Any reason I have to use this specific temp sender?

NAPA AUTO PARTS)

Or can I use this cheaper one?

BWD WT911 - Temperature Sender | O'Reilly Auto Parts

Thread count etc are the same but would they be calibrated the same to run the gauge?

 

I believe you may have other issues. As cold as it is in your area, running with a stuck open stat, or no stat, and you should have a problem with no heat, engine not warming up. I just did that this weekend, had a stat that was rated 195, but would start opening way early, and I was only getting up to 135 F after five miles at 50 mph.

I would agree with Spike on the need to stay in rad to cool off, certainly in summer. But in your case, if rad has not been flushed or rodded out, rad simply may not be cooling things off, perhaps because too many tubes are blocked and volume is reduced.

Your little gauge sender unit could be way off. Mine shows 9:00 even at 234 F. And your system did get to 212F, because that is about the kick on point for the electric fan. By removing the wire, going to zero, we know it is not a skint wire ground. The sensor is rated to go from 136 ohms cold to 17 ohms hot. But I don't have a reference what the exact ohms to temp. Will read that when sun comes up, I'm skeered of the dark.

I just went out and cranked mine and let it warm up. I put in a 160 stat today, part of an experiment. Here are the readings I saw:

Scanner - 163 F at idle, 695 rpm 59 F outside, damn that's cold....

Valve cover - 158 F

Header from cylinder 1 - 423 F

Upper hose (rubber) - 120F

Radiator beside upper hose connection - 158F

Lower hose (rubber) - 112F

Radiator beside lower hose - 132F

Radiator by return line from throttle body heater 140F

I noted that while thermostat was closed at startup, the first pipe to get warm is the one going to the heater core (due to bypass operation of water pump) - my in/out pipes were within 2 degrees when finally warmed up.

The return line from the throttle body is also bringing coolant all the time, and gets warm before the main stat opens. This shows up on the radiator near the bung hole.

 

Went to the now cooling off truck, did not crank. Scanner say 134F, gauge reads about 1 pointer thickness below the lower "limit mark" of the normal range (between said mark and cold). Ohm meter says 137 ohms from sender to ground, sender wire removed. You would want to be sure sender terminal and top insulator was scrubbed off with a small brush.

For it to work with gauge, replacement will have to be correct resistance, not way different. Since resistance is high when cold, should be able to inspect at parts store with ohm meter.

I would say that rad flush is warranted, because heat gun showed high, electric fan sensor kicked on, and gauge read high. Coolant kept it from boiling over, and the pressure cap helped. Hose temp vs water temp can be 10 - 15 F, because outside of hose being cooled by fan air.

 

RE: oil line leak

If not O-ring, could bypass for testing with god quality hose and muliple clamps (60 psi). D2 only had oil cooler thru certain VIN, then did away with it. If one pin hole leak, more will follow....

 

There are 2 different coolant temp sensors for the DI, one is for the gauge, one is for the ECU.
The one for the ECU, which is by the t-stat housing, is the expensive one, like $30, the other one is cheap, like $15.
Do not go universal or super cheap on those parts, go cheap on wiper blades not sensors.
If you go cheap you will continue to have problems.

 

And - did you triple check belt route?

 

Yes, double, triple, quadruple checked belt route. It is correct. I don't see how it could be done wrong or at least in such a manner as to turn the WP backwards.

With the small fill port open near the battery I can see water being pumped through the system. Not sure how well it would pump in reverse so perhaps a visual check isn't the best way to confirm that. Regardless, the belt is routed as shown in all the diagrams posted here (with A/C).

So I conducted a test on the temp probe today. I checked it with the eng cold (65F)and it read 0.883 ohms. When t-stat housing was at 100 deg the gauge was just under 9:00, ohms were 0.220. Later, with t-stat housing at 140, ohms were 72.4 then finally ohms at 47 with housing at 150. I didn't check the rad or hoses like you did Sav but I should have.

I wasn"t real confident in those readings so I took the temp probe out and did some more testing. Again static number was 0.87 ohms at 75F. After placing in hot water, I got 75 ohms at 180F, 70 ohms at 220F and 54 ohms at 230F.

It appears my numbers are much different than your reference numbers.

BTW, 65 deg F is NOT cold. I've been doing all this testing with the basement door open and it's 25 here! Wife doesn't like it when she comes home to entire house full of fumes. Doesn't bother me though...just makes me ssssllleeeeepppyyy. ;-)

 

Well, let me brave the artic blast of 68 once again and check with voltmeter number 2. May have to drag out a gumby suit if it gets much worse... Your fractional readings do look strange, perhaps the auto range function on the meter is displaying a secret code that computer weasels use to signify "kilohms"

That water flow you see through the threaded top hole is also the return line from the throttle body plate. It and the heater pipes get water flow all the time from the manifold, and warm up before stat, and certainly before upper hose. Of course, to have a flow the heater valve has to be on.

 

You're killing me SB!

Of course you also need a water pump that's pumping too...

 

As promised, here's what mine read with a decent Fluke meter:

502 ohms - scanner 75 F coolant temp IAT 72 F (brrrrr) - engine off for 6 hours

290 ohms - 90 F

190 ohms - 105F

100 ohms - 138 F

068 ohms - 165 F

052 ohms - 180 F


Not saying mine is right, but it is different.