Engine intake manifold oil leak

Enzio

Dang it. I was hoping mine would get 3 more inches
May 14, 2019
179
87
38
63
Minnesota
but I found out soon after that it was indeed crankcase pressure necessitating the tear down.
Naturally, I've been thinking about this constantly. This may explain a lot of small things I noticed since I put the new clutch in and have been joyfully driving around in the old Cobra II.
When I went to the exhaust guy and while he had it up on the hoist I noticed that there was a fresh oil leak coming from the left side of the block near the front. I looked close and it appeared that the oil filter was leaking just a small amount. And, from closer inspection, it also appeared that the fuel pump was leaking from the bottom of the gasket. Which matched up with the drops on the floor of my garage. Also, earlier when I was changing the clutch I noticed that the oil pan had fresh oil on the bolts. At first I thought the rear seal was leaking but it wasn't the seal. I just thought it was residue from the blown power steering line or I thought those gaskets were old and possibly just weak.
So, when I got back from fishing I was determined to get rid of the lifter problem. Which I did by pulling the covers off the lifters and starting up the engine and doing a visual on the rockers. It's hard for me to hear where the noise was coming from but in a few short moments I determined that #8 was the big problem and #4 also needed to be tightened down. Gone was the noise. (Happy Camper) But first I replaced the fuel pump and gave the oil filter a little extra twist.
That was just before the horror on the highway.

I'd like to determine whether I have excessive crankcase pressure due to a broken ring(s) before I go through the replacement of the intake manifold gaskets. All the plugs look like they are burning perfect.

Is there a way to tell if there is a ring issue? Compression test? I've never done a compression test so I'd need someone to tell me a procedure to follow and I'll run out and do it.

Thank you,
Enzio
 
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74stang2togo

NERD!
Mod Dude
Mar 7, 2002
6,373
2,267
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Naturally, I've been thinking about this constantly. This may explain a lot of small things I noticed since I put the new clutch in and have been joyfully driving around in the old Cobra II.
When I went to the exhaust guy and while he had it up on the hoist I noticed that there was a fresh oil leak coming from the left side of the block near the front. I looked close and it appeared that the oil filter was leaking just a small amount. And, from closer inspection, it also appeared that the fuel pump was leaking from the bottom of the gasket. Which matched up with the drops on the floor of my garage. Also, earlier when I was changing the clutch I noticed that the oil pan had fresh oil on the bolts. At first I thought the rear seal was leaking but it wasn't the seal. I just thought it was residue from the blown power steering line or I thought those gaskets were old and possibly just weak.
So, when I got back from fishing I was determined to get rid of the lifter problem. Which I did by pulling the covers off the lifters and starting up the engine and doing a visual on the rockers. It's hard for me to hear where the noise was coming from but in a few short moments I determined that #8 was the big problem and #4 also needed to be tightened down. Gone was the noise. (Happy Camper) But first I replaced the fuel pump and gave the oil filter a little extra twist.
That was just before the horror on the highway.

I'd like to determine whether I have excessive crankcase pressure due to a broken ring(s) before I go through the replacement of the intake manifold gaskets. All the plugs look like they are burning perfect.

Is there a way to tell if there is a ring issue? Compression test? I've never done a compression test so I'd need someone to tell me a procedure to follow and I'll run out and do it.

Thank you,
Enzio
View: https://youtu.be/X_tbksFYhl4
 
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Enzio

Dang it. I was hoping mine would get 3 more inches
May 14, 2019
179
87
38
63
Minnesota
Thank you for that. I'll let you know later. I really appreciate the quick response.
 

Enzio

Dang it. I was hoping mine would get 3 more inches
May 14, 2019
179
87
38
63
Minnesota
Well that took a long time...the o-ring from my compression tester came off and fell on top of the cylinder when I pulled it out.
compression test 2.JPG


Here are the results. Looks like #8 is a problem but I know nothing about how to read this.
compression test 1.JPG
 

LILCBRA

10 Year Member
Dec 6, 2005
1,157
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Marietta, Ga
As long as your O ring was still good and you performed the tests identically for each cylinder (which judging by the rest of them you most likely did), #8 is definitely bad. Time for a tear down. ☹
 

Enzio

Dang it. I was hoping mine would get 3 more inches
May 14, 2019
179
87
38
63
Minnesota
I think you may be right but the o-ring was definitely shot on the last one. I'll go get one and do it over.
 

74stang2togo

NERD!
Mod Dude
Mar 7, 2002
6,373
2,267
224
#8 has a top-end issue.

A dry compression test should have all cylinders within 10% of each other (except GM, who is so un-commited to quality that they feel 30% variance is acceptable).

If you add oil to the cylinders and see virtually no change (as happened here) the problem is not rings. If it had gone up dramatically, it would be rings.

The next move should be a leak-down test.

EDIT: just saw your new post, replace the o-ring first and re-check.
 
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2Blue2

I partied with that dude!, um girl, um whatever...
Mar 5, 2019
820
434
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52
Oahu
I hope number 8 was just a o-ring problem and not a piston ring problem
 

LILCBRA

10 Year Member
Dec 6, 2005
1,157
300
124
47
Marietta, Ga
It looks like you lost the O ring before you got to the #7 cylinder, so you most likely have good readings. But it's always a good idea to double check. It's like the old addage - measure twice, cut once. :)
 

LILCBRA

10 Year Member
Dec 6, 2005
1,157
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Marietta, Ga
The good thing is that if you choose to replace your heads you can most likely pick some up for pretty cheap nowadays, and you'll probably be able to get some that are better performing as well.
 

Enzio

Dang it. I was hoping mine would get 3 more inches
May 14, 2019
179
87
38
63
Minnesota
Nope the measurements stand. I didn't redo the dry but the wet was the same. #8 is done.
 

Enzio

Dang it. I was hoping mine would get 3 more inches
May 14, 2019
179
87
38
63
Minnesota
It looks like you lost the O ring before you got to the #7 cylinder, so you most likely have good readings. But it's always a good idea to double check. It's like the old addage - measure twice, cut once. :)
Lost in #6 so very good observation.
 

2Blue2

I partied with that dude!, um girl, um whatever...
Mar 5, 2019
820
434
73
52
Oahu
Number 8! What the heck is wrong with you. Can't kept together for a little while?!?
You just got a new clutch and a chance to get out of the garage regularly! But nooo!
Good for nothing dead cylinder. If your going to live under this roof you need a job!
You can't just let all your brother and sisters do all the work!


Sorry I'm just ranting
 
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Enzio

Dang it. I was hoping mine would get 3 more inches
May 14, 2019
179
87
38
63
Minnesota
Number 8! What the heck is wrong with you. Can't kept together for a little while?!?
You just got a new clutch and a chance to get out of the garage regularly! But nooo!
Good for nothing dead cylinder. If your going to live under this roof you need a job!
You can't just let all your brother and sisters do all the work!


Sorry I'm just ranting
I'm glad I didn't just tear it down to replace the IM gaskets only to have this happen again.
 
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Enzio

Dang it. I was hoping mine would get 3 more inches
May 14, 2019
179
87
38
63
Minnesota
#8 has a top-end issue.

A dry compression test should have all cylinders within 10% of each other (except GM, who is so un-commited to quality that they feel 30% variance is acceptable).

If you add oil to the cylinders and see virtually no change (as happened here) the problem is not rings. If it had gone up dramatically, it would be rings.

The next move should be a leak-down test.

EDIT: just saw your new post, replace the o-ring first and re-check.
It's clear there is a problem. But could a bad valve cause the Intake manifold gasket to blow out?
 

2Blue2

I partied with that dude!, um girl, um whatever...
Mar 5, 2019
820
434
73
52
Oahu
Everyone chanting...

Dart 363...Dart 363...Dart 363...Dart 363...
 
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Enzio

Dang it. I was hoping mine would get 3 more inches
May 14, 2019
179
87
38
63
Minnesota
The 507 or 563 HP. Would that even bolt in there? Pretty sure I'd need a new tranny for that kind of power.
I want to figure out what it is. replacing the heads is something I've always wanted to do anyway.