High water temp!

[The_Handier_Man1]

From: winnedaygo619  (Original Message)
Sent: 7/24/2004 3:32 AM

hello all i have 76 brave with the 440 in it just wanted to know if any1 knows why my temp gauge after driving her around town and temp is at 230 whene i turn motor off temp will go as high  250 then start to come back down seems weird temp to go up whene u shut her off  any info would help thanks and i have changed everything water pump ,thermostat,recored radiator, full tune up  oil change ,gauges water temp,oil psi,volts,rpm



From: denison
Sent: 7/24/2004 11:46 AM

I think it is normal for the water temp gauge reading to go a little higher right after a fully warmed engine is shut down, due to the heat stored in the head.  The iron near the exhaust valves and the manifold is hotter than the water, and once the flow stops, it will continue to heat the water a little bit.   Its only a problem if the water gets hot enough to cause any coolant to be lost from the system. 
    The 230 temp indication is higher than I would expect, though mine is a 72, and would have had a 180 thermostat originally.   It could just be your gauge reading is off - I dont consider water temperature gauges to be consistently accurate, from one gauge to another.  Your thermostat could be a few degrees off too.  It could also be that the thermal sensor in the engine head has aged. 
   I use about a 25% mixture of antifreeze to water, instead of the 50% mixture that I use in the family cars.  I dont worry about the coolant in the RV freezing up when below zero, since I never use it when its that cold.   And water conducts heat better than antifreeze does. 
But having the coolant temperature go up locally in the head after you shut down is fairly common.       



From: Sea Hag
Sent: 7/24/2004 11:52 AM

It sound like you covered most bases but 230 is still too hot . Does your radiator still have the fan shroud ?   and did you check or replace the fan clutch ? . Did you replace the thermostate ith the Crysler skirted type thermo.for the 440 ? . Did You flush and rinse out the block  ? I kno questions isn't hat you anted but just some thoughts . Sea Hag 



From: Discoverer
Sent: 7/24/2004 4:11 PM

R U sure that the temp gauge is right? ...what temp stat is in it? 



From: winnedaygo619
Sent: 7/24/2004 9:37 PM

sea hag i still have fan hroud on it fan clutch seemto be working how can u tell if it aint and yes the thurmostat is skirted type but its a 195 i think ima buy the 180  what are normal temps for this motor thanks every1 



From: olivereaman
Sent: 7/25/2004 10:43 AM

Try using a handheld temperture sensor and check the temperture right at the sending unit. Automotive temperture gauges are not known for being extremely accurate. You can also try idleing the engine for a few minutes to allow it cool down before shutting it off. If it REALLY is heating up to 230, you might want to use a strong solution of antifreeze to raise your boiling point above 230.



From: HeavyHaulTrucker
Sent: 7/25/2004 1:51 PM

Normal temp for the 440 is between 190 and 200 degrees; it will heat up to 220 within 5 minutes of shutdown, but should cool to 190 within a half hour.

I would use an infrared thermometer to verify the temperature.  I would also take readings at the upper and lower radiator hoses; if the temperature does not vary by 20 to 30 degrees or more between the two, you have a stopped up radiator and need to have it either rodded out or replaced.  This could also indicate a thermostat that is stuck open.

If the temperature varies more than 30 degrees, I would suspect a stuck thermostat that is not allowing coolant to flow -- thus keeping the radiator bottom cold and the top very hot.

You can tell whether the fan clutch is working or not by the roar; there will be a moderately loud roar at highway speed if it is working.  If you do not hear that roar, I would check belt tension first; if the belt is properly tensioned (1/4" belt deflection), then the fan clutch probably is not working.

John



From: winnedaygo619
Sent: 7/29/2004 4:15 AM

ok now im pissed i put new fan clutch in today and i let the motor heat up to about 220 then i shut motor off and i can spin the dang blades like be4 it didnt make a diffrence same like whene i had old 1 in  .i also put new coil in i dont see any sparks like be4 on pos and neg of coil so i think thats solved but i hooked my tach again and it kinda bounces  then stays steady then bounces ,but back to fan clutch any1 know why it didnt work puting new 1 in any info would help i feel kinda pissed because i have spent like 1100 bucks so far on just motor work and i dont even know how many miles are on the motor i could have bought a rebuilt motor for 1200 bucks somtimes i think i should have went that rout im just trying to get it running to were i dont have to worry about where ima drive to just get in and drive worry free  bare with me ppl im venting 
thanks for all ur replys



From: Sea Hag
Sent: 7/29/2004 9:45 AM

I believe that you should be able to spin the fan with motor off , even at temp , I can on mine anyay - It sences the air comming trough the radiator not off the water temp . The only test for the fan clutch in the manual is to remove the coil sping from the slot holding the end . and rotate it counter clock wise . it should stop 1/2 " from slot bracket . the manual calls for a 185 degree Stat - I,m running a 180 degree . Hang in there  - Sea Hag 



From: Sea Hag
Sent: 7/29/2004 10:01 AM

I forgot to mention the belt tention - the 76 dodge MH chassis manual calls for 7/16 deflection with  10 LB. of pressure applied to the top of the belt in the center between pullies . they have a special tool - I used a fishing DeLier ( Scale ) and a old small pully . I had the radiator out when I set mine . I imagine it woud be the same from the bottom side if you can't do it from the top with radiator in . - Sea Hag 



From: denison
Sent: 7/29/2004 1:08 PM

Yes, you can turn the fan blade without much trouble, but when you try to spin it and let it go - thats when it should stop within the width of a blade. By the way, my fan clutch is the viscous and thermostatic type. Cost almost $90 two years back. 



From: winnedaygo619
Sent: 8/15/2004 5:39 AM

still having heat trouble i have the 195 skirted thurmostat if i wher to put the 180 would it cool temps to normal temps?



From: denison
Sent: 8/15/2004 6:21 AM

I would think it would just run 15 degrees cooler. Are you going by the indications on the original electric water temp gauge? I added a mechanical gauge to check my old mopar electric gauge, then had to replace the mopar sending unit, which had gone bad. Though mine would read very low as a result. After 12 years of us, I had to replace the mechanical gauge when it began to read low and lower. 



From: Sea Hag
Sent: 8/15/2004 9:12 AM

The 185 degree stat is what the 76 manual called for . I'm running a 180 . If the system is orking properly the temp shouln't go much above that temp at idle . I don't believe it will lower your working or driving operateing temp , if it's going much over 200 degrees . Iwould try too flush the cooling system and check the radiator for blockage ' and make sure the hoses arn't collapsing . - Sea Hag 



From: lockman
Sent: 8/28/2004 11:15 PM

I just replaced my open style 180 thermostat with the proper 185 skirted style. Got from the Chyrsler dealer part # 3512998. Not as big a change as I was hoping, but every little bit helps. With the old unit temps ran consistently between 200 and 205 with frequent surges over 215 on hills. With the skirted type temps are constant at just over 195 with surges to 205 on hills. Oringinal factory temp guage never moves much at any time, so it is a good idea to install a real one. 



From: winnedaygo619
Sent: 8/29/2004 2:44 PM

im still having heat trouble ,done all that i think i can do recore radiator,thurmostat skirted,new watter pump,and fan clutch i have no clue what else to do maybe head got a crack in it causing to still heat up whene i turn her on temp gauge will go to under 230  and i havnt even left driveway goes over 230 whene driving



From: HeavyHaulTrucker
Sent: 8/29/2004 8:05 PM

I want you to do something...  it may sound wierd, but it is an "old time" diagnostic technique for the 440 that a mechanic friend of mine told me about.

Run the engine until it is warmed up properly... or 15 minutes.  With the doghouse off, in a nice quiet location, turn the engine off and just listen to it.  If it does not make a gurgling sound (sort of like a percolator), then your temperature guage is not reading properly -- in other words, it is running at proper tenperature but the temp guage is reading too high.

When you shut off a 440 from "operating temperature", all you should hear in a quiet environment is a slow "ticking" sound of the metal cooling gradualy.  If you hear the coolant gurgeling, then it is running too hot; otherwise, the temperature is fine.

John



From: denison
Sent: 8/29/2004 8:19 PM

I agree - a great test. If it doesnt gurgle after 15 minutes of running, you could take it for a test drive, until the gauge says 210 or better, then shut it off in a quiet location and remove the engine cover. You should still not hear boiling. If you had just climbed a 3 mile long 6% grade you might hear the boiling though.
A way to test the temp gauge: Buy a new water temp sender unit, and connect it to the RV wiring, one wire to ground on the block somewhere, and with the sender in a pot of boiling water turn the ignition on. Unless you have water in the pot really boiling, the temp gauge should only show about 180 to 190 degrees. Really boiling water might read 200 at most. 



From: cooneytunes
Sent: 8/29/2004 10:06 PM

Sounds like the gauge is off. Shutdown temp will always rise, try idling for 5 min turn on cab heat or hottest setting on defroster with blower on full, this allows heat to disapate through air and metal parts of engine, also takes some of the heat into your heater core and cooler anti-freeze (inside heater core) to circulate into the engine. If you get heat your thermostats not stuck, unless it's stuck open, which you said you replaced, so I dought it's the thermo. Temp rise is normal, but your running temp, if actually 230 is too high, You also need a 16lb pressure cap on radiator, not one from a passinger car. A passenger vehicle or light truck cap @ about 8lbs won't be enough pressure to push anti-freeze through that big of a system fast enough. Sounds like the guage.....Let us know......Timmy



From: Sea Hag
Sent: 8/31/2004 10:49 AM

One more thing you can try . when I replace my main hoses on the radiator . I noticed that the top hose was collapsing . the OEM replacement hoses from napa fit nicely but did not have the springs inside them . I removed the support springs from inside the old hoses and fished them into the new ones . I also later saw some info in the service manual  conserning the support spring inside the hoses , esspecially the lower hose collapsing as it's the pump feed side .       Sea Hag 



From: winnedaygo619
Sent: 9/2/2004 3:45 AM

thanks evey1 for ur replys i was wonduring on the watter pump is ther a speacial 1 to buy cause i bought a watter pump from napa for tha dodge 440 motor some1 told me ther are special rv watter pumps is this true ??my winne is @ the shop leaking radiator fluid from a freeze plug thats what the guy told me but he dont know why it still heating up so whene i get in back wich should be tomorow ill try doin the starting it goin around the block comming back home and see if i can hear bubbling and also try puting temp sending unit in boiling watter see what it reads im also goin to get right rad... cap i just want it to run good i have almost completed with the remodeling of the inside ill post be4 and after pics whene im done thanks for every1 help much appreciated



From: denison
Sent: 9/2/2004 10:56 AM

winnedago619: If the water pump you bought has 8 vanes, it is probably the high-flow version. There are also versions with 5 or 6 vanes of some water pumps - for passenger cars. 



From: winnedaygo619
Sent: 9/8/2004 1:05 AM

hello all i biled some watter today in the house got it boiling then went out side to my rig put the temp sender in the pot and it went right to 220 denison u think my gauge is off then eirlier today drove her around town got gauge right under 230 then shut her off walked to front by the radiator i could hear bubling not much but like every three seconds somthing like that i dunno some1 told me i could have a blown head gasket even though watter is not mixing into oil  if i get another temp sender wich 1 should i get???



From: denison
Sent: 9/8/2004 6:41 AM

If you get another temperature sender, it would be whatever the parts place listed for a 440. I doubt there would have been a different temp. sender unit for the 440-3; wasnt the entire instrument cluster the same on the pickup trucks and delivery trucks as it was in the motorhomes? Minus the extra switches for things like dual battery and aux. fuel tank of course.
Anyway - it would seem to either be the sender unit, or the temp gauge itself, and a new temp sender is cheaper and easier to try than a new gauge would be.
The 3rd possibility is that the voltage limiter is way off. This is the small relay-shaped item mounted on the back of your instrument panel, that provides a regulated voltage to the temp gauge, and fuel gauge, and maybe the oil pressure gauge. (Its supplies all 3 of these gauges on the 73s, but Im not sure about the later models.)
When the ignition is on, it regulates by switching 12volts on/off/on/off/on/off to the gauges, about once per second, and being ON only 5/12ths of the time. This makes it hard to check with a voltmeter. You need an analog voltmeter and some imagination, or a new voltage limiter to check it against. As far as I know the voltage limiter for your RV would be the same as the ones used in the pickup trucks and vans in 1975 and 1976.
Once you know your gauge is reading correctly: Its still possible you have some cooling system problem. But if it doesnt loose coolant, I would try to live with it. How big are the hills you go up, and how fast do you go up them?
Does the engine ping on regular gasoline? Im still thinking it might be overadvancing when running - another thing that is hard to check. 



From: winnedaygo619
Sent: 9/8/2004 11:17 PM

  ok i bought temp sender today and installed it factory gauge is working now im goin to post some pics of the gauge i bought and of the factory one these temps are at idle i havnt even  left driveway yet   do these temps seem right i know aftermarket gauge is at 220 whene i drive her around town it will reach 230  thanks for every1s info



From: winnedaygo619
Sent: 9/8/2004 11:25 PM

ima back lol kinda pissed because i took radiator cap of today and looks pretty bad im goin to post some pics i dont  think the radiator should look like this after it being recored and driving about 150 miles max  tell me what u guys think   



From: winnedaygo619
Sent: 9/14/2004 1:09 AM

lol i guess every1 is tired of me posting the heat troubles im having lol hahahaha cuase no1 has left a reply from my last post i think ima drive my rig of a bridge lol j/k



From: denison
Sent: 9/14/2004 7:11 AM

The pictures you posted were very well taken, but really large jpgs - a mbyte each. They only downloaded on my office computer; just locked-up the one at home. That may be the reason no one responded, or your posting got pushed off the Whats New page by a rash of newer posts.
That radiator doesnt look like it has been cleaned. If it were properly done it should have been clean enough to eat from inside. They normally spray the outside with glossy black paint, to help with radiating heat and to cover up all of the exposed brass and solder patches. The cleaning process would normally have left the fins totally clean outside. Those pix show what I would expect a radiator to look like after 5 or 10 years of infrequent use. In the bottom of the hose connection tube there is some kind of sludge. If you didn't pour something in there -in large quantity-, then what is that stuff? It certainly shouldnt be there, and wouldnt have come in a cleaned or recored radiator. They might have put a handful of a radiator stop leak in, but it should not collect in the upper hose. I presume the other picture is just the filler hose that you pulled off the front of the radiator. One source for that mucky slime would be if you had a head gasket leak, and motor oil and gasoline were being blended into the coolant. This could also be leftover from a bad head gasket that was repaired long before you got the RV. You should also check the transmission fluid - look on the dipstick for signs of any water mixed into the fluid. This could happen if there was a hole in the transmission cooler heat exchanger in the bottom of the radiator.
I would say you need to start with a really cleaned, or new, radiator. And if that sludge migrated from inside the motor, you maybe should have someone flush the block with high pressure water. To do this I think the water pump housing would have to be off, and the thermostat out, and everything elso covered up to keep water out of the carburetor/intake manifold. By high pressure Im thinking of 100-150 psi, like a fire hydrant has.
If you were to pull the bottom hose off - it might have even more of that sludge in it! One technique for getting more crud out of the cooling system is to slice the bottom hose in two with a butcher knife about 5 minutes after you shut off a motor that you had warmed up for 15 minutes. The regular drain cock is too small - the floating muck has time to settle to the bottom of the radiator and engine water jacket.
Putting a cooling system cleaner in, warming it up, then backflushing from a heater hose might help too. At least get it to where the water comes out clean. Im out of ideas. Good Luck with it.