Has anyone ever hooked up an aftermarket engine temperature gauge? I know the factory gauge says 190* on the middle mark but does anyone really know what temperature the other marks are supposed to be? You go from 190* in the middle, to the next line, and then nothing until 240*. Thats a big number jump to not know whats in between.

the left line is ~165F the one on the right i never bothered to guess at.

i always figured 165 and 215 since there was a 50* differance both ways. that is 140 190 and 240. thats not very scientific but it is useful.

150/210

150/210

is there some science behind that? if there is i am running colder than i have been thinking.

is there some science behind that? if there is i am running colder than i have been thinking.

I am going by memory but pretty sure thats what it ran. I used to have an analog gauge in there as well so that's how I know. 1998+ trucks have different gauges so that might be a little off from your's. My old crappy thermostat would always peg that upper line and I remember always seeing 210-212 and then it would fall to the lower line which was around 150. Now it gets to 190 and drops to 185 and stays in that 5F area.

I have an aftermarket manual gauge the probe is on top of the head. The factory gauge is within 4 or 5* of the after market. How these guys are telling you is spot on.

So.....its official.....165 and 215. Unless someone else can say otherwise.

well i see two different answers here, 165/215 and 210/150. -Jordan-

I'm pretty sure the lower line is ~160*F and the upper line is ~220*F

I'm pretty sure the lower line is ~160*F and the upper line is ~220*F

all right thats 3 sets of numbers now. think ill go stick my finger in the coolant and judge for myself. louder the scream the higher the temp.

Dripley don't do it... :duh:What I'll do later on when I get some time is using my ScanGauge II and a rheostat I'll find out exactly what it is...

Results are in... I tried using a rheostat and the lower values are easy to hit but the upper value kept doing werid things so I went to resistors and stuffing different resistors into the plug. Tidbit though... I found out the lower the coolant temp the highier the idle is. At 0*F the idle is like 1,100 RPM on its own...:stuned:Lower mark is 165*F...Just for fun to show 207*F...Upper limit is going to be 220*F

Once again..... You're the man Mike.

Whoa the 1998+ gauges are drawn a lot different. Yeah ignore what I said.

AAAAAAAAAAAAAAAAHHHHHHHHHHHHHHHH!!!!!!!!!!!!!!!!!!!!!!!! thats about 215. shoulda listened.