heat from pre-cats?
Thread Starter
Senior Member
Joined: Aug 2009
Posts: 914
Likes: 14
From: north carolina
Year: 2000
Model: Cherokee
Engine: 4.0
heat from pre-cats?
I know that XJ's run hot and many people have installed vents in the hood to let the heat out and have done the e-fan switch.....Mine just seems to be super hot under the hood. When I shut it off it's so hot I can barely open the hood because the latch is burning hot. I have a 2000. If the pre-cats are starting to go, I'm assuming they will cause more heat. Is there a way to test the pre cats? If I had a back pressure test done would that show anything? thanks
Junior Member
Joined: Aug 2011
Posts: 31
Likes: 0
From: nj
Year: 96
Model: Cherokee
Engine: 4.0
back pressure test will tell you if your cats are clogged. but since you do not have a complaint about performance, im gonna guess they more than likely are not clogged. and if my chemical reaction knowledge is correct, a cat that is functioning properly will be hotter than a bad cat because it needs to reach a very high temp to properly burn off the undesired post combustion chemicals.
Thread Starter
Senior Member
Joined: Aug 2009
Posts: 914
Likes: 14
From: north carolina
Year: 2000
Model: Cherokee
Engine: 4.0
it runs fine. i have no complaints. I thought if it was clogged, or even a partial clog, it would get hotter than normal. I know it has to be hot to burn off undesireable exhaust soot and particles, it just seems crazy that I need gloves to open the hood becaue the latch is burning hot.
Junior Member
Joined: Aug 2011
Posts: 31
Likes: 0
From: nj
Year: 96
Model: Cherokee
Engine: 4.0
i cant see how your engine bay would suddenly get screaming hot without the motor overheating or something. i mean mine gets a bit warm to the touch after a long ride but never to the point that i need gloves.
Thread Starter
Senior Member
Joined: Aug 2009
Posts: 914
Likes: 14
From: north carolina
Year: 2000
Model: Cherokee
Engine: 4.0
I don't think it happened suddenly, but I'm not sure. I bought it back in 2003, used it as a daily driver for 2 years. Since 2005 it's been used sparingly; maybe 3k a year at the most. One year I only drove it 800 miles. Lately I've been driving it more, so I've noticed it more. So it's hard for me to say if it was a sudden change or not.
It doesn't overheat. It runs right under 210. I just changed the coolant/thermostat/waterpump. It just seems the engine compartment is crazy hot. I want to put one of those oven thermometers in the and see how hot it is.
It doesn't overheat. It runs right under 210. I just changed the coolant/thermostat/waterpump. It just seems the engine compartment is crazy hot. I want to put one of those oven thermometers in the and see how hot it is.
Last edited by mikesignal; Apr 14, 2013 at 12:50 PM.
Herp Derp Jerp
Joined: Nov 2011
Posts: 18,251
Likes: 17
From: Parham, ON
Year: 1999
Model: Cherokee
Engine: 4.0L OBD-II
I checked the 2000 FSM for some possible specifications, instead I found this:
I could be wrong of course, but I'm inferring that the mini-cats may not be dense enough to clog like the big ones. I've heard them referred to as just a platinum screen.
Any signs of running rich?
California emissions vehicles incorporate two mini catalytic converters into the exhaust system. These catalytic converters are made of stainless steel designed to operate at extremely high temperatures.
The stainless steel catalytic converter body is designed to last the life of the vehicle. Excessive heat can result in bulging or other distortion, but exces-sive heat will not be the fault of the converter. If unburned fuel enters the converter, overheating may
occur. If a converter is heat-damaged, correct the cause of the damage at the same time the converter is replaced. Also, inspect all other components of the exhaust system for heat damage.
The stainless steel catalytic converter body is designed to last the life of the vehicle. Excessive heat can result in bulging or other distortion, but exces-sive heat will not be the fault of the converter. If unburned fuel enters the converter, overheating may
occur. If a converter is heat-damaged, correct the cause of the damage at the same time the converter is replaced. Also, inspect all other components of the exhaust system for heat damage.
Any signs of running rich?
Thread Starter
Senior Member
Joined: Aug 2009
Posts: 914
Likes: 14
From: north carolina
Year: 2000
Model: Cherokee
Engine: 4.0
gas mileage is typical, 15 city 19 hwy. I don't think it's running rich. I'm going to put a thermometer under the hood and check temps tomorrow.
I took a look at them today. They still look good on the outside. You can still tell they are stainless.
I took a look at them today. They still look good on the outside. You can still tell they are stainless.
Thread
Thread Starter
Forum
Replies
Last Post
ROCKRIDGE 4WD
Vendor Showcase
1
Dec 22, 2018 09:49 AM
LittleRed94
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
5
Oct 6, 2015 08:09 PM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)