The heads cracked and my replacements have arrived. I have searched for threads and read comments on assembly but my remaining questions are:

1. on ROD and rocker assembly I forced lithium oil grease into the air holes on the rods on both ends, left plenty on the outer ends only (none on the shafts), and left a dab where valve lifter meets rocker (on the top of the lifter and bottom of rocker)..... anything wrong or left out?


2. on the Rocker arm assembly.... manual says tighten rocker SHAFT to 16.5 INCH lbs. (23nm) and rocker ARM to 21 FT. lbs. (28nm). What does it means SHAFT? I'm not finding a clear picture to explain the difference here...

3. I notice that NOT ALL ROCKER ARMS are aligned up evenly when at 21ft. torque. They were not labeled for position when I got them back from the shop in mixed up box. Will they even out?

(un related)
4. I am still not clear when I read about locating if the problem is a head crack or a block crack .... "oil mixing with coolant" vs. "coolant in your oil" ... If there is any mixing ANYWHERE in the engine while running won't it be mixed everywhere?


Other repair notes on the 3.9 v6 can be found at:
http://freehelpinghands.wordpress.co...-repair-notes/ ‎

 

1. Oil is pumped through the pushrod by the lifters. If the grease you forced inside is too thick then the rocker won't receive any oil. It will probably be fine but I would blow the grease out of the pushrods and just coat the ends.

2. Some rockers run on a shaft. Not applicable to this engine.

3. Normal, as some valves will be open. Personally I rotate the engine by hand (socket on the crank pulley bolt) and torque the rockers only while the valves are closed.

4. Read this as "oil in the radiator" vs "coolant in the oil pan", there is a difference.

 

Torquing the rocker arms with the engine in the wrong position is an extremely important thing to be aware of.

Here are the correct steps:

1. Rotate the crankshaft so that the V6 mark on the crankshaft damper aligns with the timing mark on the front cover. The V6 mark is located 147 degrees AFTER Top Dead Center (TDC).

2. Install the rocker arms in their original positions and tighten the bolts to 21 ft. lbs. (28 Nm).

 

Just as a side note: Usually when you are torquing bolts you do that progressively or in stages. The reason this is done is in an attempt to get things more even.

I have not checked the book on rocker arm bolts but I am sure one of the guys here can tell you.

Jason

 

Can someone post a picture of the location of the marks please? Not sure where I am looking or what the marks look like.

Also - can I get a more in depth explanation of how oil can not get into the radiator unless the block is cracked?

I'm confused still because if it is a continous closed circuit and the water transfers back and forth through the radiator... then if oil mixes at any spot .. it will continue to cycle through the radiator I would think? I'm not understanding the physics of it I guess.

Thanks all for the help.

I'm working on it now and I have loosened the rockers and am waiting for help to find the marks and align valves properly so I can re-tighten and get the valve covers back on to finish this up.

 

Found the marks and got the rockers adjusted properly. Rotated the engine a couple times and checked for excessive play from side to side wiggle and retorqued as needed as well.

Hope some one can explain more clearly how coolant can get into the oil pan BUT OIL can NOT get into the radiator. I don't understand.

 

While I have no idea what your issue or question really is I will give this a shot.

There are head gaskets that sit under each cylinder head between the head and the block. There are passages in both the heads and the block. Some of those passages are for oil and others for water. The ones for water in the block are called water jackets.

Now, water jackets in head or block can develop a crack and also the gasket between the head and block can blow up allowing water to get from the cooling system into the oil pan. One of the symptoms of a blown head gasket is usually water in the oil or oil pan. The oil will be foamy and oil can have a chocolate like consistancy. A cracked head can also leak water into the Oil pan.

As far as getting oil into the radiator, it is possible but not as likely. Water in an engine is under much greater pressure than oil. Also the properties are different.

I have no idea if this is the question you were asking or not but hopefully it will give you an idea how things happen.

Jason

 

I get how the coolant gets into the oil and the previous comment about the coolant being under higher pressure keeping the oil out of the radiator starts to hit on the question I still have.... which is I don't understand how you can tell the block is cracked by having oil in your radiator drain????

Explain the physics better on this part please....someone.