Blown diesel head gasket - not MB - PeachParts Mercedes-Benz Forum

Graham · #1 07-26-2018, 09:57 PM

This is on my 2-cyl Yanmar marine diesel. Head gasket was leaking water on outside (Once through raw water cooling). Couldn't find any available mechanics, so decided to pull head myself.

Found that fire ring on head gasket at one cylinder had delaminated in one area and was blowing out past the water cooling channels. Where it had been blowing, there was pitting on the head and to a lesser degree on the block. I have had head skimmed and valves seated in a little further to compensate.

Block is in boat, so not so easy. I have cleaned it us as best I can, but I don't think I can install the precoated gasket dry. Some have suggested using copper Spray-a-gasket or Copper-Coat to compensate for imperfections.
I am not sure whether to apply spray over the pre-applied coatings on new gasket. Or to spray the block and head metal surfaces.

This pic shows a head gasket with pre-applied sealant. They say they don't need more sealant (assumes surfaces are perfect?), but that a spray of copper-coat is acceptable. Thumbnail is the block that gasket seals against.

Any of you diesel experts used spray copper on heads?

t walgamuth · #2 07-26-2018, 10:01 PM

Sounds good.

Diesel911 · #3 07-26-2018, 11:30 PM

Is the surface of the block warped?

The surface of the block does not look clean enougy. Wet Dry Sandpaper can be used to sand it down to the metal.

Does the lip of the Liners/Cylinder protrude above the surface?

Graham · #4 07-27-2018, 09:11 AM

Quote:

Originally Posted by Diesel911

Is the surface of the block warped?

The surface of the block does not look clean enougy. Wet Dry Sandpaper can be used to sand it down to the metal.

Does the lip of the Liners/Cylinder protrude above the surface?

Both head and block are within spec for flatness. The picture of the top of the block, is as it was when head was removed. Now cleaned up. Generally good, just some slight pitting in area where gasket leaked. Worse on head, but that is now machined.

Trusting that the Copper spray will handle the imperfections which are not on cylinder liner lips or cooling water ports, but on adjacent areas. Many car guys with gas engines apply the spray to the pre-coated gaskets. Just wondered if MB diesel owners do same?

The lips of the liners protrude above the block - spec is 1.2 to 3.9 thou. They seal against the silver ring s on the gasket.

bentrod · #5 07-27-2018, 12:03 PM

I can tell you who does - or did use Permatex copper spray. Isuzu, for the turbo C223T 2.2 diesel. They use a steel laminated head gasket and always would weep ever so slowly coolant and stink of it. This was a factory repair update.
And yes on some hard case got nothing to loose other engines I did the same too for pitting. It's great stuff.

mbolton1990 · #6 07-27-2018, 03:36 PM

Just spray it on the new gasket and rock and roll.
I know of a few people that run the copper spray on diesel heads with good results.

Definitely don't see it hurting anything, just follow the instructions.

Graham · #7 07-27-2018, 06:54 PM

Sounds good. So long as it doesn't interfere with the gasket sealants, can't see a problem. I guess I will use it anyway!

Diesel911 · #8 07-29-2018, 07:24 PM

I did not post this sooner as I needed to find where the Pictures were.

On my Chevy Astro Van I had a small coolant leak into one of the cylinders. Somehow rust had eaten under metal ring on the head gasket that runs around the cylinder and pitted the head in 2 places.

I surfaced the head a little with a lapping plate but the pitting was too deep right on that sealing area.

I used low temp silver solder (something like 450-500 degrees F) and filled in the pits.

I degreased the area with Brake Cleaner and followed the instructions from the Silver Solder company. I used a hand held Harbor Freight Butane Torch to heat up the local area.

You see the silver solder applied but I could not find a pic of it after it was srufaced but the sliver solder is a lot softer then the Head so it did not take long to surface it.

Sugar Bear · #9 07-29-2018, 07:36 PM

I'd use it, did it often years ago and was always successful. I regret not using it on my 103.

Good luck!!!

Graham · #10 07-31-2018, 08:31 PM

Quote:

Originally Posted by Diesel911

I used low temp silver solder (something like 450-500 degrees F) and filled in the pits.

What sort of temperatures would you get on an Astro van head? On a diesel no doubt higher. Combustion temperature is over 1000F, I think. Head and block are of course cooled.

I had head skimmed smooth and defects in block are almost too shallow to fill. Hoping the copper coat will be all that is needed.

Diesel911 · #11 07-31-2018, 10:35 PM

Quote:

Originally Posted by Graham

What sort of temperatures would you get on an Astro van head? On a diesel no doubt higher. Combustion temperature is over 1000F, I think. Head and block are of course cooled.

I had head skimmed smooth and defects in block are almost too shallow to fill. Hoping the copper coat will be all that is needed.

Actually it is about heat transfer. The coolant temp on the Van is 180F I bet that is close to his yanmar coolant temp an the Mercedes.

Your Engine Oil cannot take 1000 degrees F either but most of the combustion temp (volume?) goes out with the Exhaust and does not go into the Block and Cylinder head or the Oil and the Coolant and Oil are cirulated so the temp gets pulled away.

A good example of that is the Oil that gets sprayed up into the Pistons (lots of turbo diesels have that including big rig diesels). The Piston head is directly exposed to the combustion and has only the Oil and some contact transfer to get rid of the heat of combustion.

In any event the silver solder ought to be OK on something like the Mercedes or that Yanmar on the Block or cylider head outside of the combustion chember itself.
No good on the Exhaust Manifold which has no coolant or Oil for heat transfer.

Also it depends on the size of the pits.

If you worked in say a shop where they rebuilt Diesel Truck Engines the Engines are too expensive to experiment on.

I think I missed the obvious. When gasoline burns it also gets hot enough to melt the Silver Solder that I used. But it is not exposed to the combustion temps.

ROLLGUY · #12 07-31-2018, 10:47 PM

For block deck surfacing, I like to use a large knife sharpening stone and WD-40. It may not remove enough material to make the pits disappear, but it will get the deck cleaner and flatter than anything, short of removing the block and having it machined.

Mike D · #13 07-31-2018, 10:57 PM

Be VERY careful using brake cleaner around heat/welding.

https://www.motorstate.com/careful.htm

Some states (CA is one) no longer sell the chlorinated stuff.

Graham · #14 08-01-2018, 08:46 PM

I have the head on. I used Permatex Copper Spray-a-gasket on the block side of the gasket, but none on head side (head had been machined) The gasket has pre-applied sealant.

The Copper spray was advertised as being fast drying. It was anything but. I had to spray out on the dock and eventually had to move gasket into cabin because fuzzies were sticking to the coating

, even after 1/2 an hour. I installed after about an hour and it was still tacky and would smudge if you put your finger on it. Not satisfied with way it went on.

I had read that the original Copper Coat dried within 30 sec?

In a day or two, I will know if the head is sealed!