Officially out of ideas.
 

Replaced my radiator, cap, hoses, coolant tank, thermostat, temp sender/sensor, and throttle body gasket. Car STILL overheats. Any ideas before I take it to a shop and they charge me 60$ just to look at it?

did you bleed the cooling system after changing all those things?

leaks?
loss of coolant?

why do you say it over heats?

Take that $60 and buy a OBDII reader that can monitor the ECU data stream, specifically the engine temps stream. (I use an el cheapo bluetooth/OBDII adapter, about $30 from Amazon.COM, and a $5 program named Torque on my Android phone.)

See what temps it IS running at.

I don't see water pump on your list ...

RwP

This.

Is the dash gauge broken?



:agree:

it doesn't matter if the gauge is physically broken, our temp gauge is notorious for reading wrong

Yeah, how hot is it getting?

This link you sent me was perfect, Whenever I drive it on freeway it falls below the middle mar pretty fast, Whenever it is at idle parked or in traffic the needle goes pretty close to the red, thats when I pull over and turn on the heater or anything.

When parked or driving slow or in traffic it goes almost to the red.

Sure did.

No leaks anywhere whatsoever.

Also I did notice the fans work but they never turn on really fast like they're supposed to, to cool it down. Could this be something? I checked the relays for the fans also and they're fine. and yes theyre all connected lol. Also now that I replaced my thermostat my car tends to heat up faster then it did before. Before it would heat to the 1/4 mark by the time I get to work, now It goes to middle mark by the time I get there. Good or bad?

Obligatory:

Can you run +12V directly to the cooling fans for comparison purposes?

Get a fan switch by casper on pfyc.com. This happened to my car also and this helped, but in the end I popped the gasket from faulty fluid level sensor.

How's the oil? Sounds like a HG to me. Are you losing coolant?

If not, I agree with water pump.

After all the money to spent, what's another $60

I dunno, I don't trust the accuracy of a gauge that goes "C ---> H" and that's it.

How cold is C, how hot is H, and at what reading IS the car actually overheating?

Better to pull the (more accurate) ECT reading off the ECU.

RwP

It could be.

The main thing is, what temp does the ECU think it is?

My Malibu used to indicate about 3/4 up for 210F, and the fans wouldn't kick on low until shortly above that.

They don't go to high until an even higher temp - 223F IIRC, but check the manual to be sure.

It may be that despite where your gauge is sitting, the motor really isn't that hot at the ECT, so it doesn't kick the fans onto "HIGH".

That's why I suggest using a reader and finding out what temp the ECU THINKS the motor is.

RwP

Oil is fine. I changed the oil in january, no leaks, not watery. Not losing coolant at all either.

The first sign of a HG would be that he has white smoke coming out of his tail pipe. Then it would be milky oil. Plus his engine would idle really rough.

Here's the thing... if the light turns on, it has to be the water pump. If not, then just take out the thermostat and run without it. The OP live in Cali, so I would assume he wouldn't really miss it. I had a Cavalier without a thermostat in DC, which is known to get cold and windy, and I didn't have any problems with out that thermostat. It was just really cold in that cabin.

Pulling the thermostat may not make it run cooler - most cooling systems are designed with such and such a flow through the motor and radiator. Without the restriction of the open thermostat, the water can run by too quick, and not pick enough heat up out of the motor.

This can yield a car that pings and rattles due to being too hot, with the gauge at 1/4 ...

Or it may not on a 3.4. Dunno, but !I! sure wouldn't try that.

OTOH, there may be a restrictor you can buy to put in there in place of the thermostat. If so, the OP may try that.

But I'll stick with my notes - I don't see "water pump" on the list, and I'm curious what temp the ECU is seeing off the ECT.

RwP

Kinda scared to do that. Yes I live in cali, gets crazy hot even in the winter time lol

Yeah I talked to my mechanic/friend and he said he has an OBDII reader, he said he will bring it over. Much appreciated from everybody.

Keep us posted!

Mine only heats up to a little above half way if i have my heat off and at idle heats up to half

One yime it over heated and the fans dusnt even kick on even with new relays still dont turn on

if your fans don't kick on at all unplug your temp sensor and jump the plug to see what happens, if it works I would guess that is likely your problem

Jump it?

yes, when you unhook it there are two pins...take a paper clip or a small piece of wire and jump the connection...it most likely won't come on without the key on but unhook it and bridge the connection first, that is how we diagnosed mine

Oh gotchya :)i just got to wait till monday :/

So OBDII reader read it the same as the car, Took it to my friend whos a mechanic and he said it's the head gasket. At his shop they don't work on head gaskets. Sooooooooo... Now my other friend and I need to learn how and actually replace my head gasket.. Should be fun.. Any tips?

The OBDII reader does "C -------------->H"?

What was the NUMERIC values the OBDII reader was producing? Were the fans on low or high? At what temps did the fans turn on / switch to high?

RwP

Sounds like a pathetic excuse for a shop if they don't do head gaskets...if the shop isn't good enough to do head gaskets I wouldn't trust them to tell you if it is bad or not

They do head gaskets but not on american cars. They said because they're so busy it will take forever to get done. and I need my car every day.

[quote=RalphP;635217]
My fans don't turn on high, only low.

At what temp do they turn on low?

At what temp do you give up looking for high fan?

We're missing numeric values here at this side.

THAT said - there's a relay that flips them from series to parallel. It'd be worth it to see if the relay's hung or if the ECU's not kicking the relay.

RwP

agreed. its been asked numous times.