longhungsilver

hey guys i hope someone here can help me with this one....

My aftermarket and toyota coolant temp gauges go up and down (at different times).... the aftermarket will start at 88c and while im driving it will steadily increase to about 103 and then shoot down quickly back to 88... it does this over and over and over again.. The toyota stock gauge also flucuates like this but not at the same time...

I thought both gauges might be faulty so i took out the aftermarket gauge and installed a new one and still same problem!! (new sensor too).. Any ideas??

Ive obviously bled the air out of the system over and over again.. Ive tried it on a flat.. on a hill... and driving around with the rad cap not secure.. Ive even tried disconecting heater hoses (highest point) and pressurizing the system to push air and coolant out. No luck at all.. Any ideas? im not leaking coolant anywhere either...seems quite perculiar

thanks
Justin

the_supernerd

A thermostat that is going out can cause that. Change it before it quits working and gets stuck shut. I like genuine Toyota thermostats because they seem to work a lot better than the other brands that I have used.

foot0069

Scoll down to the part about tstats. Just put one in my new motor and love it.
Jim

http://www.4crawler.com/4x4/CheapTri...tml#Thermostat

TOYZILLA

Must be thermostat forum nite 3 in a row

longhungsilver

well bud just so u know I just changed the thermostat a few weeks ago with a stock toyota one... although it was not a dual port thermo (as i didn't know wut that was until a few minutes ago).. although i remember now that the one i took out was a dual port (alhtough it was old and needed to be changed)... could changing it to a dual port thermostat help my problem perhaps?? i read the explanation of it and i still am a bit scetchy on what its advantages are...

foot0069

Justine I think your problem is just why the came out with the service buletin. It aint a cheap piece for sure but I bet it would cure your problem.
Jim

SoCal4Running

Maybe I'm daft but I dont understand what the problem is. Your new aftermarket guage is probably way more accurate that the old stock guage. Are they taking readings from the same place on the motor??? if not that would explain the different flucuation sequence..

longhungsilver

hey bud..well they are not taking readings from the same place... i was just trying to come to the bottom of why i was having flucuating readings.. and i was having them with both types of thermostats (my truck i found out had that special thermo with the second port in it already).. I changed it out thinking it was old hence my wacky readings and it made little to no change... Theres still a definite flucuation...

I have since taken out the aftermarket gauge thinking the hack job somone did putting it in was interfereing but to no avail my gauge still goes wacky under load.

the_supernerd

Maybe the fan clutch is going out. My temperature guage fluctuates similar to what you are talking about. My guage fluctuates between about 1/4 and up to almost 1/2. I put in a new, but cheap, fan clutch when my old one quit working. The new one will not always engage, but when it does then my temperature stays at about 1/4. If you get a new fan clutch, get a good one or try refilling your old one. Switching to an electric fan might work also, but a good mechanical clutch would probably be more accurate and would cool better.

longhungsilver

Yah ive given it a lot of thought and your probably right...I figure it might very well be the fan clutch... It never seems to freewheel properly.,., l ike when the engines cold if i rotate it its stiff and slightly losens up after constant spinning..and when its warm its much the same..

I know I can get a Lordco special made in china for $65... havent had a chance to ask toyota what one of theres goes for... Also considering Electric but as far as I can tell its way to busy since the engine was desgined for a clutch style fan why mess around?

the_supernerd

My old fan clutch would spin when I first started my truck, but then it would loosen up and never come back on. The cheap one I have on now spins when I start it, and it takes a while to come on and then takes a while to loosen up. On a hot summer day it sometimes never shuts off, even when my temp drops. A good one should come on when it starts to heat up a little and then shut off as soon as it is cool. I do not know what a good brand is, but I would like to know since I want to change mine to a better one.

I have heard of refilling the stock one with new fluid, but when I went to the Toyota dealer they said that they do not carry the fluid anymore. Maybe someone else on here knows something about that. Here is a link about refilling them:

http://www.off-road.com/~estegall/te...fanclutch.html

That is not for a 22R, but it should be similar.

the_supernerd

I just looked up a fan clutch on www.1sttoyotaparts.com and they are $91.27, which is not too bad from the dealer.

Robrt32

My old 77 ford has done the same thing for years, Whn i first got from my dad and noticed i changed the therm a few times and never made a diffrence.. I quit worrying about it and haven't had a problem.. but i still keep my eye on it pretty good.. Which i drive heavy machinery so watching my gauges at all time it just habbit for me

longhungsilver

thats pretty much me lol not worrying to much but keepin my eye on it a little bit anyways out of habit

longhungsilver

that sounds pretty decent.. i know i can get a chinese one from lordco for 70 bucks... im thinking about changing it but its not overly common a thing to ever service on a toyota... their fan clutches are usually so good and mine seems to be acting up maybe a little but could it cause this sorta of descrepancy? I suppose it could...it might also be the cause of my poor gas mileage if its spinning to much and not allowing the car to reach its operating temperature...hmm wheres abouts does any of your needles get to on the stock toyota gauge (i have an 89 4runner).. mine sticks about 1/3rd of the way in that area... definetly not at the half mark (although it goes over it for a bit before the thermo opens)

the_supernerd

Mine stays about 1/4, and it goes to about 1/2 sometimes. If it starts to go over 1/2 then it is usually starting to overheat. My fan clutch went out a while back. My temp would range about how it does now, but if I climbed a steep hill and the temp would go over 1/2 and the fan would not come on. My dad's truck will stay at about 1/4 and I can hear the fan come on for only a few seconds at a time.