4.0 OHV fresh rebuild using lots of oil!!

[zwsmith81]

I’ve got about 600 miles on this engine rebuild and it was using oil like crazy. We’re talking one quart every 75 miles. Took the heads off for inspection. Here are some pictures of the results. Hoping someone here can help me out with what might be going on. A couple spark plugs are oily around the threads and look horrible. Obvious fresh oil in the intake passages on the heads and intake manifold. Could I possibly not had the lower intake manifold tightened properly and oil was shooting up into the intake port through a gap in the gaskets? Any input is appreciated as I try to rule out the possibilities.
Bored.030 over with new .030 over pistons. Hastings .030 rings. The ring gaps were at or a little above the recommended numbers. Did a compression test before tearing down and average was 190 psi. Heads, valves, seals are all new. Everything was replaced in this engine. Found 3 lifters sticking in the bores. This would explain my valvetrain tapping noise.

 

[zwsmith81]

More photos.

 

[zwsmith81]

https://share.icloud.com/photos/0d8oxivtBiCXaFdjKhPfEio2Q

This is a small video clip of the exhaust smoke.

 

[BigAssTim]

I know when I was trying to replace the gasket for the intake plenum, if I used the one like yours (with the green silicone surfaces) I could never get the plenum to seat correctly (as I see you have the same problem noting the amount of sealant you had to use front and rear of your block.

Since then, I have completely removed the engine for rebuild and have been too lazy to put it back together. I did purchase a new gasket to use that will sit flush like the original ford item. Could this contribute to your issue? Not sure...

Is the engine eating the oil, or leaking it everywhere?

B.A.T.

 

[BigAssTim]

Ya know, looking at the fouling on the pistons and watching your video, being the armchair google/youtube/rangerstation expert technician I am, I think the oil is likely making it into the intake.

This is the gasket set I will be using as it more closely matches the stock Ford ones I removed:

More Information for MAHLE / CLEVITE MS16320

B.A.T.

 

[BigAssTim]

First and Second pics are from the standard ford gasket right after removal. There isn't much RTV.

The last pic is me using gaskets like you - notice how big the gap is? I think it was 1/4" ~ 3/8" in size.

 

[Shran]

I don't suppose you ruled out a bad PCV valve? Did you have any blow-by prior to tearing it down that would indicate a ring problem? Any issues that you can see with valve seals? The old 2.8's were well known for worn valve seals back in the day and they would burn copious amounts of oil while running... used to see old Rangers & Bronco II's running around with a cloud following them.

I guess it's possible that you could be losing it through the intake gasket but I'm kind of skeptical of that if you followed the torque sequence for the lower intake. And, I would think you would see gas or coolant in the oil if that were the case. How did the oil look?

I have used both styles of gaskets and had good results with both. I think the two piece style MIGHT be more forgiving to heads that have been machined without matching the lower intake though.

 

[zwsmith81]

I know when I was trying to replace the gasket for the intake plenum, if I used the one like yours (with the green silicone surfaces) I could never get the plenum to seat correctly (as I see you have the same problem noting the amount of sealant you had to use front and rear of your block.

Since then, I have completely removed the engine for rebuild and have been too lazy to put it back together. I did purchase a new gasket to use that will sit flush like the original ford item. Could this contribute to your issue? Not sure...

Is the engine eating the oil, or leaking it everywhere?

B.A.T.

It was eating it. I found a damaged oil scraper ring on cylinder five so I’m currently having the machine shop fix that problem. It must’ve slipped out when installing the piston. I bought a new gasket set
for top end from domestic gasket and it’s a one piece design with end silicone gaskets for front and rear. Hopefully that provides a better seal. I’d say it was the ring problem on cylinder 5 but I had oil in almost all the intake runners when I pulled it apart.

 

[zwsmith81]

I don't suppose you ruled out a bad PCV valve? Did you have any blow-by prior to tearing it down that would indicate a ring problem? Any issues that you can see with valve seals? The old 2.8's were well known for worn valve seals back in the day and they would burn copious amounts of oil while running... used to see old Rangers & Bronco II's running around with a cloud following them.

I guess it's possible that you could be losing it through the intake gasket but I'm kind of skeptical of that if you followed the torque sequence for the lower intake. And, I would think you would see gas or coolant in the oil if that were the case. How did the oil look?

I have used both styles of gaskets and had good results with both. I think the two piece style MIGHT be more forgiving to heads that have been machined without matching the lower intake though.

I ruled out the PCV before I tore it down. The valve seals were all replaced so that shouldn’t have been the problem. I didn’t find any coolant in the oil. I see your point with that. I think I’m going to go with the one piece intake gasket this time. Summit racing tech guys claimed that oily spark plug threads point to oil leaking into the chamber through the oil gallery so I don’t know what to think!

 

[zwsmith81]

Here’s cylinder number 5

 

[BigAssTim]

It was eating it. I found a damaged oil scraper ring on cylinder five so I’m currently having the machine shop fix that problem. It must’ve slipped out when installing the piston. I bought a new gasket set
for top end from domestic gasket and it’s a one piece design with end silicone gaskets for front and rear. Hopefully that provides a better seal. I’d say it was the ring problem on cylinder 5 but I had oil in almost all the intake runners when I pulled it apart.

I'm thinking its likely both. A single cylinder wouldn't cause oil to be in all the places you stated.

That cylinder 5 looks rough! Are you having it sleeved so you can keep the piston at the same size?



p.s. When I get going on my rebuild again, would you mind me asking you questions if I have them?

Thanks!

-BAT

 

[Shran]

Well, #5 is a problem, but certainly not THE problem... did you install the lower intake or did the machine shop? Simple curiosity on my part there. Was there any gas in the oil?

Who assembled the rest of the engine? Assuming the machine shop did it - I feel like a knowledgeable assembler should have caught the problem with the ring on #5 so it makes you wonder if it was just a genuine mistake, or if they had a newb working that day and made other sloppy mistakes. If you were the assembler, I'll give you a pass on all that, 'cuz I might have made the same mistake.

 

[BigAssTim]

It looks like the ring on #5 had the ends of the ring at the hole in the side (per pic) and it likely wore down from lack of support on the ends of the ring and eventually slipped down the side of the piston. I’ll definitely make sure I keep mine away from said hole when I reinstall mine!

 

[zwsmith81]

I'm thinking its likely both. A single cylinder wouldn't cause oil to be in all the places you stated.

That cylinder 5 looks rough! Are you having it sleeved so you can keep the piston at the same size?



p.s. When I get going on my rebuild again, would you mind me asking you questions if I have them?

Thanks!

-BAT

I’m having it sleeved so I can use my .30 over pistons.

 

[zwsmith81]

Well, #5 is a problem, but certainly not THE problem... did you install the lower intake or did the machine shop? Simple curiosity on my part there. Was there any gas in the oil?

Who assembled the rest of the engine? Assuming the machine shop did it - I feel like a knowledgeable assembler should have caught the problem with the ring on #5 so it makes you wonder if it was just a genuine mistake, or if they had a newb working that day and made other sloppy mistakes. If you were the assembler, I'll give you a pass on all that, 'cuz I might have made the same mistake.

I was the engine installer so it’s all on me. I’m a perfectionist when it comes to vehicles so this hurts pretty bad. I did all the homework, spent the extra money replacing everything, taking extra time to install and still screwed it up. It’s been about 15-20 years since I put together an engine so I definitely lost some confidence. The rings were all at max gap or a little over (.22-.26 gap) so I was a nervous wreck about that. I’ve been reassured over and over by multiple machine shops that that won’t cause any problems. That bottom oil scraper ring must’ve ever so slightly slipped out of my compression clamp during install. So I am still nervous about the oil consumption. I took my time installing and torquing the lower intake manifold but when I took it back apart the bolts seemed awfully loose. I didn’t notice any contamination in the oil, but it was burning it pretty bad to go through 3-4 quarts in 600 miles. The valve seals were already installed in the new heads so I’m trusting they’re good but am tempted to change them out anyway. I don’t want to tear this thing down again!