High temp woes

[Anak]

Without seeing your metallic particles it is hard to say anything, but I can say that from my own experience with Cold Case radiators they leave a lot of aluminum chips in the radiators. Whatever cutting they are doing in the process of manufacturing seems to leave chips behind. I would hope they would be trying to clean those out, and maybe they do some cleaning out, but it is far from thorough.

 

[Vitzaa]

Didn't get any aluminum shavings... But I get what you're saying.

The metallic particles literally look like metallic dust clumped together. They're extremely fine, smaller than a grain of sand.

Either way, it's all good. I'm just glad to be running normal temps again and am looking forward to splitting open this filter to see what it's picked up.

 

[ShoeterMcgav]

How did you reverse flush the radiator (i know you mentioned a kit, but curious about the process)? Or hook up air for that matter? Into a special radiator cap? Or did you remove a hose? Curious how you flushed it "both" ways.

I'm less worried about the actual radiator and more concerned with whats past the water pump. Im getting ready to swap both, so I want to get all the gunk out of the block and heater core before swapping the new components in.

 

[Vitzaa]

How did you reverse flush the radiator (i know you mentioned a kit, but curious about the process)? Or hook up air for that matter? Into a special radiator cap? Or did you remove a hose? Curious how you flushed it "both" ways.

I'm less worried about the actual radiator and more concerned with whats past the water pump. Im getting ready to swap both, so I want to get all the gunk out of the block and heater core before swapping the new components in.

If you have junk, I highly recommend an acid treatment. I'm going to be doing this myself in the next week to get the remainder of junk out. I'm running 200-210 on street and up to 220 on highway w load so I'm guessing some junk is still clogging things up...
Did some research and am gonna go with a citric acid flush. Remove thermostat, reattach thermostat housing and mix 2.5lbs of acid with water. Pour in and top off w water. Start and purge air, shut down, Let the fizzling stop, top up with water, put cap on and get up to temp... Let sit a couple hours, drain and flush w water a bunch of times. Finally flushing w distilled a couple times and a quality HOAT coolant (g05).

As far as back flushing, here's the gun

Mityvac MV4570 Automotive Radiator/Cooling System 85-150 PSI Combo Air and Water Flusher with Multi-Size Nozzle, Zinc Die-Cast, Ergonomic Design, Field Serviceable https://a.co/d/1EEgohX

Basically, remove radiator, keep cap on and drain connected, place gun into the radiator outlet sealed tight to it with a rag between gun and metal... Turn water on and hit the air trigger a couple times. Sends shit flying.
Same w heater core, just be careful w pressure.

The citric acid should dissolve all the calcium/rust safely without damaging anything internally. It does meet to be heated though to work. Think of it as an internal hot dipping for the block.

I'd also recommend installing an inline coolant filter coming out of (or going into) the heater core. Make sure to do a bypass on the plumbing as the filters aren't able to support high volume.

I can attach a pic of my setup if you need one.

 

[Bent]

195 stant superstat first.

Stant has been sold to Motorrad. The superstat is not a Super thermostat any more. They are stamped Motorrad, and the brass breather pin is no longer part of the unit. That is what I noticed with just a visual inspection.

I sent it back and ordered the Gates, surprise!

Gates are also Motorrad, and the same as the M.R. version of the Superstat. Really bummed me out. Stant superstats were my go-to for years.

Agree with the standard water pump. A lower temperature thermostat is not going to solve anything. Maybe reduce gas mileage. A 195 that works properly is what you want to put in. Test it before you install.

ETA: you don't need a special gun to flush in either direction. A regular hose nozzle wrapped with a rag will seal up just fine

 

[Vitzaa]

Stant has been sold to Motorrad. The superstat is not a Super thermostat any more. They are stamped Motorrad, and the brass breather pin is no longer part of the unit. That is what I noticed with just a visual inspection.

I sent it back and ordered the Gates, surprise!

Gates are also Motorrad, and the same as the M.R. version of the Superstat. Really bummed me out. Stant super stats were my go-to for years.

Agree with the standard water pump. A lower temperature thermostat is not going to solve anything. Maybe reduce gas mileage. A 195 that works properly is what you want to put in. Test it before you install.

ETA: you don't need a special attachment to flush the system and need the direction. A garden hose with, or without a standard high flow hose nozzle wrapped with a rag will seal just fine.

Tried the garden hose sealed and it's not even close to the pressure/agitation that the gun produced. MASSIVE difference!

 

[Bent]

Tried the garden hose sealed and it's not even close to the pressure/agitation that the gun produced. MASSIVE difference!

Hmmm...

 

[ShoeterMcgav]

Ah. I'm not going to work that hard to clean the radiator I'm replacing it.. more concerned with the heater core and engine.

Acid treatment seems excessive for my junk.. I have hot air in the winter and never overheated

 

[Vitzaa]

Ah. I'm not going to work that hard to clean the radiator I'm replacing it.. more concerned with the heater core and engine.

Acid treatment seems excessive for my junk.. I have hot air in the winter and never overheated

All that junk swimming around the engine and clogging up the heater core will dislodge and clog up the new radiator... At least that's what's happening with me. I must have removed that radiator at least 5-6 times at this point.... The acid treatment really isn't bad and will save you the work again later

 

[GritCityXJ]

I have had good luck with AC Delco Gold/Professional water pumps. They are new, not rebuilt.

Had a similar problem with my son's '95. Turned out to be a stuck thermostat. We tested it before installing, but it failed almost immediately. Tested and installed a failsafe Motor Rad off Amazon. Problem solved.

Agree. Have owned 3 XJ’s find top quality OEM water pumps and 195* are all you need. 270k on my latest no issues. Make sure you purge air out of coolant system? Burp that b….

 

[Vitzaa]

So I did the citric acid treatment, worked great.
I kept it in for 1-1.5hrs but should have kept it in longer. It just kept bubbling and bubbling, indicating that the calcium build up was reacting with the acid... I decided to drain and flush because the liquid started turning black/smelly, which might have been due to the heater hoses eroding. Gonna do the flush again (until the bubbling stops this time) but replace the heater hoses with some 2' generic hose.

Prior to the flush, temps hung around 210-220, hwy and city...
After the flush, I'm 190-200 (185tstat) city driving and 210 on hwy. I went on a prolonged uphill drive And hung around 220. It quickly decreased once the road leveled out.

Anyways, I think I'm almost done with this heating issue. Gonna pull the radiator today and back flush to see if anything is still lodged in it.

Also, cut open the coolant filter and found a solid tablespoon of this fine sand like magnetic particles. I think it's stopleak from the previous owner.

 

[Bent]

Never heard of a Ferrous stop leak. Mostly aluminum, and ginger root.

 

[Hangarone]

I have a 1998 with Golen 4.6, automatic, 4.55 gears on 37" tires. I have replaced every mechanical component, tried every flush, tried blocking off heater core, went back and forth from mechanical fans to electric, alum radiator and stock, separate trans cooler etc... with no luck over the last two years. Recently bought the HP tuners module and looked at the ECU timing map. The factory ignition timing is very conservate and the ECU is programmed to further retard timing at higher IAT and ECT. I believe this "safety measure" causes late combustion increasing heat around the exhaust ports and coolant passages specifically in the head. I added 3-4 degrees of advance to the main map (not the idle or deceleration ranges) and limited the IAT and ECT retard tables to only pull 1-2 degrees of timing vs 4-5. So far jeep has shown no sign of high temps at all! BUT, temps here have been mild and I have not been wheeling since the tuning changes. This also seemed to really wake up the stroker, as I have been a little disappointed with performance. I am in the process of installing a wide band O2 to look at AFR to make sure I am not running lean as well. It is my theory that timing plays a big role in these rigs overheating and hope this helps someone struggling with the same issues.

 

[Rob Mayercik]

That is interesting for the later rigs that have OBD-II and a reprogrammable ECU, though it won't help the older (non-tunable) models.

Still, something to chew on.

 

[Black1990jeep]

This...

1999 JEEP CHEROKEE Summit Racing SUM-382012 Summit Racing™ Classic OEM Radiators | Summit Racing

Free Shipping - Summit Racing™ Classic OEM Radiators with qualifying orders of $109. Shop Radiators at Summit Racing.

www.summitracing.com

Copper/brass, no plastic. double row, not single like my mopar aluminum and plastic radiator. Much cooler running now with this new radiator.

your issue aint airflow as your temps are high on the freeway.

You can test with no thermostat, just confirm the T-state aint failed closed (or test on stove top)

 

[Fred]

Hesco water pump. 90 XJ, 4.1l, 11-1 HO head, Hesco cam and water pump, cheap two row aluminum radiator, bored t-body, Mopar header, 2.5" exhaust, not shown full roll cage, it's a heavy bitch. Moves out quite well at 6k feet, I only need the e-fan in stop and go traffic when it's hot, or when I'm in 4-lo going uphill at 11k feet. I put in the hood louvres because I thought it would run warm after the engine build. It's the coolest it's run in the 32 years I've had it. Rock rails from the very first Moab trip.

 

[Vitzaa]

I'm so frustrated with this temp thing!!!

I've done another acid treatment and got more calcium out. Removed and back flushed the radiator probably a dozen times at this point. Also back flushed the heater core and kept getting junk out. Threw the bypass filter on.

I'm currently running the bypass filter straight out of the heater core and it's direct without a bypass route for the coolant. Radiator is clean without sediment.

Went two temp ranges cooler on the plugs and motor sounds happier.

Currently in northern California so outside temps have been 90's to below 110.

Hwy cruising with minimal load in below 220.
Hwy with load I'm getting to 230 before I have to turn the heater on, which keeps temps rising slower
City driving I'm staying 210 (will cool down to 200 sometimes in lower gear)
At idle, the temp rises one degree every two seconds.

Can't run ac, and have to use heater to keep the motor from overheating...My wife is pissed, kids sweating in the back seat.

I honestly feel like I'm up against the wall with this. Don't know what else to do...

 

[Vitzaa]

This...

1999 JEEP CHEROKEE Summit Racing SUM-382012 Summit Racing™ Classic OEM Radiators | Summit Racing

Free Shipping - Summit Racing™ Classic OEM Radiators with qualifying orders of $109. Shop Radiators at Summit Racing.

www.summitracing.com

Copper/brass, no plastic. double row, not single like my mopar aluminum and plastic radiator. Much cooler running now with this new radiator.

your issue aint airflow as your temps are high on the freeway.

You can test with no thermostat, just confirm the T-state aint failed closed (or test on stove top)

I've got the mishimoto performance rad, which should be the same thing
Tstat works. Tested with water on the stove

 

[Vitzaa]

I have a 1998 with Golen 4.6, automatic, 4.55 gears on 37" tires. I have replaced every mechanical component, tried every flush, tried blocking off heater core, went back and forth from mechanical fans to electric, alum radiator and stock, separate trans cooler etc... with no luck over the last two years. Recently bought the HP tuners module and looked at the ECU timing map. The factory ignition timing is very conservate and the ECU is programmed to further retard timing at higher IAT and ECT. I believe this "safety measure" causes late combustion increasing heat around the exhaust ports and coolant passages specifically in the head. I added 3-4 degrees of advance to the main map (not the idle or deceleration ranges) and limited the IAT and ECT retard tables to only pull 1-2 degrees of timing vs 4-5. So far jeep has shown no sign of high temps at all! BUT, temps here have been mild and I have not been wheeling since the tuning changes. This also seemed to really wake up the stroker, as I have been a little disappointed with performance. I am in the process of installing a wide band O2 to look at AFR to make sure I am not running lean as well. It is my theory that timing plays a big role in these rigs overheating and hope this helps someone struggling with the same issues.

I think this is my next option... Unfortunately, I'm not talented enough to play with these numbers.

Can I PM you for some guidance?

Also, I'm wondering if throwing it on a Dyno is the ideal way to get things squared away with tuning... Does anyone know a Dyno shop in northern Cali that can work some magic?
I don't mind throwing some more money at this. My wife constantly repeating the should have got a newer wrangler is starting to get pretty annoying as I truly love everything about this xj, except this overheating thing.

 

[RCP Phx]

Replaced the pump, fin direction was identical to my previous pump. Made no difference.
That doesn't mean the rotation is correct!