running hot

[siii8873]

well since my valve job, head shaving my truck is running hot. It runs over 3/4 way up from white bar to the red "hot" bar. Never ran this hot before.
I popped the hood and it did spew some fluid on top of radiator and overflow jug if Full. Think I'll change the thermostat and cap see if that helps, they were removed during the work. Any other thoughts?

[jac04]

Bob-
Where are you on the gauge?
I assume you've adjusted the valves & your timing is set correctly, right?

Here is the normal range for mine, obviously higher during hot weather.

http://i79.photobucket.com/albums/j126/jac04/000_1488-1.jpg

[siii8873]

yea based on the gauge and where it historical ran. Previous to head work it ran at the low end or just below your low mark. It is now 1/2 way between red and high mark. I had put a higher temp thermostat in it last fall to get some heat and it was fine all summer like this until now.
I didn't change the timing and seems to run better than before (as I would expect with valve job)
The guy that did the head job for me said he left the valves a little loose because he replaced the exhaust guides. Does not sound tappy.

[jac04]

I would still check the valves & timing. Did you re-torque the head at all? That can affect valve clearance. You can also check the electrical connections of the temperature sender. It's still the same sender, correct? Just looking for something that changed when the head work was done.

[siii8873]

thanks Jeff,
my thought too what changed with this work? I was questioning the gauge reading also. When you pop the hood the engine is not popping and crackling like it's way overheating yet it did spew some fluids which it has not done before. Maybe overfilled but I would think it should void itself out the overflow bottle pipe.
I'm going to change the thermostat and adjust the valves.

The rover gods just don't want me to work on the bugeye. Everytime I get started I need to hold off and work on one of the other two.

[jac04]

Maybe overfilled ...
Maybe. Almost every time I drain & refill coolant on a Rover (or even on my 68 Camaro), I get some overflow out of the radiator the first time I get it up to temperature. It seems like the radiator is finding its "happy place", even if filled it to the proper level to begin with. I then make sure the overflow bottle (if used) is at the proper level, and all is well.

[rejeep]

seems silly to ask...

but did you burp the system?

did you try and run w/o a stat?

[siii8873]

I'm not sure how to "burp" the system. Never had to in past.

[siii8873]

I went out to work on the truck and something came to mind. How do you time an electronic ignition? Other than by ear that is. I know how to static time a points ignition but have never adjusted the timing on this vehicle with electronic ignition. It does ping a little under load. Does this mean it is a little to far advanced or retarded.

[rejeep]

advanced

[Terrys]

Never had to 'burp a 2.25. There's virtually no chance of 'trapping' air when filling. Jeff, the black plastic bottle on a series truck isn't an expansion tank, it's strictly a catch bottle for possible overflow, if the cap lifts. Under normal operating temps, the cap shouldn't lift.

[jac04]

Jeff, the black plastic bottle on a series truck isn't an expansion tank, it's strictly a catch bottle for possible overflow
Correct. Didn't think I called it an expansion tank, just a overflow bottle. Either way, I've almost always had them 'puke' out a little coolant after refilling.

[Terrys]

I then make sure the overflow bottle (if used) is at the proper level, and all is well.
I guess this is what confused me. I would think "Proper level" is empty.

[siii8873]

I cleaned the sender unit connection, looked OK. Emptied the overflow bottle and ran the truck. The guage raised to about 1/2 way and then creeped up to the 2/3-3/4 range up from white toward red. It stays there.
I pulled it in garage and checked under the hood. No spewing of fluid and overflow tank was still empty. I felt the top and bottom ratiator hoses, top very warm, bottom almost cold. As you feel up radiator cold at bottom and gets hotter as you get toward top. Does this sound correct?

I want to check the timing but uncertain how to do this with a crane electronic ignition. I have a timing light. What should the dynamic timing be set at? Should the vacuum advance be plugged or left operational when adjusting the timing. The engine does ping a little when under load.

[LaneRover]

I cleaned the sender unit connection, looked OK. Emptied the overflow bottle and ran the truck. The guage raised to about 1/2 way and then creeped up to the 2/3-3/4 range up from white toward red. It stays there.
I pulled it in garage and checked under the hood. No spewing of fluid and overflow tank was still empty. I felt the top and bottom ratiator hoses, top very warm, bottom almost cold. As you feel up radiator cold at bottom and gets hotter as you get toward top. Does this sound correct?

I want to check the timing but uncertain how to do this with a crane electronic ignition. I have a timing light. What should the dynamic timing be set at? Should the vacuum advance be plugged or left operational when adjusting the timing. The engine does ping a little when under load.

If the radiator itself wasn't warm than I would guess that the thermostat never really opened up and that is why the bottom hose was still cold.

Wait just re-read this. The hot comes into the radiator at the top and feeds back to the engine at the bottom, as the coolant flows through the radiator it cools down ('radiates' the heat away) so cooler at the bottom makes sense but if it is just cold than you either aren't getting much flow or the thermostat only opened a bit if at all.

[Sputnicker]

If it's pinging it's too far advanced. Timing an electronic distributor is no different than one with points. Loosen the clamp and turn the bottom of the distributor body. Use a light, or just retard it until the pinging goes away. Then see what your temperature does.

[jac04]

I guess this is what confused me. I would think "Proper level" is empty.
Well, I checked the Green Bible. The black tank is technically called an expansion tank (ET). The tank is supposed to have fluid in it - the manual says to maintain about 1/4 full.

When the system gets hot and the rating of the cap is exceeded, the main spring on the radiator cap compresses and allows fluid to escape into the ET. Note that the hose from the radiator is plumbed to a fitting that leads to the bottom of the ET, and the overflow tube exits from the top. When the system cools, it creates a vacuum that can open the secondary valve on the radiator cap and fluid is pulled from the bottom of the ET back into the radiator. There should be some level of fluid in the ET so that air is not introduced into the system.

I believe this type of overflow system was used to keep toxic antifreeze from being dumped on the ground. My old 63 IIA and my 68 Camaro both have systems without overflow bottles. They would spit out a little fluid and then be fine. Not sure if the caps didn't have the secondary valve, but there seemed to be no ill effects of not having an expansion tank system.

[JimCT]

It is to keep the radiator full of antifreeze and not air, when the coolant contracts it draws the coolant back into the radiator from the overflow tank.

[siii8873]

yea I know turning the distributor adjust the timing. With points I install a test light from points lead to ground and turn engine and see where the light lights in relation to TDC and adjust accordingly. In this condition none of the mechanical or vacuum systems are in use.
When doing a dynamic timing the vacuum systems will be in operation so I wouldn't think it should be set the same. That is what I would like to know is if anyone knows what settings when using a light.
Thanks

[siii8873]

Update
Pulled the T-Stat out this last weekend. Tested it and it opens. Adjusted the timing a few times with test runs. Improvement in pinging but cannot get rid of it completly. Could this be corrected with a hotter spark plug maybe.
I installed an 82deg TStat and this with the timing has reduced the temperature some.

[LaneRover]

Have you checked to see if the weights in the mechanical advance portion of the distributor have full movement?

[siii8873]

Ran the truck again today. The gauge is still reading higher than it historically did 2/3 way up from white cold band to red hot band. I checked the radiator after running it up to temp. Top is very warm and bottom is cold.
I am running an 82 deg stat which I checked in a pan of water and it opens. From driving this truck every day for over 1-1/2 years fjust seems something a little off.

[jac04]

Bob-
Did you ever figure out why the gauge was reading high?

I just drained & refilled my Lightweight because I had to replace a leaky hose. Nice & cool outside. Ran the vehicle until the gauge came up to normal range. Never really checked before, but the top radiator hose is hot, bottom is cool. Must mean the radiator is doing its job quite well (I'm sure the 8-bladed military fan helps as well). This leads me to believe that your gauge may be off.

[siii8873]

Jeff, thanks. I had done the same thing with my 109, drove to work and checked the top and bottom hoses after fully warmed up, Top very warm and bottom nearly cold, about same as the 88 I'm troubleshooting. Right now I'm thinking it's the gauge also. Can't change them as one is capillary and one electric. I'm driving it.

UPDATE:
pretty sure I have a gauge/sender or voltage stabilizer problem. Yesterday it was in the high 30's when I got into the truck. Started it and lokked at the temp gauge. It was registering just above the white with a cold engine.

I do have a problem w/ my fueal gauge when it gets a little below a 1/4 tank also. It will stay flat for a while then shake like crazy and then stabilize out. Understand that this could be a volt stabilizer problem.

[disco2hse]

You can stick a thermometer in the radiator while the engine is running. Shouldn't be run over 95ºC IIRC. It might boil a bit without the pressure cap on so watch out for that.

Your other alternative is to get a gauge with numbers on it.