95 Tracker cooling issues

[luigi daniel]

Hello, all !
I've had some issues with the cooling system: engine coolant temp didn't rise more than 65 Celsius ( checked effectively with a laser thermometer as JTGH showed on previous posts) and, on the other hand, my son have had the coolant boiling when driving on very long slopes in the mountains). The thermostat was changed for new ( 82 deg C as nominal specification) and no improvement ( I have installed also the O-ring on it, as its seat is 4 mm deep)
I've ended up buying an aftermarket thermostat ( WAHLER p/n3119.88 with 88 deg C opening temp) and this has solved the problem apparently. I haven't had the chance to drive it on the mountains again to see if overheats. I am still concerned about the radiator fan viscous coupling operation that might be the real cause. I will buy a tachometer to see how it works on different outside air temperatures and I'll keep you updated.

[jtgh]

if it is cold out the viscuos fan clutch must be free wheeling.
there is a test for it.
it is on my cooling page.
you didnt state ambient temps. that makes is hard to under stand your context .

under temp, (under normal , condtions.)
boiling under load.

now that IS a set of symptoms.
It sounds to me like air in the block.

first off do not trust the dash guage. us the IR gun to speak truth to you.
the thermostat:
is it mounted with the wax pellet side down.
is the air bleed forward.
do you have 1mm lip or the 4mm lip in the Stat housing , intake side, that holds the stat.
there are 2 manifolds made and all kick drivers must know what car they have.

1mm - uses no Oring , but used old fashioned gasket , paper
4mm - uses spec, o-ring 'd stat and must used only with that... see TSB i posted.
or see that on my hard to find parts page.

Long slops in the mountain with a load ? trailer , carring 1 ton of bricks....??


if you are concerned of the fan clutch ,just remove it, it is not needed until 120f day in summer idling at a red light for 20 minutes.

take it out, end of consern , so you can consentrate on real problem.

Boiling over,
maybe you have a beginning bad head gasket.
look for signs of that in :
filler neck. oil, carbon, sludge.
overfill tank, same.

steam out tail pipe , fully hot engine.?

if you need data or links. hollar at me.

cheer.s

[fuzzy1]

yeah, hate to say but the 'boiling' sounds very famliar to just before the head gasket went on my Raider. Suspected timing chain, carb probs, did thermostat, chains, weber... ran 2 months till the day on highway when it got hot very fast & went poof. The heat expands the small gap allowing compession pressure into the cooling system. If it's violently pushing coolant into the overflow tank (mine was enough to blow out the overflow tube even though the tank wasn't full) I'd suspect head gasket is going. Wish I'd known this symtom beforehand, bc i abused it & warped my head. Raider is a toolshed now.

[jtgh]

yes, please do save your engine.

there are tools to test for this.
2 in fact
rad pressure leak down.
next
rad combustion gas detection device ($40 and all rad shops have it)

i show both here.
over-heating-why?
photo of both too.

cheers.

[jtgh]

words have meaning.
the word [phrase] "Over Heating" has a diff, meanings to people

1: goofy dash meter reads too high or too low.
2: you have solid signs of proof, steam venting from something? where? tell that.?
3: you put the IR gun to the stat housing and other points and sure enough she is HOT.

Never, ever use #1 as anything other than , gee something is not right.
realize the sender for the guage is designed to measure the temperature of water and not air! ( and is inaccurate at best, after all, there are no numbers on it , right ?)
That guage is a toy grade device. treat it as such.

now lets say you have a head gasket just starting to go bad, (not a blow out) but the beginnings....
now you have air (combustion gases) surrounding the STAT and the Sender.
That gas floats to the top , no surprise there.
both devices, will be confused, both will be unpredictable in this mode.

so stop using the dash gauge and invest in a real tool that always tells the truth.
I use an IR gun , as that will save all the burned fingers and spilt coolant.
shine it on , every thing in the loop
top tank
bottom tank rad
all hoses,
thermostat bottom housing.

and best of all look of overfill tank signs.
loss of fluid is always a sign. (short term)

that stat will open ,then close and will go quite nutz trying to do its job and fail at it.
I is not designed to operate in air. or gas. only a liquid.

that should help the weary.

cheers.

[jtgh]

the IR gun is $10, less than a copy of Indian Jones.

what a deal.

Harbor Feight has a sale one them now.

this poster i think has one.

i retired my mercury thermometers. and my thermistor wire .

it set me free. love it.

[luigi daniel]

Thank you, all !
There are not abnormal signs on rad filler neck, exp tank or tail pipe. The new thermostat is correctly installed onto its 4mm deep pocket. Course I didn't trust the temp gauge ( which shows half way) and used my IR meter. The issue with overheating/boiling was singular ( driving the car with 1 passenger and luggage only but on a very hot summer day and queueing on very low speed on looooong step mountain road).
Anyway, to save the engine, I am getting the things together to set up an order for the testing devices shown above and to have them mailed together in Romania.
Your help is well appreciated ! Thanks again !

[jtgh]

sounds like you are basically ok.
but overheat is bad,
it might of had an air bubble on top of coolant loop.
but that usually drops the dash gauge.
i hope yours works out good.
happy trials.