over heating

87pathfinder · Mar 14th, 2006, 03:32 PM

ive got a 1987 pathifnder when im on the highway the temp get hot i have to turn the heat on latley since its getting hot out the antifreeze is bubbling out through the hose in the overflow tank. you can hear it bubbling and boiling but then it starts coming out of the hose. im thinking i need a new radiator.any help would be great

robs97kingcabpu · Mar 15th, 2006, 05:37 PM

Before you drive it any more, check to see if you have any water in your oil (pull dipstick and look at oil to see if it is a milky, whitish-brown color). This would mean you have a blown head gasket or cracked/warped head. If not, check to see if your thermostat is sticking (start with a cold engine, warm up to operating temperature. As it is warming up, feel the upper radiator hose to see if it gets hot; it should as the thermostat opens up to allow the hot water back to the radiator). Not to alarm you, but always check to make sure these more critical problems are not the cause first, so you don't ruin your engine.

bkea · Mar 15th, 2006, 09:16 PM

You definitley don't want to overheat the engine so get busy checking things out. I went through all of this years ago with my truck. Changed the hoses, thermostat (twice) etc and it was the radiator. Had it boiled out and rooded out and it lasted all of one month. Finally rpelaced it and all was fine. Not to fret because you can get a pretty good radiator from internet sales. Ebay has them for around $100 +shipping.

dvdswanson · Mar 15th, 2006, 11:52 PM

with the engine cold remove the rad cap, start it up and wait to see if 1. t-stat opens and water flows through the rad, this will tell you if the t-stat is working and tell how the radiator is if it is clogged or restricted. 2. if you have electric fans, (when at high operating temp) it will tell you if they are working, or if you have a fan clutch if it is working, 3. look for leaks around w/pump and hoses/hose clamps.

87pathfinder · Mar 16th, 2006, 02:32 AM

i didnt change the thermostat i had a mechanic do it. it has been over heating for a while that why i changed it hoping that that was the problem.

87pathfinder · Mar 16th, 2006, 08:44 AM

i just added a quart of oil the oil was clean no milky look. i replaced the thermostate a few months ago when i first noticed the problem. im gonna check the upper hose when i get home to make sure it is getting hot. the one fan i have is always moving. the coolant seems to move in the rad when i start up the motor. no leaks anywhere so im thinkin it is the rad but anymore suggestions i'll definatly be grateful.thanks again for the help

jerryp58 · Mar 16th, 2006, 06:36 PM

Quote:

Originally Posted by 87pathfinder

i just added a quart of oil the oil was clean no milky look. i replaced the thermostate a few months ago when i first noticed the problem. im gonna check the upper hose when i get home to make sure it is getting hot. the one fan i have is always moving. the coolant seems to move in the rad when i start up the motor. no leaks anywhere so im thinkin it is the rad but anymore suggestions i'll definatly be grateful.thanks again for the help

The coolant shouldn't really move (flow) in the radiator until the thermostat is open; at least it should flow a lot more when the thermostat is open.

Any chance a hose is collapsing?

Is the fan clutch operating correctly; maybe it's blocking air at speed?

Air in the system from the thermostat change?

robs97kingcabpu · Mar 17th, 2006, 02:42 AM

Quote:

Originally Posted by 87pathfinder

i just added a quart of oil the oil was clean no milky look. i replaced the thermostate a few months ago when i first noticed the problem. im gonna check the upper hose when i get home to make sure it is getting hot. the one fan i have is always moving. the coolant seems to move in the rad when i start up the motor. no leaks anywhere so im thinkin it is the rad but anymore suggestions i'll definatly be grateful.thanks again for the help

Did you bleed the system when you did the thermostat change?