kpudden

Scanguage shows @230 today while driving on the highway...history is less than 1 year ago i replaced the fan clutch (to fix an overheating issue that began only when wheeling in CO) and fixed the overheating issue at that time. Now the same type of symptoms are occuring, but here in OK in the flats. I had a very slow leak on the top radiator hose, i replaced it cause i thoguht maybe i was getting some air into the system...on that note, i did a flush and replaced the coolant with 50:50 of the green stuff (i know i shoulda went red!!) Air could be a problem, but i ran the vehicle several times for 20 minutes with the cap off and heater on to purge bubbles. Now i am trying to replace the T-Stat...is it on the top side on hose like typically found or is it on the engine on the lower side? Hope its not my clutch, i turned it and it feels the same when the engine is warm as it is when cold.

WHAT AM I MISSING???

kYLE

scuba

Thermostat ?

mt_goat

Lower side, might try a TRD 160 t-stat. How old is the rad? Do you have a winch bumper up front by any chance? Mine ran hotter with the winch bumper until I redesigned it.

slisdexia

the fan clutch should lock up when it gets really warm and loosen when it's cold. These aren't hard and fast rules but that is the theory anyway. When the truck is idling in warm weather and at a stand still, the fan clutch should lock up(or close to) so the fan doesn't turn slower than the belt driving it, thereby pulling more air through the radiator. I'd double check that too.

DailyDrive

When you start up from cold, how fast does it get to 190F? How long does it stay there? How long does it take to climb up to 230? Does it plateau out at 230 for long periods of time?

kpudden

Thanks. i will double check the fan clutch again tonight...kinda sucks cause its not even a year old yet. The guy at the parts store says the fans typically loose 100 RPM a year on average. THe fan clutch was not and OEM so i may have bought a lemon...

kpudden

So far, i have replaced the top hose coming out of the radiator (it had swelled and was leaking VERY slowly, but could be letting air into the system), i have done the thermostat (confirmed the first one was ok by putting it on the stove and watching it open at the right T), and i drained and flushed out the green yesterday and went RED w/DI water. No change, idle temp on scanguage is 195, driving on a flat stretch of highway at 55 the temp shot up to 215 last night. I let the system run for 15 minutes with the cap off to burp the system. Hoping its not a damaged water pump, but it could be since this one now has @70K on it since it was replaced with the TBELT.

DailyDrive

I gave you a hint what to look for, but you seem to like to poke and replace parts, instead of troubleshooting

kpudden

I am not too quick on the "hints" apparently...might have to be a bit more subtle with me

As i said, at idle its @195, driving it shoots up to 215. On an incline i see even higher temps...got a fan clutch on order to try out this tonight. If this works, great...i'm done. if not, i am thinking water pump cause everything else is new. If the fan clutch isn't the culprit, i'll return it.

mt_goat

I might just note if your coolant is running hot your oil will too since its cooled by the coolant. I added an extra oil cooler for that reason.

Have you added a winch bumper up front? That can block a lot of air flow to the rad.

Also check that your AC condensor isn't clogged with crap, as well as the rad.

edwinb4x4

...make sure you have coolant on both sides of the engine...
here's what u need to do, unplug the top rad hose and pour the coolant there also until it's full (a little bit of overflow) then plug it back to the rad, retighten - test drive --

hope this helps

DailyDrive

Well, let's try this again.

To begin, your fan clutch can't be the problem at highway speeds, so don't waste time there. A natural 50mph+ rush of air is more than enough by itself.

Then you need to do this test. Record outside ambient temperature. Start up the truck from cold. Look at the gauge, and measure the time it takes to get to 190F. It should be a steady temperature climb. After it gets to 190F, what happens next? If you let it sit idle for 15 min, does it stay steady at the thermostat temp?

kpudden

YES

kpudden

Its been a while, but i still haven't nailed down the problem after replacing everything with the exception of the radiator....one thing i did notice is that the cooling fins on the top part of my AC Condensor are bent from what appears to be from power washing. I am going to pull the Condenser and use a tool to bend the fins back straight and also clean out all the bugs.

Anyone ever have to do this? Any caveats? I hope this does it cause i am getting

mt_goat

I've cleaned out the bugs and straighten my fins on the condensor many times. I try to keep good flow through it

98runner210

Sounds like a radiator issue. Like said above, highway speeds are enough to keep it cool. So i would rule out the fan clutch. I would look at airflow, radiator clogged or a thermostat.

kpudden

how are you cleaning it and straightening the fins? Are you taking the condensor out or just removing the grill and working with it in place? I have a little tool that has teeth spaced various distances apart that is used for fixing the fins, but it when i use it it collapses some of the fins inward so i think i may be doing more harm than good.
Thanks.

mt_goat

In place, it helps if you don't let it get too bad lol. I use long pointed tweezers I have and pull up a chair because its a slow process. I'm careful not to do more damage.

I have also cleaned it with compressed air a time or 2 (from the back side) when I had the radiator out.