Gutted cat now running hot?!

95Trooper

Well-Known Member
Joined
Mar 23, 2008
Location
WNC
I took my muffler and tailpipe off today and gutted the cat on my '98 Cherokee with the 4.0 today and now the Jeep is running hotter than normal and I smell coolant pretty bad. It would run 190-210 anywhere between there but never go above that and now now it's running 230*...what is causing this? I'm putting the muffler and tailpipe back on tomorrow so I hope that fixes it!
 
Once you put the muffler and pipe back on, you will probably run cooler. FYI If u live in an emissions county you won't pass with a gutted cat.
 
im putting my money on an unrelated issue. WTFab has run the race jeep without a cat for 3 races and not overheated
 
It's not overheating, it's just getting hotter than it ever has and it started after I drove the Jeep after I gutted the cat on it yesterday so I know that has to be it. I just really hope putting the rest of the exhaust on it fixes it.
 
BigClay said:
Once you put the muffler and pipe back on, you will probably run cooler. FYI If u live in an emissions county you won't pass with a gutted cat.
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There are ways around a gutted cat I know .
JeepinJarhead03 said:
having a gutted cat ahead of an O2 sensor can also cause the engine to lean out increasing heat as well
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The rear o2 sensor is the monitor for the cat it has nothing to do with fuel trim , opening up exhaust will not cause it to over heat , you need to check around the exhaust to see if you knocked a vacuum line loose or you may have a unrelated issue .I have seen a clogged cat cause a engine to over heat . Also have you checked the coolant level?
 
I'm with Hurley, I don't think the two issues have anything to do with each other, purely coincidence. Gutting a cat would never create a lean condition to make it run hot, if that was the case free flowing exhausts would create problems.
 
Checked my radiator yesterday and it was pretty low on coolant so I filled it up and drove it and it did fine. Never went above 210*...drove it to work this morning and it did fine..went on lunch to chic fil a and the temp started rising again and all i could smell was coolant..got back to work and pulled the dipstick out and the oil looks very milky. I'm guessing blown head gasket or cracked head? I've only had the Jeep for a month and it's always had a terrible miss and knock to it. I'm guessing this was the cause of it :(
 
95Trooper said:
Checked my radiator yesterday and it was pretty low on coolant so I filled it up and drove it and it did fine. Never went above 210*...drove it to work this morning and it did fine..went on lunch to chic fil a and the temp started rising again and all i could smell was coolant..got back to work and pulled the dipstick out and the oil looks very milky. I'm guessing blown head gasket or cracked head? I've only had the Jeep for a month and it's always had a terrible miss and knock to it. I'm guessing this was the cause of it :(
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Yup. Got nothing to do with the cat. Probably head or head gasket. Time to build a stroker out of it.:bounce2:
 
Is there any way I can tell whether it's the head or the head gasket without actually pulling the head? I don't have the money for all this. Someone at my work told me about liquid glass...has anyone ever used this and does it work?
 
95Trooper said:
Is there any way I can tell whether it's the head or the head gasket without actually pulling the head? I don't have the money for all this. Someone at my work told me about liquid glass...has anyone ever used this and does it work?
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Advance sells this stuff called White Angel or something like that, it has a money back guarantee. Talk to the guys at the commercial counter to get it. I have seen it work. You have to follow the instructions to the letter. Good Luck!
 
sorry bout the misfire on the cats - i shouldn't post when I'm floating on meds - it atleast made sense for some reason at the time:p

the 0630 head wasn't really known for cracking, over the years and 3 or 4 dozen hg jobs on 4.0's only one's that i ever had come back from the machine shopped cracked were the newer 0331's

a gasket new headbolts and machine shop work shouldn't cost ya over 100 bucks and a weekend - takes about as long to get the old gasket material off the block as it does to R/R

if you're gonna dump stuff in it trying to stick a cork in the leak, just remember to flush that mess out when you get the problem resolved
 
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