Truck overheating

Hey guys, I just acquired a 2002 Tacoma with the 3.4 auto. As I was driving it home I noticed at in town speeds the trucks temp gauge started climbing towards hot and got about 3/4 to hot then went back down once I hit the highway. Highway speeds are running cool, a little lower than normal. It hasn't actually run hot yet but it's scaring the shit outta me. I'm suspecting maybe a bad radiator or thermostat. Could anyone chime in and give any suggestions? By the way it has 160k and the timing belt/water pump was done at 95k.

 

I'm gonna guess fan clutch but I could be wrong.

 

How close is 3/4 to hot on the gauge? These rigs tend to have the needle pointed just a hair above the half mark at operating temperature.

 

make sure the fan blades and shroud are in good condition. i.e. 1 of the 4/5 blades isnt entirely missing or half the fan shroud is broken off.

see if your radiator fins aren't just clogged. you can spray water with a gun from behind out the front to try and dislodge any bugs, leaves, or dust. you should be able to see right through the radiator fins.

change the radiator cap. it's inexpensive and it's a cheap way to be sure it isn't something simple.

how dirty does the coolant look? clean is pink. mildly dirty is a sort of orangish/brown. brown/dark = bad. and does your reservoir have spare coolant? and do you have 50/50 coolant/water mix?

thermostat might be sticking. not too expensive to replace. thermostat, gasket, and 50/50 coolant. might as well after what you said about the cooling system servicing. and does your reservoir have spare coolant?

fan clutch - when you first turn your truck on after cooling for hours, you should hear the fan spinning really fast/hard then slowly get quiet over a minute or so. if it's quiet right from the start, it's not turning as fast as it should at low rpms and is bad. can also try and freespin the fan by hand with the engine off. there should be good resistance. if little to no resistance, bad. i.e. when holding a new fan clutch alone in hand, you can't turn it. but when mounted to an engine you can turn the blade by hand with good resistance.

 

My radiator had a hairline crack in the upper plastic and did the exact same thing as you are explaining now. First I'd make sure the coolant is full and see if it runs cool. If so I bet you have a leak somewhere

 

sometimes they don't replace the thermostat and put in new antifreeze, even when they do the timing belt waterpump job. id say replace thermostat and drain out and put in new OEM antifreeze unless you can verify its new antifreeze at the time of the belt/waterpump job. id put money on the thermostat not opening all the way. from what you stated that it got real hot and then eventually cooled down the temp guage sounds like the thermostat is sticking. easy job to replace

 

true

 

X's 2

I'd think if it was the thermostat it would wanna overheat at high rpm highway speeds.

 

Borrow a scan gauge and get real readings. It's 'possible' to have a malfunctioning gauge.

But as part of baselining any new-to-me vehicle, especially with high miles, ALL the fluids get changed. So that might be on your list regardless of what else you find out.

Bonus points though for looking at your gauges. Too many people don't. And overheating is a leading cause of premature engine death.

 

Yeah get one! I love mine, won't not ever have one at this point! So useful for SO many things!

 

Low coolant or fan isn't functioning properly. When you reach highway speeds it cools down bc of convection. However, if your coolant level drops low enough it will overheat regardless.

I'd try starting her up and look for visible leaks. Check hoses for leakage, radiator + cap. Air could be getting sucked into the system if you have a faulty head gasket or cracked head.

Try cranking her up (when cool) and then remove cap (WHEN COOL) and give it some gas. If there's air in the system you will see bubbles. Could be large, or very small. If that occurs I'd bet its a leaky head gasket/cracked head.

It's def. not a sticking thermostat or waterpump. Good luck and let us know when you figure it out and what the problem was.

 

Ever watch Road Kill on YouTube? Just take the hood off.

 

Update! Apparently no one gives a shit about bigfoot SOOOOOO FUCK HIM!

Seriously tho..anything, anyone, anyone, Bueller.....

I'm obsessed with coolant systems.

 

another tip off to "maybe" having a bad fan clutch is if it gets to warm engine temps within 1-2 minutes of a cold start, most times it should take at least 4-5 minutes to reach temp on average. lots of other things can cause this too but if you suspect the fan, its another clue.

im not overheating but my needle does ride "just above" the middle of the gauge and my 99 it was right in the middle.

for only $55 you can replace it with the most popular replacement which is the HAYDEN 2671 http://www.ebay.com/itm/111734881236?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT

or if you want oem quality then $89 for the AISIN FCT-013 http://www.ebay.com/itm/Engine-Cooling-Fan-Clutch-AISIN-FCT-013-fits-95-04-Toyota-Tacoma-3-4L-V6/131504110679?_trksid=p2047675.c100010.m2109&_trkparms=aid=333008&algo=RIC.MBE&ao=1&asc=20131231133846&meid=a6fc2da9168e4e7092209a36e7d6743d&pid=100010&rk=7&rkt=8&sd=111734881236

im going to replace mine "just for the hell of it" because I figure its got 120k miles of use on it plus its 12 years old so even if it still works, it cant be working as well as when it was new, plus I live in a very hot climate so its better to replace it now before the truck does start overheating on me.

nothing kills our engines faster then running them hot, even just once can ruin your heads.