Ok, so I got my motor put together. Fresh from the machine shop, built head, and machined block. Put it all together, used a Mitsu MLS head gasket, torqued to 90ft lbs with ARP's, and get oil in cyl 4 and 2. When doing a leak down, cyl 4 leaks into cyl 2 and vice versa. Head is new, new valves, new guides, new seals. When doing a leak down, very little air is coming out of the oil fill hole (expected as the motor only seen idle time, so it is not broke in yet), but nothing near the amount of air escaping from cyl 2 or 4. I need help and am lost!!!

Cyl 4 and cyl 2 leak into each other? How are they missing cyl 3?

Did you make sue to rotated the engine so all the valves were closed on the cylinder you were testing?

^ I know, idk how that happens, and yes cyl 1 and 4 are at TDC.

When ctl 1 is on compression/power stoke all valves are closed, cyl#4 will be on exhaust stroke so the exhaust valves will be open.

follow the firing order, so start at #1, test that cylinder, then rotate the engine 180* at the crank, test the next that would fire and so forth and so on

If the fire order is 1-3-4-2

starting at cyl1 @tdc, leak test cyl1, rotate 180* test #3, rotate 180* test #4, rotate 180* test #2

^ huh? If cyl 1 and 4 fire together, then they both open the intake valves at the same time, and exhaust valves at the same time. So both cyl at TDC, then both the intake valves and exhaust valves are closed (compression stroke).

Regardless the cylinders should not leak into one another. There is no pressure escaping out the oil fill hole, so it's not going past the rings. I also get oil in cyl 2 and 4, which is causing excessive smoking. . .

TSITurbo95 said:

^ huh? If cyl 1 and 4 fire together, then they both open the intake valves at the same time, and exhaust valves at the same time. So both cyl at TDC, then both the intake valves and exhaust valves are closed (compression stroke).

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Cylinders 1 and 4 do NOT fire at the same time (none of the cylinders do). When cylinder 1 is at TDC of the compression stroke, cylinder 4 is at the top of it's exhaust stroke. So with #4 at TDC of the exhaust stroke, the exhaust valves are open and there might even be some overlap with the intake valves although I'm not certain of that.

Regardless the cylinders should not leak into one another. There is no pressure escaping out the oil fill hole, so it's not going past the rings. I also get oil in cyl 2 and 4, which is causing excessive smoking. . .

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Are you certain that both the head and the block were properly surfaced for a MLS gasket as seen in this thread?

http://www.dsmtuners.com/forums/new...face-4g63t-cylinder-head-mls-head-gasket.html

To do a leak down you have to find that cylinders top dead center on the compression stroke so the valves are close. It won't work if you put number 1 at TDC and move along the line. If you have the valve cover off it will make it very easy because you can see the cam lob position.

Bogus, in that method, I am sure not, but they were freshly resurfaced surfaces. I am going to try a composite HG and give that a try.

Take the cams out. That takes all the guesswork out of it. All the valve will be closed.

Edit: Popping the rockers off will do the same thing.

kthackst said:

Take the cams out. That takes all the guesswork out of it. All the valve will be closed.

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True, but most people don't want to do a timing belt job just for a leak down test when it's so much easier to just spin the motor to the position that you need.

romeen said:

True, but most people don't want to do a timing belt job just for a leak down test when it's so much easier to just spin the motor to the position that you need.

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Yep but he said he was taking the head off so why not pull the cams if he is unsure of the firing order.

I also edited it to just say popping off the rockers because that would allow the valves to stay closed without needing to mess with the timing belt.

You can also have your issues if the ring gaps are all lined up or upside down. Jst do your leak down with the firing order and you will be fine. Once you do that, then decide what you need to do.

Sigh, as I stated before, no air coming out of the oil fill hole or dip stick, so it's not going past the rings. It is just leaking compression into another cyl, as well as oil is getting into cyl 4 and 2. All new valve seals, and guides and valves.

I am going to retest it with the cams out since I have it apart anyways. Anyone have any idea on where the oil is coming from? Cyl 2 and 4 have it the worst, and 1 and 3 have a very little in it.

Check your intake and exhaust ports for oil. If you got new guides and seals and they were installed incorrectly you could still be leaking. The other options are oil pushing past the rings, running down the return through the brand new hg (I highly doubt it), there is only one high pressure and that is by cylinder 4, or coming from the head somewhere like guides or seals.

^ Checked the intake ports on my head and didn't see any oil in there, so I am assuming its getting past the rings, perhaps because the rings arent seated correctly? Motor only has 5 mins of idle time. I put it back together and am going to drive it a bit and hopefully it pans out.

P.S. Did a leak down with the cams out, and all is well. Tested to 90psi, only 3-5psi leakage.

Hopefully that is all it is.

I know when I did a leakdown on my car I couldn't check 1 and 4 or 2 and 3 at the same time. It would appear that one of the cylinders still had some valves open. So I had to do 4 then rotate 180 degrees and check to see if 2 or 3 to see which one would hold pressure. Then I rotate it again and get cylinder 1. Rotate 180 and get the last cylinder. Just because both cylinders were at TDC doesnt mean the valves are closed on both.

^^ I find it easier to just take the cams out. Cuts out the bullshit. Doing the timing belt takes like 20 minutes if you have a BSE.