I'm guessing headgaskets...

[NCheek]

Ok, for the past little while, I have noticed a missing coolant trend in my F-250. I had kinda written it off to the apparent leaks in the top of my radiator because it always seemed to stop at about that level.

This weekend, I noticed that I had some fluid that had dripped out of my truck while it was parked, but when I looked, I couldn't find anything, until today.

I went out to the truck to get my bag, and noticed that she had sprouted another puddle, so I popped the hood, and was startled to see bright green antifreeze on the top of the engine.

If the cylinder arrangement is

8..........7
6..........5
4..........3
2..........1

then the coolant was puddling around the #4 GP and had run back along #6 and #8, and down the back of the engine. The odd part was the fluid on the ground appeared orange/ brown, and slightly oily, So I suppose it washed a bit of the engine for me. As part of the troubleshooting, I started the truck, and there was a very fine, but noticeable bubbling from the pool on top of the #4 cylinder.

I am assuming that this would be a manifestation of a failing head-gasket, but my question is, can I drive it 120 miles home if I get a 7 lb (as opposed to 13) radiator cap and maybe some Bar's Headgasket Stop leak, OR would it be more advisable to wait for my girlfriend to bring me home to get my F-350 and my trailer? Also, could the 7 lb cap bandaid it to get me to my off campus classes?

 

[6 Nebraska IDIs]

Not necessarily. There are small freeze plugs in the top of those heads and IIRC a few of them carry water. You might have one of those popping out.

 

[NCheek]

On a side note, I have been dragging goosneck trailers around for the past few weeks, and this weekend, I pulled a 20' enclosed goose from huntsville, tx to orange, tx (140 miles) and pulled it as fast as my EGT's would permit, generally hovering around 1000* and 65 mph without hills or wind. And I thought the old girl was doing good for having nearly 300K and no turbo pulling that damn sail...

 

[6 Nebraska IDIs]

Yea thats DARN GOOD!

 

[RLDSL]

Yea, and some of the heads don't even have the freeze plugs, and the valley pan gasket is all that holds it in and if that fails you will get that situation

If it has the freeze plugs, and they have been replaced at some time by a shop with non stainless ones, they will fail for sure sooner or later . If you get in there and find that. replace the things.

 

[NCheek]

Well, my engine is so dirty that I can't really tell what is going on down there. If anyone has some fancy diagrams that could give me some idea of what I'm looking at, I would appreciate it.

Unfortunately, I can't count out the HG because I think I remember a slight bubbling in the coolant last time I topped it off while running...

As far as the pulling goes, she did good for stock exhaust, pump up one flat, and God-knows-what kind of timing... The trailer wasn't really that heavy, just a pretty sizable frontal area, on top of the neck was probably 4' high x 7'6" wide, and completely flat; no fancy bubble, or the most remote semblance of aerodynamics.

 

[RLDSL]

Bubbles don't alwys mean anything only way to tell if your head gasket is blown is to run a combustion gas leak test , the kit cost about $50 at Napa, about $70 from Snap on. You put a coloured dye in a chamber over the rad filler and draw air through it for a few minutes and if the dye changes to a yellow green you have a blown HG. If as in your situation, there is a possibility of a failed valley pan gasket, you need to disconnect the CDR and re route the blowby gasses through a hose away from the test area so they are not contaminating the test via the intake /coolant leak

 

[NCheek]

Good to know, I will look into that tomorrow. But as far as rerouting the CDR, if it is an operational stock unit, why would there be any chance of a false positive in the area around the air filter housing?

 

[Brimmstone]

make sure you get the one for diesel engines though. They make two different types of chemical. One works on gassers the other works on diesels

 

[david85]

I second the valley pan gasket as a possible problem. In reality if the head gaskets failed on the top side, the leak would have sooner gone into the crank case or into one of the intake runners.

Another thing. 6.9s do not have the plugs that were mentioned. The 7.3s do, but 6.9s are simply cast open there and rely on the valley pan gasket to seal them off. Never had a problem with mine ever leaking there, but it is the most likely point of failure from what I've read so far.

The good news is its fairly easy to fix because you only have to pop the intake off and the valley pan is now exposed.

 

[6 Nebraska IDIs]

Nick, if it is the valley pan gasket here's a little tip from me. Not sure how many other guys do this but I have always coated the exhaust manifolds with copper gasket spray. It literally coats the things in copper. I've never had one blow out doing that.
So when I rebuilt my brown trucks motor I copper coated the living crap out of the VP gasket runners. I think I did 6 coats for each side.

 

[david85]

Nick, if it is the valley pan gasket here's a little tip from me. Not sure how many other guys do this but I have always coated the exhaust manifolds with copper gasket spray. It literally coats the things in copper. I've never had one blow out doing that.
So when I rebuilt my brown trucks motor I copper coated the living crap out of the VP gasket runners. I think I did 6 coats for each side.

Actually, I coated mine too. Knowing what I know now, I would simply clean it off, and reseal the old one in with RTV sealer (unless there is some real damage done to the gasket).

 

[RLDSL]

Good to know, I will look into that tomorrow. But as far as rerouting the CDR, if it is an operational stock unit, why would there be any chance of a false positive in the area around the air filter housing?

You get the possibility of a false positive because the combustion gas leak detector , senses combustion gasses in the cooling system. If the failure point is at the valley pan gasket where the intake joins up, there is a high probability that blowby gasses from the cdr that have entered the intake manafold and are going down the intake runners, will cross with the coolant if there is a leak point there . After the coolant reaches temperature and the thermoatat opens up ( place a piece of cardboard in front of the rad to help it warm up or you will never get the test done, coolant has to be fully circulating) you will pump air through the cylinder from across the top of the coolant which will draw up minute particles of combustion present in the coolant. If the cdr was left attached, you could contaminate the test by sucking blowby gasses into the coolant through the leak and wind up doing an unneeded head gasket replacement, and end up thinking you fixed it , because you put a new valley pan on when you were finishing up

Any time you run a test, you always have to eliminate all the variables to have a valid test.

 

[RLDSL]

Nick, if it is the valley pan gasket here's a little tip from me. Not sure how many other guys do this but I have always coated the exhaust manifolds with copper gasket spray. It literally coats the things in copper. I've never had one blow out doing that.
So when I rebuilt my brown trucks motor I copper coated the living crap out of the VP gasket runners. I think I did 6 coats for each side.

I like to shoot them down with spray Hylomar a few light coats

 

[RLDSL]

make sure you get the one for diesel engines though. They make two different types of chemical. One works on gassers the other works on diesels

Actually, the original works for both. There used to only be one type. If you use it for diesels it just takes longer It only takes like 30 seconds on a gas engine and about 3 minutes on a diesel for some reason. I didn't even know they were making a special one for diesels now That's handy. Just bought a new bottle a couple of weeks ago, wish I'd known that.