Overheating/cooling issue...still baffled

[Blk95gs]

Ill try to break this down...

the car only overheats when driving down the highway around 60-80 mph when the car is at 3000+ RPMS for extended periods of time, or when sitting still.

I replaced the thermostat, which was stuck closed, still no help. Then noticed a pin sized hole in the coolant overflow bottle. Replaced. Problem is, the lower rad. hose is STILL COLD, and i can hear coolant gurgling in the upper pipe/thermo housing. Could it be that i have a clog somewhere? I cant think of anything else, bad water pump? Help, its starting to get hot out...

 

[BISHILVR]

Clogged radiator???, just pull it out and take a garden hose and run water through the top and see if it comes out the bottom hose as fast as you put it in. If not it's probably clogged.

 

[jb95gst]

I have noticed mine is doing the same thing. I did the fan switch that is listed on the vfaq.com and it turns both my radiator fan and ac fan on high when I switch the fan on.
My car was not completely overheating, according to my logger the temp was 222 deg. After turning on the fans with the switch it will drop to around 200 +- 5 degrees. I believe mine has something to do with my FMIC, but I am installing some Spal fans soon, so we will see. I just thought that was wierd though also that it only does it while cruising at high speeds, and not when going slower.
JB

 

[sjwelna]

Are you sure your water pump is working properly?

 

[jb95gst]

I replaced my waterpump 13,000 miles ago when I rebuilt my bottom end, so I would assume it is working correctly.
JB

 

[GritsnGravy]

If the top gets hot but the bottom doesnt, you have a clog somewhere in your coolant passages. Good luck!

 

[rad]

Coolant comes out on passenger engine side, doesn't matter if it's hot or cold. It then flows to FIAV valve in the throttle body, and to the heater core. It then comes back to the lower pipe, and back to the pump.
When the coolant is hot it ALSO flows into the radiator, and comes out through the bottom, meets with fiav/heater flow and then the pump.

Does your heater work? If it's always cold check your water pump, it might be clogged.

[EDIT] forgot to mention, if heater works well your thermostat is stuck closed. Put it in hot water to be sure.

 

[Blk95gs]

The thermostat is brand new, but you never know. I am gonna try to do a pressurized flush of the system and see if it helps at all.

 

[cait sith]

When's the last time the water pump was done? Take off the belts and see how smooth it turns. It should turn smooth, and not feel "gritty".