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Coolant in oil. Need help identifying cause.

3103 Views 84 Replies 14 Participants Last post by  eric32
This is sort of related to my other post regarding a cam swap. In the process of learning more about that process, it was discovered that the dumped oil contains a good amount of coolant. The results of the oil test can be found here. Suffice it to say, there is coolant in the oil. So I am now taking a detour on my way to a different cam as this issue will have to be addressed first.

I am looking for help identifying where the coolant may be seeping into the oil. I will do a pressure test tomorrow, but for now I have pulled the spark plugs out and stuck an endoscope into all the cylinders. The results are below. Note that the truck has not been driven or started in about 3 days prior to my doing this work.
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Here are some picture from the endoscope. All pistons look about the same - pretty carboned up. Some, however, have what appears to be moisture. Can you guy draw any conclusions?

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Whichever cylinder corresponds to the plug you have marked #5 is the cylinder eating coolant.
Spark plug porcelain is steam cleaned to practically new.

Now you've got to find out why and where the coolant is coming from.
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The plugs are numbered in accordance with the cylinder numbers.

"Now you've got to find out why and where the coolant is coming from." - Do you think pulling the head will answer that vexing question?
Because they were just photo'd in a straight line group in numbered order, I wasn't sure if they were numbered in accordance to the Chevy, with 1, 3, 5, 7 on the driver side and 2, 4, 6, 8 on the passenger side.....
Or if they were done Ford fashion, 1, 2, 3, 4 on passenger side, 5, 6, 7, 8 on drivers side.
(Because that puts #5 in two different locations)

I would do a leakdown test in that cylinder before pulling the head so that you might discover if the leak is head gasket or cylinder wall/head crack versus it coming from the intake or exhaust port leak (intake gasket leak or exhaust port crack).

A note....the 400 deck surface is known for going out of flat more than any other small block (large bore means less deck material), so if the block wasn't deck true'd at rebuild it could be a head gasket issue....but you have to test your way to that conclusion logically, not just assume it "has to be the head gasket".
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You got more fish to fry!
Your oil test shows higher metal content too. A possible source is your cam going flat.
IMHO a complete rebuild is likely needed.
I think RWENUTS is probably right..
Copper - Lead - Tin levels all high....that's bearings for sure.
High Iron levels, that's likely cam / lifters.
High Silicon and Aluminum, that's piston skirts or ring lands.
Yes, that would be a vacuum leak.
More evidence your coolant loss could all be from the intake gasket after all...

You may need the double thickness intake gasket to get that intake to seal up, it's basically your only hope with that intake and head combination.
Problem is the basic aluminum EPS intake is made for the smaller, shorter stock port opening rather than the wider and taller port on those Dart 215cc heads.
You run into the same problem with a lot of older vintage aftermarket Hi-Po intake manifolds that were designed for stock headport size and fit. They won't cover and seal along the top of the bigger modern port roof.

You are probably going to need a different intake manifold, I don't think the .125" thick intake gaskets are going to do the trick and raise the intake enough to get it to seal up. I've never tried it with that big a gap.

Reading back through your initial post on this engine and the machine shop invoice..... From the way the invoice is worded and the evidence your looks to me like they rebuilt and assembled a 400 short block, then customer picks it up and finishes it ....
At which point the rest was slapped together by someone who really didn't know completely how to do it..
He takes it home and puts the big heads and small intake on, doesn't check fits, slaps that Thumpr in there, bolts on all his bling and fires it up.

Are you feeling the same vibe?
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Typically, the 215cc heads are used with single plane intakes, which are typically taller and more solid in the needed area.

For a dual plane intake, you'll probably need a Performer RPM or clone like it. Weiand Stealth or Speed Warrior, the Brodix dual plane, Performer RPM Air Gap, Summit Stage 2....I'm not sure what all is out there that may fit.....I've always used single planes with heads like that.

Weiand Team G and Edelbrock Victor Jr are a couple of the single planes that make nice street intakes on 383+ cubic inches.
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Yes, there is a separate submerged cooler element inside the radiator tank.
Coolant in the radiator cools the element and the transmission fluid without mixing them.
Am I crazy or is my harmonic balancer puller not designed for this specific harmonic balancer?
View attachment 628619

It would appear I need this tool instead right?
That is correct, the three finger puller is not the right style puller.
You need the style in the kit you linked from Amazon.
The picture on the box, all a roller cam.
Different material, different wear properties, different finish.

On a flat tappet cam, the only thing polished is the bearing journals.
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Looks like " head gasket in a can" , some kind of pour-in cooling system sealer with sodium silicate in it??
If you find it elsewhere in the cooling system it will confirm.
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Your video is the classis result of flat tappet cam not making it through break in, those lobes are whipped
From what I've's going to have to be completely torn down.
You don't like to do it over, and dislike waiting even do you feel about doing it over 2 or 3 times??
All the while waiting anyway since many parts are still supply disrupted.

You remember that oil analysis you had done, in a previous thread.??....levels of lead, tin, copper all high....lead/tin/copper is the layers of overlay in the main, rod, and cam bearings.....which are all being damaged by that debris material from the cam and lifter being pumped through them.

You just put new parts in, they'll be getting ground up by that debris as well.
DON'T cross your fingers and hope that the fancy lifter coating will save won't.
Might as well just set the money on fire and watch it burn.
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