You may want to take your fan/fan shroud out its all one piece and clean the radiator good, it comes out easy, two bolts and then lift up, you can even keep the overflow tank attatched. I did when I took mine out to replace the radiator.

see this thread
https://www.jk-forum.com/forums/show...ht=overheating

the griffin radiator has 25% more cooling capacity

 

Ya know, I actually tried that the other day. I removed the two bolts at the top and it didn't really want to come out. I tried pulling straight up, but didn't want to break anything. I tried jiggling it too. No luck. I stopped trying because I didn't want to snap something off.
Did yours just lift out without resistance or did you have to tug pretty hard?

 

Go to another dealer

 

What the dealer is telling you IMO is bullsh*t, and although you would loose some power, this should not cause a problem to the extent of overheating. On the other hand however, the added weight and friction of larger tires could be a contributing factor in overheating. As stated, this alone should not be the cause of overheating a fairly new vehicle. Although these larger tires would put more stress, on the system with stock gearing, there could be other factors at work that when coupled together could cause a problem. For instance previously adding weight by replacing stock bumpers with aftermarket that weigh 5 times as much, the new tires could then be the straw that broke the camels back.
The first phase of troubleshooting is to ask, "what changed". Look back at the the first time this problem occured. Now what happened just prior to that?
I do not know the circimstances, but perhaps you were in the mud which may have caked the radiator coils, causing the cooling system to be less effective. If that is the case then look there. If however you have not added any weight other than the tires, since a small lift shoud not cause any cooling system issues, then the new tires should well be looked at as the cause.
I have not had any issues with our JK auto, even after the added weight of an AEV front bumper and a 3/4" spacer to re-level. Our JK came stock with 4.10's and we have not increased tire size from the stock 245/75/16
I can say however that after adding an aftermarket front ARB with winch, rear with tire carrier, underbody skid plates and 33" tires on my 94XJ 5spd, even though I re-geared to 4.10's I did notice that it was running hotter, to the point that I installed a new 3 core radiator. This in fact fixed the overheating problem.
Aftermarket components are things we like to add to personalize our Jeeps, and we sometimes do this without thinking about the long run. Most dealers on the other hand are used to seeing stock vehicles come in for work. When there is a problem they see the things that stick out, and aftermarket wheels with larger tires do stick out. Rather then running to a dealer for a problem, unless of course the vehicle is under warranty and bone stock, one should have their shit togegher, (for lack of better grammer), Assess problems with your Jeep, and try to repair yourself, rather than throwing a bunch of mods into it then when a problem arises run to the dealer for the answer, and cry the blues when the answer he gives you is not the one you want to hear.
I'm not attacking you personnaly, but rather just putting this out there, because from what you posted I have no idea what the cause of your overheating problem is. I would have to agree with what the dealer stated though, just because of your posting info. With the tires you have installed, 4.10's would be a good choice for gearing, maybe even 4.56.

 

Nope didnt have to tug hard, the bottom of the fan shroud just sits into 2 v-groves, maybe lean it back towards the engine a little bit, if you look at this pic you can see the 2 v-grove bracket things on each side of the rad. Mr T cleaned his off and stopped overheating also. If you cant get it I would definately take it to another dealer.

 

As a non-mechanic, I don't have the expertise to assess the problem with my Jeep, much less fix it on my own. Believe me, if I were, I wouldn't go to the dealer (who should know his product?). Also, I'm not taking it personnaly or personally as I didn't run anywhere or cry...
but I'm about to now.

I love this forum for the depth of knowledge and advise it offers to everyone, especially for those of us who don't know our heads from a hole in the ground. We can talk in candor with experience Jeepers without the queasy feeling you get when only talking to a dealer, or a place like 4WheelParts. Hey, I'll do whatever it takes to make my Jeep run properly, as I just want to have as much fun as possible with it without continually breaking it. Or maybe THAT's a Jeep thing!

 

Sounds like you are attacking, if not him atleast others who don't know how to fix problems with their vehicles. Sorry not everyone knows how to fix or trouble shoot their vehicle like you do.

 

Thank, I'll try again when I get it back. Not sure I'll have time tonight. If this is the actual cause of the problem, I'll be very excited because cleaning is one of the things I don't need a professional for!!

Thanks again to everyone for their advice and ideas.

 

Maybe thats why the auto transmissions are overheating and catching on fire because like I said every auto I've seen is routed through the radiator also.

 

yep that has been the speculation that its the trans overheating and flowing out the dipstick and onto the cat/exhaust.

I never heard of a vehicle that didnt go through the radiator also.