The Stovebolt Site Forums The Shop Area Engine Shop Head gasket

checked my oil the other day, and found it was "milky" on the dipstick, which can only mean one thing, a blown head gasket right?

i've been reading my service manual on this topic and it seems pretty straight forward, the only issue i see is trying to get head out without a hoist.
Anything i should be careful with while doing this?

Actually, there are several ways for the oil to get contaminated with coolant,and the head gasket is the least serious. Heads, and even cylinder blocks have been known to develop cracks, from overheating, freezing, and occasionally just from old age. Before you pull the head, I'd reccomend a pressure check of the cooling system to try to isolate the source of the leak. Disconnect both radiator hoses and splice them together, and make a loop of heater hose from one connector to the other. Now you can adapt an air line with a pressure regulator to the cooling system, and apply about 20 pounds of pressure. With the spark plugs, valve cover, and the pushrod cover removed it might be possible to pinpoint the source of the leak. Sometimes pulling the head will hide evidence of where the leak is coming from.
Jerry

Hy Josh_51GMC, have you changed the oil since you started your engine? If you have and it has turned "milky", a blown head gasket is only one of the possible causes. Have you noticed a loss of coolant? When the engine is running at operating temparature remove the rad cap and look inside the rad to see if you can see any bubbles moving by the filler neck. The block may also be cracked, good luck.

Are you sure it's coolant? Are you loosing coolant?

Do drive a lot of short trips, not enough to really warm up the engine?

Okay, so Jerry what your saying is that i basically disconnect the 2 main hoses for the radiator and some how attach them to eachother? you lost me after the heater hose part haha.. i will definitely check my coolant level, if not tonight then tomorrow.

Thanks so much for the tips

Run a flex hose from the water pump outlet to the outlet in front of the head. Plug one of the heater outlets and put an air connection in the other one. That way you will protect your radiator and heater core. Leave about 20 psi on the engine for a while and look for a leak.

I don't know if I would subject an old rad to 20 psi pressure. I understand the process but I would assume that is an old rad in there.

When I remove the head from mine, I construct a support area on one of the front fenders using a soft towel, some bubble wrap and a piece of plywood. I then stand inside under the hood with my feet on the frame. I pick the head up and place it on the fender. I am 5' 11" and it works for me.

my old truck has milky oil a lot on colder days when it hasn't had time to boil off the moisture in the oil, I mostly notice it inside the oil filler hole. maybe this is what you are experiencing. Make sure this isn't the case before you tear the whole thing apart.

Josh,

Here is a tip for removing the head. Makes for an easy job for two people, no hoist needed.

Remove valve cover, Remove rocker arm assembly, remove head bolts. Get a 2X4, mark the centers of the two outside bolts that hold on the rocker arm assembly onto the "2" inch side of the board. Drill holes in the board. Bolt board to head.

Piece of cake to lift the head off using the 2X4.

Kurt

Brokenhead, what your saying makes a lot of sence. the last time i had the truck running and sitting at running temp was when the weather was still hot out. but the main thing im worried about is when i took the valve cover off i had milky oil coming out on top of the rockers and also on the dip-stick. maybe thats the case? is there anyway to check is?

if i do have to pull the head, i will most likely pull the rad, and one front fender, i dont think i can squeeze in there (im 6'3")

im just going to go get the truck up to running temp and see if i see a loss in coolant

That's the reason for getting the radiator and the heater core out of the mix- - - -"Splice the upper and lower hoses together"- - - -That means put the pressure on the engine block and head only, not the radiator and heater core! I've also done that kind of pressure test by plumbing a garden hose to a similarly-isolated block and head, and using city water pressure.
Jerry

Jerry,
I read too fast and missed the part about the rad. Thanks for that added explanation.

Fred

So just a heads up about what I found, I let my truck sit and get up to temp, and coolant was barely bellow the level I had it at when I poured it into the rad. Let the truck run a bit more, just to see if it would burn off any moisture, checked my dip-stick and it was covered in "milk". So I drained my oil, and probably half the amount I poured in came out in a oil/milk mix.... Is it possible to burn off that much oil??

well it sounds like you have more than condensation. The head isn't all that heavy, you can just pick it up. I mean it weighs more than a birthday cake, but isn't unmanageable. I was saying it takes a good hour of driving at highway speeds to get all the moisture cooked off, but I only really noticed this on my trip from san diego to montana during the winter. I've noticed it occasionally over the last 25 years, but only during the really cold times.

While you were watching the coolant level did you notice any "bubbling"?

Does your engine have a road draft tube with a vented oil fill cap?

Do you drive mostly short trips in the truck?

One more thought. On the 2-piece hood, water will drip or run onto the valve cover and enter thru the air vent in the center. It goes right into the motor. I just lay a 2x4 on top the motor to deflect any runoff, if it sits out in the rain or during wash. Just a thought before a teardown. I almost did what you are about to do and that was my problem.

Roy Rodgers - there were no bubbles that i could see, but the colour kind of confused me, it almost looked like a melted creamsicle. im guess from any rust deposites that have built up over time? this was the first time running a rust preventative coolant. i do not drive the truck at all as i am still waiting for a couple brake parts.... and whats a road draft tube? is that the tube that comes out the passenger side of the block?

Edub10068, i noticed yesterday that the drain tube for the cowl vent was dripping watter right onto the valve cover at the back slot... that could have something to do with it but i highly doubt for the amount of water that was in with the oil.... but im really curious now, since i have drained my oil and everything, is there any way to check?

The cowl vent may have something to do with it, depending on how much water gets in. And how much water gets on the truck.

My 58 would get the oil milky between changes when my grand dad drove the truck. But he never really worked it, just a short trip here and there. So the engine never did really get hot enough to boil off any condensation that built up.

When I started driving the truck, I put it to work. It worked for a living and so it got hot and stayed that way for a while each day. I also put a vented oil fill cap on it so the vapors could get out of the valve cover. Mine didn't have slots in the cover.

I also took the road draft tube off and cleaned it to make sure it could provide ventilation for the engine.

I don't know if any of this applies in your situation, but if the cowl drain is letting the water come down on the valve cover, and run into a slot for ventilation, then it wouldn't take a lot of moisture to get the milky look , especially if the engine is only ran for a few minutes at a time.

And the road draft tube is on the passenger side of the engine.

No bubbles is a good sign, and the rusty color may be the rust coming loose in the water passageways.

Okay, I think im going to either put a cover over the slots, or move the cowl vent tube away, put some new oil in and see what happens. How long do you think it would for the new oil to turn milky if it is a head gasket issue

You will probably want to flush the engine out. It may take a couple oil changes to do it. You may want to thin the oil with some kerosene, run it at idle for a bit and then drain it. If you do this 2 -3 times it should clean up. Then fill it up with fresh oil and keep an eye on it. I do caution thinning the oil down make sure you don't drive it, just a fast idle.

If you are getting no bubbles in the radiator, the leak in the head gasket (if there is one) must be very small. Just see how it goes. There is a lot of water coming thru that tube actually that will dump on the valve cover. Im betting you have the same problem as I have had many times.

I had the same problem many years ago with the cowl vent tube dumping water on the valve cover and then water getting into the engine through the vent slots. I solved that one by installing a longer rubber drain tube that I could direct to the side of the engine. No problem since then.

Kurt

Alright, well i think I'm going to go buy a jug of engine flush and maybe a 5 gallon drum of oil haha. Hopefully the downspout was my problem, cause i mean my radiator is still full to the level i filled it at, it doesn't make any sence for that to be the source of all the water.

Thanks for all the info guys, definitely saved me from ripping my engine apart