J10 seems to be getting much hotter with a new water pump

[candymancan]

So the kriginal iron pump went out. And i replac3d it with a GMB aluminum pump. Same pump i put on my 90. No issues installing it besides a couple long bolts that were a B to get out.

Filled it up and burped it for a bit, drove it around for 30 miles. And filled up the reservoir a few times as i went. Temps were fine but i noticed when i got to town and parked it for say 15 min and went back out. The heat soak really jumped the temp up much higher than im used too.

Drove around the parking lot. And then sat idle for 5 min and the temp kept creeping up and up and got close to the (red) line so i turned it off.. went into walmart to cool down.


After about 35 min or so i came back.. and checked and it dropped down to the first notch on the cool mark. So i carefully poped the cap off.. was cool no pressure inside. But it didnt need topped off.

So i drove it home. No issies . Stayed at the first notch on the cool line.

But again today when basically idling. Or driving slow in the woods to pull out a rotten hunting stand. Again temos creeoed back up to the midway mark and keot going higher.


Ive never seen this before until after i did the waterpump. So any ideas ? Clutch fan is fine. Spins like 2 inchs if i try to spin it so it isnt bad. When cold i mean.

Coolant level is full. The only thing i didnt do is replace the thermostat. But i dunno.. radiator is blazing hot so i dont think its that. But i have a new one ill put in. Just in case

The fan has no shroud. But again its never done this before.

I added a pic of this jeeps guage. The red line is where its usually always at.. driving highway speeds it might go a tad bit higher but thats it.

The teal line is where its going too idling now which is odd.

The other pic is the new pump. The blade design is different.. but my 90 has the same pump. If anything its higher flow the outlets and inlets are all larger diameter and casted way better than the iron pump.

The blades seem to be the right direction too i think.

The only other thing is its been low 70s outside. First time fir me on this J10.. ive had it running for only the winter months.. so 20-50f outside usually. Not sure if the higher outside temps are causing it.

[seventynine]

Odd. Mine with that same temp gauge usually run with the needle straight down once warmed up. Defective pump?

Which would suck…these AMC water pumps are a pain in the butt to get out. Gotta love the 4 bolt Chevy 350 pumps

The pump on the outside of the time chain cover which has its own gaskets that can get unsealed in the process. Bad design.

[candymancan]

When i first turned it on.. and was burping it.. i noticed it was flowing heavily in the radiator. I dont think its defective. Was odd how it was flowing right away though.

I knee i shoulds just done the thermostat. I wonder if i even have one or something.

It seems like it working.. the radiator gets scorching hot. It only cools down when driving. Like the fan isnt pulling enough air.

Yea my 90 when i did the pump broke the seal on the timing civer.. terrible design. I had to tighten those 4 ling bilts gorrila tight.. to make a seal again thankfully it hasnt leaked in years lol

And ya i agree getting to the pump was annoying. With factory a.c. hidden bolts all over.

If yours is reading on the bottom. You sure your gaugis working right ? Or the sensor.

[letank]

double check with an infra red thermometer.

[candymancan]

Ok i got a infarred thermometer.. couldnt find my old one.

When the gauge is half way in the green.. the thermostat housing reads 225f. Upper hose reads. 175.. radiator top reads 225. Lower hose reads 175f. Water pumps read 184.

Seems a tad hot to me. But im not sure.. im going to check and verify with my 360 on my 90 and see what its reading.

Maybe this gauge is just super sensitive.. and 5-10f is a big jump up or down for it. I still feel it should be cooler. And it does get cooler if i am driving like 55mph. Feel like my radiator/fsn arent pulling enough heat from it when its at idle or traffic.

But the clutch fsn spins maybe half only 1.4 turn when cold. So it seems ok. But i noticed it doesnt seem to be increasing in speed when it gets hotter n hotter..

Not sire if this infarred therm is reading the temp off rubber hoses right.. why would thr upper hose be 175 if the thermostat is 225.. and the lower hose is 175.

Edit. I also unpligged the temp sensor.. which was rusty.. cleaned it up.. put it back on.. same temps. Infarred therm shows 215f there

[letank]

On the 85, with my infrared and 195 thermostat I read 195-198 at the thermostat housing, a bit higher on the upper hose in the 198-200, about the same on the radiator top, and forgot about the lower hose, I posted some years ago that we should get at least a 50F differential on a 65-70F day. Oil pan reads at 225F.

My gauge read at the low 1/4, and a bit lower on a colder day.

I also have the GMB water pump. I can idle for whatever time, such as a construction traffic jam as it has happened a year ago for 30min of really crawling speed.

After shutting down and checking the temp 5 to 10 min later the temp will go up such as gas refill time, depending on the outside temp, yes temp can go up 3/4 into the green, but will quickly go down when the engine is running, probably within 3 min.

[candymancan]

So thrn mine is reading 20f higher than yoirs like i thought.

So why isnt it cooling right. Im going to have to flush the system. I pulled thr coolant out and boy is it dirty.. lol oved 2 gallons of new coolant and water and its already got a brownish but still green tint to it and its cloudy looking.

I wonder if me doing all this stirred up sediment in the system. Can i flush the block and radiator with a hose this way i csn continiiusly flush until im satisfied ? I do have well water though which has high iron in it. Thays the only thing

[letank]

It gets tricky, on another project it was rust central in the cooling even with correct temperature reading. But as you , the coolant was turning cloudy . I redid a flush with the garden hose system from Prestone (Prestone flush and fill) , and redid again... and making sure that the coolant is on top of the radiator filler neck, no air space.

Some suggest to unplug the drain plugs in the bottom of the engine toward the rear to clean out any sediments...

WELL WATER could be your issue.... I use steam distilled water. I had friend on well water and their inside dishwasher had a rusty hue... the friends said that it happened within a month.

But someone drain plug snapped... so reverse flush could be the way

viewtopic.php?t=6052

[SJTD]

Can you guys still get the real two part flush? The magic about it is that when you reduce rust in the chemical sense, meaning convert it back to iron, it's volume is about a tenth what it was so it loosens up and flushes out.

[candymancan]

I never used well water.. i am asking can i shove a hose in there to flush it continiously

[letank]

I never used well water.. i am asking can i shove a hose in there to flush it continiously

good, as you mentioned that you had well water... as a substitute for flushing it will be fine.

I used the tap water to flush my system, about 25 gallons (filled up 5x5 gallon buckets) to obtain clear outflow with the reverse flushing, and the engine running at operating temperature so the thermostat is opened.

[akguy09]

My J10 with a 304 and a 6 cyl rad is usually about 205 at the t-stat housing with a 195 tstat

[devildog80]

Your temps sound near identical to my '84 GW, when I was trying to find my cooling issue. New pump moved more fluid, but still running warm while driving, ultimately found the new radiator was the answer. And my old radiator coming out was heavy. I know the brass ones weigh more than the new aluminum, but only imagine how much crud is inside of it, adding pounds after 40 years in service.

My build thread - 84 Grand Wagoneer Revival

[candymancan]

Starting to think it is actually the fsn clutch.

Noticed HOT idle. My wagoneer fsn clutch blows tons of air i can feel it blowing on my face just standing in front of the grill you know from it reflecting off the engine...

The J10s does this.. when cold.. when its HOT i cant feel any air blowing on me. And watching it.. its way faster when cold.. and much slower when hot. It should be getting faster when hot. Not slower.

Im going to buy this duralast fan clutch. Same exact one that BJS and Teamgrand wagoneer sells. Just double in price for BJS. because theyre scammers like that.

Your temps sound near identical to my '84 GW, when I was trying to find my cooling issue. New pump moved more fluid, but still running warm while driving, ultimately found the new radiator was the answer. And my old radiator coming out was heavy. I know the brass ones weigh more than the new aluminum, but only imagine how much crud is inside of it, adding pounds after 40 years in service.

My build thread - 84 Grand Wagoneer Revival

If thats the case youre running hot. My 90 i checked the temp probe in the intake with infarred gun. Its 203f max 207 wouldnt go higher. Tstat housing the same. On my J10 its 225 on both lushing 230 if i waited a long time. Its running way hotter than the 90, nearly 20f higher.

If im rolling at 30-40 mph temps drop a lot on the gauge. Which means it isnt the radiator but the fan.

Makes sense i think since i just noticed the fan is slower when hot.. than cold.. it should be faster hot and slower cold. Think that means the clutch fan is bad

[devildog80]

That does sound like the clutch fan, in you're case could be the issue, as mine does work as designed. Slow when cold, fast when hot, but my old radiator was just not allowing enough cooling. Hence, radiator was my magic smoke solution.