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water in oil

Discussion in 'Chevy Trucks' started by Garet, May 11, 2001.

  1. Garet

    Garet Senior Member
    Messages: 106

    Well, drained my oil to replace it today and found grey swirls in it. I guess it's probably time for a new head gasket. I can replace the h gasket but is there a way I can test the block and head for cracks without having to send it off to get magna-fluxed?

  2. Fierospeeder

    Fierospeeder Junior Member
    Messages: 28

    You can do a leak down test, pressurize the combustion chamber with an aircompressor. Its a device with two gauges and you pressurize the cylinders with a certain psi. After it gets pressurized the air goes through various places, if the rings are bad you can hear it coming out from the oil filler cap or pvc.

    jc whitney sells it and some auto parts stores sells the item. There should be some instructions on them. I cant remember what is suppose to happen for bad gaskets, water bubbling??
  3. Garet

    Garet Senior Member
    Messages: 106


    How reliable is this product? I found it on Jc Whiteny. The thing costs around $60 so I need to make sure it actually works. Anybody use something like this to test for leaks?
  4. Chuck Smith

    Chuck Smith 2000 Club Member
    from NJ
    Messages: 2,317

    This is very tricky. Those kits for doing leak down tests, aren't specific as far as determining if the block, or if a head is cracked. They will just let you know which cylinder isn't holding pressure. Not only that, but it could even be an intake manifold leak. The coolant passes through the intake to the heads. A gasket leak there, could put water in your oil too. When it's a head gasket, you can sometimes see exactly where it was leaking when you pull the head off.

    A few things can help you figure out more about the leak. If you have dual exhaust, look to see which tailpipe has steam coming out of it.
    You can get the motor hot, and pull the spark plugs on one side, and see which spark plug hole has steam coming out of it. If none, then pull the plugs on the other side, and check for steam. This is where a dual exhaust is helpful in determining which side to look for, to find the leak. If you have steam coming out of any of the spark plug holes, then you know which side is leaking. You'll be pulling the intake to get to the head, so you'll be fixing any leaks there in the process.

    As far as those kits go, when you pressurize a cylinder, you first have to pull the valve cover on that side, and back off on all the rocker arm nuts, to allow all the valves to close. Otherwise, air can leak out a partially opened intake or exhaust valve.

    Just my $.02

  5. Garet

    Garet Senior Member
    Messages: 106

    block and head cracks cracks

    Is there any way to tell if the block or the head is cracked without using the magnafluxing method?
  6. John DiMartino

    John DiMartino PlowSite.com Veteran
    Messages: 2,154

    If the water is getting in acylinder,it will usually miss for a few seconds when you start it,and that cylinder will have a perfectly clean,and green tinted electrode.I suspect the intake if its not overheating,and you have no bubbles in the radiator when its running.A good shop will have a dye they can put in the coolant,if there are combustion gases in there it will turn immdiately,this will tell you right away if you need to pull the heads,possinbly have a cracked head.