What engine temperatures are you all running in the summer months? When ambient temp is 90s with 100% humidity my 1998 4 liter V8 runs about 195-205F (90-96C). If I hit 205 I turn off the a/c to bring the engine temp back down. I’m trying to figure out what’s normal for a D1 4.0 so I can calibrate whether my cooling system is healthy or needs some deeper preventative maintenance.

 

Your temps are totally normal. Recall the stock t-stat is 88 deg CELCIUS which is about 190 def F.

I use a severe duty fan clutch in the summer.. Hayden 2991. It roars like a garbage truck but helps keep things cool. Slow traffic is not a problem if I shift down to 1,2, or 3 and keep revs around 1,500 - 2,000. Full stop at traffic lights can be problematic.

 

I also have the Hayden 2991 thanks to WaltNYC's suggestion from a few years back. I can also confirm it sounds like a garbage truck. But summer temps are down. I switch back to stock fan in the winter.

 

Another suggesting regarding fan clutches.... put a bit of anti-seize on the water pump threads prior to installing the fan. When you change it back to a 'standard duty' clutch in the autumn, a simple tap on the wrench will have it spinning off in seconds. Otherwise they tend to corrode onto the water pump threads and are an unnecessary pain in the ***.

 

I completely agree with anti-seize on the fan to water pump threads.

 

These do sound like a garbage truck. Funny, I have people stare at the front end when I fun up to the store and leave it running.