91 stx overheating

[91rebelranger]

So i took my truck through a pond and blew out the radiator. when i got home i replaced the radiator, thermostat, water pump, and put an electric fan on. the truck would heat up a little quick then the temp would drop and slowly go back up. I tried pullin the thermostat and it just made the truck overheat alot faster. My heater core isnt leaking and i have no smoke coming out of the exhaust. When i changed the oil it wasnt milky or anything. Yesterday the truck started a slight knock to it also. Cant figure this problem out and its frustrating meissed off:. Give me some advice guys. THanks

 

[MAKG]

Sounds VERY much like air trapped in the upper hose. Especially if the knocking continues after you turn the engine off.

 

[91rebelranger]

how exactly would i go about getting the air pocket out of it. i parked it in my driveway which is level, turned the heat on, let the truck running the radiator cap off and kept filling it until it overflowed. with the cap on i was still not building up pressure in that top hose either.

 

[MAKG]

If you're not building pressure, there is a leak.

It's good practice to replace the radiator cap whenever you change coolant....

 

[robo]

remove the temp sender from the top of the engine [ when cold] and fill the cooling system all air will be removed from yhe block. this will eliminate any air. if it still overheats than i would check for a cracked or warped head.

 

[91rebelranger]

i just got done letting run for awhile. adding coolant as it got low and after it seemed like it was full i put a new radiator cap on it. still overheats but not as fast and it only does it when i go up a hill and after i top the hill the temp just stays where it is at. thanks

 

[91rebelranger]

with the new cap it is building some pressure. thermostat is back in also. if i had a cracked head wouldnt i have a loss of power and smoke coming from the motor.


where exactly is the temp sending unit?

 

[MAKG]

OK, are you going up a hill SLOWLY?

'Cause this might be that electric fan....

Heads can crack in a variety of places, and not all of them make smoke. Modest cracks won't screw up power right away.

 

[91rebelranger]

usually but when i went up today it was fast tho. the fan is new.would it help if i reversed the fan?

 

[MAKG]

It would help if you took it off and put a working mechanical fan back on.

No offense, but if you don't know which direction to mount the fan, you REALLY shouldn't be modifying a critical system. If you mounted it backwards, it absolutely could cause overheating.

 

[Ranger5.0]

Ya, the E-fan should be pulling air IN through the grill and through the rad. IS the fan juss mounted to the rad witk no type of shroud to direct the airflow? Why do you have an e fan anyways? I have to use one due to fitment issues, and i HATE it with a passion. and no, they done free up horse power. The parasitic drage lost by not having the mechanical fan on is now replaced by the extra load on the alternator. Anyways...Heads can crack and alow combustion chamber pressure to enter the cooling system, they can alow coolent to be drawn into the combustion chamber as well. This doesnt always create the sweet smelling steam from the exaust. What kinda condition are your rad hoses in? Could the suction hose be colapsing when its runing, which would restrict coolent flow? is the T-stat the same temp as the one you removed? a combination of a higher temp T stat and the e fan alone could cause the rapid overheating. btw, how hot is it getting?

 

[91rebelranger]

i did put the fan on the right way. it is pullin air in through the radiator. im not that retarded. the reason i put it on is because i wasnt able to remove the clutch fan from the old waterpump. my truck hasnt had a fan shroud on it since i bought it. the highest temp ive let it get to is the "L" on that electric guage. the hoses dont look bad at all. and they are building up pressure now. just heats up slowly and it seems that if i have the heat on it stays cooler.

 

[91rebelranger]

as for the thermostat im not sure what the temp on it is rated for. it was a lifetime replacement thermostat from advance

 

[MAKG]

The stock thermostat is 195 deg. If there is ANY doubt replace it.

It is the thermostat's job to regulate the temperature.

Though "L" is not a temperature and if you're relying on that, you really have no idea what your cooling system is doing. How do you know your problem isn't floating voltage regulation, for instance?

Lifetime replacement is a joke. It means the manufacturer has figured out that their margins are so large that it's cheaper to give away replacements than actually implement quality control. It's not at all unusual to go through a whole string of defective ones.

And honestly, if your thermostat fails, will you really care about the $8 thermostat as opposed to the $400 heads?