steam and hissing sound coming from engine
Thread Starter
Teching In
Joined: Jan 2011
Posts: 15
Likes: 0
steam and hissing sound coming from engine Hopefully yall can help me out, I have a 99 trans am when at a red light the car surges and has steam coming from under the rear of the hood on drivers side, and the surging gets worse in the rain while stopped. when I pop the hood there is a hissing sound and steam coming from the back of the engine compartment. Could it be the steam crossover pipe or something with the pcv? Need help thanks in advance.
Borrow a cooling system tester from your local auto parts store. Make sure the coolant is full and screw the tester on. Pump some pressure into the system and watch for the leak to occur.
Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
If your leaking coolant then you should be having overheating issues and have to add coolant from time to time. You could pressurize the system until you hear the hissing and try and put your hands on the freeze plug or the coolant plug and see if the hissing sound changes indicating the source of the leak. Also get a mirror back there and see if you can see where the leak is coming from usually there is a visual indication of the source as well and if the engine has antifreeze in it then you should be smelling that stuff also if its leaking. The surging may or may not be related. Do you have a check engine light on or have you seen your check engine light flashing at you while driving? Even if your check engine light is not on there may still be codes the ECM has registered so get an OBDII scanner and scan for codes as well. Good luck!
If you see steam from the back of the motor, and assuming there is no other known reason for the surging, you probably have a leaking head gasket. Do a compression test on the suspected cylinders. Also, keep in mind that a head gasket can leak to the outside but not into the cylinder. But since you stated the motor was surging, that's why I suggested a compression check.
TECH Addict
Joined: Dec 2017
Posts: 2,182
Likes: 970
AC condensate = what condenses out of the air, onto the (cold) evaporator, just like on the outside of your (cold) beer; and drips out of the housing
Completely normal; in fact the more the better
Symptoms of a bad head gasket depend entirely on where EXACTLY it's bad. That is to say, what it allows to leak into what else. Needless to say, the VAST majority of them fail where the pressure is HIGHEST, which is, between cylinders. They don't all that often involve coolant or oil or overheating. About 99% of all car problems that people automatically blame on head gaskets are something else, and in case they get fixed during a head gasket replacement, are basically just collateral damage.
Forget about head gaskets. Most likely, not your problem.
Look and see if your AC condensate is dripping on the exhaust.
Completely normal; in fact the more the better
Symptoms of a bad head gasket depend entirely on where EXACTLY it's bad. That is to say, what it allows to leak into what else. Needless to say, the VAST majority of them fail where the pressure is HIGHEST, which is, between cylinders. They don't all that often involve coolant or oil or overheating. About 99% of all car problems that people automatically blame on head gaskets are something else, and in case they get fixed during a head gasket replacement, are basically just collateral damage.
Forget about head gaskets. Most likely, not your problem.
Look and see if your AC condensate is dripping on the exhaust.
