Possible blown head gasket?

[Sonny]

Was doing 75mph for about 45 minutes Saturday and thought I begun to hear an exhaust leak. At 45 it was not heard. Stopped at a light and felt a hard miss as the car shook and was low on power. Limped it home. Below is the driver side compression test and plug condition. All plugs are new. 3rd cylinder is down on compression and that plug was clean like new. Others brownish. Vacuum gauge fluctuates from 5 to 19 at idle and runs rough. Slight brown film on bottom of radiator cap (normally clean). Coolant green but cloudier than normal. Is this a definitive blown head gasket? I checked all vacuum connections and hoses, and brake clean on intake runners produced no change.

 

[Cranky]

Could be a burnt valve. Is there any pressure going into the radiator when cold? Dual exhaust? Can you hear a 'hiss' of air in the pipe when running the starter with the coil wire off? That's just a couple of tests to try to isolate gasket vs valve....

 

[Fran Blacker]

Check 3 cylinder for valve train problem or broken valve spring. Maybe you get lucky and it's something simple.

 

[pnora]

Buy a test kit and see if there is combustion gasses in the cooling system.

 

[440Coronet500]

Is it blowing white smoke from the exhaust? If not I'd look at the rocker and valvetrain. 440'

 

[Ranger16]

Buy a test kit and see if there is combustion gasses in the cooling system.

You don't even have to buy it. You can "borrow" it from AutoZone or any other parts store that has a Loan-A-Tool program. Pay for it and get a refund when you return it. All you have to pay for is the test fluid.

 

[Sonny]

Is it blowing white smoke from the exhaust? If not I'd look at the rocker and valvetrain. 440'

No white smoke.

 

[khryslerkid]

Leak down test. Also leak down test on radiator.

 

[WileE]

You can look inside the radiator with the cap off and the engine running. See if there's any air bubbles.

 

[Runcharger]

I'm betting it is though.

 

[R413]

The only thing that makes a clean spark plug is water in the cylinder. It has to be going through a lot of water to have steam come out the pipes. A burnt valve gives incomplete combustion, it wont clean the plug.

I’d say it has water in there. Lower compression is a problem.

 

[Photon440]

Even if it is a head gasket, you could be fixed on a Saturday.

 

[Sonny]

I just removed my valve cover and the intake rocker on number 3 is super loose. Push rod goes up and down 1/4” with little force. Looks like the lifter died. Could that cause my issue above?

 

[dvw]

I just removed my valve cover and the intake rocker on number 3 is super loose. Push rod goes up and down 1/4” with little force. Looks like the lifter died. Could that cause my issue above?

Very little intake opening means not much air/fuel entering the cylinder. Thus less compression, no volume. Thus cleaner, less fuel. Your on the right path.
Doug

 

[Cranky]

Hope it's not a flat cam lobe.....check for that too.

 

[Sonny]

When I push on the push rod, the lifter squishes very easily about a quarter inch or so Up and down.

 

[Sonny]

Bad news confirmed. Hole in lifter, damaged cam lobe and metal everywhere.

 

[dadsbee]

DANG!

 

[khryslerkid]

Ouch!

 

[Moparnocar]

What causes that?? Low zinc oil?