilbert AZ/Las Cruces NM
Year: 1996
Model: Cherokee
Engine: 4.0 upgraded
You asked for facts so....
Just so you know you need to run a 195* tstat.
lowering the T-Stat hurts the motor and puts more wear on the engine.
the reason? the 4.0 is designed to run at 210* - fact
not allowing the motor to fully warm up will cause more damage - fact
why? the most damage is done to the engine between start up and running temp, if it takes longer to reach running temp you are doing more damage - fact
having a lower engine temp than designed will not allow the piston seals to seal completely causing a loss in power (altho it can be small you do lose power) - fact
the loss in power will caused a drop in MPG - fact.
run a 195* as designed as you NEED the engine to run at a steady 210* - fact
Just so you know you need to run a 195* tstat.
lowering the T-Stat hurts the motor and puts more wear on the engine.
the reason? the 4.0 is designed to run at 210* - fact
not allowing the motor to fully warm up will cause more damage - fact
why? the most damage is done to the engine between start up and running temp, if it takes longer to reach running temp you are doing more damage - fact
having a lower engine temp than designed will not allow the piston seals to seal completely causing a loss in power (altho it can be small you do lose power) - fact
the loss in power will caused a drop in MPG - fact.
run a 195* as designed as you NEED the engine to run at a steady 210* - fact
CF Veteran
Joined: Apr 2009
Posts: 4,734
Likes: 12
Year: 2015, 2012
Model: Grand Cherokee (WK2)
Engine: 3.6L
96_XJ, thanks for expanding my reference to too cold a thermostat in my earlier post, near the top of this thread.
The OP is nineteen and says he knows a lot about engines.
I bet he doesn't know as much as the engineers that designed these things.
The OP is nineteen and says he knows a lot about engines.
I bet he doesn't know as much as the engineers that designed these things.

So 210* is normal..I thought it was a little high and was the reason I said something about a lower t-stat!
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,578
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Umm cams can be swapped from any 1975+ AMC/jeep straight six..Fairly sure on that as well as its been posted many times! Modfications maybe required but it is possible!
Swapping in the cam from the 96-01 wouldn't be an issue either..and since I'm doing a complete rebuild, if there was a bearing size issue...I'd be taken care of! But theres not so its not an issue!
And I have a very damn good clue about what I'm doing, thats why I'm doing it!
I'll have my EGR bungs welded shut today and see what happens! I bet my jeep runs just fine
Swapping in the cam from the 96-01 wouldn't be an issue either..and since I'm doing a complete rebuild, if there was a bearing size issue...I'd be taken care of! But theres not so its not an issue!
And I have a very damn good clue about what I'm doing, thats why I'm doing it!
I'll have my EGR bungs welded shut today and see what happens! I bet my jeep runs just fine

Honorary Moderator
Joined: Mar 2010
Posts: 8,135
Likes: 16
From: Gilbert AZ/Las Cruces NM
Year: 1996
Model: Cherokee
Engine: 4.0 upgraded
You are correct. 19 and no don't know as much as those engineers! As far as being engine savy...I've got 8 rebuilds under my belt including a IS300 thats making 701whp right now
So 210* is normal..I thought it was a little high and was the reason I said something about a lower t-stat!

So 210* is normal..I thought it was a little high and was the reason I said something about a lower t-stat!
the factory gauge is not as reliable as a nice aftermarket
I get minor blow by..almost none so I don't think thats the issue. My manifold is caked with exhaust soot..smells like burnt fuel! Its got to bethe EGR. No oil to be see in the manifold, minor deposits on the valves!
Now is it the EGR's fault? Probably not...somethings got to be causing it do to this...probably because my 02 wasn't working and numerous other issues with the jeep. Thats all taken care of, and EGR is now deleted..well plugged for now. Will be deleted on the new motor!
CF Veteran
Joined: Apr 2009
Posts: 4,734
Likes: 12
Year: 2015, 2012
Model: Grand Cherokee (WK2)
Engine: 3.6L
What is the fine for disabling or defeating a factory/government mandated emission control?
Is it $10,000.00 or $100,000.00? And/or up to a year in jail?
2 horsepower and a little less carbon deposit doesn't seem worth it to me.
But what do I know? I'm only 55. Smarter than a 19-year old?
Besides, what right do you have to foul the air I and everyone else breathe?
Is it $10,000.00 or $100,000.00? And/or up to a year in jail?
2 horsepower and a little less carbon deposit doesn't seem worth it to me.
But what do I know? I'm only 55. Smarter than a 19-year old?
Besides, what right do you have to foul the air I and everyone else breathe?
If you didn't see what I wrote, I run a cat still. Actually its brand new..litterally a week old..Since I see where this is going. I say good day and live your life how you choose. I'm not here to argue!
Removing my EGR wouldn't add any extra polutants to the air as long as my cat is doing its job! And seeing how I passed emissions already, ya I'm doing my part to stay clean
Oh and I even run the new recyl. oil from autozone just to help do my part! Thanks though.
Removing my EGR wouldn't add any extra polutants to the air as long as my cat is doing its job! And seeing how I passed emissions already, ya I'm doing my part to stay clean

Oh and I even run the new recyl. oil from autozone just to help do my part! Thanks though.
Senior Member
Joined: Jan 2011
Posts: 689
Likes: 2
From: Upstate N.Y
Year: 2000.1999,1996
Model: Cherokee
Engine: 4.0
Umm cams can be swapped from any 1975+ AMC/jeep straight six..Fairly sure on that as well as its been posted many times! Modfications maybe required but it is possible!
Swapping in the cam from the 96-01 wouldn't be an issue either..and since I'm doing a complete rebuild, if there was a bearing size issue...I'd be taken care of! But theres not so its not an issue!
And I have a very damn good clue about what I'm doing, thats why I'm doing it!
I'll have my EGR bungs welded shut today and see what happens! I bet my jeep runs just fine
Swapping in the cam from the 96-01 wouldn't be an issue either..and since I'm doing a complete rebuild, if there was a bearing size issue...I'd be taken care of! But theres not so its not an issue!
And I have a very damn good clue about what I'm doing, thats why I'm doing it!
I'll have my EGR bungs welded shut today and see what happens! I bet my jeep runs just fine

CF Veteran
Joined: Apr 2009
Posts: 4,734
Likes: 12
Year: 2015, 2012
Model: Grand Cherokee (WK2)
Engine: 3.6L
If you didn't see what I wrote, I run a cat still. Actually its brand new..litterally a week old..Since I see where this is going. I say good day and live your life how you choose. I'm not here to argue!
Removing my EGR wouldn't add any extra polutants to the air as long as my cat is doing its job! And seeing how I passed emissions already, ya I'm doing my part to stay clean
Oh and I even run the new recyl. oil from autozone just to help do my part! Thanks though.
Removing my EGR wouldn't add any extra polutants to the air as long as my cat is doing its job! And seeing how I passed emissions already, ya I'm doing my part to stay clean

Oh and I even run the new recyl. oil from autozone just to help do my part! Thanks though.
If you didn't see what someone else wrote, lack of EGR contributes to high NOx.
NOx is a major component of smog.
Had any smog in California before?
*cough* *cough*
Honorary Moderator
Joined: Mar 2010
Posts: 8,135
Likes: 16
From: Gilbert AZ/Las Cruces NM
Year: 1996
Model: Cherokee
Engine: 4.0 upgraded



