Head gasket

[grngoat]

So my slow build of my 1971 is somewhat under way. Today I decided to change all the fluids in the truck. All is going well until I drain the oil. It came out milky colored and real thin. I presume water has entered. When I bought the truck last month the seller said it hadn't been cranked in over a year. Could this be condensation or a sign the head gasket is gone? The truck starts and runs fine, no knocking or any other indication there is a head problem. Besides pulling the head is there a way to tell if the gasket is shot?
Thanks,
Lee

L

 

[npulver]

you can do a compression test, should tell you even which cylinder is leaking the coolant.

 

[npulver]

When I bought the truck last month the seller said it hadn't been cranked in over a year. Could this be condensation or a sign the head gasket is gone?
L

Sorry for posting twice in a row, but to be honest it could be either/or. If you live in a humid climate and vehicle hasn't been started in a long time, it can definitely acquire some moisture from the air and put it in the oil.

Like i said, first i would do a compression test, if it seems good, change the oil (which seems like you already did) and check the engine oil in a few hundred miles and see what it looks like. Chances are though, if the compression test comes out good, you should be good to go.

*Noticed your location after posting this (lol) being as your in SC, it can definitely be the humidity that just got into the oil.

 

[AzPiggy]

Let engine sit for a day or two, take spark plugs out, turn engine over. See if water comes out. Not scientific but works if water is building up. A compression test may give false readings if rings or valves aren't seating well due to high miles or carbon build up. Also check tailpipe for that familiar sweet smell of radiator fluid. It's what I would do. These are free easy steps before you remove the head.

 

[npulver]

Let engine sit for a day or two, take spark plugs out, turn engine over. See if water comes out. Not scientific but works if water is building up. A compression test may give false readings if rings or valves aren't seating well due to high miles or carbon build up. Also check tailpipe for that familiar sweet smell of radiator fluid. It's what I would do. These are free easy steps before you remove the head.

To get rid of the negative reading from rings (not valves) you can add a little oil to the cylinder your compression testing. If the cylinder is good, your compression will be higher than if you did it dry.

 

[Gumby]

It's worth the $30 or so to just change the oil. Put some fresh oil in it. Start it up. Let it get warm, but keep an eye on the overflow and temp gauge to make sure it's not a bad HG. Watching the tailpipe is good too. You might well get a lot of steam, but it shouldn't smell like antifreeze. Let it get up to a high enough oil temp to burn off the condensation and unburnt fuel that might still be in there after the oil change. Check the dipstick. If the milkyness comes back you got an HG problem.

Check the plugs too. A bad HG will steam clean the plug on that cylinder.

That big iron block will get condensation in it from sitting and short trips. Thin oil is fuel contaminated that suggests incomplete warm ups as well.

 

[jdfording]

I had the exact problem when I bought my 71 55. If I were you I would just go ahead and do the gasket now. I had water in my oil and figured since it was sitting so long it was moisture. Drained the oil and replaced the filter. Seemed ok for a few miles. Sounded fine and then I started getting a knock. Drained the oil and it looked like chocolate milk again. Ended up doing the head gasket and now have to do the rod bearings. If I would of done the head gasket the first time I'm sure the rod bearings would of been fine.

The head gasket on a 55 is very easy. I had mine off in about an hour. Installed in about the same time. Hardest part is cleaning all the old sealant off the head and block. You should also pull the engine side cover because there is a brass oil tube that runs from the oil pump to the rocker arm rod and and it runs up through the head. I ended up cracking mine and had to have one made. You could probably get away with not pulling the side cover if you have some help lifting the head on and off to guide the tube through the hole in the head.

If you have any questions about the removal/install just pm me. I was amazed how easy this job was and I'm not a super mechanic like some of these folks.

 

[grngoat]

Thank you all for your responses, this is where I am at now. Changed all the fluids and got new tires on her. I have driven approx. 50 miles since the oil change, check dipstick after each outing and the oil looks like it just came out the bottle. Hopefully I have dodged a bullet. Would it be worthwhile to dump a little Seafoam in and drive a couple hundred miles then change the oil again?

Thanks, Lee