This in info that has been pulled from many different conversations here over the years, but gives you an idea on what to be aware of...the most important is regular FLUID maintenance, and utilizing Oil & Fuel additives to protect your engine
(EX: Fuel additive: Amsoil Diesel Injector Clean / Cetane Boost / and Howes 103060 Treat-Diesel conditioner with each fill-up. For Oil: I alternate every other change between Archoil & Turbo Maxx)
FLUID CHANGE INTERVAL for DIESEL:
Engine Oil: every 5,000 Miles
Transmission: Every 20,000 miles
ENGINE COOLANT CHANGE: Every 15,000 miles
Transfer Case: Every 20,000 miles
Differential fluid: Every 30,000 miles
If you have 4x4: Wheel Bearings & Hubs greased every 30,000 miles
Power Steering & Brake Fluid: every 50,000 miles
Have the AC System charged every 2 years
Have the Van “lubed” every 2 years
Have an Alignment done every year or two (depending on how much off-pavement driving you do)
IF SPORTSMOBILE: Follow the alignment specs in the Owner’s manual – if you don’t inform the shop of these special spec’s then your driving characteristic will be completely off.
DIESEL ENGINE TEMPS
***It's really going to vary between vans ( Weight, Gearing, Tire size), but here goes anyway:
• ECT: 200-225F
• EOT: 210-230F
• TFT: 200-240F (stock cooler)
• TFT: 150-180F (Tru-Cool 40k cooler)
• It's really a range depending on ambient temperature, hills, type of driving, and what mods you have. If your stock, as long as your EOT-ECT spread is less than 15F your golden. Don't get too worried if your ECT is 220-230F. Diesels like to run hot and the vans run hotter than the trucks...Biggest issue is the tranny getting hot. The above portal thread is a good read.
Assuming a stock tune and and coolant thermostat.
• Engine Coolant Temp (EOT)
• 180* Engine Map is in various warm up or EGR regimes. Explains why you feel more power and trans shifts at lower RPMs above 180*
• Around 212* thermostat thinks about opening.
• 218* thermostat opens fully.
• Fan will cycle noticeably above 216* ish BUT depends of other temps, measured load, and A/C pressures.
• Fan will fully engage and not cycle above 226*
• These temps seem to vary a little depending on van, so don't become mindful of hot coolant until you're seeing sustained ECT above 228*. One thing to be aware of when running hard is that it cools down quickly once over the pass, etc. Hottest I've seen 230* for a few minutes.
• Engine Oil Temp (EOT) should be below or 6-10* above ECT / 12*or more above ECT I would start to consider a restricted oil cooler.
• Rumor has it that a EOT above 236* will shut the motor down.
• If your trans has a thermostat it will open at 160*. Some 5r110's don't have them. You will get a wide array of what is ideal trans temps and where to measure the temps from. My opinion is sustained I'm comfortable with under 200*. My trans (John Wood) with larger cooler and fan lives most of it's life between 164* and 180*. Highest I've seen with this setup is 192*.
Now - after reading all this;
I have a heavy Van (challenges 12k lbs, 4:56 gearing, and 35" MT Tires) so the engine works harder to move that weight. I was also concerned about higher temps on steep grades, slower 4x4 crawls, and have found the following upgrades helped tremendously to manage all my temps;
***Mishimoto aluminum Radiator
***Mishimoto Low Temp Thermostat (The stock thermostat essentially restricts your coolant until your engine temp gets to about 216 - The Mishimoto will fully open much earlier, this helps max circulation which actually allows the temps to run cooler)
***Derale 15870 Hyper-Cool Extreme Trans Cooler w/manual dash over-ride switch
***5-Star Tune (I use the 50hp tune), and I had them add a program that would kick the fan on earlier than what the OEM was programed to do. Believe they adjusted this so my fan now engages about 6 or 7 degrees earlier, but because of these mod's I've made the fan doesn't come on very often...just when I start stressing the engine, and that's exactly when I want/need it most anyway).
Here is my history before/after these mods For comparison:
HWY Travel: Coolant = 214-216 Steep Grades: 222-230 NOW: 198 -210
HWY Travel: Oil = 218-222 Steep Grades: 225 -231 NOW: 202 -220
HWY Travel: Trans = 185 - 190 Steep Grades: 200 - 210 NOW: 170-182
EDIT: Once I installed the Derale Trans cooler (it was installed so fluid flows through it before it reaches the radiator) the Coolant temps dropped about 3-4 degree's - which in turn helps Oil temps.
You do want to keep EGT's below 1100 as much as possible, and if you get into the 1200 range, it should be for a very short period of time (under 1 minute from what was explained to me). Best way to lower EGT's is to drive your RPM's up a bit (down shifting accomplishes this)
Hope this provided some insight.