Results 1 to 19 of 19

Head Gasket Bad?

This is a discussion on Head Gasket Bad? within the LT1 forums, part of the Vehicle Specific category; Been getting a PO307 misfire code lately. Opti,plugs,wires,ignition coil and that #7 injector has been replaced. I replaced the plug ...

  1. #1
    Member
    Join Date
    Feb 2006
    Location
    Western North Carolina
    Posts
    114

    Red
    97 Z28

    Head Gasket Bad?

    Been getting a PO307 misfire code lately. Opti,plugs,wires,ignition coil and that #7 injector has been replaced. I replaced the plug wire with another one and I still get the same code. I have noticed that here lately that my coolant level is dropping and that makes me think that I may have a bad head gasket.Would this cause this problem? The car will run fine for a day or two then it will stumble for a second then I get the code.

  2. #2
    Member
    Join Date
    Feb 2006
    Location
    Western North Carolina
    Posts
    114

    Red
    97 Z28

    Checked the exhaust and I have some white smoke,but I don't smell antifreeze. I do here a puh,puh,puh,puh sound from the exhaust.(hope that makes sense) I also noticed some condensation inside the exhaust tips. It's around 50 degrees here and the car is at operating temp.

  3. #3
    Member
    Join Date
    Feb 2006
    Location
    Western North Carolina
    Posts
    114

    Red
    97 Z28

    Uh oh. I checked the oil cap and I have what appears to be dried chocolate milk in the cap. I also saw yellow looking foam in the oil fill neck. Could this be antifreeze eventhough dexcool is orange? Is the head gasket near that cylinder causing the problem?

  4. #4
    Senior Member 5.0THIS's Avatar
    Join Date
    Oct 2001
    Location
    Colorado
    Posts
    3,704

    red
    95 Z28

    Well, it sounds like you're mixing oil with coolant somewhere. You can have the cooling system pressure tested, and that will tell you. Drain your oil and see if there is any water in there. Regardless, I wouldnt be driving the car.

  5. #5
    Member
    Join Date
    Feb 2006
    Location
    Western North Carolina
    Posts
    114

    Red
    97 Z28

    Quote Originally Posted by 5.0THIS View Post
    Well, it sounds like you're mixing oil with coolant somewhere. You can have the cooling system pressure tested, and that will tell you. Drain your oil and see if there is any water in there. Regardless, I wouldnt be driving the car.
    The local parts store has a coolant system pressure tester as a loaner. I was thinking about getting it and seeing if I can see anything.I was under the car today and I didn't see any leaks.Where should I be looking? I am also going to pull off the oil filter tomorrow to see if any water is in it.If there is,is that a good(bad) sign that the gasket is bad? Thanks

  6. #6
    Senior Member 5.0THIS's Avatar
    Join Date
    Oct 2001
    Location
    Colorado
    Posts
    3,704

    red
    95 Z28

    You need to drain the oil in the pan, as if you were changing the oil. If there is water in the oil, that is a bad sign, any way you look at it. A blown head gasket is just one of many ways that oil can mix with the water. If there is oil in the water, then there is also the potential for motor damage, specifically your bearings and rings.

  7. #7
    Driving as fast as I can dafaic's Avatar
    Join Date
    Aug 2005
    Location
    Waxahachie, TX
    Age
    37
    Posts
    170

    Silver
    97 TA M6

    my car has been loosing coolant and i found a slow leak between 5 and 7 on the outside. I changed my oil immediatly even though the mobil1 only had 1000 miles on it cause the leak was new. You don't want to be driving the car with a bunch of coolant in there. Like he said bad for the motor...

  8. #8
    Member
    Join Date
    Feb 2006
    Location
    Western North Carolina
    Posts
    114

    Red
    97 Z28

    Quote Originally Posted by dafaic View Post
    my car has been loosing coolant and i found a slow leak between 5 and 7 on the outside. I changed my oil immediatly even though the mobil1 only had 1000 miles on it cause the leak was new. You don't want to be driving the car with a bunch of coolant in there. Like he said bad for the motor...
    My leak isn't slow. It stays full,until I run the car and then it takes anywhere from a 1/2 gallon to a gallon of water to fill it up.

  9. #9
    Member
    Join Date
    Feb 2006
    Location
    Western North Carolina
    Posts
    114

    Red
    97 Z28

    Did a coolant system pressure test.The psi went from 18 to 17 in ten minutes.Going to check again in another ten minutes to see where it's at.Does this mean that I may have a small leak somewhere?Which doesn't make since to me since I'm loosing coolant rapidly.Could it be enough to cause my misfire problem?

  10. #10
    Member
    Join Date
    Feb 2006
    Location
    Western North Carolina
    Posts
    114

    Red
    97 Z28

    Still holding steady at 17psi. So in 20 mins,the pressure has went from 18 to 17psi?

  11. #11
    Member
    Join Date
    Feb 2006
    Location
    Western North Carolina
    Posts
    114

    Red
    97 Z28

    Did a pressure check with the car running and the gauge went from 17psi to 30psi in a minute.Is this normal? That was the first time the car was started today.Going to check the oil next.Thanks

  12. #12
    Member
    Join Date
    Feb 2006
    Location
    Western North Carolina
    Posts
    114

    Red
    97 Z28

    Drained the oil and didn't see any water. I did see some tiny air bubbles.Don't know if that is a concern or not.I do have large ampount of white smoke coming from the exhaust and I put a piece of cardboard at the tips and there was water droplets on the cardboard.
    Last edited by Red97LT1; 02-25-2007 at 01:39 PM.

  13. #13
    Senior Member 5.0THIS's Avatar
    Join Date
    Oct 2001
    Location
    Colorado
    Posts
    3,704

    red
    95 Z28

    It may all be burning off in the chamber. That would hopefully mean you havent damaged anything else in the motor yet. But look at it this way... the coolant is going somewhere. If it isnt leaking on the ground, then it is going into the motor... and if it isnt in the oil... it's pretty easy to start narrowing this down...

  14. #14
    Member
    Join Date
    Feb 2006
    Location
    Western North Carolina
    Posts
    114

    Red
    97 Z28

    Quote Originally Posted by 5.0THIS View Post
    It may all be burning off in the chamber. That would hopefully mean you havent damaged anything else in the motor yet. But look at it this way... the coolant is going somewhere. If it isnt leaking on the ground, then it is going into the motor... and if it isnt in the oil... it's pretty easy to start narrowing this down...

    So I can assume that I do have a bad head gasket,but it"s not that bad yet? Could it be bad at the #7 cylinder and that's why I keep getting the misfire on that one?

  15. #15
    Senior Member 5.0THIS's Avatar
    Join Date
    Oct 2001
    Location
    Colorado
    Posts
    3,704

    red
    95 Z28

    burning 1/2-1 gallon of coolant is bad. It will get by the rings and into the oil at some point. You cant drive it like that.. or at least I certainly wouldnt.

  16. #16
    Member
    Join Date
    Feb 2006
    Location
    Western North Carolina
    Posts
    114

    Red
    97 Z28

    Quote Originally Posted by 5.0THIS View Post
    burning 1/2-1 gallon of coolant is bad. It will get by the rings and into the oil at some point. You cant drive it like that.. or at least I certainly wouldnt.
    Oh,don't worry. I have shut her down until it gets fixed.It's fuuny,when I returned the pressure tester to the parts store,the guy asked me what I found.I told him and he said that his car was doing the same thing as mine,except he was getting a misfire on the #5 cylinder.He replaced everything I have and the problem still existed. Replaced the gasket and problem is gone.I have been dealing with this for a month and a half and I'm ready for it to be fixed.

  17. #17
    Driving as fast as I can dafaic's Avatar
    Join Date
    Aug 2005
    Location
    Waxahachie, TX
    Age
    37
    Posts
    170

    Silver
    97 TA M6

    well i retorqued the bolts on my heads and looks like my leak is gone for the time being. If it comes back off the head comes for a new gasket. Good Luck
    Click for full size
    lt4 hot cam, l.e. heads, gold 1.6rr, hooker lts, 3"ypipe, hookercatback, no cats, subframes, b&m ripper, k&n cai, msd6a-coil-opti, udp, tr55 g's, ta girdle, 4.10's, boxed control arms, Madz28 tune, specstg3, alum. elbow. No traction

  18. #18
    Member Chad97z's Avatar
    Join Date
    Aug 2005
    Location
    Dallas / Irving
    Posts
    396
    Quote Originally Posted by dafaic View Post
    well i retorqued the bolts on my heads and looks like my leak is gone for the time being. If it comes back off the head comes for a new gasket. Good Luck

    those bolts have a specified torque and angle. If you get it too tight and the engine gets pretty warm, it will expand and break a bolt.


    I had a leaking head gasket once. And it was leaking most the water into the cylinder and burning off when I started it up. I never noticed any smoke. I first began the water level in the radiator kept going down. I kept getting a low water level light. But I never found any water on the ground so I shrugged it off. Well, one day I turn on the engine from sitting over night and it had a slight miss, but it wasnt very bad and the computer didnt even detect it then it stopped missing after it burned off the water. As the leak got worse, it started to miss harder and then I got a check engine light. And then eventually there was so much water in the cylinder that it locked up the engine once when I was trying to start it. I guess water doesnt compress too easy =) So that was the last time I tried to start it in that condition. After I disassembled the engine, there was carbon everywhere Except the one cylinder that had water. The bad cylinder had been steam cleaned. I had very little water in the oil but there wre some signs of snot under the intake manifold..

  19. #19
    Member
    Join Date
    Feb 2006
    Location
    Western North Carolina
    Posts
    114

    Red
    97 Z28

    Sounds like just what mine is doing. I haven't drove it in 2 wks.My mechanic stays so busy that he couldn't get to it til monday the 12th.I'll be glad to get her back. I think I'll have him check my vacuum lines and my rockers to see if anything needs to be adjusted since the heads will be out.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Head gasket help...
    By DIDZ in forum External Engine
    Replies: 6
    Last Post: 10-07-2010, 04:14 AM
  2. Ls6 head gasket
    By sedric in forum External Engine
    Replies: 3
    Last Post: 07-13-2010, 05:17 PM
  3. no head gasket
    By V8MUSCLE in forum Almost Anything Goes
    Replies: 27
    Last Post: 03-05-2010, 03:39 PM
  4. STS blown head gasket?? What head gasket
    By 2000sts in forum Forced Induction
    Replies: 4
    Last Post: 08-26-2009, 03:23 PM
  5. Replies: 4
    Last Post: 11-13-2007, 09:58 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •