Weird cooling issue

[jokeplayer]

It doesn't make any logical sense to me...

When I'm in traffic it runs nice and cool due to a 180 degree t-stat, 3-core GDI radiator, 2-speed Ford Taurus fan.... but as soon as I hit 50+mph the temp starts rising. It doesn't matter how hard I'm on the throttle... I could be WOT for miles or crusing with it in 5th at 50+mph and the temp will rise but as soon as I drop below 50mph, it cools back down!!!!!!

I changed the t-stat, flushed the system, and cleaned out the fins on the radiator and the problem disappeared for about a week but now it's back.

I'm thinking it might be weird air pressures behind the radiator at 50+mph...... or it could be running lean, but i've got some exhaust leaks which means it should be running rich due to the presence of extra oxygen. The new manifold and y-pipe should be here today. Well, after reading more it could be a clogged radiator. Or timing - but I set the timing back to factory a couple months back when I had to smog it.

Thoughts? Suggestions?

[83nismo]

try fliping on ur heater if your temp drops and is fine then i would say look at your e-fan make sure its turning in the right direction...the wind could grab ur e-fan and slow it down or send it spining backwards...

[jokeplayer]

I have tried. I tried turning on the heater full-heat, full blast and turning the electric off.

And the electric ran fine for a couple years..... it's something else.

I did spray out about 4 lbs of mud out from the fins in my radiator.... I wonder if the hot and cold patches caused deposits to cling to inside of the radiator.

I need to do brakes and wheel bearings tonight.... if I have time I'll swap the new exhaust in and see if that helps with the lean/rich situation.

[83nismo]

I would yard your radiator and take it to your local shop they clean them for like $35 dude the place up here makes it so nice you tink you got a new one + they do the inside too!

[jokeplayer]

Yeah, I'll have to check out the local radiator shops. There is some visible white crap stuck to the coolant veins in the radiator....

[Chris]

kinda like this guys problem... http://www.yotatech.com/f116/need-help-fast-overheating-issue-118608/ (maybe not, i'm tired and really didnt read it all the way through)

[jokeplayer]

Interesting. Yeah, I did some searching in YT and missed that one.

I need to put the new exhaust on still and then double check timing and that dang TPS I guess.

[Johnboy]

what it MIGHT be is your heater core is blocking up and when at higher speeds its trying to push more water through and it doesn have the room for it to flow properly. pull your heter core out and take a look.

[jokeplayer]

Good call! I'll add it to the lift of stuff I need to do this weekend while the girlfriend is gone.

[83nismo]

ooooooo wow so yotas are like jeeps paon in the *** tps...i hate those things...some needs to make something to block it off :idea:

[jokeplayer]

Yup, yup. Such a pain to set correctly. And my good meter is tweakin right now! So I'm gonna have to trust my little $3 back up meter to check the resistance.

[83nismo]

wow I'm really gunna crunch numbers to see if the can be bypassed some how.

[Johnboy]

nope, toyota's need the TPS so the air/fuel can be reugulated correctly.

[83nismo]

yes i know all fi rigs use them n need them but i can build things such as new brans ect...that would be able to take that info from other parts of the rig...theres so much soft where out there its not even funny...

[jokeplayer]

Ok... so clogged radiator or malfunctioning water pump?

I'm not losing any water unless it boils over of course.

[83nismo]

radiator would be my first bet any one ever use coolant stop one that thing? have you tryd water weter?

[jokeplayer]

No leak stop... and the block was hot dipped when I had it rebuilt. The current radiator does have some white build up on top of the rows. The new radiator arrived yesterday. I'll probably put it in on Monday.

I've got a bottle of water wetter that I'm gonna add when I fill the new radiator.

The new exhaust didn't help any.... but it needed to be done.

[83nismo]

if not did u try tps that would be my next step

[jokeplayer]

Radiator *seems* to have fixed it. I ran it real hard up and over a couple of the local passes on the highway and the temp didn't budge... keep your fingers crossed.

[83nismo]

thought so good to hear.

[98nismo]

whats water wetter?

[jokeplayer]

Water wetter is made by RedLine (Oil) and is supposed to recrease your running temp. I've heard good things about it from others.

[83nismo]

*decrease* alot of people run it in 2 strokes...

[jokeplayer]

'recrease' - Good catch :)

[tommy gun]

do you have a 5sp or auto?

[jokeplayer]

5spd. The new radiator seemed to fix it. But I do have a mystery leak in the cooling system that I can't track down. I need to buy a cooling system pressure tester.

[83nismo]

...head gasket...

[jokeplayer]

*Shhhhh don't say such things*

It's my DD, I need it to get to work everyday.

[83nismo]

mmmm...gf have a car? car u can barrow? onsitly I would look into it if it is nip it now or you will be really mad...

[tommy gun]

..what...

[83nismo]

its his daily driver...

[98nismo]

he's trying to say its better to find a blown head gasket sooner then later

[83nismo]

thanks brad