390 Intake gasket???
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390 Intake gasket???
Guys, have a problem with the 390 in my 79 F-100. It overheated on me the other week so I went out and got a water pump and thermostat and installed them. That did not solve the problem. I took it out after getting it all back together and it heated up after about an hour of driving. I noticed that it kept smoking, or steaming but I figured it was due to it being cold outside. I seen the gauge was climbing so I got it back home to find out after it cooled down I had now fluid in the radiator. I checked the oil and that shows no anti-freeze mixed in. So could it be the intake gasket? I always turn to you guys for some direction on trying to solve my issues. Anyone have any ideas?
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Sure sounds like you're sucking water, I'm assuming when you say smoking/steaming it's coming out the exhaust? Pull your spark plugs and check them out. See if one, or any, look cleaner and/or different than the rest or have any signs of moisture. If you're lucky it's an intake gasket...might be a head gasket.
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I'll Pull the plugs tomorrow to see any signs of moisture. I first thought of the Head Gasket but I don't see any signs in the Oil and I'm hoping that it turns out to be the intake.
Thanks for the reply
Thanks for the reply
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Impossible to be the intake if you aren't seeing water in the oil. With the way the engine is designed the gasket is submerged in oil while trying to seal the water passage, so if the water were to leak you have both H2O in the oil and oil in coolant.
Sounds like a head gasket to me. With the engine cold, start the engine with the radiator cap off and look for bubbles. Other than that use a pressure tester if you can, that will tell you immediately if you have a problem.
I have to ask, are you sure you have a 390 in a 1979 truck?
Josh
Sounds like a head gasket to me. With the engine cold, start the engine with the radiator cap off and look for bubbles. Other than that use a pressure tester if you can, that will tell you immediately if you have a problem.
I have to ask, are you sure you have a 390 in a 1979 truck?
Josh
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From: Eldorado Ca. USA
you can use a compression tester hose with the scrader valve removed to pressurize each individual cylinder at TDC. A bad headgasket will put bubbles in the radiator as well. A cheap (improper) fix would be to buy a bottle of Sodium Silicate from the drugstore. Flush your coolant, bypass your heater core, run it for a couple of days, drain, refill with coolant, enjoy not having to tear your engine apart. Its a dirty car salesman trick, but I have seen it work, and last.
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Josh, yea its a 390 out of a 73. It was already placed in when I bought her. I have been going over it replacing things that need and dressing it up a bit as we go. The scary thing is i'm not a mechanic, but learning each step of the way. thanks for the input. I only wish it was the intake gasket hands down.
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Josh, I spoke with a man i work with and he said that possibly the anti freeze is leaking into the exhaust valve thru the intake gasket. Is this possible?
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Impossible to be the intake if you aren't seeing water in the oil. With the way the engine is designed the gasket is submerged in oil while trying to seal the water passage, so if the water were to leak you have both H2O in the oil and oil in coolant.
Sounds like a head gasket to me. With the engine cold, start the engine with the radiator cap off and look for bubbles. Other than that use a pressure tester if you can, that will tell you immediately if you have a problem.
I have to ask, are you sure you have a 390 in a 1979 truck?
Josh
Sounds like a head gasket to me. With the engine cold, start the engine with the radiator cap off and look for bubbles. Other than that use a pressure tester if you can, that will tell you immediately if you have a problem.
I have to ask, are you sure you have a 390 in a 1979 truck?
Josh
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How did you come up with this one? He would be seeing coolant into his oil. I'd check air flow too. Is the fan working properly? Does it get hot from stop/go? Are you running stock fan?
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Well I am running the Stock fan, and when this first heated up I replaced the water pump and thermostat. I have a four core radiator so I filled it with three gallons of anti freeze. When i got it all back together and started it up I noticed that it looked like a lot of steam from the exhaust, more then normal. Even after it warmed up. When I returned home, the gauge was pointing to the H just like the first time. So I waited for it to cool down and checked the radiator and sure enough it was down below the fins. I see no wetness on the floor where she sits or over the engine. So I am really confused.
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Well I am running the Stock fan, and when this first heated up I replaced the water pump and thermostat. I have a four core radiator so I filled it with three gallons of anti freeze. When i got it all back together and started it up I noticed that it looked like a lot of steam from the exhaust, more then normal. Even after it warmed up. When I returned home, the gauge was pointing to the H just like the first time. So I waited for it to cool down and checked the radiator and sure enough it was down below the fins. I see no wetness on the floor where she sits or over the engine. So I am really confused.
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Impossible for coolant to make it's way to the exhaust crossover.
For coolant to make it's way to the exhaust you have:
Blown head gasket (most likely)
Crack in cylinder head near exhaust valve (not likely)
Either do a test like a mentioned or what MasterBeavis mentioned, it will tell you right away something is wrong and maybe even where.
Look at the sparkplugs again.
How long does it take to burn up all the coolant?
Josh
For coolant to make it's way to the exhaust you have:
Blown head gasket (most likely)
Crack in cylinder head near exhaust valve (not likely)
Either do a test like a mentioned or what MasterBeavis mentioned, it will tell you right away something is wrong and maybe even where.
Look at the sparkplugs again.
How long does it take to burn up all the coolant?
Josh
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From: Near Yosemite CA
If you are talking steam/smoke from the exhast pipe, 99% it is a head gasket, and there does not have to be a mixing of the oil and antifreeze to be a blown head gasket. Could be just one water passage leaking into one cyl. and that will do it. Also when you replace the head gasket, and any time you are refilling the radiator, make sure you mix your anti-freeze 50/50 with good distilled water, or good tap water, or if available, holy water to prevent further problems (just kidding! although you never know?!! 
)
Pulling your plugs is always a great diagnostic tool and seeing what they say. As long as you don't have A/C, head gaskets are pretty quick and painless. I just did them on my 73, and it has A/C.
)Pulling your plugs is always a great diagnostic tool and seeing what they say. As long as you don't have A/C, head gaskets are pretty quick and painless. I just did them on my 73, and it has A/C.
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thanks for all the info. I did mix the anti freeze but probably not 50/50. Also I didn't burp the radiator, but will look into that also.
I ran it for about two hours (took it to see my wife at her lunch break) and it went from being full to below the fins. Also it does have AC so now i'm wondering if I want to venture this task or possibly have someone that knows a bit more then I to do it. I have been working on this engine for about four months and I would love to solve this and hopefully get it running smooth.
I ran it for about two hours (took it to see my wife at her lunch break) and it went from being full to below the fins. Also it does have AC so now i'm wondering if I want to venture this task or possibly have someone that knows a bit more then I to do it. I have been working on this engine for about four months and I would love to solve this and hopefully get it running smooth.
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There is no need to "burp" anything with the coolant escaping that much.
I am guessing you are not running a coolant resevoir? Just have a hose from the filler neck running down the side of the radiator?
Is/ Does that hose puke any coolant out when the engine is hot and the coolant is completely topped off? I do not remember the specs, but I believe Ford calls for the level in the radiator to be like 2 inches below the neck.
Still say it's a head gasket.
As for tearing the engine apart, get a Haynes/ Chlymers manual, a 12 pack of beer per day of work and friend that will still be a friend after it's all said and done.
Why do I say that? I live, eat, sleep and breathe the FE engine, but it does have it quarks, like the pushrods running THRU the intake manifold for one.
The tricky parts are remembering how you took the distributor out and loosening all the header/ manifold bolts. Remember too that you install the head gaskets the correct way, they can be installed backwards and it royally screws up the cooling.
How long have you had this truck and did this problem just instantly occurr?
Josh
I am guessing you are not running a coolant resevoir? Just have a hose from the filler neck running down the side of the radiator?
Is/ Does that hose puke any coolant out when the engine is hot and the coolant is completely topped off? I do not remember the specs, but I believe Ford calls for the level in the radiator to be like 2 inches below the neck.
Still say it's a head gasket.
As for tearing the engine apart, get a Haynes/ Chlymers manual, a 12 pack of beer per day of work and friend that will still be a friend after it's all said and done.
Why do I say that? I live, eat, sleep and breathe the FE engine, but it does have it quarks, like the pushrods running THRU the intake manifold for one.
The tricky parts are remembering how you took the distributor out and loosening all the header/ manifold bolts. Remember too that you install the head gaskets the correct way, they can be installed backwards and it royally screws up the cooling.
How long have you had this truck and did this problem just instantly occurr?
Josh