I see no reason to! OEM is what systems is designed for. We go down a rabbit hole, as we deviate from stock.
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I see no reason to! OEM is what systems is designed for. We go down a rabbit hole, as we deviate from stock.
What year do you have?The correct OEM temp for the thermostat to open on a 100 series land cruiser is 195F. Once the engine coolant reaches the operating temperature, usually around 195 degrees, the valve in the thermostat will open and close as you drive in order to maintain a coolant temperature typically between 195 to 225 degrees Fahrenheit. If you are running an engine that runs under 195F at operating temperature then you are not operating the engine at temp that it was design to run. Many people switch the 195F to a 185F thermostat which is not the one intended for the 100 series land cruiser.
I'll add: Whereas deviating from stock design, is a rabbit hole best to avoid. That is, in a pure stock rig.
Testing the ECT sending unit is a good idea. The FSM does have a procedure for this. But a simple test, although can be misleading. Is to shoot a temp gun near the sending unit. Compare that to ECT tech stream read out. I shoot my IR temp gun, just downstream of thermostat. I also try to shoot on front water by joint near sending unit. I'm usually with a few degrees of tech stream reading.Is there any reason to replace the Coolant temperature sensor as part of PM? I was trying to link a thread where a guy replaced because a code was thrown and his old one looked really bad.
Yeah I've been looking for what factory consider normal operating temp range. I do suspect we've variation in the years and milage of engine. But I'm sure hitting 197F or higher in normal driving, is indication of system issues that needs correcting. 06-07 I've biggest question on as to what is "normal" from factory. But I do have logs indicating that 187F (high I hit) is baseline in the 06-07. That with full metal skids and belly pan, the temps jump up to ~192F average (w/o heavy bumpers). That was Merlot 07LC w/63K miles. In it, I did hit in the 201F when I ran it up (high RPM run) w/bellypan, trying to heat CATS. So was not a good ECT test. It also was without doing a full coolant system service. But just driving around with the full metal skids and belly pan, it did run hotter.The guy was wrong about the thermostat, but the other part about asking a toyota tech, there is merit in that.
There is a range of temps that are normal.
There is deviation in the coolant temp sender.
There are 7 degrees of variance in the thermostat opening.
There is a number of some degrees of variance in the valve lift at 203 degrees. Only a specified opening of 10mm of travel at 203 degrees. IT could be less travel at 203 degrees, which is bad, or more than 10mm of travel at 203 degrees, which is good. It also needs to close at 104 degrees.
The fsm does not state a normal operating coolant temp. (that I know of) You can only infer from the opening and closing of the thermostat that it is related to normal coolant temp operating range.
You can take into account the AC compressor shut down temp and the idiot lights turn on characteristics on the combo meter.
Changes over facelift years- exhaust and intake designs, evap systems etc will all affect coolant temp, and oil temp. They have changed to higher and higher temps over the decades.
New part change outs may keep coolant temps lower to a level that YOU think is correct. Educate yourself.
Chase whatever temp you like but if it's in the operating range of the thermostat, and a certain amount above and below, it's normal.
Don't rely on my opinion, do your homework.
I'll add: Whereas deviating from stock design, is a rabbit hole best to avoid. That is, in a pure stock rig.
That said:
In a build rig we should be able to get temps back factory normal. Or rather engine running at factory spec. But with added weight, large mass of metal absorbing than radiating heat and blocking air flow. Some mods may be called for, in certain parts of the globe.
@gungriffin does have a lower temp thermostat. His TRD package requires it apparently. He has a heavy built rig, and has stated he's not seen the boil fuel issue. He runs his rig all over Colorado in all season.
This is further andodate evidence that engine heat is our primary cause of fuel boiling. Fuel blend is secondary. Failure of EVAP component, is last and should give us a DTC (code).
For a 99 that is definitely running hot.So I just thought I'd update anyone who was following my search of lowering my temps. Did a 2000 mile roundtrip, AC on, outside temps between 78-98. Cruising at GPS 78 mph, temps fluctuated from a low of 195 to 203. Couple traffic times, temps went as high as 205. Stayed in that range well. This seems OK? Although many people report temps of 185-190 cruising. Not sure why. New stat I put in was a 82C.
For a 99 that is definitely running hot.
ECT 184-187f (98-02)
I just did a short 15 mile city asphalt st and concrete HWY OAT 97-98 Sunny 3PM in mile high city hot and dry. IAT running 106 to 115f. ECT 184-187f, A/C off. Touched on 189f for 3 seconds then back down to 187F, while parked and idling to email the log data.
I've logged a few well tuned pure stock w/coolant systems serviced 98-02. They're consistently run 184-187 A/C off. A/C on, 1-2 f higher if that.
ECT 187-190 (05LC heavy), A/C on 190-194F.
05LC w224K miles. Log yesterday after coolant system service (old fan clutch). Had to double wash radiators and still could see crud around edges. No belly pan of skids. Steel bumpers, winch, tire rack swing, ladder, rack, sildders, OME lifted. Tundra engine of unknow miles in 100 series.
Not knowing your year, stock or built. Makes difficult to say if that is what your best ECT can get down to. Adding that info to the signture line would be helpful.In an earlier post I shared that during my 600 miles road trip where OAT temps ranged from 95-100 I only ever saw 203 when doing 75 uphill over a pass, and even then it was a blip. In those scenarios it tended to average 195-199.
Cruising at high altitude, same outside temps but no hill climbing I was seeing between 192 and 195. Normal temps for me in sub-90 degrees are 185-188 pretty much all the time.
The only thing left to do that I can think of is to add foam to the radiator assembly and replace the thermostat. Will be tackling that soon. I'm hoping that gets my temps down a bit more, but I live in Western Washington where it's hard to do any extreme temp testing.
A new radiator cap seemed to help me. I did not have an oem one on there (no Japanese characters) but it was 1.1 bar.In an earlier post I shared that during my 600 miles road trip where OAT temps ranged from 95-100 I only ever saw 203 when doing 75 uphill over a pass, and even then it was a blip. In those scenarios it tended to average 195-199.
Cruising at high altitude, same outside temps but no hill climbing I was seeing between 192 and 195. Normal temps for me in sub-90 degrees are 185-188 pretty much all the time.
The only thing left to do that I can think of is to add foam to the radiator assembly and replace the thermostat. Will be tackling that soon. I'm hoping that gets my temps down a bit more, but I live in Western Washington where it's hard to do any extreme temp testing.
I just learned from @abuck99. That the coil on front of fan clutch, even new OEM. Are reportedly varying from one to another.I agree, should not affect ECT. Provided it allowing proper flow of coolant in and out of reservoir. But recheck level under cap periodically, after 8 hour cool down, with heaters set to hot, the drive before cool down. The check needs to be when cool OAT in the morning out of the sun, and with front higher than rear of vehicle, to get best results.
What I have found with non OEM caps. They do not fit as tight. That when I pressurizing system for test or to blow out during a flush, with ~10PSI into rad through reservoir hose. I'll see and hear leakage out of non OEM caps.
Once coolant system to spec. Which includes the foam arounds side and top of radiator (lower foam seems to have less effect). Tune engine and make sure no vacuum leaks and PCV valve working. Also run a fuel system cleaner through the gas. I like 44k and or Chevron Techron (at different times). I also have been using IK20TT denso spark plugs. Don't have any comparison to non TT, but may drop cylinder head temp a tad, but IDK.
Watch fuel trims too see if running lean.
I just learned from @abuck99. That the coil on front of fan clutch, even new OEM. Are reportedly varying from one to another.