I know this has been talked about over and over and I know the correct design engine temperature is to be 210* with a 195* thermostat installed. I cannot convince our grandson that this is correct. He thinks that 210* +/- temperature that his jeep is running at is too high and wants to remove the 195* thermostat and replace it with 165* or no thermostat at all to make it run cooler. I know by putting a lower temperature thermostat 165* or no thermostat at all will not make it run cooler after it does reach temperature. How do I convince him that the 210* temperature is correct and anything lower than that will not be smart?
06 Wrangler TJ 4.0 engine temperatures
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mrchief
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I'm guessing here but I think he means that even a stroker motor is designed to run at the same engine temps as factory (at the end of the day, even a stroker is still an iron block, pushrod engine).
Your ECM reflash may have modified fuel maps and ignition timing, but even on a stroker you're still going to target ~195º (which yours seems to be doing) as an operating temperature to maximize cylinder pressures and combustion efficiency. My 408 stroker (about 500hp/555tq) runs between 203-208º before and after the stroker build and the fuel mapping and timing is optimized around those temperatures.
Hood vents or even no hood shouldn't appreciably affect operating temperatures if the cooling system is working and functioning as it should. In your instance, the hood vents reduce underhood temperatures (and IAT temperatures depending on your intake setup) but that rarely affects engine temps.
2005 Jeep Wrangler Unlimited, 4.0 engine, Auto Transmission. 3" JKS lift with BFG 33 x 12.5 x 15 tir
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I want to thank everyone for the input provided. But the grandson thinks he know more then everyone else and will not even read the information.
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That's OK, the older he gets the smarter you become in his eyes. I've seen that movie, it always ends the same.
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You have a 408 stroker in a Jeep? Wow! You just won, it's like dying with the most toys.
My brother has been building and racing cars for 36 years and he told me venting the hood wouldn't help. After spending major bucks on the radiator and a new clutch fan I was desperate. It was going close to 220 in traffic but would cool off when I started moving. I can take the engine apart and rebuild it myself but I can't tell you why it worked to make it run cooler.
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Well when the jeep runs like crap, get worse MPG, throw CEL codes.... You'll know where to start.....
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get him a set of spark plugs and a guide on how to read them for xmas, maybe after seeing the current ones covered in crap he may rethink having the engine always running rich.
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What's your secret to keeping your engine compartment so clean?
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Thank you! S100, Simple Green, and Tire Shine. I have had the engine out twice, though and replaced both fenders while I had it out. (The old ones had a couple of rust bubbles in the paint) I painted them as well as the inside of the hood, so I'm cheating a little on the 22 yrs old. I enjoy painting with a gravity gun and it has to be right. No runs and no orange peel. In other words, someway for whatever I can find I work on the Jeep an hour almost every day. The goal is to make it a 'brand new' 1999 TJ. Obviously I have obsessive issues! I'm including a pic of the rear fender well. You cannot make Jeep fender wells look good, so you make them disappear. I also painted the intake and header, Golen engines of course painted the block. I guess that's the long story, that's what happens when you ask an older guy about his toy.
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Mine looked close to that when I bought it and no amount of scrubbing at the car wash ever gets off the dirty haze of road grime. The same S100, simple green and tire shine is what you use on the inner fender wells too? Looks like it's still on a dealers lot!
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Thanks again! Like I said, I like to paint. The frame has absolutely no rust and I painted it. While I was painting the frame and undercarriage, I noticed the frame was built with slots in the sides to take some weight off. But it also lets water, mud and salt in with no way to get out. This may have been addressed in later models like yours. If not, find the lowest points on the frame and drill a 3/4" hole in the bottom, then flush it out now and then. S100 or Bike Brite will take all of that built up grime off of your firewall. Spray it on, agitate it very quickly with a horse hair type brush and spray it off. If you have a leaf blower or air compressor you can be finished in 10 minutes and it will look like you've worked on it all day.
One more thing, Area51. That's a good looking Jeep but I have one recommendation to really spruce it up. Buy some Forever Black bumper and trim reconditioner. It's not cheap, but it's an actual black dye for your end caps, etc. a rag with acetone will take it off the accidental paint coverage. It will make your fender flares look new also. Forever Black Bumper Trim 6 Oz. (NEW Improved Formula Larger Size) New | eBay $17.99. I do not sell it, EBay does. I just like and recommend products that work.
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I didn't like the high engine temp and under hood temps either so I installed 180 degree thermostats in both the TJ and the LJ and the engine temp gauge runs at 180 now with no engine codes or drivability issues.
I also have hood louvres and you can feel the heat venting out.
I can actually open the hood now and not worry about burning my hand on the hood prop rod or other engine bay parts.
Part of the issues with the 05 and 06 ECM's failing is related to incorporating the tranny ecm causing more internal heat and the other is the high under hood temps in general baking the ecm's from the outside.
Think what you want but lower engine and under hood temps are not a bad thing.
Is 160 too cold for the engine ? I don't think so but it might be for the ECM and emissions components but if it is swapping out a thermostat on a 4.0 is about as easy it gets so no big deal
Trial and error is a good learning tool
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I also have hood louvres and you can feel the heat venting out.
I can actually open the hood now and not worry about burning my hand on the hood prop rod or other engine bay parts.
Part of the issues with the 05 and 06 ECM's failing is related to incorporating the tranny ecm causing more internal heat and the other is the high under hood temps in general baking the ecm's from the outside.
Think what you want but lower engine and under hood temps are not a bad thing.
Is 160 too cold for the engine ? I don't think so but it might be for the ECM and emissions components but if it is swapping out a thermostat on a 4.0 is about as easy it gets so no big deal
Trial and error is a good learning tool
.
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This is one of those cases, where I would ask myself this... Engineers are not known to design without purpose, there must be a reason they selected the clutch-type fan and a thermostat set to remain closed until it reached 195 degrees. Would I, as a driveway DIY mechanic, have reason to believe I could do anything any better than the engineers?
Then I come back to the reality that I probably can't one-up the engineers that put this thing together and I decide to not tinker with something that is working the way it was intended.
I agree with the many others here on the fact that the computer will likely try to compensate for the cooler temperature of the block, if modified to run as cool as the kid wants, by adjusting fuel/air/spark in effort to run at what the computer sees as maximum "efficiency" or maximum "performance" (both terms make me chuckle when talking about a TJ). I would think that would be a domino effect that would not be all that great in the end result.
It is also true, that I believed my Dad was a complete idiot when I was a teenager. I was in my twenties before I fully began to realize how much he knew. A hell of a lot more than I ever knew, that is for sure!
As an adult, I finally began to really appreciate the little nuggets of wisdom he passed on to me. He has been gone over two years now. I was able to tell him how much I loved him and how much I rely on all the knowledge and life skills he gave me before he passed. I feel fortunate to have heard his messages of wisdom over the years, even if I wasn't actually listening at the time he gave me some of that advice as a youngster. He also taught me everything about mechanics. Thanks Dad!
So yes, the kid can not read any of these posts, do what he wants and can think you have know idea what you are talking about now. I hope that, someday, he is able to come around to appreciate all the knowledge you are trying to share with him.
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When I had Golen Engine Service rebuild my 4.0 to a 4.6 Stroker, I contacted a company who reprograms ECMs. He asked me everything being changed including compression, cam lift and duration, exhaust, throttle body, injectors, etc. He used to work for Chrysler and helped design the ECM for the TJ. He reprogrammed the computer to accommodate the changes including the header and straight through exhaust. He told me I would need a 180 degree thermostat and possibly an aluminum 4 core radiator. I got both and it was running at 215 degrees, higher in traffic. I cut out and louvered the hood. It now runs just above 180 regardless of traffic. It may not help everyone on here to let the heat out of a virtual oven under the hood, but it sure won't hurt.
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Agreed, since I added hood vents to my TJ the operating temp usually remains close to the thermo temp. If the OP's grandson wants to take a step in the right direction then he could add hood vents and stick with the OEM thermo.
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