Car is overheating...what's the problem?

[Redline]

Need your help on this one, guys/gals. I'm stumped, and so is my mechanic...

Just last weekend my car started overheating while idling. I figure it was a faulty thermostat (as indicated in Haynes as well), so I spent all of Tuesday replacing the old with a new. I noted that both the old and new thermostats looked exactly the same, so I wondered why my car was overheating. Checked the temp level and everything looked fine, so I turn in for the nite.

The next day, I take the car out for a drive. About 30mins after driving it, the car starts to overheat again, this time even worse (even at cruising speeds, the air from outside wasn't enuf to cool the engine) Since my dad was helping me out with the thermostat change the previous day, we were both as to why the car was overheating again, so we dropped it off at our mechanic so he could take a look.

For the last 2 days I have been without a car. Reports from our mechanic reveals nothing unusual...he can't find the problem causing the overheat. He thinks it might be the water pump. Meanwhile, he replaces several other parts: wiper linkage (fubar'd for a while now), 2 drive belts, timing belt, 1 engine mount, and the water pump.

Today, I went to get the car back. Mechanic says that he hasn't found a specific problem, but did a rad flush anyways along with replacement of the above listed parts. Total cost: $1000 CDN Just 2 hrs ago, I took the car out to a nearby gas station to fill up (5 mins from house). Guess what? As I idled at traffic lights, the car began to overheat AGAIN! Altho it wasn't as bad/fast as before, I noticed that it would climb to about 3/4 of the gauge and hold (sorta). If I'm driving then the temp goes down.

So anyways, what I'm asking is: what other problems could I be having? What else could be going wrong? I really want to be able to drive again without worrying...

p.s. sry for the long post

Redline

[amerikim]

Sounds like maybe your first problem was fixed (maybe) but you still might have air in the system. Turn your heater to full heat for 10-30 minutes when driving around and keep checking your coolant levels. Is your coolant boiling over when you stop? That is a good indicator of air trapped in cooling system.
Could also be your radiator is clogged and scaled up but your mechanic should have noticed. Ever use something like stop leak? That is nasty stuff and I would only use it in dire emergency.
Hope you find your solution.

[Mikey21]

Dude first thing to do is get a new Mechanic!!!

Does your car have electric fans or fans mounted to the water pump?

If electric make sure they come on are running at speed(moving air).

If mounted to the water pump is the fan clutch broken(you should be able to spin the fan when engine not running. It should have resistance, not free wheeling).

Could be a blown head gasket. You can sometimes tell if head gasket is blown by starting a cold engine with the radiator cap off. If the head gasket is blown air bubbles will come up thru radiator.

Hard to diagnose a car without seeing it. Easy to diagnose a car when it's in front of you. Hard to swallow paying $1,000 with no results!!! Get a new Mechanic.

[I4 to V6 Swap]

I would guess there might be air in the system still. If not, then maybe the fans are not kicking in. If the fans are coming on, then it might be, as stated above, a blown head gasket.

[Luckynumber5]

my cam is doing the same thing! ive got a 92 3vzfe, its now so bad i cant drive it, though mine seems to be the water pump for sure seeing as now the radiotor dorsnt even heat up but the temp guage climbs and coolant starts to boil out the reserve

[amerikim]

Luckynumber5, your thermostat is stuck..cheap part..

Edit:but you could be right.

[5spd V6 ClrTail]

If it's the waterpump, it would leak. The V6 doesn't have electric fans, it has a heavy duty engine driven fan, so the fan isn't the problem.

[Calvin327]

Coolant Temperature sensor is faulty? My car used to ilde badly and overheat like crazy, found out that was the problem.

Calvin

[Luckynumber5]

just had the damn thermostat replaced lol, im using this as an excuse to "do some work"

[Redline]

thx for the replies, peeps.....keep them coming!

My mechanic is a trusted friend of my parents. He did diagnose the fan as one possible cause (as stated by 5spd V6...my camry is a V6, so no fans at the water pump). Right off the bat...not enuf flow from the fan. But, the fan was/is moving while idle, so not sure how much flow I'm s'posed to be getting.

Don't think that the rad is clogged. I did a rad flush at the beginning of Spring...didn't have any problems throughout Summer. I'll try running the heat for the next few days; hopefully it'll clear up the problem. Lastly, I'll get the head gaskets checked. I sure hope it isn't the gaskets

[karazy]

Don't forget to test the new thermostat. You wouldn't be the first one to get a defective new part.

[Redline]

^ how should I test it?

[Bishop13]

Run the engine to normal temperature and then pinch the lower hose (preferrably w/ gloves on ) and slowly release to see if there is any pressure relief. Also, check the top hose as it should be warmer than the lower, if the upper hose is cool after reaching normal operating temperatures, the thermostat is stuck closed.

[Hajoca]

Take thermostat out and put it into a pan of water and heat on stove top.

You will see it work. Sometimes the Tstat installation is what keeps it from working.

Have you back flushed the entire system?
(I mean garden hose in the upper hose, no Tstat and run the water through the engine. Then do same with the Rad.)

I usually drill a 1/16" hole in it [Thermostat around the mounting flange] to let air out of the system.

[Jzs147-RR]

When mox had overheating problems that blew his gaskets later it was actualy the waterpump bearings.The problem is the pump is under the timing cover.We noticed that the cover had started to melt from the heat of the thing and that it did not even start to leak(not that you would see much its hiden).