ck1

Hello all, I have a 98 4runner v6 and have been putting coolant in it every other time I fiil up for about 4 years. I dont put alot, just enough to top off the over flow. There are never any puddles, it just drinks it. Also I dont know if its related but a mild knocking sound coming from the water pump area is getting louder. Any ideas?

ARB1977

How does the oil look? Check your ATF to make sure that its not strawberry milk shake color.

FogRunner

Define "top off the over flow",, are you just filling it to the full hash mark on the bottom end of the overflow bottle or are you fill it all the way up to the top ??

FOG

BigBallsMcFalls

if he is filling the overflow tank, then that is what is spilling over


overflow tank, when engine is cold, should have maybe 2 inches of coolant in it...
never full. never half full (unless engine is hot, then maybe it is half-full)

ck1

Thanks you all for the replys. Here is what I can tell you. I only fill the overflow when the engine is hot so when it cools the radiator sucks it in.

No I havnt checked the ATF fluid, my tranny isnt connected with coolant is it?

My engine oil is fine, never turns any color other than dirty.

SkidPalace

It is still a bit unclear if you are overfilling the overflow reservoir. You should only fill to the fill line when the engine is at normal operating temp, not to the top of the tank. And unless you are only topping off your coolant after you pull a trailer up a 3000 foot incline on a 105 degree day, you are not topping it off only when "hot".
And yes, your tranny is connected to your radiator. The fluids are only separated by a very poorly designed heat exchanger that fails often. Use the search tool for "stawberry milkshake". It will frighten you.

SkidPalace

Also, if your coolant is really disappearing without leaving any leaks or puddles, consider that it may be leaking into your combustion areas through a bad head gasket or cracked head. It would manifest itself as a sweet smell from your exhaust and a white smoke if bad enough.
Welome to YotaTech, btw.

Kiroshu

Prob over fill unless its spraying out a defective rad cap or coolant hose near the intake manifold and or throttle body and would evap before it hit the ground... Time for a pressure tester!

beck85

Leaking into the combustion chamber should leave you one, or some, very clean spark plugs. A small leak, needing aqua every fill up will not always produce a puddle.

yamagirl

Interesting...I have a 00 taco prerunner with 180K, since the T/B W/P was done 80K/ years ago, it has used probably a quart of coolant,it just dissapears,no leaks,no crusties..nada,just did the plugs and all were identical moreless. trans looks normal also,can help but think theres still a H/G problem on some. The 180K 98 runner dosent have this issue in the 35K we've owned it.