Ever since my last cam and oil pump swap my car has been using coolant somewhere. If I let it sit and idle for about 15 min it does not use any water or run hot, but I drove it about 115 min down the road and was on my way back and it was running hot so I cheacked the coolant and it was about a gallon low. There is no coolant in the oil and none out the exhaust. There are no leaks under the car either. Definately not the water pump either.

 

check your passenger side floorboard to make sure its not ending up on your carpet from the heater core

 

its not the heater core

 

Water pump, bet on it. It's the only intermittent coolant loss LSX motors ever see on a semi regular basis. Change the water pump and I'll bet it stops.

 

Water pump gaskets seep alot too...mostly on a cold engine. It may bake off once you start it and get it warmed up.

 

If it is the water pump, you'll see the seepage on the timing cover (provided you are running coolant and not just water). The weep hole is behind the pulley...

What I'd suggest -

1. Check your timing cover for signs of coolant drippage
2. When the car is cold, just take the radiator cap off and fill it to the top.
3. Do that for a few cycles

Mine did something similar for a little while after I had just filled my radiator back up...I just kept filling the radiator up, and it eventually stopped doing it. I think it was just the air pockets getting worked out of the system.

 

You got to watch those waterpump gaskets

 

how long since the cam swap? when i did mine i had to start my engine up and let the thermostat open, did this 3 times. During this i dumped in at least a gallon of coolant. then the next morning i had to add another 1/4 gallon. But it sounds like its just working out the air pockets like what MeentSS02 said

 

This is my 5th cam swap on the car. I put it on a lift while it was running inspecting the water pump and nothing.

 

Back when I had my stock motor one time I was losing coolant. Couldn't figure out where the heck it was going. I could smell it, but I couldn't see a leak or anything. Then I got a tune and it was fixed. I was running real lean.

 

I hope thats not the problem. I can smell it running rich though.

 

Since you did a cam swap, you might want to make sure your tune is good, if you haven't already done so. Especially if it isn't leaking from anywhere.

 

The radiator has been sending it coolant to the resorvoir and causing it to overflow. Why?

 

Is the fluid boiling? Checked your oil for radiator fluid in it? Sure you got all the air out of the system when you did the cam swap?

 

The oil is fine and gold. BTW I am not running a thermostat if that matters.

 

Will not running a thermostat affect it using coolant?

 

Put it back in. You need to run one on these engines. The stat regulates the fluid so it stays in the radiator longer to allow it to cool. No stat and it runs full force through the system and doesn't cool off enough.

 

The car runs at a consistant 210. I drove it 300 miles round trip this weekend and never ran hot, but was about a quart low on coolant. Could not having a thermostat make it use any coolant or do like im saying. Why would it overflow out of the resorvoir?

 

Someone?

 

Not sure about the leak but no t-stat here for a year and the car runs fine even in 90 degree heat. It will not affect coolant loss. Looking at the data in the tech 2 the car will run about 185-190 on average in summer temps. Are your fans set to come on at a lower temp? If not I recommend it, it helps. Look at your temp with a scanner. The cars I've seen can be off by 20 or more degrees on the dash. Mine reads 20 hotter.