93 Z28 w/ 70,000 mi. - Drove to work the other day and when I pulled into the parking lot steam was coming from under the hood on the passenger side along with the smell of coolant. It was coming from somewhere below the radiator cap. Also a small amount of coolant was dripping from the plastic parts underneath. I'm thinking pin hole in hose or radiator. Drove the car home, no steam. Let it idle for 1/2 hour with ac off so that it would come all the way up to temperature to try to duplicate it. No steam or drips!?!? Any ideas? Could a bad thermostat or waterpump cause anything like this? Still has the original parts. Thanks!

 

You may not be getting any steam because you may be out of coolant. That is a bad thing. Go to the auto parts store and rent a coolant pressurizer for $5... some places are free. Fill up your coolant and put the pressurizer in place of the radiator cap. Pump the pressure to 17 lbs. You will see the leak. Do this on a cool engine. It sounds as if you low level sensor is dislodged or you may be developing a crack in the radiator. If it is green coolant, keep it green. Orange keep orange.

I just did the water pump this weekend. Dealer charges $580 including the 4 hours labor. I did it on Sunday in about 5 (first time). If it is leaking there I'll help you out. PHEW! It wasn't easy the first time but I know where the bolts are now.

Also, when you pressurize your cooling system, remove your air intake hose so you can see the waterpump. It will leak directly onto the crank pulley if it is the water pump. Keep us posted.

 

Thanks for the info Wild1. I just got around to working on this. Fortunately have another car to drive until it's fixed. I got the pressure tester and found 2 problems. 1) Bad radiator cap. 2) Leaking from the radiator under pressure; right side black plastic towards the top.

The coolant had leaked out until the level was below the crack. That's why I was not seeing the steam and/or leak all of the time. Car never overheated oddly enough. The coolant level was about 4 to 5 inches low in the radiator.

Can this kind of leak be fixed? Or is it time for a new radiator?

Thanks.

 

if its leaking from the radiator chances are your gonna have to replace BUT you can try some of that plastice pressure weld stuff thats like 7.99 at napa, like a jb weld for plastic with a pressure test on it, force that stuff into the crack or whatever it is on the radiator and see if that holds, might be a temp fix but its better then a down car for however long... just a suggestion.....

 

Those pressurizers are worth their weight in gold. Really, you will find odd leaks everywhere. The pressure/radiator cap could be why the pressure cracked the radiator. I've seen some sad cases where a $10 part cost an entire engine.

About the radiator, I'd take it out to a radiator shop. They can apply the fix and will pressurize it to see that it holds. You can do the plastic weld yourself and use the pressurizer to test.

Helpful hint. I also use the pressurizer to bleed the air out of the system. It works well, and you can stuff a rag under the two bleeder screws to soak up the coolant as it is spit out. This will help the opti stay dry.

Keep us posted if you need any more assistance.

 

i had the exact same problem with a crack on the black plastic, i patched it with that radiator repair stuff and within a month the crack had gotten larger/longer and it was just useless. I priced out the parts at the dealership and it all came to like $80 but then you have to have a radiator shop press in a new black tank. I ended up finding a hardly used radiator for $75 here on the board...

 

There's a local radiator shop that will replace the cracked tank for $89 if I pull the radiator out and bring it in to them.

If I bring them the car it's $159 and they will do it all. Seems reasonable...just not sure how careful they would be not to get coolant on the opti assuming they bleed the system as they are supposed to.

Either way I should have it fixed in the next week or so. Thanks again for your help.

 

you can remove the radiator without harming the opti. You can remove the drain plug to remove the coolant from the radiator. Have a pan ready for the lower radiator hose... there is some residual coolant in there... remove the wires and other hoses and your done. You may need to catch ATF if your car is equipped with an A/T.