New to me 4runner overheating on long hills....
06-26-2015, 01:36 PM
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New to me 4runner overheating on long hills....
Hey all, been a while since I posted on here... I still have my 93, but she's just a trail rig these days...
I bought a 96 runner last week, the price was right, it runs great, and the body is in excellent condition, Frame not too rusty, its got 33 tsl boggers on it, and like most 3rd gens, the rear diff cover is rusted. Other than that... for $800, I thought it was a good deal.
So the other day, I was going up near Mt Washington, and I noticed the gauge start to rise, pulled over to let her cool down, and noticed that if I keep it revving at 1500 rpms or so, it cools down ok, but going up the long steep hills, at 3k, she gets hot, I turned on the heat, and had none... thought she must be low on coolant... let her cool, made it the rest of the way to my destination and let her cool a few hours, then pop the cap to find she's full. Started up fine, drove the rest of the way home no issues...
fast forward to today, going up another steep hill (on purpose to see if it did it again), and sure enough, right around the top she started overheating again... this only happens on hills, at any speed on flat ground, she's fine... so I get out to check the radiator, and sure enough, the rad is ice cold... both hoses hot as hell tho.
Now... I'm not new to motors, especially not yota motors, but am new to the 3.4l, my initial suspicion is the t-stat, or clogged rad... rad looks fairly new, and its not like theres hot and cold spots... the whole thing is cold, minus the very top... I think that rules out a clogged radiaor, and a weak water pump. if it was a weak water pump, the whole rad would get hot, and revving it to 1500rpm in neutral prolly wouldnt cool it down. The part that gets me is... if the t-stat is stuck, why does it run just fine till I work it up a hill?
I really dont believe its a blown head or head gasket... there's no coolant loss, it runs strong with no misses, no white smelly exhaust etc.. I know the signs of a blown hg and it dosent exhibit them.
Obviously, my first step is gonna be to remove the t-stat (temporarily) and flush the cooling system... if I can make it up hills no prob after that, great.... if not, back to the drawing board.
most of the posts I've read here on the 3rd gens overheating have led to blown hg's, or incorrectly installed hg's, or fan clutch, etc... just thought I'd drop by to hear other peoples thought...
Oh, and the vitals... its a 96, 3.4l 285k on the ticker
ETA: also forgot to mention that I did try burping it... no air came out after 30 min of idling on a steep hill in my driveway with front and rear heat on full blast.
I bought a 96 runner last week, the price was right, it runs great, and the body is in excellent condition, Frame not too rusty, its got 33 tsl boggers on it, and like most 3rd gens, the rear diff cover is rusted. Other than that... for $800, I thought it was a good deal.
So the other day, I was going up near Mt Washington, and I noticed the gauge start to rise, pulled over to let her cool down, and noticed that if I keep it revving at 1500 rpms or so, it cools down ok, but going up the long steep hills, at 3k, she gets hot, I turned on the heat, and had none... thought she must be low on coolant... let her cool, made it the rest of the way to my destination and let her cool a few hours, then pop the cap to find she's full. Started up fine, drove the rest of the way home no issues...
fast forward to today, going up another steep hill (on purpose to see if it did it again), and sure enough, right around the top she started overheating again... this only happens on hills, at any speed on flat ground, she's fine... so I get out to check the radiator, and sure enough, the rad is ice cold... both hoses hot as hell tho.
Now... I'm not new to motors, especially not yota motors, but am new to the 3.4l, my initial suspicion is the t-stat, or clogged rad... rad looks fairly new, and its not like theres hot and cold spots... the whole thing is cold, minus the very top... I think that rules out a clogged radiaor, and a weak water pump. if it was a weak water pump, the whole rad would get hot, and revving it to 1500rpm in neutral prolly wouldnt cool it down. The part that gets me is... if the t-stat is stuck, why does it run just fine till I work it up a hill?
I really dont believe its a blown head or head gasket... there's no coolant loss, it runs strong with no misses, no white smelly exhaust etc.. I know the signs of a blown hg and it dosent exhibit them.
Obviously, my first step is gonna be to remove the t-stat (temporarily) and flush the cooling system... if I can make it up hills no prob after that, great.... if not, back to the drawing board.
most of the posts I've read here on the 3rd gens overheating have led to blown hg's, or incorrectly installed hg's, or fan clutch, etc... just thought I'd drop by to hear other peoples thought...
Oh, and the vitals... its a 96, 3.4l 285k on the ticker
ETA: also forgot to mention that I did try burping it... no air came out after 30 min of idling on a steep hill in my driveway with front and rear heat on full blast.
Last edited by Team420; 06-26-2015 at 01:38 PM.
06-27-2015, 06:49 AM
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After draining and filling, im fairly certain its a cloghed radiator... It drained hella slow, and the coolant was pretty rusty and nasty looking...
Anyone had any success with the prestone super flush stuff?
*update*
I flushed her out this after noon, what a mess! Some really nasty stuff came out...
It helped, now half the radiator actually warms, but the other side stays ice cold, and it still overheats on the longer steeper hills, so I put some zerex super radiator cleaner in... directions say to drive for 6 hours, then flush, and fill....
Either way... I obviously need a new radiator before the dreaded strawberry milkshake occurs...
Anyone had any success with the prestone super flush stuff?
*update*
I flushed her out this after noon, what a mess! Some really nasty stuff came out...
It helped, now half the radiator actually warms, but the other side stays ice cold, and it still overheats on the longer steeper hills, so I put some zerex super radiator cleaner in... directions say to drive for 6 hours, then flush, and fill....
Either way... I obviously need a new radiator before the dreaded strawberry milkshake occurs...
Last edited by Team420; 06-27-2015 at 02:19 PM.
12-20-2020, 02:11 PM
#4
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97 limited.
I’m getting ready To bring in my Toyota in my garage with wheel spacers and my 3 1/2 inch rough country I was able to clear my 305 correct me if I’m wrong but I do believe there are 285 is just wider and I rub hard my son ripped a fender flair off. I’ve cut vendors before but I’ve been looking to see if anybody had any tricks on the third GEN to keep the same look
01-12-2021, 04:57 PM
#5
Clogged rad.......more than likely had some anti leak junk put in there.
i had the same issue.....no overheating until you were on a grade.
if its a 3rd gen......the rads are a high failure part and should be changed. Antifreeze contaminates the trans fluid and transmission.. its called the strawberry milkshake!!
i had the same issue.....no overheating until you were on a grade.
if its a 3rd gen......the rads are a high failure part and should be changed. Antifreeze contaminates the trans fluid and transmission.. its called the strawberry milkshake!!
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