Cooling Fixed! Bet you can't guess how...

An often overlooked cause of overheating is a worn/damaged cat or muffler. Where does the majority of the heat dissipate from? No, not the radiator, but out the exhaust. I thought I had a cooling problem licked. After replacing just about everything in the cooling system, except for the thermostat housing, I was still running too hot. I was ready to put up the white flag and sell the thing, but it finally dawned on me what the problem was – I had a damaged muffler.
I was so focused on the cooling system that I mentally blocked everything else out – including the boat sound coming out of my muffler. The baffles in my muffler were coming apart and blocking the air flow, which in turn caused the engine to overheat.
I can smack myself in the head for that one.

Now here’s the BIG question. Should I tell my wife that I blew 300+ on the cooling system that probably was not necessary? Or should I keep my mouth shut and let her think that I’m just the super-stud mechanic of her dreams. Hmmmm, I thought so… zip!

That's something I should look into but I figured that since I replaced the whole exhaust system less then 3 years ago that I shouldn't have to worry about it. I am getting a lot of heat from the floor area. Seems to be burning my feet when it's over 65 degrees outside. Just the other day the heat shield fell off the cat so that got me thinking.

I would just let the $300 got away........my new acronim (spelling ?) for Jeep is Justified Expence Every Payday.

Now all I have to do is figure out where this vib is coming from since I installed the SYE and DS.

Just think of the 300 as prevntive repairs. The problem of heat traveling back up the exaust is not new but i hand it to you I never thought of it causeing a cooling proble. I know one of the reasons that somay manifolds crack is the cat gets cloged and starts to back the heat up to the manifold and its tomuch for it to take. I know some may call me on this saying I'm full of it but i've seen it many times.

I found this thread in a search, so sorry for the late reply. I am having this constant problem of overheating in the summer, almost always on the trails. I have replaced everything as of last summer/fall, including belt, water pump, rad.(2 core), fan clutch, tstat, and tstat housing. I noticed a while back that the exhaust has a funny sound to it, like right under my feet, or the pass. feet. Maybe this is my problem? Great excuse to get a new cat back, right? Thanks

XJRockcrawler said:

I noticed a while back that the exhaust has a funny sound to it, like right under my feet, or the pass. feet. Maybe this is my problem? Great excuse to get a new cat back, right? Thanks

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If you have noises inder the passenger's feet - you'll prolly wanna add a cat to the cat-back!

Yeah, that sounds right. I've tried everythihng else I can think of to cure the heat problem, so why not. I found a Dynomax cat back and a cat on SUmmit for like $225 shipped, so I might go with that.

Just had a funny experience with exhaust. My wifes xj pipes got pressed up a bit the last time I had it on the lift, I guess, ;maybe the new trans mount lifted the pipes a bit, and on the way to north ga. the muffler rested against the drain plug right above it and conducted heat up to melt a round spot in the carpet. My wife kept complaining about the smell but I couldnt smell it. Its going to the exhaust shop soon.