Sfrey77

3 row aluminum radiator with a separate trans cooler. no kinks in hoses, space fan blowing constant cool air through it. with the radiator cap on, over heats after about 5 to 10 minutes at an idle. upon cold start up rpm is at 1500 once it warms up to normal temp it goes down between 800 to 1000rpm. figured i might have too much poundage on my radiator cap. traded it out with a 13 pound cap and it boiled over into the overflow tank. stayed at a good temp for a little while longer but it still eventually got up to the H. any input or advice is greatly appreciated thank you

rworegon

RPM's sound about right.

By space fan blowing constant cool air do you mean the heater is blowing cool air when in the heat position and the fan is on?

Was the radiator just put in? Other cooling system work recently done? If so, it sounds like you have air in the cooling system and what it's overflowing when a bubble 'burps' tries to burp out of the radiator.

Get the radiator so it pointed uphill, remove the cap, start the engine, run the heater on high heat and fan, and add coolant as the air burps out of the system.

You do have a proper coolant/water ratio in the system?

Sfrey77

just put the radiator in yesterday, the fan is just a regular fan you can buy from walmart thats hanging off the radiator support to circulate air through the radiator. its already parked nose upward in my driveway i though it was air pockets at first. when i ran it the first time the coolant level dropped 7 inches or so, filled it and the level stayed sound. no other recent coolant system work done. running straight water until i find the root of this problem.

rworegon

Was it overheating before you changed the radiator?
Did you fill the block with water through the upper hose when refilling the system?

Sfrey77

i did not fill the block before i installed the radiator. i picked it up with front end damage and no radiator in it. previous coolant problems i wouldnt know. the radiator thats on there now is a 3row racing radiator i had laying around brand new never used. i assumed the cap had too much pressure so i swapped it with a 13 pound cap and it allowed for the fluid to boil out into the overflow tank and keep the temp in the middle for a little bit longer. even with the the cap though it still jumps up to H after about 15 minutes of run time

justin_4runner

i would pull the thermo stat and boil it to see if its opening like it should, if its working then i would start looking at the water pump.

rworegon

I'm more concered about the potential dry block start.

Does this sound similar.....see the first few posts and then again at post 21 through the end:
https://www.yotatech.com/forums/f2/5...-heads-246493/

Sfrey77

ive already checked the oil and im not getting the milk so that rules out head gasket. im going to go see if i cant get a little more coolant in the block through the upper hose, try and weed out the cheapest possible problems first.

rworegon

Good plan..........but, keep that thread in the back of your mind.

If you pull the t-stat, be sure to install in with the jiggle valve in the 6 o'clock position. This is the 5vz-fe engine, correct?

Sfrey77

well, dry start it was. after a few minutes of the garden hose in the upper radiator hose it filled up. hooked everything back up and ran it for 30 minutes with no problems. it even runs slightly colder than center mark on the temp gauge.

Sfrey77

as far as nomenclature for the engine goes this is my first 4runner so im very new to them, all i know is its 97 sr5 v6 2wd.

rworegon

If the front cover of the motor says 3400 on it, it's a 5vz-fe.

Ouch, on the dry start. Hopefully, all is good with the head gasket and the heads did not warp.....time will tell.

Ok, now to do this right flush the garden hose water out of the system. Use distilled water and a gallon of Toyota RED coolant. If you can only get Toyota Pink coolant, it is pre-diluted.

Sfrey77

great, thanks! you seem to have a good bit of experience with 4runners, any helpful tips and tricks?

rworegon

None on 4Runner's, but many years of maintaining my own Tacoma - bought new with 1 mile and now has 192,000. Experience on other makes over the years too.

It helps that Toyota used the same engine, transmissions, etc. in different models so tons of knowledge is transferable.

Sfrey77

yeah i was thinking about doing a engine and trans swap with a 4wd conversion eventually