oil looks like milk coffee. What do I troubleshoot?

[zimm17]

Just changed the oil to finish my winterization. Water is bright milk coffee colored. I'm going to run a compression check.

I did just replace the intake manifold, maybe it's a water crossover. Or maybe a head gasket or worse. How do I check and troubleshoot?

[Last Real Texan]

Do a leak down and listen for where the sound of hissing air is coming , ie . valve cover or from the dip stick......Most likely a head gasket.

[zimm17]

Just did a compression test- 118 to 130 in all cylinders. Most plugs look good. Back left two corners have some light rust, the front left corner looks very clean. All others nice brown color.

I'm suspecting the intake gaskets since I had to remove/install the intake 5 times before I ground enough of metal off the edelbrock intake casting bosses for it to seat down into the intake valley.

I think I'll spring for a leakdown tester at the store.

[Chili 18]

If you know it was fine before the manifold. It makes sense that is the source. Doesent the botton of the manifold also seal the lifter gallery on the GM blocks? If it has closed cooling [antifreeze] you should check for oil in there too. Did you use silicone or gasket sealer when you set the manifold? I know some folks dont like it, but does help with this kind of thing. Did you have the heads off too? Then head gasket is an option. May be worth retorqueing it in case they came loose or the gaskets compressed. The variation in plug colors could indicate leaks in those manifold ports too.

Hope thats all it is and it didnt run too long this way...

[zimm17]

I'm suspecting the intake. I didn't remove the heads. In fact the engine was just rebuilt last winter and I did the 10 hour oil change beginning of summer and the oil was new looking. Since then I've added the closed loop cooling, intake, and dana exhaust. I'm pretty sure the intake is screwed up since I had to grind metal away just to get it to sit down. The cast lip on the heads where the valve covers sit was interferring.

I'm going to flush the engine out with varsol, run it a minute, then an oil change, run it, change oil again and leave it for the winter. I'll pull the intake in the spring. With the cap off the cooling I'll have no pressure so hopefully no leak into the new oil.

[Barry Eller]

Hello, Barry Eller here from across the bay in Gulf Breeze. Your intake sounds like the problem. But check your exhaust risers as well, I had a water in oil problem once with my old 454. The exhaust riser started leaking, water entered through the valves. Pull your spark plugs and inspect them to see if they look "steamed cleaned".

Good luck. Dan Nye and I are planing a run after the holidays down to Destin. We probably will go in my boat and have lunch and come back. Practice run to get a few more breakin hours on my new engine.

Just got a new prop and will be trying it out soon. Balistic 3 blade 25". I have been running a hydromotive 4 blade 23".

Good luch with your problem and Happy Holidays.

[MOP]

Spin it over and get the cylinders oiled up real good, save it first then investigate the cause.

Phil

[BUIZILLA]

If you only got 118-130 on that engine, you've got more problems than you think....

JH

[Chili 18]

Hmm.. compression does seem low. For an 8.5 :1 shouldnt it be more in the 170s...

Perhaps try the oil test. Put a capful of heavier oil in a cylinder before your test and see if the oil seals the rings up enough to give a rise in the readings. If so.... The water could have done some pretty good work on the rings.


Yikes...

What is the C.R. on your engine?

http://www.geocities.com/dsmgrrrl/FAQs/compression.htm

Here is a link about compression testing with some specs on rice motors at various compression ratios. C.R. is C.R. regardless of brand? Isnt it pros? 8.5:1 in a toyota should be the same psi as 8.5:1 in a GM. Please correct me if Im off on that!



edit...

After a bit more searching, it seems cr testing is a grey area. Im over my head on the finer points of the subject..
http://www.groupk.com/comp.html

[zimm17]

Great...low compression. I also only get 30psi oil pressure max. I'm thinking it was a junky rebuilt engine that the previous owner put in. Oh well, I'll be on deployment most of next year's boating season. I'll reseat the manifold and hope to get a few rides out of it next spring. Then I'll have the money for a nice new engine when I get back.

soooo, new engine... I'll have to start another thread!

I could get a 540, a 496HO, a used 525HP.... I wonder what would be best

[mrfixxall]

[QUOTE=zimm17]Just did a compression test- 118 to 130 in all cylinders. Most plugs look good. Back left two corners have some light rust, the front left corner looks very clean. All others nice brown color.
I'm suspecting the intake gaskets since I had to remove/install the intake 5 times before I ground enough of metal off the edelbrock intake casting bosses for it to seat down into the intake valley.
I think I'll spring for a leakdown tester at the store.[/QUOTE

zimm,,try doing a compression check this way..unplug your ignition module instead of the coil wire so theirs no arcing going on..open your throttle blades on the carb all the way so air can get into the motor then crank the motor over and check the compression.this way may give you a more accurate reading..good luck..

p.s. i have a 415 hp 502 forsale with 100 hr on it.