95 sidekick weird overheating problem

ScottSD · 02-06-2008, 02:54 PM

my 1995 sidekick jx 16 valve recently started overheating. I noticed water coming out of the weephole on the water pump, replaced that and the thermostat. Now what's weird is I took it for a test drive (60 mile round trip), didnt overheat in that period of time, but when I got home and pulled in to the driveway, the needle jumped up near the red, not into it. I turned the engine off and just turned the key enough to see the electrical, and saw the needle was dropping back down the optimal temperature within a couple of minutes, what on earth could be causing this now? coolant is full, water pump and thermostat housing are both secure and leak free.

jtgh · 02-06-2008, 11:15 PM

1: keep adding fluid at it burps day to day. (air bubble at sensor)
2: gauge bad, wires, or sender with 1 term at stat housing bad, corroded or loose.
gage is stand alone, ECU does not see it .

ECU= Puter

Shconer · 02-07-2008, 12:27 AM

Or could be a blown head gasket if the vapor lock doesn't go away or is reoccurring or coolant is pushing out the overflow if it is you'll be able to hear it a few seconds after you turn the car off.

jtgh · 02-07-2008, 12:42 PM

clean fresh fluid, it looks nice and clean,
then drive,
does it push garbage in to the overflow tank and then when you look down the filler neck you see signs of oil, carbon and junk floating in the liquid. (not pure and green)
the head gasket is bad.
there is a proper test that can discover this, a pressure leak down and a contamination tester can both find this .
baring that , just careful observation of the quality of fresh antifreeze and water will tell the truth.
also pull a full compression tests on each cylinder can help.

substitute , pink, orange or whatever you are running if not green.

Shconer · 02-07-2008, 09:24 PM

Just to note when my head gasket blew it contaminated the fluid very little so there may be little or no sign of this.

ScottSD · 02-15-2008, 12:15 PM

Ok, I replaced both sensors in the stat housing and that seemed to get it, for a few days at least, now as I drive, it will slowly overheat, and i mean very slowly, like after around 60+ miles the needle will slowly start to work its way up a little higher to the half+ mark, but very slowly. I noticed if I take it out of gear and just coast, the needle will drop back down and buy me some miles before it starts to inch up again. This has me wondering if the fan clutch may be slipping, but thought I'd get your opinion before I just order one.

Shconer · 02-15-2008, 02:31 PM

You really need to do a compression test and/or coolent pressure test. Throwing parts at is expensive and not the way to go about it. It's not the fan, I have a electric fan and havent turned it on in months plus at those speeds theres more than enough air to cool it. It really sounds like a head gasket.

jtgh · 02-15-2008, 07:23 PM

i dont think your car needs a fan clutch in N.Dakota, at this moment. Most are blocking radiators ,this time of year.
right?

I think you would be best served by getting your hands on an IR heat gun for 1day, rent one at Autozone or equiv?
Buy one for $20.

then, find out if it is really overheat or is that crummy bimetal spring in the gauge going funkly , just like they all do. after 15 years of heating and cooling.
finding out the binary truth can really help you.
is it the engine or is the dang stupid guage.

overheating

the biggest lesson in this business a technician is measurement error. Never ever trust one source, never forget to validate your instruments and have them checked for calibration , annually.

Thak that barrowed IR gun, point it at boiling water. 212F.
then point it at the stat housing.
now you are seeing the truth for the first time.
trust me.

jtgh · 02-15-2008, 07:31 PM

oops do over, i forgot to re-Read your first paragraph.
you replaced the sensor before the reported bad leaking pump?
any time a pump is bad, it absolutly must come out.
if not , you will destroy the cam belt when it siezes !
when that happens the engine WILL be destroyed,
YOur engine is an interference engine.

pump sieze, destroying cam belt and cam belt cover, cam stops, pistons destroy valves , break pistons , bend rods, and maybe
crack hollow crank in half. YUP.
if lucky the block Might survive.

It's a 16v thing.

ScottSD · 02-16-2008, 11:16 AM

no no, I replaced the sensors after the water pump and thermostat, not before. I'll see if I can find one of those IR guns somewhere, not the best town to look for something like that, nearest autozone is about 150 miles away, but thanks for all the input, avoid the cost of a fan clutch at least.