View Full Version : Oil Analysis Report. Coolant in Oil!

April 16th, 2015, 09:39
Hello everyone,
I had an oil analysis done the other week after an oil change and the report came back saying that there is coolant in the oil. The jeep has always had a rough idle since I bought it with 110,000 miles on it. I have replaced various things most recently a full tune up. That helped the idle somewhat but it is still a little rough. Im afraid I have a leaking head gasket. My question is, what can I do to determine if the engine (bearings, rings, ect..)is ok and if just a head gasket replacement would be sufficient?? Ill try and attach the Blackstone Report. Thanks yall

April 16th, 2015, 10:58
If you really wanted a good look, I would drop the oil pan and pop a cap off one of the rods and check how the bearings are wearing. Could also plasti gauge the bearings to see what stage of wear. could also look into the cylinders and check for scoring or excessive wear, check if the cylinder walls still have "cross hatching".

As for the rings a good old compression test can tell if they are still doing there job.

Looking at the report the Aluminum and Iron compared to the "average" engine seem rather high, I would bet the Aluminum is from bearings. And the iron from rust in the block being picked up through the coolant and mixing with the oil.

IMO if the engine doesn't knock the bearings are fine for now. I would however do a head gasket, this would allow you to get a good look at the pistons and cylinder walls as well.

April 16th, 2015, 11:09
The levels of potassium and sodium do indicate coolant getting to the oil, but they are not very high. If your oil pressure is good, I would not focus too much on the bottom end at this point. I would pull the head and look for obvious problems with the head or head gasket. Look at the cylinder walls. Have a cylinder head shop go through the head. Put it all back together, change the oil a few times at 500 miles, and then test again to make sure everything is good. The iron does seem high, but may be reasonable for lots of cold starts/city driving. If you really had a big coolant leak, you'd have sodium and potassium hundreds, thousands, or off the chart.

April 17th, 2015, 06:17
Pull the head, have it inspected for cracks. Replace head gasket. Change oil and then run another analysis.

April 17th, 2015, 07:01
Hey guys, I appreciate the help. I got a quote from a local machiene shop to deck, replace seals, and tank the head for $150. That doesnt seem to bad to me. I thought about changing the intake manifold while I was in there to a newer style but after reading up on it sounds like there isnt any difference. So the plan is just to machiene head, and replace head, exhaust and intake gaskets. Ill let you know if this works.


April 17th, 2015, 08:08
Get the head checked for cracks and get a valve job.

April 23rd, 2015, 08:32
Well how about some updates.. I removed the head, exhaust, and intake manifolds as one piece. That was one heavy SOB! The head gasket appears to not be blown or really leaking.
http://i1171.photobucket.com/albums/r560/bdenglund/Jeep/64580658-d129-4f8f-ace9-3710fdfe08e8_zpscr0gf25y.jpg (http://s1171.photobucket.com/user/bdenglund/media/Jeep/64580658-d129-4f8f-ace9-3710fdfe08e8_zpscr0gf25y.jpg.html)
http://i1171.photobucket.com/albums/r560/bdenglund/Jeep/4-23-201520037_zpsh4chabab.jpg (http://s1171.photobucket.com/user/bdenglund/media/Jeep/4-23-201520037_zpsh4chabab.jpg.html)

There are some questions about the gasket though. AS you can see in between some cylinders there is continuous black discoloration but between others there is grey discoloration. Why is that?

April 23rd, 2015, 08:43
That same discoloration is transferred to the head and block as you can see in the pictures..
http://i1171.photobucket.com/albums/r560/bdenglund/Jeep/4-23-201520034_zpsko58jhub.jpg (http://s1171.photobucket.com/user/bdenglund/media/Jeep/4-23-201520034_zpsko58jhub.jpg.html)
[URL="http://s1171.photobucket.com/user/bdenglund/media/Jeep/4-23-201520039_zpsf27pkt90.jpg.html"]http://i1171.photobucket.com/albums/r560/bdenglund/Jeep/4-23-201520039_zpsf27pkt90.jpg (http://s1171.photobucket.com/user/bdenglund/media/Jeep/4-23-201520035_zpszerbrsoy.jpg.html)

Looking over the head I could not see any cracks specifically but Im hoping the machine shop comes up with something.

Another thing I found was scoring on the #1 Cylinder wall. It is the only cylinder that has any that I can tell. Is this amount of scoring going to be an issue?
http://i1171.photobucket.com/albums/r560/bdenglund/Jeep/4-23-2015%20042_zpsg50sfbxx.jpg (http://s1171.photobucket.com/user/bdenglund/media/Jeep/4-23-2015%20042_zpsg50sfbxx.jpg.html)

I also found out that the engine is a re-manufactured one. On the side of the block there is a stamp that says MARSHALL REMANUFACTURED. I don't know anything about when, why, or how long ago the block was installed. There is a serial number also. I may give MARSHALL a call and see what I can find out.
I also noticed that the pistons have .040 stamped on them so iguess the block has already been bore to 40thousandths.
http://i1171.photobucket.com/albums/r560/bdenglund/Jeep/4-23-201520041_zps339tvps5.jpg (http://s1171.photobucket.com/user/bdenglund/media/Jeep/4-23-201520041_zps339tvps5.jpg.html)

So that is where I am at now. Just waiting on the machine shop...

April 25th, 2015, 18:07
The 040 on the pistons might not mean it was bored 40 over. I recall seeing them on stock pistons, but I don't recall the meaning atm.

April 28th, 2015, 12:25
Anyone have any comments about the piston walls? Im Still waiting to hear back from the machiene shop...

April 29th, 2015, 08:29
If it was running okay and no other problems aside from the coolant I wouldn't worry about it. How deep are they? Can you feel them with your finger nail?

April 29th, 2015, 11:22
Hey Talyn, they were deep enough that I could barely catch them with my finger nail. I plan on putting the head back on and running it regardless since money is tight. Thanks for the reply, your famous.. :)


April 29th, 2015, 13:33
I'd like to see closer and better shots of the block and gasket between 5 and 6.

That looks like it may have been leaking there?

May 1st, 2015, 09:14

Well I got the head back from the shop and it is indeed cracked.
So now I need a new head. I have done the searches and it sounds like ATK, Alabama Heads, and Clearwater are the choices. And blah blah blah $Hesco$. The shop can get me a remanufactured head for 425$. I thought that was a little high for something that may have the same problem down the road. Everything I have read said to get a "new" head.

Any recommendations on where to purchase one?

May 1st, 2015, 10:23
From the OA report you have a 91. That's a 7120 head? I'd think you could find one for $50-100 at a junk yard and have your shop go through it for less than a new/reman head from an online seller. Just a thought. The only heads not to put back down are the original 0331 non-TUPY heads used on 2000-2001 XJ's as those have a very high chance of cracking.

May 5th, 2015, 12:04
Called Clearwater today. The head is on its way. Any suggestions on new head bolts and a new gaskets. I like the felpro brand but they have 3 diffrent options. I figure I'll just go with their SD gasket.

MD - I thought about going and getting one from the salvage yard but figure to just get a new one and not worr about cracking heads in the future. It seems like they are all prone to cracking.

May 5th, 2015, 12:28
Go with the MLS gasket. Go with any of the standard head bolts. They are all about the same quality. Unless you want ARP.

May 5th, 2015, 14:23
I use the standard Fel Pro head gasket 9076PT1 (IIRC) and head bolt set. I am not sure there is any benefit to the more expensive options for a stock 4.0.

May 5th, 2015, 14:25
The MLS gasket is stronger, and compresses just a little bit thinner giving you better quench. Should be about the same price.

I run stock head bolts too.

May 5th, 2015, 14:42
MLS is about 50-100% more than the standard gasket. I think you can use any of them and be fine but the MLS may be more sensitive to surface imperfections than the normal gaskets? I haven't had to take a standard Fel Pro gasket off because it failed. Last one was at 150,000 when the head cracked.

May 5th, 2015, 19:56
Those are not stock pistons and are indeed .040" over.

May 5th, 2015, 19:58
And to add... they are Federal Mogul/Sealed Power cast pistons.

May 5th, 2015, 20:56
Thanks Digger! I was wondering why they would have .040 stamped on them. I guess a standard MLS gasket would still work with the bored out block.