Hey all, I have a 2006 Cobalt SS/SC. I've had it maybe 2 months now? And I've continuously had to keep topping off the coolant overflow tank. I can put it back to the cold fill line and drive it two times before I need to add coolant again. I don't see any obvious leaks anywhere and the car runs strong, no sign of coolant in the oil either. Is there somewhere or something I can check? PLEASE HELP!

 

Here lately no one replies on here. Kinda sucks

 

Little more info on your car will help. Mods, miles, etc.

If you drive 4miles and have to refill it again then you have a serious leak, if your drive it two times is 300miles you still have a fairly serious leak, or you have a huge air bubble in the system and need to bleed it correctly.

You could add a UV dye to the coolant and then hit it with a UV light to see the leaks.

 

I'm at the dealer now. The Service manager just told me that they did not see any external leaks and that the pressure test it was losing a little pressure slowly. So a small leak. They are going to lunch now and are going to let it sit through lunch. I'm betting it's a head gasket but we don't know for sure yet. What's a fair price for labor on this job? I need this car can't wait and do it myself. I want to get the parts myself can someone provide a list of part numbers I'll need. What kind of gasket would you use as a replacement?

 

Also would this be a good time to buy some upgraded parts? If so what?

 

Car has 167520 miles it's got an zzp larger radiator, a zzp intake, maybe a ported throttle body? And that's all I know of right now. I just got the car. Would someone recommend going with the stock head gasket or getting a MLS aftermarket one? Also I'm guessing go with ARP for the head studs? The dealer will be doing all of this work for me as I don't have time. I'm just gonna bite the bullet

 

Go with stock head gasket and stock head studs

 

Do you have any other performance issues? Misfires knock etc.

We have seen a few blown head gaskets but could also be something else.

 

Not that I'm aware of. My Dad did say the other day that it sounded like my car was missing but I don't personally believe it is but I haven't performed any tests to verify that for sure. I'm still waiting in this solitary confinement of a room awaiting to hear from the service manager on what the problem is. I'm betting it's a head gasket, porous block, cracked head, or bad radiator cap. Any of them would be a good guess in my opinion. I know the car is fairly solid I drove it back home 3 hours the day I got it.

 

Why is that? Not trying to say your wrong, but I just want to know your reasoning is all. Thanks

 

The stock head gasket is an MSL gasket. Stick with the stocker. Too many issues with the cometic aftermarket ones.

 

Alright I'll go with the stock one then. What about head studs? Stock or ARP or what?

 

Nothing wrong with the stockers... I run them, but the ARP's are nice due to the ability of not having to replace them if you ever need to remove the head again, and the fact they are ARP.

 

Okay service manager just came in and told me they don't know where it's going. The tech looked directly at the piston and there's no coolant dripping on them. They did a dye test no leaks externally. They did the pressure test and he said it leaked 1 pound of pressure over an hour span. He said that could also be their gauge maybe not sealing up completely. I'm at a loss I don't know what to do?? He did inform me that the plugs were a little toasty and suggested replacing them with no labor charge just pay for parts. 10 dollars a plug he said they were iridium I took him up on the offer. All in all I'm out 80 bucks and I've got some new plugs and still don't know where the leaks at. Any insight anyone???

 

Maybe try replacing the coolant tank cap if there is a pressure loss... They can go bad.

You could be allowing air to seep into the cooling system causing it to look like coolant is dropping.

This worked on my Cavalier back in the day.

If you have no visual signs of coolant in the oil or exhaust it is more than likely not a head gasket issue.

How is your heat in the car?? Warm??

 

Okay awesome! So are you saying replace the overflow tank cap? Or the actually radiator cap or both? Thanks! I was actually telling the service manager that I thought it could be the cap.

 

The coolant tank cap.

No cap on the radiator on our cars.

Let me know how you make out. It's a cheap enough potential fix to give it a shot.

 

My overflow tank sensor is bad anyways should I replace the whole tank cap and all?

 

You could, but you will need to drain the coolant and re fill as per the proper fill procedure.

It's not hard, I can give you the proper instructions on how to refill the coolant and purge the air from the system.

 

Yeah sure give me the instructions please. I think my dealer wanted to charge me 100 bucks for the overflow tank with cap and sensor is built in. They wanted like 180 dollars labor to install it. That a fair price or no? Instructions on replacing the overflow tank?

 

Paid 40 for plugs, 40 diagnostic fee, 100 for coolant tank it didn't include the cap so I called Napa and ordered a cap for 13 bucks that will be there tomorrow. I need instructions on how to install this overflow tank properly please. Thanks in advance.

 

There are two places you need to drain the coolant from before you refill....

1. the radiator via the drain plug at the lower passenger side corner.

2. the water pump via the plug found at the bottom of the pump.

You need to fill the head first in order to properly add coolant to an LSJ.

Below is a shot of what I used to perform this step (3/4" heater hose and a funnel).



Fill with coolant until it dribbles out of the head. Make sure to have a rag placed underneath to catch the coolant that runs out.

I then filled the radiator via the upper radiator hose.

Reinstall the upper radiator hose to the head.

Fill the rest of the cooling system via the engine coolant expansion tank.



Time to start the car.... (make sure to perform an oil change before starting the car)

If the installation was performed correctly, she should fire right up. The car might be a little rough for a sec or so until pcm sorts everything out.

Turn your heat and fan control to max, and let her idle for a bit. The coolant in the expansion tank will begin to drop.

Refill until the system fully removes all the trapped air.

 

Sorry I appreciate your help but there's no reason I should have to change the oil after adding coolant. Also no reason I should drain the coolant in order to replace the expansion tank. I simply need to bleed the air out of the system once I install the new expansion tank.

 

No you don't need to replace the oil... I took this from my how to thread for installing a cylinder head. Ignore that part. Thought you would get the jist, guess I was wrong.

If you want to do this right and avoid trapped air... drain the coolant. I know what I'm doing with these cars, if you don't want to follow my advice than so be it, but you will be back asking the same questions again. I can guarantee it.

It's not a hard job to drain & fill the coolant.. Follow my instructions after installing the tank, and you will be set.

 

Oh okay lol yeah I had figured you had posted a "how to" that was from something else but included the steps I needed. I was just double checking to make sure that you didn't think I needed to change the oil every time I add coolant LOL. Because that would have changed my trust in you LOL. It's all good though man. I"ll give this a shot. Thanks for the help it's greatly appreciated!