cooling troubles!

[90YJWranglerfirstjeep]

Just Replaced. My water pump and.now its running to hot, so I took the thermostat out! And I was also wondering if my belt from the power steering to my pump was to tight could that effect it from cooling down as well.

 

[Jester32]

You will overheat easier with no thermostat. You need restriction for heat absorbstion. Often air gets traps in the cooling system. Make sure your not spinning the water pump backwards as well.

 

[90YJWranglerfirstjeep]

I made sure the pump is not spinning backwards, its does good on the open road and city limits, but when I kick in the the four wheel drive that's when it starts to over heat

 

[superj]

so its your fan, not your cooling system. if it was your cooling system, it would over heat on the highway too

 

[JPNinPA]

2X on checking the fan. Spin the fan. It should turn 2 to 5 times when the engine is cold. If it spins less than one or more than five the clutch is shot.

Also did you burp out all of the air of the system after changing the WP? Air will do a similar thing.

 

[90YJWranglerfirstjeep]

Not that I know of! I am.still learning on this jeep, is there a proper why to burp the air out! I been running it and its been good it still hits 260 and I noticed when that happens it starts to suck all my anti freeze out of my backup resevor

 

[superj]

i just did my pump also. i filled the radiator up with the top hose and the hose from the heater core unhooked. then, once i got to the point where i was worried about water coming out of those hoses, i connected them back and then finished filling the radiator. i let the jeep run for about 15 or 20 minutes while i was watching the radiator and hte temp gage. i have not had a bit of trouble since i put it back together though. (well, not with the cooling system. now my stupid alternator is making a squeeky bearing noise like its about to give me trouble)

 

[jfrabat]

You will overheat easier with no thermostat. You need restriction for heat absorbstion.

I dont agree with this one; with no thermostat, you will run TOO cool, and this will wear out the engine faster (engines like to operate at a certain temperature; in our case, at around 190*), and will also increase fuel economy because the ECU will not detect that the engine has reached operating temperature, and thus you will work in open loop mode.

so its your fan, not your cooling system. if it was your cooling system, it would over heat on the highway too

What he said!

 

[Jester32]

Actually the thermostat creates a nessacary restriction to slow coolant down With no restriction the coolant can't absorb the heat properly. Very common problem. And mis conception

 

[jimbob2001]

Previous. Poster is Correct! Cooling. System is Designed to work with a Thermostat --- It does create a Necessary restriction for the cooling system to work properly-- it allows the coolant to circulate thru the system at the correct rate--- allowing the HEAT from the coolant to DISSIPATE---at the proper rate --and maintain the correct-- Temperature --- this allows ECM --- and all systems to function OK- (smog etc) - Jb

 

[JPNinPA]

Actually the thermostat creates a nessacary restriction to slow coolant down With no restriction the coolant can't absorb the heat properly. Very common problem. And mis conception

Previous. Poster is Correct! Cooling. System is Designed to work with a Thermostat --- It does create a Necessary restriction for the cooling system to work properly-- it allows the coolant to circulate thru the system at the correct rate--- allowing the HEAT from the coolant to DISSIPATE---at the proper rate --and maintain the correct-- Temperature --- this allows ECM --- and all systems to function OK- (smog etc) - Jb

I'd like to see a reference for this fact. May be I could learn something.

From my understanding the coolant circulates through the engine all the time at a constant rate. The pump gives it that rate, flowing above the natural hot/cold circulation. The thermostat keeps the coolant flow within the engine loop until the thermostat temperature is reached. Once the thermo opens the coolant is allowed to flow into the radiator and exchange with cooler coolant.

So if there were no thermo it would just take longer for the engine to reach temp if it does at all. At idle it will reach temp given the ambient temp is not below freezing. While driving above 35 mph it will not. This is due to the air being forced through the radiator cooling the fluid inside.

 

[jimbob2001]

Gentlemen: Previous Poster has ASKED for a REFERENCE for this fact. OK. Many fine ARTICLES exist in AUTOMOTIVE Texts -- And On the Internet -- which will support - - My Post and Jesters Post! But, just to clear it up-- Here is Thermostat 101 : The PURPOSE of the Thermostat is to MAINTAIN the Engine Operating Temp. - Within its Design Parameters. This ENGINEERED Temp. Range will GIVE the BEST Balance of: POWER (HP), ECONOMY (MPG), AND. LONGEVITY (Eng. Life BETWEEN Rebuilds). In short--- The Thermostat MAINTAINS a PROPER ENGINE TEMP! IF YOU --- CHOOSE to Run your Engine WITHOUT a Thermostat--- A NUMBER of things CAN Happen! None of them Good! Sometimes --- People will PULL the Thermostat -- when FACED with an: OVERHEATING Problem! Thinking: My Engine will RUN Cooler!! Oh boy! Well -- NOT so fast! Better IDEA: Leave Thermostat IN - - Troubleshoot the Cooling System Problem! FACT 1 : Generally Speaking an Engine with NO thermostat --Will RUN. Cooler! But -- There have been CASES where Engines with NO Thermostat HAVE Over-heated! TRUE! (Jester was CORRECT!) Sounds Nuts - - But it is TRUE. Just a case of running an ENGINE -- WITHOUT. All of its-- DESIGNED PARTS! I mentioned that -- Generally speaking -- an ENG. Without a Thermostat will RUN COOL. (Usually). What BAD things MIGHT. Happen to an Engine RUN without a Thermostat? 1. HEATER will Run COOL! Not good on cold winter day!
2. When an Engine is RUN cooler than its DESIGNED Operating Temp. -- The Internal Clearances will be way out of Whack! (Too Loose) 3. Moisture Build-up in crankcase - can lead to excessive SLUDGE in Motor. 4. Gas Mileage can suffer (MPG) 5. Engine --- LIFE shortens! In short -- Nothing GOOD!! Not a good idea. I hope this pretty Much clears the AIR ---- I. INVITE Comments????? Thoughts? - JB-

 

[JPNinPA]

Gentlemen: Previous Poster has ASKED for a REFERENCE for this fact. OK. Many fine ARTICLES exist in AUTOMOTIVE Texts -- And On the Internet -- which will support - - My Post and Jesters Post! But, just to clear it up-- Here is Thermostat 101 : The PURPOSE of the Thermostat is to MAINTAIN the Engine Operating Temp. - Within its Design Parameters. This ENGINEERED Temp. Range will GIVE the BEST Balance of: POWER (HP), ECONOMY (MPG), AND. LONGEVITY (Eng. Life BETWEEN Rebuilds). In short--- The Thermostat MAINTAINS a PROPER ENGINE TEMP! IF YOU --- CHOOSE to Run your Engine WITHOUT a Thermostat--- A NUMBER of things CAN Happen! None of them Good! Sometimes --- People will PULL the Thermostat -- when FACED with an: OVERHEATING Problem! Thinking: My Engine will RUN Cooler!! Oh boy! Well -- NOT so fast! Better IDEA: Leave Thermostat IN - - Troubleshoot the Cooling System Problem! FACT 1 : Generally Speaking an Engine with NO thermostat --Will RUN. Cooler! But -- There have been CASES where Engines with NO Thermostat HAVE Over-heated! TRUE! (Jester was CORRECT!) Sounds Nuts - - But it is TRUE. Just a case of running an ENGINE -- WITHOUT. All of its-- DESIGNED PARTS! I mentioned that -- Generally speaking -- an ENG. Without a Thermostat will RUN COOL. (Usually). What BAD things MIGHT. Happen to an Engine RUN without a Thermostat? 1. HEATER will Run COOL! Not good on cold winter day!
2. When an Engine is RUN cooler than its DESIGNED Operating Temp. -- The Internal Clearances will be way out of Whack! (Too Loose) 3. Moisture Build-up in crankcase - can lead to excessive SLUDGE in Motor. 4. Gas Mileage can suffer (MPG) 5. Engine --- LIFE shortens! In short -- Nothing GOOD!! Not a good idea. I hope this pretty Much clears the AIR ---- I. INVITE Comments????? Thoughts? - JB-

Please, stop shouting in your posts as it does not make it easier to read nor understand. You are actually loosing creditability quickly.

I asked for references, like books or manuals etc that will shed more information on a single topic. Looking for a basic science based explanation of the condition. It would benefit many beyond the OP and myself. It will reach anyone who references this post.

I do not dispute the need or general operation of a thermostat. I agree running the correct thermostat is best in the long run. But thermostat stick shut and open a lot. So removing it to see if that is the cause is a short term test, is not bad. Thermos fail right out of the box occasionally so it may be worth the effort.

I wanted to understand the two statements better.
In a normal operating engine how does running no thermostat cause overheating?

Special causes - What are they and is it due to the thermostat?

And
How does slower "restricted" coolant absorb heat properly?


If you don't have references. That is fine. If I come across them I link them.

 

[superj]

HowStuffWorks "How does the thermostat in a car's cooling system work?"

This is how the thermostat works ( but I believe their decision on wax is wrong as I think it is probably the metal spring contracting that open the thermostat at a certain temp but not having built one, I cannot say for sure)

If you hit the links to the other pages, it talks about the cooling system too.

 

[jimbob2001]

I. Do have SOME References for you. -- Read this and YOU can become an EXPERT on Cooling. Systems! LOL!! I thought you COULD ONLY shout VERBALLY-- Not in Text!??? I'm not sure IF you were KIDDING -- OR NOT? Did ANY ONE Else get that ImpressioN??? My Posts tend to contain a lot of TECHNICAL Content --- That is just me.(but they are usually right on the money!) I believe Jester had the ORIGINAL Post on this Thread --- I Simply AGREED with him. He was 100 % correct. Comment?? Here is the. REFERENCE Material you ASKED For: 1. Auto Cooling Systems Basics. Author: Randy Randle. (2-99). Paperback. 2.. Engine Cooling Systems HP1425-- Author: Ray. Bohacz. (Kindle). Lot of Theory and. Design in this ONE! HP. Applications Covered. 3. Automotive Cooling Systems. By: Tom Birch (Good troubleshooting section) (5-80). Those Three Books could provide some LIGHT Reading Material. All. Can be found on the: Internet! Is that enough REFERENCE Material ? EnjoY! I'll try to keep the SHOUTING. Down to a Minimun -- Did NOT know I was that LOUD! Hope I DID NOT. Hurt your Ears. I may Not have 900 + Posts on this Board (Like Jester- whose Posts are always Right on the Money!) But, I do have 40+ years of EXPERIENCE working and Tinkering with Cars --- I think I have gained some SMALL amount of knowledge- Just a Gearhead! LOL! Let's all just PULL together -- On this Jeep Forum -- TO SHARE information --- Remember - No Flaming -- Its in the Rules. (Ask our Administrator). I. Submit this Post with all due repect to ALL of our Members--- KEEP ON JEEP'IN! And in the Spirit of the Season: Happy Holidays!! JB

 

[JPNinPA]

I thought you COULD ONLY shout VERBALLY-- Not in Text!??? I'm not sure IF you were KIDDING -- OR NOT?

FYI
All caps - Wikipedia, the free encyclopedia

Enough said.

 

[jimbob2001]

Yeah. - - That is. Enough said. Enjoy the Reading Material.

 

[JPNinPA]

Wonder if the OP solved his problem or if he got scared away??

Anyway, I did some reading of the reference material and such that people suggested. And Thanks for the references. I haven't acquired all of it yet, but, I plan to. So, here is what I found.

(I do not recommend running no thermo as stated I recommend using the correct temp thermo 195* for TJ’s)

If you recall here is my questions

I wanted to understand the two statements better.
In a normal operating engine how does running no thermostat cause overheating?

Special causes - What are they and is it due to the thermostat?

And
How does slower "restricted" coolant absorb heat properly?

Keep Your Cool - Website about Triumph and MG cars has a section on cooling. Not sure of the source. Precludes all with classic and custom vehicles issues - does state no thermo causes an issue by not allowing coolant in the radiator long enough to cool. Also quotes using 14 lb radiator caps vs. TJ 18 lb radiator caps so some things are different. The explanation for overheating is probable but different than earlier explanations and my initial questions.

Second was: Auto Cooling Systems Basics. Author: Randy Randle. This book focuses on cooling systems and discusses high performance, race and historically poor designs. This could be misleading if you’re not aware what engine or condition they speak of. There is a chapter on the ford flathead that specifically states not to run without a thermo. However there is information promoting the use of high flow thermo to get more 12-14 gallons per minute flow than stock 8 gallons per min flow. The use of high flow water pumps to gain 90 gallons per minute vs. stock ~50 gallons per minute. And Low pressure radiators to not allow the build of pressure and slow flow through the engine allowing heat to build and create hot spots in the engine.
Page 175 on High performance thermostats states “Once the engine is warmed to operating temperature, the ideal thing then would be to get rid of the restriction created by the thermostat, so the cooling system could work more efficiently."

There is several mentions of too high a flow not allowing the radiator to cool but only during high RPM and/or heavy loads.

There is also mention pg 106 of vapor bubbles being created not allowing fluid to reach the surface to absorb the heat. This causes hot spots. This is said to occur in heavy load and high stress conditions such as racing.

I researched more finding mostly the same findings than the above. One did describe the actual water flow being in a short loop in the front of the engine like the 4.0. Here the high flow might not allow the fluid from the #6 cylinder from circulating. Other engines have been designed for front to back circulation but not the 4.0.

There was also some variation on the term overheating. Occasionally it was used to describe the fluid boiling out, or temp to high on gauge. Other times it described the superheating of the system resulting in engine damage but without the temp gauge indicating the condition or the fluid boiling out.


So far there are a number of special conditions where no thermostat can cause you to overheat, though none stating faster. Some suggest building system for high flow and low restriction. Again, I do not recommend a TJ to run without a thermo for more than a test or short duration.
As far as slower restricted coolant absorbing heat properly. This is likely a typo and meant to state lower flow coolant to match the radiators ability to cool the fluid prior to recirculation in the engine.

Not sure I’m going to find a definitive answer especially for the 4.0 without experimentation.

 

[jimbob2001]

Glad you liked the REFERENCE. Material I suggested. There was some Good INFO in there. I especially Liked the Book by Rundle -- Dealing with HIGH Performance automotive Applications! Not sure IF the guy who started the Thread -- Got it all Worked out--- HOPE he got it all sorted out. We STARTED the Thermostat discussion -- Because he Replacéd Water pump-- Then Removed Thermosat-- BECAUSE. Jeep ran HOT. Recall? For the Most Part, It is Always a GOOD IDEA to Run Your JEEP with the correct TEMP Thermostat-- IF there is a Problem -- Then Troubleshoot THAT Problem. You mentioned the FORD Flathead Engine -- I owned a '46 Ford Flathead Motor -- A Motor I Used in the 60's for a DUNE BUGGY! Had a TON of Fun with that Little Buggy! (But being a TEEN-AGER -- I THRASHED the HECK out of it) STILL was a LOT of: OFF ROAD FUN! Those were the days --- I ALSO was into MOPAR Muscle Cars-- GTX- Cudas-Challengers! ( I Raced some of that MOPAR MUSCLE) Chrysler had some GREAT Cars! Pretty GOOD ENGINEERING-- Torsion Bar Suspension - Electronic Ignition-- HEMI Heads!) Ahh---- Them were the GOOD 'Ole Days! I digress some what. Where DID the Time GO?? What were we talking about? COOLING Systems. Keeping your Cool -- NOT Over heating. Thermostats. A shout out to -- Jester for his GREAT Posts on this Thread\Discussion! He had some very good COMMENTS----- Thanks! I Hope our fellow Jeepers --- Enjoyed the Exchange of Ideas and Information, Contained here on this Board ---- COMMENTS??
JB

 

[Turbogus]

On the 360 in 'BB'

originally it was set up with an electric pusher fan. Looked kind of funky so reversed the polarity and turned it into a puller fan (yes the fan direction checked out, a piece of paper was held fast on the frontside of the radiator when the fan was spinning up). Only during the realatively hot summers here in Oregon the mechanical temp gauge would approach 210* at highway speeds. Since then I've added a winch (I know it effects airflow to the radiatior) flowkooler waterpump, 180* thermostat and fan shroud. One thing I noticed about using a flowkooler~I had to incorporate a spring inside the upper radiator hose, I noticed one day while in the cab while reving the throttle while happening to peer into the engine compartment the new upper hose was collapsing.
Despite these steps last summer had 'BB' on the road and 210* was reached again. Coming to terms with this I just keep an eye on that mechanical gauge whenever I'm wheeling.