this dang thing is still giving me heartburn. 94, 8 cylinder with AWD.

A couple years back I bought this one, and have been chasing my tail v. this "running hot".

New thermostat, radiator, fan clutch, hoses, flush, water pump. Hell... what else is there?

It will NOT idle in traffic without hitting 220. I know this is not "normal" what the hell am I overlooking?

Timing?

FWIW I just replaced the t-stat with a new 180 degree one, it runs up to 210 and all is well. park for a minute and it starts eking upwards, until the a/c cycles off. Ambient temperature isn't even close to summer, so I know that this isn't going to be a viable vehicle in a month.

why does my cooing system suck?

 

Air in the system?

 

Shine a strong light thru the core to see if you're getting enough air flow thru it. It could be plugged with bugs and debris. Likewise with the A/C condenser.

 

Verify that the fan shroud is installed and that the flexible air dams on either side of the radiator are installed.

Verify that the fan is installed properly, as-shown in the image.

 

The only other thing I can think of is when you replaced the water pump, did you get the right one? Meaning, the pump for the v-belt runs in the opposite rotation direction than the one for the serpentine belt. You have to be careful about this if you ever replace the fan also. I wonder about the clutch. I think that's just a fluid coupling.

 

Dave, the fan clutch was just replaced, and the air dam is also installed. the fan is whirling in the correct direction, air flow is good.

For all practical purposes, the entire cooling system is new.

What else can be causing this?

For S&Gs, I pulled the t-stat entirely. The result of that was it took a long time to heat up. Then ran hot when I got stopped it traffic.

If I turn off the A/C, it will eventually cool back down, but it takes a while.

I'm stumped.

 

Right now I'm going to tell you that without a thermostat at all, it will overheat because the coolant is passing thru the radiator too fast for the heat to transfer to the air. It's designed to run at 195* for the mixtures to be right.

If it were mine, I'd install an additional electric fan to help at slow speeds.

 

With the engine cool, remove the radiator cap to verify that the system is full of coolant, not air on the top.

 

Just double checked and added a quart of water.

There is no room for an additional fan unless I put it in front of the mechanical fan, and then kinda doubtful. I also think that would restrict flow.

I am going to blast it out with a hose, just to... IDK... rule that out, I guess.

As far as running it without the t-stat, It took forever to get to operating temp, but didn't run hot until ambient temp was in the 90s, a/c was running, and I left it running in the parking lot for 15minutes with the wife on board.

 

That means the engine has air, instead of the required full of water.

Remove the radiator cap safely, best when the engine is cool.

Then, run the engine with the radiator cap removed.

Once the engine is warmed up, the thermostat will open, permitting full flow through the engine. (My assumption is that the thermostat is installed properly.)

When the thermostat opens, the fluid level in the radiator may drop again. Continue topping off the radiator until it will not accept additional fluid. It doesn't hurt to blip the throttle to dislodge air.

My assumption is that the radiator cap is working properly and that the tubing to the overflow bottle is intact / leak free. The level in the overflow bottle must be between the tick marks.

 

Where?

There is no room in the front to put a pusher fan, and no clearance between the fan and radiator.

I actually have an electric fan, relay, and t-stat controller that I tried to run instead of the mech fan. It did the exact same thing. I have everything needed to do what you are suggesting, except for the real estate under the hood.

Maybee between the radiator and condenser?

there is another issue here, as I am sure it didn't come from the factory doing this.

 

Okay, without the room for an additional fan, I guess that's out. The only other suggestion I can think of is have you cleaned out the block? If you're using hard water to mix with the coolant, you could have mineral deposits in the block's water jackets. There are clean-out drain plugs in the center of each side near the bottom just above the oil pan. Pull those plugs to see if they are clear. On some engines, I've had to drive a phillips screwdriver into the hole to get the coolant to drain. If they are crapped up, run a cleaner or CLR and water to break up the deposits, then flush the system.

In my neck of the woods, many people are on wells and that water is like liquid limestone! Since buying this house, I use distilled water or buy premix. I recently replaced my home's hot water heater that was 20 years old and it weighted about 200 lbs from the crap in the bottom!

 

When I had my engine out and apart, I scraped the water passages as-far as-possible through all the openings and through all the removed expansion plugs.

There was a little crud, but not much.

Now it is nice and clean.

 

I'll give that a whirl. there is no telling what the previous owners did/didn't do as far as PMCS. It was a mess when I got it.

 

It has been raining an insane amount here in coastal Georgia, so I haven't popped out some freeze plugs just yet.

However; I have been thinking about this overheating issue.

Yesterday, I noticed an odd, new, and poor shifting pattern. I decided to check the fluid level (no leaks of any kind) and discovered it 2 quarts low.

Topped her off with 90w, and we will see if that has an effect.

Of course, I used the right stuff, and the old girl ran a good bit cooler. And shifted a lot better. We shall see with time.