Headgasket Thoughts

[quickie70]

^^^ agree with this. you could flush it, but a heater core is a "stacked plate" design, and not a bunch of rows of tube, so sometimes the flush will only flush the top 1/4" of the heater core. if you eliminate it completely, it'll help narrow down the culprit, but if it's actually getting hot, the heater core will have little to no effect on the engine cooling, but it will have an effect on a poorly placed sender. Put a mechanical gauge, even temporary, in the bung next to the thermostat and check it out.

[bmoeller]

Mark is right. The sender location has a lot to do with the temp swing on the needle. 2nd gen trucks do it as well. Cooling system is far more than adequate to keep the engine cool. That is why the needle is steady with a load. It is normal, and nothing to worry about, overall. If you have coolant loss issues, then I'd be concerned.

[ahale2772]

I did a headgasket on my truck, and a few of the smaller holes had weird gooo bound up around them, also Backflowed the heater core and the radiator, made absolutly no difference, truck was actually running cool, and still is cold blooded

[xohcef]

Alright so I guess I'm just going to have to have some faith in the trusty ol cummins. The temp gauge and how it acts is the least of my worries now. I have had a nightmare of an electrical problem come up and now the temp gauge is not reading right anyway along with a few of my other gauges/lights freaking out at me.

[ahale2772]

throw A mechanical guage on there, ifen if you just tie wrap it somewhere simple to use it as a reference to see if the stock on is accurate