Normally I’d assume so, but then it would read 0% idling in park. (At least, on a ScanGauge, which calls it throttle.)
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Just take the hood off and install a blower. I’m pretty sure I heard that fixes overheating issues per @racedinanger and @BradD …or maybe it was Roadkill that said that. Freiburger and Finnegan listen to AutoOffTopic, right?
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On your engine load question, I know mines an isuzu, but I’m at 2-3% load at idle without accessories. 25% does seem high for idle, but 50% doesn’t seem that bad for 70mph 
I have a 190* thermostat. Generally my engine runs 180-190 if I don’t have the AC on even in the crazy heat. With AC it’s under 200 until I got an incline, then it will climb until I turn the AC off or get up the hill. My mechanical fan set up was hoyle at slow speed, fine on the highway, but this electric fan set up is the opposite, great around town but not quite enough for getting up to Flagstaff.
Hope something in there helps
I’m told 20% load at idle is likely due to a combination of the automatic transmission and alternator—but I still feel like it should be a bit lower. In any case, I found a better scanner app; cleverly enough called Car Scanner. Go figure.
The below is after idling for five minutes in a shady parking spot with the AC running. TPS is definitely doing something odd. I wasn’t even touching the pedal. And, with the engine off (but the key in the ON position), I got a range of 0-89% max.
I tried slowly depressing the throttle to look for any flat spots en route to WOT. Didn’t see anything.
In any case, I’ve got a new Aisin thermostat and two bottles of Prestone flush/clean coming from Amazon. I’ll have to check with Josh on the radiator, but assuming I have all the parts together, I think I’ll do it up right next weekend so I can install all new everything-but-the-water-pump-and-heater-core in a single week.
Will report back soon.
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So, get this: I’ve checked the coolant level three different times since doing the refill by the book (FSM). The radiator and overflow have been properly full each time.
We decided to try making a run up the hill to take a hike. I was nervous, and I took it real easy all the way there. We did 50 uphill in a 65 zone. We got passed–a lot. But we never got above 204.8°.
Of course, it was 10-15°F cooler when we were on the hills and we weren’t loaded for bear, but still. We got back on the 17 southbound and immediately did a 20-60mph, uphill blast out of Camp Verde–with the AC on.
(Check that crazy TPS action under cruise control against calculated engine load up top. Weird, right?)
I left the OD off and held speed almost all the way. The final crest in sight, and seeing the speedo drop below 50mph in third, I grabbed second and punched it. Crested the hill at 70, touching 210°F for a couple seconds before quickly settling back down to 195-203°F for the rest of the trip.
Fezzik did great. And when I think about a flush and a new radiator later this week, ooo-wee. It’s gonna be real nice. Think I might replace the TPS by itself and see if that does anything on its own.
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225,149
- general update
Picture from the above mentioned trip up the hill.
Fuel gauge had me eager to fill up, since I did 200 miles on the first half of the tank. Just filled the tank.
320.6 miles on this one. That’s 16.9mpg (13.9l/100km). It’s a new best for ol’ Fez! I’ve pretty much been getting 13.6mpg (17.3l/100km).
Wo0t!
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That’s really good MPG’s!!
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Lots of stuff to read through here… And I’m just getting caught up.
I think the info put out by 90s OBD is helpful but it seems to me to be often inconsistent… That’s opinion grounded in experience but no real facts. 
In terms of cooling…trapped air was also my guess as I got partway through your recent trials. I’ve been there so many times until I finally started evacuating it properly. It’s still sometimes tricky to get it out.
200° plus or minus a few degrees is about dead on from what I’ve seen. But ambient temps of 107°? Holy crap man. How do you live?
Maybe I missed it but what’s the status of your fan clutch? Shroud still in place? Sounds like your cooling is now under control but I’m just covering all bases.
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Good question. Fan clutch appears good. It’s tight when the engine is hot. Fan shroud was missing a bolt in the upper passenger corner, which I promptly replaced.
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- oil change
- proper coolant flush
After changing the oil, I drained the brown pond water from the radiator and overflow bottle. Then I removed the lower radiator hose, thermostat, and upper radiator hose.
When I went to set the lower hose down next to the truck, all kinds of brown, crusty stuff fell out.
That’s not good.
And yet, it is–because it’s exactly the sort of thing that could restrict coolant flow through the thermostat. At least, that’s my theory.
I stuck the garden hose into the top of the radiator and let it run until the water coming out the bottom ran clear. Then I stuck it in the upper water neck until the water coming out of the thermostat housing ran clear. Then I hooked up a high pressure nozzle and sprayed through the radiator, oil, and trans cooler fins until that water ran clear.
Finally, I reinstalled the thermostat housing (without the thermostat), both radiator hoses, and filled the system with a bottle of Prestone cooling system flush and a little over a gallon on distilled water.
Let Fezzik idle with the heater on for 20 minutes. No leaks. Temp got to 160°. Went for a 20 minute drive with the heater on (in 106°). Temp barely made it past 183°.
Now the plan is to drain and refill with another bottle of flushing agent and distilled water Sunday, then drain and refill a couple times Tuesday-Wednesday until the water runs clear, then replace the hoses, thermostat, and cap, and fill with 50/50 mix by next weekend.
Updates to follow. Thanks!
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Got a serviceable radiator core! I was discussing temperature data on Facebook (more on that in a moment) and local good guy Ryan mentioned he had a spare I could use. I mentioned it to Josh. He presumably spoke with Ryan. And the core was dropped off at the shop Monday. Fingers crossed it’s here for the weekend. When it’s supposed to be 115°F/46°C.
Gen 2.5 standard operating temperatures. Nobody really knows, I guess.
Here’s what I’ve found after searching a dozen different keywords around the world:
- Factory thermostat starts opening at 190°F, then fully open by 212°F. So I guess 212° is okay.
- Temp gauge in the cluster doesn’t move above normal until 240°F?!?! Not sure about that.
- “Modern” cars are known to run as hot as 240-250°F?!?!?! #shenanigans
It would seem I’ve got some testing to do. Got a pair of cheap, dial thermometers inbound from Amazonia. I might just setup my Coleman stove on the intake manifold, drop the gauge sensor in a pot of water with a thermometer, and see how hot it has to get before the gauge moves.
Word on the street is that, once that gauge starts moving, you’ve got about a minute to do something about it. Figure I’d like to know when my dummy gauge is going to call me a dummy.
Beyond that, I’ve got my second Prestone flush in there right now without a tstat. I’ve adjusted my coolant redline to 220° in light of the 212° detail. And I’ve seen as high as 210° without a tstat in place while idling in drive with the AC cranked when it’s 111°F/44°C.
The plan is to drain and flush tonight with distilled water, then refill with distilled and a bottle of CLR. Assuming I have the new radiator by Friday, I can drain and refill until it runs clear before installing the new radiator, tstat, hoses, cap, and 50/50 coolant mix.
That’s the plan, anyway. Fingers crossed.
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That doesn’t really surprise me. Granted, I’d expect a smaller six to run a bit cooler on average, but I’d also expect it to handle upwards of 220 without issue. FWIW, under load…trailer uphill on a hot day, 220+ is fairly common in the aluminium V8 in the D2 (with a rapid recovery to sub-200 on level ground).
The glorified idiot light they pass for a gauge in some cars is also why I started running a ScanGauge permanently. Cold, Normal, and Toast are simply not sufficient indicators, I like being able to see the temps in real time and adjust driving style as needed.
Are you running Water Wetter in the final fill? Tried it on a recommendation last time I flushed coolant and was surprised how well it worked. It didn’t do too much for my max operating temperatures, but recovery once the load is off is much quicker.
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Have you ever tried thermocure? I’ve heard enough about it that next time I service the pajevo cooling system I’m gonna give it a whirl.
I don’t miss towing a decent sized trailer in the summer with a small Turbo Diesel. Even as I miss the fuel economy, I don’t miss spraying the intercooler at the bottom of a hill before scrutinizing the EGT guage the whole way up.
If you still consider a Delica L300 on occasion @Brian, just think about how well it would do in 100+ temps. 
Yeah. I hear ya. There’s a very good chance my trip-ending overheating issues a few weeks back were due to a little bit of air and a little bit of crud in an otherwise healthy system. That said, cooling systems are pretty damn critical. It’s in my best interest to get it sorted. Knowing WTF it’s SUPPOSED to be doing is just good insurance at this point.
Agreed, but I think my supplemental gauge installing days are behind me. I’d prefer a more accurate solution than the instrument panel dummy gauge (especially now that I know how dumb it may truly be), but entropy feeds on complexity, imo.
If I know the AC thermal cutoff happens at, say, 230°F…
And I know the dummy gauge starts moving at 240°F…
And I know my truck will gets to 225°F at 85mph, uphill, fully loaded, with the AC on, in 115°F…
And I know my cooling system is 100% tip-top; no leaks, no air, no crud…
I’d say I feel pretty damn confident about things in general. It’s the not knowing that gets ya, right?
Assuming I get the temps sorted, I’m gonna be actively shopping for gears. 4.90s and stock tires should be a hoot.
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The only snake oil I believe in! I use it in every car!
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I’m not running water wetter yet, but will once it all goes back together. I think I have actual water wetter, though I’m told a capful of liquid dish soap has the same effect.
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Oh man, cooling system issues are fun. Draining, flushing, draining, and flushing over and over. Usually, do to someone along the way having used tap water instead of distilled. This tool is a good investment if you want to streamline your cooling system filling procedure. Pulls the system into a vacuum so there’s virtually no possibility of air getting in the system. A must for us BMW folks. It also checks for leaks because if it doesn’t hold vacuum you know you have a small leak somewhere. Also, I agree, water wetter is good stuff!
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This makes me think the primary action of water wetter is as a surfactant, which would make sense, though given the oily nature of ethylene glycol I would think dish soap is not the right choice due to the other ingredients.
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I’m very interested in that… I have a vacuum pump, might have to rig my own version up…
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I bet you could build something nearly identical without to much hassle. I bet McMaster Carr carries all the pieces you’d need, they have everything.
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