over heating problem

[mud deep]

hey guys my name is jay...i have a 1987 toyota 4x4 pick up...
it was over heating on me so i tuke the thermast out of it.now it over heats with in a few mins of the truck being started and the sometimes it take 30 to 40 mins to over heat what should i do...and yes the fan does work...

 

[2ndGenToyotaFan]

Sounds to me like the radiator is plugged up... can you see any scale clogging it up when you look in the cap? Dont open the cap unless it's cooled off.

 

[mud deep]

what do u mean scale..

 

[2ndGenToyotaFan]

usually white, crusty stuff... it'll clog up the rad, and cause it to not disperse heat very well.

The reason I'm thinking that, is because when you take a t-stat out, usualy the truck will never warm to proper operating temp.... Whish is why you probably took it out to begin with... but if it's still overheating, then the radiator must not be working very well.

 

[mud deep]

oh i see...okay so if i take the cap off and i look in the rad. if the is any like clody flakes or anything floating in it,flush it right

 

[2ndGenToyotaFan]

It might be beyond a flush, but yes, that's a good start. If a flush doesn't work there are "other" ways... IE muriatic acid.... but that gets dangerous... A new rad is only $130ish.

 

[mud deep]

okay.. i started the truck up and let it warm up and then i shut it off and when i was feeling the rad.. right in the midle it was cold and the rest was hot....

 

[2ndGenToyotaFan]

That could be because the fan was pulling air through the middle cooling it off right there... or it could mean it's clogged up in the middle and there's no water flowing....

Anyone know a good way to check if a radiator is clogged up? Cause other than replacing it, I don't...

 

[beatdown83fj60]

Well I know for a fact that the one in my Runner is clogged (among other things) and when I was still messing with its problems it actually had cold spots on the radiator and the lower hose would barely be warm when it was getting close to overheating. Maybe if you drained it and poured water through it you could get an idea of how clogged it is, but I think you'd need another radiator to compare the flow to. Needless to say don't do what I did and keep driving it lol. I think I made a few small problems much larger by saying "it's a Toy it'll be fine" lol.

 

[Jerry D.]

On a couple of Runners in the family, we have found that the radiator external gets plugged with mud/dirt and doesn’t allow air flow throw it. Tried to wash/spray clean while in the Runner, but finally had to remove the radiator to get a good flush across the entire radiator due to the fan shroud configuration.

Looking at the front of the radiator, it looked OK, but from the back side after I took it out, it was plugged solid with mud/dirt.

Good luck

Jerry D.