The Frustration-Meter is definitely pegged out.
Some of you may remember my posts from several weeks ago about dropping a bolt inside the engine with the intake manifold off. After removing the front axle and dropping the oil pan, I finallyremoved the bolt and proceeded to put the engine back together. I was feeling pretty good. This started as a job to change a blown head gasket.

When I turned the key yesterday, the engine turned over but wouldn't start. Determined that I hadn't put the distributor back in correctly, so I fixed that today. Started right up, but then...

Ran kind of rough for about 20-30 seconds and then the radiator overflow (just below the radiator cap) started spewing a light brown, oil-water mixture. Turned the engine off and drained the radiator...some water, some oil-water mixture. Figured I should drain the oil pan too, and got the same oil-water mixture.

Had the heads checkedwhile they were off. No cracks. When I checked the old head gaskets, there was one small area on the gasket at the #2 cylinderthat looked bad, so I assumed that was the culprit. I was very meticulous in putting all of the new gaskets in place.

Is it possible that I have a crack in the block that would allow the oil-water interaction? Would a compression test help diagnose the problem?Would very muchappreciate any suggestions.
Thanks,
Steve

1996 Blazer, 4.3L 4WD

 

I guess anything is possible. However the oil doesn't run into or around thepiston chamber. Typicaly if the cylindar wall was cracked it would let the water from teh surrounding water jacket into the piston and out the tailpipe.

the oil does flow through the block in various places, so it is possible.

Did the gasket you installedblock off the back two water jacket passages in the head/intake manifold?I know that isn't coming out right, and hopefully someone can clean up my English.maybe some pics will help..

Is this what youroil looks like?
Bottom of my Intake.
Notice the lack of water passage on the leftside in the pic?
Now look at teh next pic, see the opening in the block and gasket for the water passage?
If you didn't get a good seal in the intake to head gasket your oil and water will mix.
At this point Iwould sya you need to verify your installation work before you go tossing the engine.

http://chevytruckworld.tenmagazines....nr2/245113.jpg
http://chevytruckworld.tenmagazines....nr2/245116.jpg
http://chevytruckworld.tenmagazines....nr2/245121.jpg

 

Good pictures. Thanks.

Yep, that's what my oil looks like. The intake manifold gaskets that I installed did not block the two rear water jacketpassages. Now that you mention that, I do remember that the old gasket did have those areas blocked off. Sounds like I'm going to be pulling at least the intake manifold again, so I'll be sure to get the right ones this time. The others came in a FelPro head gasket set.

Would really be great if this fixes the problem. Thanks for your help.
Steve

1996 Blazer, 4.3L 4WD

 

No big deal if oyu have the openings in the gasket or not, the big deal is if you completely surround the water passages with RTV to seal it in.

I poured fresh oil all over the engine once I had the intake off to wash the oil/water mix through the oil pan. Clean the crap out of the engine, get all that water out of there. If that water gets between a bearing and the crank or rod you will toast the bearing. Change your oil filter too. Once you get it all back togehter, run it just long enough to verify the leak is fixed, shut it off and change the oil and oil filter again. Drive it 50 miles or so on the new oil, and do another oil change. Then change it as needed.

Thos pics came from my '93 after I did an engine swap. I dropped in a '85 4.3L blcok into a '93. I had to drill one head accessory bolt and drilled too far. I put a how into the water jacket. My fix was WB Weld, and new gaskets. Plus the oil change routine. My son has been driving hte truck every day since for the past 1 1/2 years wihtout any trouble.

 

Finally got a chance to get the engine put back together and was about to start it. Checked the dipstick and there was water on it. I didn't do too well in Chemistry, but I remembered that oil floats on water, so I drained the water out of the oil pan until oil started coming out. For all of the water that came out, the whole oil pan must've been full of water! Seems that when I was putting water in the radiator, it was ending upin the oil pan. All of this water got into the oil without the engine running.
Theradiator level is only goingdown about 3 inches. Does this mean that the leak is high?
I refilled it a few times over several days, not thinking that there could be a leak somewhere.
When I put the intake manifold back on, I gave the water jacket passages a good layer of RTV, so I don't think that's the problem.
Any ideas?....Help!!!

Thanks,
Steve
1996 4.3L 4WD

 

Here are my compression numbers...
#1 - 180 psi
#3 - 170
#5 - 175
#2 - 175
#4 - 190
#6 - 195

Based on what I've read, seems like these numbers indicate no head cracks and no head gasket issues. Correct?
#5 plug looked a little fouled but the cylinder pressure looks okay to me.
Still losing approx 3" of water from the top of the radiator.
Does this lead me back to the intake manifold gasket?
Any thoughts would be much appreciated.

Steve
1996 4.3L 4WD

 

Cylinder pressures look ok. They're all with in 10% of the average which is good.

Sure sounds like an intake manifold gasket leak to me. You could try a pressure test of the cooling system to see if you are getting coolant either into the oil or into the cylinders (you'd have to pull the plugs again.

How quickly does it leak down 3" from the radiator?

 

The 3" goes downfairly quickly...no more than 5 minutes or so.

Could you please describe how to do a cooling system pressure test. My plugs are still pulled so no biggy on that piece of it.

Thanks,
Steve
1996 4.3L 4WD

 

Definitely sounds like something didn't get put back together right if you are loosing it that fast. At that point, a pressure test won't tell you much of anything other than you have a massive leak.

 

Thanks, Kyle. Pretty much what I was thinking about the pressure test, too.

Besides the intake manifold gasket, is there anywhere else that the water would be coming from? Ruled out the heads and head gaskets with the compression test. Is a crack in the block possible? Or would that have shown up with the cylinder compression test? I don't have a problem disassembling the intake manifold again, but would just like to do any other necessary troubleshooting before I do if it could be something else.

Also wanted your opinion on intake manifold gaskets. I've been using rubber gaskets from Auto Zone, but I also have a $65 set of metal gaskets from the Chevy dealer. Shouldit make a difference which gaskets are used?

Thanks much,
Steve
1996 4.3L 4WD