need some help with running hot

all right before you bust my ball to much please hear me out .and if this is still in the wrong section ill have it moved .
so here it goes .in the morning its fine .if i drive it down the highway 65ish it starts running hot . like 230-240 . it hasn't run into the red yet but its running way hotter than it should but it only happens on the freeway .and then it will take forever to cool down ,the only exception to this is if I'm going down hill for a ways and then it cools right off .but it can sit at a idle for ever and not over heat.
so here what Ive done ad what some of my concerns are .
engine swap to a 98or 99 I'm unsure of the specif year but it has the newer intake and the better head #'s .
what Ive replaced so far .
new rad aluminum
new 16 lbs rad cap
new fan shroud
new t-stat .it will run u to 210 on the gage and then ill see it cool down
new water pump .doesn't seam to be moving water tell i rev it up and then i can see the water rushing .
new heavy duty gc fan clutch
new plugs,cap rotor and wires . the plugs are for a 99
most all of the sensors are new except the tps,the one inside of the dizzy ,knock and temp sensor but it seams to be working correctly with when the aux fan turns on .
new hoses top have a new bottom .gonna install to night .
I'm going to install a trany cooler to night .
new antifreeze that i dilutes a bit with distilled water .
so this is all went into a 89 i kept the renix electronics . it runs really good . it dose seam like its down a little on power tho .
the header is relatively new and I'm running 2.5 exhaust all the way back . has the older cat tho .
so my rad fluid looks good tell i add water to it and then it gets kinda murky brown .
there no sweet smell in the exhaust and the pressure out of the pipe seems good .
no water in the oil
new trany fluid and filter .
geared correctly for the tires .
i cleaned out the ac condenser seamed to help out a little .
so to night i plan on back flushing the whole system ,i did the heater core when i swapped the engine ,drilling some holes in the t-stat .putting new lower hose with spring. i didn't see it collapse when reeving the engine but its older and doesn't have the spring in it .and putting on the tranny cooler .
the parts store looked at me like i was crazy when i asked them about testing the fluid for exhaust gasses .
so I'm kinda tired of trowing money at this .and i could really use ur help .
do you guys thin that I'm running the wrong spark plugs ?
could my cat be clogged ? i talked to a mechanic down the street and he said that i wouldn't really be able to go if it was .
do i have a head gasket leak ? same guy said to check the upper rad hose during start up to see if it gets hard really fast due to exhaust gasses building up in it . i tried it it seamed fine .
it didn't run hot before the swap ,well it seam like it was but the temp was good .so I'm kind of at a loss except for the things listed .
I'm i on the right track ?what do u think is wrong ?
oh yea this is with the ac on ,its to dame hot not to have it on ,the aux fan is running when the ac is on.
sorry for the long post .
thanks for all of your help.

so nobody had anything to offer ?.......
well i added the new hose and tranny cooler .i drilled a couple of holes in the thermastat .and flushed the block .
and gess what the dame thing is still running hot .mater of fact its running hotter i couldnt frinkn belive .
what i did notice is that the temp is staying stable tho. and when i turned off the ac the temp did go down . it sucked ass showing up to a first date all swetty : (.
so what i was seeing when refilling the system is this thoe . the t-stat didnt seem to be opening untell the aux fan came on at 220 .ish the gage ist exact .and then it would cool down to 210 mark .
so i went and got a new t-stat and im gonna add some freon to the ac system and see what happens .

Whats your main fan? clutch fan? straight fan? E-fan?

99 mech fan with hd gc clutch.
89 eletric

change the electric fan to a 96 or newer. It has more blades and moves more air.
make sure you are getting a 190 or 195 deg. stat.

Did you burp the system with the heater on to get any air bubbled out?

Make sure your water pump is a reverse rotation pump.

Also try jacking the front of the rig up and run the engine with the radiator cap off to help get the air out. You should have no more than 50% antifreeze in your coolant. I use about 25% and water wetter in mine. You may want to do a compression check just to be sure there's not a head gasket issue.

Is your o2 sensor working correctly? You can check it, or just replace it if it's old (like original).

Running very rich or very lean can cause higway overheating.

How many RPM's do you run at highway speed.

(I fight the same condition as you, and have tried all of the same things, but I have a high compression stroker.)

if it only happens on the freeway it is probably your clutch fan, google how to test cause i dont remember it is either supposed to be hard to spin when hot or easy. you should be able to find the info i think it is even in the chiltons. and i got 20 bucks that says thats your problem.

waylander said:

if it only happens on the freeway it is probably your clutch fan, google how to test cause i dont remember it is either supposed to be hard to spin when hot or easy. you should be able to find the info i think it is even in the chiltons. and i got 20 bucks that says thats your problem.

Click to expand...

when it's hot, the fan should be hard to turn (engine off, turning with your hand on the fan) when compared to cold.

at highway, the fan obviously is not the problem as fan pretty much free spinning as the moving is what plowing tons of air through the radiator.

id suspect there's problem with coolant get through the engine. probably simple as a bad thermosat, need to check check check blah

The water pump is the correct rotation .new ish like a coupel of months. 02sensor .new fan clutch. I was puttn n a new thermastat and broke the housing so ill find out if that was the problem to marrow

High backpressure, like with a partially clogged cat, can cause a lot of heat retention in the cylinders. If you can stand it, unbolt the system at teh downpipe and take it for a drive.

Which aluminum radiatior did you get? A good 2x 1" core unit like a Ron Davis or Griffin or Be Cool?

I'm having a similar problem. I've replaced the entire cooling system. I'm doing the compression test next.

If it usually happens on the freeway, it is NOT the fan. You don't even need a fan at 65MPH. And adding freon can can only let the AC put more heat in front of the radiator. Your comment about the radiator fluid looking murky after you add water does not sound good. Did you flush everything and does it still look murky in the new fluid?

check for bubbles thermostat wont open, new radiator

sso my freeway crusing is about 2500rpms.
The rad is a 1 of 2 core , I can't rember the name right off the bat.
The new fluid dose look better after the flush, I think that it was coming from the heater core.and it dose have fluid ,I filled it and there is no valve to stop the flow so its allways cirulating trough it .
I didn't have anymore bubbles after putting holes in the thermastat.
I think the thermastat was bad .it did maintain a constant temp but it was to high.
Ill find out if the new t-stat is gonna do the trick tomarrow .
I tought that if the freeon was low that the ac system had to work harder to cool down and that the compressor was not getting the lube that it needed ?
If that dosent work ill try it sans the cat and see what happens .it dosent smell like its running rich .

I'm willing to almost bet your thermostat is sticky......try a Mr gasket "balanced" thermostat(about $10 so why not?).
I too had all new cooling parts and refused to believe the new stat was the problem.

EDIT**
Looks like you are changing the stat.....should cure the problem.

well i guess ill up date .
id blow the dame thing up if i didn't have so much $ sunk into the dame thing .
so this is were I'm at now .
new t-stat.with drilled holes ,top and bottom .
new lower hose with spring .
new t-stat housing
new trans cooler
well diluted anti freeze .i back flushed the block and heater core .
so its still doing the same dame thing ! gurrrrrrrr..
I'm pretty sure that the WP is the correct 1
so at a idle sitting in the driveway from a cold start a/c off .
the temp will rise to 220 ish tell the aux fan kicks on and then goes off at 210.this is what the temp gage on the dash reads .
tell about 220 when the fan kicks in the watter just kinda sits there and will back flow out of the filler neck of the rad .when the fan comes on it will drop down a little but there's not really any water movement .if i give it some gas i can see the water level drop and it looks like the water is moving the correct way.
on the freeway in the morning it seams to hold at about 220 , its a click past the 210 mark . when it gets hot out it moves over even farther and will go almost to the red with the a/c on .if i leave it off (a/c)it will sit in the middle of 210 and 260 .going down the freeway.
I'm kinda at a loss of were to go from here .i could live with the temps but it leaves me no buffer zone for when i want to take a trip up the hills .this engine isn't that old and i shouldn't be running that hot with every thing that's been done .
sorry for the long post i just want u guys to have all of the info .thanks for your help!

...are you sure your temp gauge is working correctly?

it seams to coordinate with the aux fan coming on and off .
i imagin that it could be but it seams right .IDK ill have to find a way to cheak it .

How to check gage..................http://www.naxja.org/forum/showthread.php?t=1001892