my 99 camaro has just started overheating like crazy. i checked the fans and replaced the motors thinking it would fix my problems. it is losing coolant but i have no clue where from. it will run fine for abt 30 miles or so then the temp just shoots up. when i stop coolant boils out my overflow cap. can someone please help me out.

 

Sounds like a blown head gasket.

Any white smoke? Change the thermostat.

 

Your temp needle can be buried into the red all the way to the right on these aluminum LSx's and absolutely no coolant will boil out. Its happened to my engine two times. AS LONG as the cooling system is free of any large air pockets. Pressure in a healthy coolaing system is what allows higher temps (beyond 212*F) to boil. Air in a cooling system is what allows coolant to start boiling at at lower temps.

MOST LIKELY,
You are getting air into your cooling system because a piston is pushing air past a breach in one of your head gaskets and into your cooling system. Thats causing the coolant to boil at lower temps and then get blown out the overflow reservoir.

Now you could be lucky and just need a new radiator cap. Or maybe you have a little pinhole leak somewhere.

Allot of times people drive around with a leaky water pump or pinhole leak somewhere and over time coolant gets pissed out without them knowing. Small leaks and even slow water pump leaks begin to leak after the engine is shut down, so the coolant leaks out when they walk away, and then later when the engine cools down it pulls in air. There's the air pocket in the system now that lowers boiling points. This happens till a certain point is reached, then "bam" you overheat badly one day.

So don't go looking for for a leak somewhere while the engine is running, allot of times it won't show itself until the engine is shut down. When you shut an engine down it gets hotter and pressure in the cooling system rises for about 30 minutes. Thats when some of these little leaks start pissing coolant out.

My suggestion: Go buy a new radiator cap, top off the coolant and make sure there are no air bubbles in the system, and see if it fixes the issue.
If it still happens, put the front end up on ramps, get the engine all the way up to operating temp and turn it off, then spend some time waiting and looking for leaks for about 20 minutes. Or just turn it off and wait 10-15 minutes, then go back and look for leaks.

THEN....you can start spending money on a cooling system pressure test, or a leakdown check to find a bad head gasket.

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thanks. there is no smoke at all. i was thinking it might be a head gasket but hoping not

 

Like stated replace the cap and pray, worked for me
How ever if your losing coolant from other than your cap you have another problem too....

 

It's your thermostat, Pull out your thermostat and test it, Boil some water, and put the thermostat in it while the water is boiling, pull the thermostat out after 5-10 minutes, and see if it opened from the middle at all. If it doesn't, thermostat is bad, and I suggest you get a 160 degree new one from autozone

 

i just changed my cap and thermostat a month ago but i will try that again

 

Bad t-stats don't cause coolant to boil over. If you want to, try a new cap. If that doesn't work, do a coolant system pressure check next. But only do the pressure test with all 8 spark plugs removed.

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How many miles on your car? These are obviously very solid engines and I've personally never seen one go through a head gasket....unless you cooked the motor previously. Heck, mine has quarter million miles and hasn't yet. Just rent a pressure tester from Autozone and you'll find your leak I'm sure. Do you see any coolant under the car after it has been sitting?

 

80k. No I haven't seen any leaks at all. That's what's crazy.

 

ok. i just poured water in my overflow res. and it was leaking around the rubber where the dip tupe goes in. would that cause any of these problems

 

NO.

Get a new cap.

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If you have a slow small leak somewhere you're not going to find any coolant on the ground and you're probably never going to actually see it leaking. Its going to leak out as steam while you're driving around and after you shut the engine off.

If you think you might have a blown head gasket.....go get a pressure tester and find out. Guessing only goes so far.

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Make sure your tool from autozone is %100 working I could kick myself, the solution is spray a water/soap mix around the fittings on the pressure tester to make sure THEY don't leak, giving you a false result Only do this if it fails, if it doesn't awesome.

Get yourself the new cap and cooling pressure tester from autozone all in one shot and report back.

 

get rent tools from auto zone ( pressure tester). I did that and found bad cap. Replace new cap and stop issues.

 

Ok. I just replaced overflow and now car is fine

 

How do u take out air bubbles out of cooling system

 

Bleed air by pulling hose from steam crossover tube.

 

Where was your overflow reservoir leaking from...?

When you replaced the overflow reservoir, did it come with a new tube/hose...?

 

So....you just replaced the over flow tank, and the engine does not overheat. That can't be. The over flow tank has nothing to do with overheating. Unless the hose that leads to the over flow tank was blocked and when you started getting hot the coolant pushed its way past the blockage, but then could not go back to the radiator......thence causing an air pocket in the radiator.



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