Temp question 352 - is this too hot?

[audioguru`]

So new to old vehicles and curious about the temperature gauge. Generally it stays around 60-70%. Is this normal for the truck? Seems to have a newer radiator. I did check the coolant level (added some), also burped the system with the cap off. The one thing that is odd is when I start the truck and its warmed up, the gage will be much farther over to the hot side, and take a few seconds to move back down, but it does so quickly. I am not sure if this is a gauge quirk (looks to be original gauge) or if I have a issue I should be watching? Here is a pic with the farthest it has ever gotten to the right while running (it gets farther for a few seconds on startup).

Background info: I dont have a fan shroud, no power steering or brakes. Running a edelbrock performer with aluminum intake. Fan blades look like they are metal, not sure if they are OE or not? Has a generic coolant overflow tank that has an open vent (small tube runs from the radiator fill to the tank, the tank is not sealed, it has a overflow that spills to the ground when it reaches a certain level.)

https://www.dropbox.com/s/48uwbr1y4g7ajnt/tempf100.JPG

[Toyz]

I personally would prefer the temp to be roughly centered in the gauge after warming up fully. The position you are showing may simply represent a slightly higher thermostat setting, and should not be a problem if it doesn't get hotter in the middle of summer. One of the things which leads me to that conclusion is that it sounds as if the thermostat is opening at a slightly higher temperature, but once open, the system is actually cooling to slightly lower than that setting. If it's a concern, pull the thermostat and verify it's rated setting. Depending on the part of the country and winter usage, you could go with a 160 degree thermostat; a 180 should have been original, if it is stamped higher than that, I would drop to at most a 180 degree.
Paul

[Mr. Jones]

First off,welcome to the site...I am very impressed with your truck original seat cover,door panels,your dash pad looked great,no cracks that I could see.I'm thinking the headliner probably looks good too.
My 352 did the same thing yours is doing,I switched to 180/185 thermostat,problem solved.Never passes midway and the heater was very comfortable this last winter.
DAN
KANSAS CITY

[audioguru`]

Thanks! A couple cracks but overall seems well kept, headliner was redone in some late 80s green foam. It is OK, but i'd like to go back to the stock one down the road.

Not sure what I have engine wise, someone has obviously done a fair bit of engine work. The top hose gets nice and hot, bottom hose is warm, so seems the radiator is cooling. I don't plan on driving in the winter so mostly just concerned with summer capacity. My biggest concern is the very hot reading that comes down a few seconds after starting.

[simonscr]

Being an electric gauge, you could have to much voltage going to the gauge causing it to read high, meaning a defective voltage stabilizer. You could also have a bad temp sender on the engine that is not reading correct. The voltage stabilizer (or constant voltage unit ) feeds power to the temp, fuel, and oil pressure gauges. The voltage stabilizer is easy to test. I do not have the spec handy on what the voltage should be coming out, someone should be able to chime in with that. The temp sender can also be checked.

I would check the engine with an infrared Thermometer, to see what it is actually reading. Then you can see if the engine really is running hot, or if you have a gauge reading high.

[Toyz]

As noted, the high initial reading which drops after warming "usually" indicates a thermostat that is not opening until it reaches a higher temperature. I would suspect someone has installed a 192 degree thermostat, or the stock one is just a little balky. However, this can also be a symptom of insufficient coolant level, causing the thermostat to open late. If your fuel gauge is not suspect, I would discount voltage regulator issues, as they are both regulated. The fact that the gauge reads lower after fully warmed would also tend to eliminate regulator problems. The sensor could also be incorrect; Ford has done some strange things to keep customers from sensing a concern when one really doesn't exist, but, again, it appears yours is operating in what I would consider "normal" parameters, other than during warm-up.
Paul

[ICEMAN6166]

the thermostat could also be in backwards, it will stll work but take longer to open and result in higher temps.
i would check it out.

[audioguru`]

Perhaps I did bad job of describing whats going on. When I start out cold it warms up normally, the gauge varies between 60-70% while running, even in stop and go. The top hose gets good and hot, which should indicate a open thermostat. My primary concern is hot starts (like running to the store, come back out after 5 minutes), when I do a hot start it moves quickly to the right and reads 80-90% (towards H, not past), but drops very quick after the engine is started and coolant is flowing, after a 2 seconds or so I drop to normal operating and stay there. From the looks of it the temp sender is about the age of the edelbrock intake (I'd guess late 90s).

I will get an infrared gauge see where we are temp wise, and also look into a thermostat. I think* I need the later style 1 1/8 size since I have edelbrock aluminum intake. Perhaps I should also just put a new sensor and a real gauge set in also? Any one have any recommendations (thinking the 3 set I can mount below the dash).

so much appreciate how helpful and friendly everyone is here! What a great community.

[Toyz]

Heat rises, when the hot engine is shut off the temperature at the sensor increases for several reasons. the coolant is no longer circulating, thus it continues to pull heat from the engine with limited means of shedding that heat.
Again, I think this would be considered a normal state of affairs.
Quality aftermarket gauges are often more accurate than the factory units, dependent on sensor placement. They will serve as a second source to determine the accuracy of the factory unit, plus the degrees shown are fairly accurate. I would expect to see a repeat of your concerns on the aftermarket gauges, however.
I remain somewhat certain that your concerns can be mitigated with a 180 degree thermostat. An advantage of the "sweep" speedometer cluster is that it was available with optional gauges at the edges of the panel. Thus, the centering point for a holesaw to cut out the mounting hole for either 2 1/8, or even 2 5/8" gauges is already apparent on the back of the plastic panel. I prefer to use that centering reference to start the cut; once the guide bit has cut through, I cut from the finish side to help insure a clean cut on the face.
Edit, upon re-reading your latest post, two additional thoughts came to mind. The infrared will probably give you a fair appraisal of temperatures; but may not match the actual coolant temperature. Also, the 1 1/8" reference sounds unusual to me if you are in fact referring to thermostat diameter. If you were referring to the temperature rating of the thermostat, I would stay with the OEM or slightly lower, ie, 180, or even 160 degree if winter temperatures are not a concern.
Paul

[ICEMAN6166]

Perhaps I did bad job of describing whats going on. When I start out cold it warms up normally, the gauge varies between 60-70% while running, even in stop and go. The top hose gets good and hot, which should indicate a open thermostat. My primary concern is hot starts (like running to the store, come back out after 5 minutes), when I do a hot start it moves quickly to the right and reads 80-90% (towards H, not past), but drops very quick after the engine is started and coolant is flowing, after a 2 seconds or so I drop to normal operating and stay there.

this is quite normal (heat sink) and as you say it drops quickly.
if you on those hot start occasions did not start it and get the flow going but instead turned the key to acc and watched the gauge you would notice it takes quite a while to drop.

you do not mention other factors that can possibly contribute to higher temps such as any obstruction from crud that may have accumulated in the cooling passages over the years, a good backflush would certainly be worth considering.

i personally have had a lot of FE engines and the gauge always stayed in the 30-40% range other than for instance while snow plowing, lots of back and forth at low speeds and always with a 195* thermostat.

here is a pic of the towtruck i used to have, notice the edelbrock intake and where the temp gauge is



not sure if yours is similar but in order for the stock gauge to function correctly the end that reads the temp must be immersed in coolant .

[Astrowing]

Also a little extra advance will ensure it runs cooler especially at idle. I went from 6 degrees up to about 10 and temp dropped from about 60% to about 40%. I have a 1958 tbird 352. Very happy with power.

[audioguru`]

So it has been a busy few weeks. Just getting back to this. I put a laser sight thermometer on the temp sender and it read 200 that is after driving light in town driving / traffic, then parking it in my driveway and idling. Reading different spots this is the hottest part, the water outlet itself was 190, and the bottom radiator hose was 130, So I think I am probably good, when I get a moment I will throw a 180 - stat in.

Also noticed that there is no fan clutch, and a flex-lite fan installed. Im going to get a 1" spacer to get the fan closer to the radiator (it is pretty far from it, and I have no shroud). I am on the hunt for a original fan... provided I can get one cheap. At this point might be cheapest to go electronic and get the fans with a shroud from the pick and pull off a taurus, though I have always preferred the mechanical fan setups.

[audioguru`]

Did the thermostat today. Wanted to provide a follow up in case anyone is curious. With the 180 deg t-stat the gauge is nicely centered in the middle. I also confirmed the one that came out was a 196 degree stat. So thanks to everyone for suggesting that was the issue! Seems to run better too (I had noted previously it pulled harder in the middle temp range before it got to 60%).

Also, there is some confusion about water outlets, I have a performer 390, and what appears to be the cast "Everhot" brand outlet, it is the 2.5" variety though, and takes the larger t-stat. From the looks of it I could use a smaller outlet - but the larger one seems to work fine. Another oddity is that most parts places spec the same gasket for the larger outlet and the smaller one, at least on the large outlet the paper gasket fit well and seems to be holding fine.

I also found in the process I have a 1 row large radiator with plastic tank and aluminum body. There was a little crud, but honestly not bad. I ordered a 3 row all metal as it was on sale at advance. For 200 bucks I should hopefully not have to worry about running short on radiator come summer.