Hi there, thank you in advance,

Long story short, I am a DIY, but I might have bitten off more than I chew. After replacing the head casket on both sides of the 1994 4.0 6cyl truck, I turned on the car and it turned on and it actually runs. But in a matter of 30 seconds or so, there is literally gushing oil, looks like a waterfall of oil from the valve cover on the passenger right side, the valve cover where you put the engine oil. I am talking about a lot of oil. To the point where it drains all the oil of the truck. I checked the bolts and they were all tight. I took it apart and the rocker arm looks okay.

The only thing I can think of is I mixed the exhaust and intake valves when I was looking at my format. Or there is a lot of pressure building on that side to the point where the oil is leaking by almost the qrt it seems. The thing that is strange is I followed the same process on the left side driver side and that side looks dry. Not really sure what it could be, I took the cylinder heads to the shop and got them checked they said they were fine before the install.

Mind you I changed the head casket because the car was over heating. But know there is a huge major oil leaking and I am sure its coming from the valve cover.

Any Advice.

 

Take off the valve cover and make sure the drains are open

Image here of a 4.0l head: https://i.ebayimg.com/images/g/n1IAA...Tv/s-l1600.jpg

You can see the 3 flat rocker assembly pads above each pair of valve springs, the center pad has a hole next to the bolt hole for rocker assembly, that's the only oil feed to the top of the head
That Oil goes out thru the rocker assembly and coats rockers and valve springs

On the top of image at each side are the oil drains, these open holes let oil drain back into the oil pan to be reused
Both should be wide open

 

Red is the oil drains is that what you are referring to ?

 

or is it the blue

 

The Blue

Center is oil coming IN, under pressure

 

Yes, the red above is actually where the water flows. I took the car apart again and believe it or not there was something there, it was what seemed like black electrical tape on the side corner of the oil drain. but it was so small. It still doesn't make sense to me how, that would be the problem. I was thinking the oil should still be able to drip down. I should be able to put it back together tomorrow, but I am nervous, driveway is full of oil already hahaha.

However, I do have another question, I put a straw in the middle oil hole of the cylinder head when I took it out, it went through. However, when I put the straw in the bottom block of the engine it does touch bottom about after 4-7 inches is that normal?

Wish me luck, I will make sure to keep you posted.

 

No, the Red circles at top are where air/fuel mix come in from lower intake manifold

The oil feed in the head gets oil, under pressure, from Cam bearing passage

Look at this picture of 4.0l OHV Block: https://static.cargurus.com/images/s...1600x1200.jpeg

Front of engine is to the left, lower cylinders are 4, 5 and 6
Look at the upper head bolt hole between 4 and 5
That's the oil feed hole in the block side from Cam bearing
Head has a corresponding hole that feeds oil to top of the head and the center rocker arm support
On the other bank the oil feed hole is between 2 and 3, fed by a different cam bearing passage

Above the cylinders are the Lifter holes in "the valley" of the engine, between the lifter holes are Drain holes allowing oil to drain back to the pan
The head drain holes drain into "the valley" which then drains into the pan

 

I might need new gaskets lol taking it apart and putting it back together like 3x to trouble shoot. But the good news is I think the oil drain is the issue. I did two experiments:

Assuming the oil drain hole is the red spot I marked, pretty sure it is.

1. With the cylinder heads on I put a funnel in the red spot (hopefully oil drain) and placed oil, it didn't drain automatically but it drained - which seemed promising.

However:

2. I put the valve cover back on and poured oil as usual and this time, the oil just started leaking again on the side of the valve cover almost worse than before.

Now the question is how do I test, check, experiment, troubleshoot the oil drain and or what could be causing the issue I really want to avoid tinkering with the lower block of the engine.

 

Valve cover gasket should not leak oil out even if its full