Flushed coolant, still a click above 210?

[Ben824]

Following. I have a well rebuilt engine in mine. CSF radiator. NEW EVERYTHING in the cooling system including a heater core and it still will run a little hot. I ran a really heavy duty cleaner through it because someone suggested that while the engine was rebuilt, it could still have some crud in the system that wasn't totally cleaned out during the rebuild. That noticeably helped but I will still tick up passed 210. I am running a Duralast pump and fan clutch. Never had problems with the pump even when I had the same setup that ran at 195-205 before with my old CSF radiator before I made the mistake of using the garbage all aluminum radiators. But the fan clutch before was OEM. I was told that parts store fan clutches are sub par and that only the OEM pulls enough air reliably.

 

[Ecomike]

The Hayden Grand Cherokee ZJ fan clutch is an awesome upgrade, even though it is not OEM. It is and has tight fit issues!!! Runs very close to the radiator, so you need good engine-tranny mounts and there is a trick to install them.

210F operating at 105 F ambient in 100% Houston humidity with AC on max, at idle for 1 hour is something I never quite achieved. But I did get a 200-215 F operating range using the OEM style (Murry-Israel) T-stats. Never ever gets over 220 at the T-Stat now. Still a renix closed system, CSF radiator and ZK clutch with a volvo bottle cap and one brass nipple mod to the POS plastic aftermarket bottles. My two OBD cars operate at OEM spec temps of 210 to 222 F.

 

[Ecomike]

I ran a really heavy duty cleaner through it because someone suggested that while the engine was rebuilt, it could still have some crud in the system that wasn't totally cleaned out during the rebuild. That noticeably helped but

Indeed, the engine block cleaning vats (steel shot blasters and washers) at engine re-builders are not designed to descale or remove boiler coolant scale, Calcium and magnesium carbonate, silicate and hydroxide (basically dried cured concrete) that is a heat insulator, and it forms from leaking head gaskets (CO2, carbon dioxide) reacting with the silicates in the coolant, and from calcium and magnesium in tap water (always use DI or distilled water to make up or add to coolant, never tap water) reacting with silicates in the coolant. Only a hot strong acid for a long time will cut it and that risks eating up the metal in the radiators and welds and heater cores. Two safe options are DuPont Sulfamic (safest) acid, or acetic acid (Vinegar)!!!! Be sure to rinse several times and then neutralize any remaining acid before putting a coolant mix back in. Be sure to the drain the block and radiator 100% (freeze plugs????)!!!!! after the flushes.....

 

[Ecomike]

I got an IR thermometer and a Hayden 2625 fan clutch coming in today (I know I know, don't throw parts at it until I know whats wrong... but I figured at 150k miles it cant hurt to replace it)

Will report back with what I find. Thank you all for the input.

Check around the intake, exhaust manifolds for any hot spots!!!!...exhaust leaks also with that cool new IR gauge. It will also help you see when the T-Stat opens....

 

[Transpoquick]

I would try a 180 thermostat.
Works good on this part of earth.

 

[erykv1]

I would try a 180 thermostat.
Works good on this part of earth.

I'll do that as my last resort, I know it cooled properly before with a 195 so I'd like to fix it if possible.

------------------------

Update. Changed out the fan clutch this morning... man that fan shroud was a PITA to work around. I don't see how anyone can remove the fan shroud as there was no room to wiggle it out. I had to drop the fan assembly from the bottom of the car to get it out.

Anyhow, I drove around and the temps went back up a click. I took out the IR thermometer and took some readings. Please note, the cheap thermometer I have has a set emissivity value of 0.95, I am not able to change it to match the material constant, but it should give a close enough idea as to what the temps are.

Assuming each click is in ~12.5* increments, I drove around until the jeep was warmed up and temps stabilized. Didnt seem to go over ~222.5*F. Everytime I pulled over and let it idle, the temps would eventually drop down around to 210*.

Seems like the temps around the t-stat are really high, but the radiator hoses are much cooler. Is this symptoms of a t-stat issue? The t-stat I have is a Stant 45359 SuperStat. I didn't drill a hole in it when I installed it, but it seemed to have pretty good reviews.

What do you guys think?

 

[ehall]

That's a little warm but its not bad. Short-term spiking might be the radiator cap, sometimes they get sticky and the relief stops working where it should. http://www.napaonline.com/napa/en/p/BK_7031702/BK_7031702_0443751063

 

[erykv1]

That's a little warm but its not bad. Short-term spiking might be the radiator cap, sometimes they get sticky and the relief stops working where it should. http://www.napaonline.com/napa/en/p/BK_7031702/BK_7031702_0443751063

I'm afraid it will get hotter if I get on the freeway.

I also replaced the rad cap when I overhauled the cooling system with a Stant 10231 Radiator Cap - 16 PSI Vented. I guess getting a faulty one is a possibility?

I just am confused as to why it ran fine for 4 months before anything happened.

 

[RedHeep]

The laser is just a guide, make sure you're close enough to ensure that the optical part of the gun is testing what you're aiming at. The difference in materials will make a difference in the temperature readings as well. You're going to get a different level of accuracy on an aluminum housing than you will on a rubber hose.

Usually it's close enough for government work, but it's also easy to see that it's a best guess machine when you know that the coolant isn't dropping 80 degrees from one end of the upper radiator hose to the other end.

You need to take a temp reading of the top and bottom of the radiator, as well as one side to the other. Then you can see how effective your radiator is, like Mike mentioned above.

It very much looks like your radiator isn't doing it's job to me. I played this game for a long time and when I finally put a mopar HD radiator in my XJ, I couldn't get it to get a degree over the thermostat opening. I drove to work on thursday afternoon when it was 92 degrees outside with the A/C on full and I never saw the needle get vertical to 210.

Check your radiator temps and do a little reading on how to get your IR temp gun to work the best.

 

[Rod Knee]

I played the overheating game for 2 years with a 3 row CSF. Did the whole cooling system, did all the temp checks, etc. and it would heat up on the highway and cool down at idle. Everyone said head gasket, so I changed it (twice, because I'm the guy that tears the first gasket).

Still did it. Bought a mopar radiator and it runs exactly at the thermostat all day when it's 100 degrees outside. Tossed the 3 row magic answer in the scrap pile.

We all have our own stories I guess.

I had the exact same experience. Changed out all components multiple times except the CSF 3 row radiator because it was the biggest, most bad ass rad. money could buy and I just knew that it couldn't be the problem. Nothing worked. Time went by and the CSF radiator finally started to leak so I replaced it with a stock radiator...no more overheating.

 

[Ecomike]

The difference in materials will make a difference in the temperature readings as well. You're going to get a different level of accuracy on an aluminum housing than you will on a rubber hose.

The issue is not accuracy. The rubber is an insulator and heat moves very slowly through the rubber, and the surface has more time to cool in the breeze the fans make, thus the rubber outside does drop a bunch from the inside to the outside cover. The heat can not move through the rubber fast enough (thermal insulator) to maintain the outside rubber at the inside rubber temperature.

Good comments on the other stuff!!!!

 

[Ecomike]

when I overhauled the cooling system.

I just am confused as to why it ran fine for 4 months before anything happened.

What exactly did you do to the cooling system before the temps went up, or did go up before?

My 96 (Ford Taurus) and 2001 (Saturn) factory settings are on at 222 for the Efan and off at 210F. So 220 F may actually be normal for a 2001 Jeep (OBD-II EPA fuel and emissions needs pushed the OEMs to do this, and synthetic oil helped make it possible).

Could the old or new T-stat have been damaged or bad, over cooling before on the old one (if you changed it, of if it is the old one is it damaged and not opening fully?) Bad new or old Temp sensor that the PCM uses to turn on the e-fan? Bad Temp sensor wiring or dirty connection to the PCM giving it bad data...which affects the efan on/off temps

The 96 temp gauge moves from 210 to 220 and back unless the AC is on, then the Efan is on 100% at max and the temp stays at 210 F, the 2001 sits at 220 F all day long once hot and the T-stat regulates the flow. It drops also if the AC is turned on which turns the efan on all the time. Try it with AC on, doors open, and even try defrost to see what it does. You may not have a problem!!!!

 

[Ecomike]

I noticed a while back that most of the dealers stocking and selling CSF radiators started lying and calling the 2 row radiator a 3 row radiator. I caught 5 of them lying about it back around 2007. Mine is a true 3 row and it barely fits, barely 1/4 " of clearance to the ZJ clutch. Must have good engine and tranny mounts to get away with both. More space, about 1/2" with the stock OEM clutch.

 

[erykv1]

What exactly did you do to the cooling system before the temps went up, or did go up before?

My 96 (Ford Taurus) and 2001 (Saturn) factory settings are on at 222 for the Efan and off at 210F. So 220 F may actually be normal for a 2001 Jeep (OBD-II EPA fuel and emissions needs pushed the OEMs to do this, and synthetic oil helped make it possible).

Could the old or new T-stat have been damaged or bad, over cooling before on the old one (if you changed it, of if it is the old one is it damaged and not opening fully?) Bad new or old Temp sensor that the PCM uses to turn on the e-fan? Bad Temp sensor wiring or dirty connection to the PCM giving it bad data...which affects the efan on/off temps

The 96 temp gauge moves from 210 to 220 and back unless the AC is on, then the Efan is on 100% at max and the temp stays at 210 F, the 2001 sits at 220 F all day long once hot and the T-stat regulates the flow. It drops also if the AC is turned on which turns the efan on all the time. Try it with AC on, doors open, and even try defrost to see what it does. You may not have a problem!!!!

I almost never use my AC. My heater core is also currently bypassed but I'm not sure if that makes a difference. I understand that sometimes turning the heat on allows the heater core to dissipate some heat alleviating temps. Unfortunately after the cooling system overhaul this winter, the heater core took a dump shortly after and I have not had the time to rip the dash apart.

I replaced the cooling system with the following after the original radiator sprung a leak:

-New Upper & Lower Radiator Hoses
-New Stant 45359 195* Superstat & Gasket
-New Stant 10231 Radiator Cap
-New Gates 42004 Water Pump & Gasket
-New Spectra CU1193 Radiator

The jeep ran fine all winter / spring never over 210*.

The only thing I didnt get to do was give it a proper flush. However I did it last week when I flushed the coolant with the prestone flush kit & their flush & cleaner. There is a possibility that the residual gunk in the system has clogged up the radiator?

Thank you all for the input thus far :worship:

 

[Ecomike]

Unfortunately that is very possible.

"There is a possibility that the residual gunk in the system has clogged up the radiator? "

It may not be too late to run tap water and some DuPont Sulfamic acid (about 1 lb per gallon as I recall, powder, it dissolves in water) to descale the radiator and block!!!! We us it in industrial cooling/heating system heat exchangers.

https://www.google.com/search?q=sul...la:en-US:official&client=firefox-a&channel=sb

I use the pure powder by itself. You might want to research it some for whether or not it needs inhibitors for brass, or not, for extended use. What I recall from my early research on it 25 years ago was that it is safe for short periods on brass. Not sure about aluminum. I use it on stainless hardware mostly, but plan to use it on my jeeps if the need ever comes. I suspect on a scaled block and radiator it will get consumed and become much less aggressive pretty fast, before it could attack the brass. Hell Walmart and Target are selling blends of it with other stuff like water, LOL.

https://www.google.com/shopping/pro...d=0ahUKEwjghMjL-P3MAhVOE1IKHWXsDB4Q8wIIqAEwAA

 

[Ecomike]

If you do this descaling with Sulfamic acid, rinse/flush it with tap water with a Prestone heater hose (garden hose) flush kit, and then use some alkaline neutralizer next, like sodium carbonate (Backing powder in the grocery isle, NOT baking soda it will foam too much), to kill any left over acid, then rinse the hell out of it, all with tap water again, then drain the block and radiator 100% (may need to use a freeze plug to truly drain the block), Or buy about 10 one gallon jugs (about 89 cents each, in the drink isle at the grocery store) of DI/Distilled water with 2 gallon batch flushes (engine running for 5 minutes). Do at least 3 DI water flushes, then go with 50/50 antifreeze.

 

[Ecomike]

It is also possible the Stant T-stat is stuck or sticking part way open.

 

[erykv1]

Unfortunately that is very possible.

"There is a possibility that the residual gunk in the system has clogged up the radiator? "

It may not be too late to run tap water and some DuPont Sulfamic acid (about 1 lb per gallon as I recall, powder, it dissolves in water) to descale the radiator and block!!!! We us it in industrial cooling/heating system heat exchangers.

https://www.google.com/search?q=sul...la:en-US:official&client=firefox-a&channel=sb

I use the pure powder by itself. You might want to research it some for whether or not it needs inhibitors for brass, or not, for extended use. What I recall from my early research on it 25 years ago was that it is safe for short periods on brass. Not sure about aluminum. I use it on stainless hardware mostly, but plan to use it on my jeeps if the need ever comes. I suspect on a scaled block and radiator it will get consumed and become much less aggressive pretty fast, before it could attack the brass. Hell Walmart and Target are selling blends of it with other stuff like water, LOL.

https://www.google.com/shopping/pro...d=0ahUKEwjghMjL-P3MAhVOE1IKHWXsDB4Q8wIIqAEwAA

Thank you for this Ecomike!

I did backflush the radiator with the prestone kit until the water came out clear (removed the thermostat, then let the prestone kit flush with a hose for about 15 mins), but I guess it might have not been enough pressure to get the gunk out if there was some remaining.

To be honest, if it turns out it is the radiator, I think I will go ahead and replace it again with a new unit. I think I may replace the t-stat first as it is much cheaper.

Is there some allowable delta in temperature difference between the upper and lower radiator hose that indicates the radiator is not doing its job?

 

[erykv1]

Just drove around, didnt go over 210*

Ambient temps today: 70*
Ambient temps yesterday: 82"

10 degrees can make a diff between overheating or not eh?

 

[RedHeep]

Your ambient temperature shouldn't have a drastic effect on your coolant temperature.

It means that your cooling system isn't doing its job effectively. Especially at 80 degrees outside.