motor temperature

[gcochran223]

truck is a 86 k15 silverado 350 th400 with vortec heads.

 i bought the truck as a roller and installed the motor so i am not sure if all the gauges worked correctly. i got all of them working but the temp gauge. i installed a new temp sender, the single connection 1/4 spade type and found the green wire out of the engine bay harness and connected it.

 i get connectivity, and when i start the truck it runs for about 2 minutes and gradually goes up above 210-220-230 then ill usually shut off the truck to be safe. i have checked the antifreeze and its full.

when i touch the top hose going into the radiator its not even hot so I'm wondering if the factory gauge is working properly? is there a way to test this or is my best bet to just buy a analog gauge and install it to see if it is actually overheating?

any information, suggestions, tips appreciated. thanks

[1979ChevyMorgan]

Is it a bad thermostat? Also if you have recently changed out the cuilent youll have to burp the system, do that by running it with your cap one click lose. It should be lose but not come off.

[gcochran223]

i didnt change the coolant i added some after the heater core swap out. i burped it before and just did again to be safe. when i check with a ohm meter i get 44 ohm with the key off and when the key is in the on position and vehicle running i get zero.

[Captkaos]

Is the sending unit from the head or a replacement for the truck?

Chris Lucas
73-87chevytrucks.com
captkaoscustoms.com
squarebody.biz

[gcochran223]

it was a replacement one for the vortec head i just ordered from summit the other day.

[rich weyand]

The sender needs to match the gauge, not the engine.

Per Ray McAvoy: "The 1979 & newer temperature gauges are designed to work with either a GM #8993106 or #8993146 sending unit. The #8993106 has 1/2" NPT threads while the #8993146 has 3/8" NPT threads."

[gcochran223]

yeah i just found that out after talking to summit tech support. the gauge they first referred me too is a vdo for vdo gauges. so they are sending a standard motor one for a 86 truck.

vdo- http://www.summitracing.com/parts/vdo-323094/overview/

standard- http://www.summitracing.com/parts/smp-ts76/applications/engine-type/v8/make/chevrolet/engine-size/5-7l-350

the summit guy got kind of salty when i asked for them to send me the standard one since the first tech support referred me too the vdo.

i wasnt too sure if i needed a special one for a vortec head or not thats why i called summit over advance auto.

[rich weyand]

No special ones on an engine or head basis.  210 degrees is 210 degrees no matter which engine it is.  But the gauge and the sender have to agree on how much sender resistance corresponds to 210 degrees for the gauge to indicate 210 degrees.

[gcochran223]

thank you for your help, much appreciated.