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Yes it is another overheating thread

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  • Yes it is another overheating thread

    Ok so I thought it would be the head gasket, until I did a compression test, these were my cold crank number (I did not wamr the engine up before doing the test so they read lower than they would if the rings had warmed up and expanded) I got 165, 165, 170, 170. The variances as your can see are within spec and it am not losing compression so the motor is healthy for almost 200k miles.

    I can drive the car normal and everything is great, although I did notice that coolant seems to be going to the overflow tank and pouring out, the heater does not work no matter what speed I am at, also heater core inlet is warm (not hot) and the outlet is cold until you get to the engine side of the hose then it is hot.

    I am thinking of doing a radiator flush, I am also going to remove the thermostat and boil it to see if it is opening.

    More or less anyone got any ideas where else I can check to eliminate potential causes?

  • #2
    check that over flow container. i recently did a head gasket, radiator, thermostat and hose change on a car and it still over heated. so i examined the over flow tank like crazy and found a very small crack in the cap so while driving it was pulling air into the system and causing it to overheat..


    • #3
      Ya know I was thinking that too since this container looks ragged. I was actually thinking yesterday that there could be a leak there too, when I am at idle and I rev the engine it cools the motor down too.


      • #4
        I will update tonight to keep a running tab on this. I have a very nice pressure tester to see if pressure is being released in the system.


        • #5
          Well a buddy of mine had a pressure tester, I then had to search all over and found that Napa carries the adapter for smaller radiators. I tested the cap pressure and the radiator cap was bad, as well I found lots of bubbles coming from the plastic around the radiator, so I had some gnarly leaks.

          In the meantime I also had to replace the cam cap, the plastic dude on the back side of the exhaust cam... That was fun trying to find and I found one. As I was torquing down the cam cover bolts one of them snapped, I believe someone over torqued this at some point 7lb/ft is not much force... So I got that all fixed and new valve cover gasket. No more oil leaks...

          Now back to the radiator. I got a hook up and spent $140 on a new thicker radiator, stock replacement but thicker, hoses, thermostat, and fluids. I removed all the good stuff and then went to pick up the parts. As I removed the tstat I saw that some idiot had modified the tstat and cut out everything letting fluid continually flow through. I will go over why this is bad at the end in case any of you though of this as being a "good" idea. Now everything is in and the car runs perfect, it shakes a little on idle but I will be cleannig IACV and other various valves.

          Ok so here is why an open tstat is a bad idea on a stock car. So first you have a stock single core radiator, this cools the fluid coming from the hot engine, coolant is there to mix with water to increase he boiling point and lubricate the cooling passages. This allows the water/coolant mix to flow through the engine as the engine is creating heat, and more heat means you are making more power ideally. Well the stock computer and engine is designed to operate at a certain temp. The tstat opens up when the fluid reaches that temp, and allows the coolant/water to pass through and start helping pull heat away from the motor through the radiator to cool off...

          Now if you have an open tstat and allow coolant/water to pass through non stop then the coolant/water heats up and will get hot quick since it is now a free flowing system and heat is being passed through the radiator then goes directly back into the engine, on a single core stock radiator it cannot cool off the coolant water mix fast enough so you are just flowing hot fluid through your engine, this does not allow the heat to be "released" at the radiator. Not to mention the other valves/sensors that rely on temperature to function properly.

          I know some of you may have your own opinion on this matter but being around cars now for over 20 years and plenty of empirical evidence to support failures of an engine due to improper cooling systems one part of it being the tstat, I will maintain my thoughts and am sharing with others so they don't do something like this.