4.3 LX water in the oil...

[Swedefj40]

So after getting my carb issues addressed, it was time to put it in the water and check that my bellows are leak free and the lower shift cable is working right. I did my pre trip in the driveway and found this:



Obviously there's water in the oil. I checked the coolant in the Heat Exchanger and it was way low too. The oil was changed in the fall of last year and the engine hasn't been run until the other day when I got my carb issues sorted out. (long story short, replaced old weber carb with a new one, new one kept backfiring and never worked so put the old one back on).

Anyway, I did a compression check and it was #6=180psi, #5=155psi, #4=140psi, #3=135psi, #2=180psi, #1=165psi.

I don't have access to a leak down tester yet but what I did was I pulled all the spark plugs and rigged up the air compressor and charged each cylinder (@ TDC) with 50psi and checked for venting. I felt around the adjacent cylinders for air and this is what I got:

Air in #1 - I get air out of #5 & #4
Air in #2 - I get air out of #5 & a little bit out of #1
Air in #3 - I get air out of #1 & #6
Air in #4 - I get air out of #2 & #1
Air in #5 - I get air out of #3 & a little bit out of #2
Air in #6 - I get air out of #4

I had a couple of really loud backfires trying to get the new carb to work so I'm thinking maybe that blew the head gaskets? Not sure if anything can be deduced from this but I'd like your input anyway before I start ripping the manifolds and heads off of this thing.

 

[tpenfield]

Best to get the leak tester and get some numbers, but the milkshake oil may be telling the story.

 

[Lou C]

Any water in the cyls? Is this a full closed or half closed system? If no water in the cyls I’d be looking for bad intake manifold gaskets. That will put water or antifreeze right in the cam valley & motor oil. Head gasket leaks can be confusing to diagnose. One way is to see if you are getting bubbles in the coolant of your closed system; this would be combustion gas getting in the coolant which is a clear sign of blown head gaskets….they make testers to determine this for sure….
If the coolant is low and oil high and milky = head gasket likely

 

[cyclops222]

My usual negative thoughts about that oil & water Milkshake mixture in a engine all winter. Can be very bad for all shiny machined surfaces. All cylinder surfaces. Same for cam & lifters. You really need a cylinder head take down before anymore running. First pull off the Valve Covers. Good Luck on a bad one.

 

[Bondo]

I don't have access to a leak down tester yet but what I did was I pulled all the spark plugs and rigged up the air compressor and charged each cylinder (@ TDC) with 50psi and checked for venting. I felt around the adjacent cylinders for air and this is what I got:

Air in #1 - I get air out of #5 & #4
Air in #2 - I get air out of #5 & a little bit out of #1
Air in #3 - I get air out of #1 & #6
Air in #4 - I get air out of #2 & #1
Air in #5 - I get air out of #3 & a little bit out of #2
Air in #6 - I get air out of #4

Ayuh,...... Did you do this test at each cylinder's TDC, or with TDC at the timing tab,..??..??

 

[Swedefj40]

Any water in the cyls? Is this a full closed or half closed system? If no water in the cyls I’d be looking for bad intake manifold gaskets. That will put water or antifreeze right in the cam valley & motor oil. Head gasket leaks can be confusing to diagnose. One way is to see if you are getting bubbles in the coolant of your closed system; this would be combustion gas getting in the coolant which is a clear sign of blown head gaskets….they make testers to determine this for sure….
If the coolant is low and oil high and milky = head gasket likely

I didn't notice any moisture in the cylinders when I pulled the plugs. The plugs are new and were put in when I was trying to get the new carb to fire up and they still look great after getting it fired up and running. It's run twice this spring for about 20 minutes each.

It's a '96 4.3LX (0F761554) and closed cooled system.

 

[Swedefj40]

My usual negative thoughts about that oil & water Milkshake mixture in a engine all winter. Can be very bad for all shiny machined surfaces. All cylinder surfaces. Same for cam & lifters. You really need a cylinder head take down before anymore running. First pull off the Valve Covers. Good Luck on a bad one.

Fresh oil in it all winter. I also checked the oil in the spring when I dewinterized it and it looked perfect.

 

[Swedefj40]

Ayuh,...... Did you do this test at each cylinder's TDC, or with TDC at the timing tab,..??..??

I pulled the distributer cap off after I got it to TDC #1 and checked the #1 cyl. I then rotated the crank until the #6 tab on the distributer plate (?) was at the sensor (pickup) and checked the #6 cyl. If that makes sense?

 

[Lou C]

Is it a Vortec engine (intake has 8 bolts instead of 12 bolts like the pre Vortec)? If so these had a bit of a history of bad intake gaskets leaking water or antifreeze into the cam valley. If so it’s a much easier fix than head gaskets.

 

[Swedefj40]

Is it a Vortec engine (intake has 8 bolts instead of 12 bolts like the pre Vortec)? If so these had a bit of a history of bad intake gaskets leaking water or antifreeze into the cam valley. If so it’s a much easier fix than head gaskets.

12 bolt... says Vortec on the valve covers but I think they're lying

 

[Scott06]

12 bolt... says Vortec on the valve covers but I think they're lying

No GM started using the vortec name for the 4.3 before they came out with the now known as vortec heads . So ea
ry to mid 90 s had vortec on valve cover but 12 bolt intake and with out what is now known as vortec heads …

 

[Bondo]

I pulled the distributer cap off after I got it to TDC #1 and checked the #1 cyl. I then rotated the crank until the #6 tab on the distributer plate (?) was at the sensor (pickup) and checked the #6 cyl. If that makes sense?

Ayuh,..... Yer test only works right, if you put each individual cylinder at it's TDC, so that, that cylinder's valves are closed,....

 

[Swedefj40]

Ayuh,..... Yer test only works right, if you put each individual cylinder at it's TDC, so that, that cylinder's valves are closed,....

Yeah, I understand that. Am I wrong in assuming that everytime the tab on the distributor rotor lines up with the sensor, it fires to that cylinder or am I missing something here? So that a full revolution on the distributer would've fired all 6 cylinders during that one revolution? I started at TDC on the #1 cylinder and then moved the crank about 120° which lined up the rotor for #6 cylinder which should be it's own TDC right?

 

[Bondo]

Ayuh,..... When I do it, I pull the valve covers, so I can see that both valves are closed,.....

 

[Scott Danforth]

with a milkshake in the oil. drain the antifreeze from the glycol side and pressure test. should hold 15 psi forever. test the anti-freeze you pull out with a refractometer. make sure it is good.

my guess, with the antifreeze low, the coolant freeze point is way to high, so it froze.

 

[Swedefj40]

with a milkshake in the oil. drain the antifreeze from the glycol side and pressure test. should hold 15 psi forever. test the anti-freeze you pull out with a refractometer. make sure it is good.

my guess, with the antifreeze low, the coolant freeze point is way to high, so it froze.

Yeah, I'll look into pressure testing it. The coolant level (and heat exchanger) was full all winter and was checked again just before I tried firing it up this spring. I also had the raw water side flushed out with RV antifreeze as well to be safe when I winterized it.

 

[Swedefj40]

Oh, and I also wrapped the engine in heat trace.

 

[Scott Danforth]

With proper 50/50 mix in the block, and properly drained raw water side, the block is good for -34f

If you didn't drain before attempting to flush with RV PG, then at best, assume +30f before something froze

Did you drain the manifolds?

 

[Swedefj40]

Well I did the acetone test on the exhaust manifolds and they were okay. I'm definitely going to have to replace them at some point though as the rust is getting pretty bad. I tried to do a pressure test on the block but I couldn't get the right parts to get a good seal to pressurize it. I am pretty confident that it's fine though as, like I've said before, It's closed cooled and I had it wrapped in heat trace every winter.

Here's a shot of the Port side after the exhaust manifold was removed. #4 Cylinder is definitely wet.


This video gives a better look: VIDEO

Here's the Starboard side, and the #3 Cylinder is also wet.


Starboard side video: VIDEO

I next pulled the intake...


Here's a better video of the intake sides and valley: VIDEO

One more shot of the underside of the Intake:


And subsequent video: VIDEO

Anyway, I will be doing a leak down test in the next few days (now that the tool arrived), and then go from there. So what do you guys think? Anything obvious!

 

[Swedefj40]

With proper 50/50 mix in the block, and properly drained raw water side, the block is good for -34f

If you didn't drain before attempting to flush with RV PG, then at best, assume +30f before something froze

Did you drain the manifolds?

No I didn't bother with draining the exhaust manifolds as they have coolant in them as they're part the closed cooling circuit. The elbows above are raw water cooled though but flushed with RV antifreeze.