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Massive Oil Consumption

pcf_mark

Bronco Guru
Joined
Jun 11, 2010
Messages
3,574
FYI a leak down test will tell you about the compression rings and cylinder seal but not the oil control ring package. Oil in the intake is telling me not rings. Valve guides, valve seals, intake gaskets, PCV. Oil rings would spew it out the exhaust but it is going to be difficult for it to coat the back of the intake valves and runners up into the intake as you describe. If you put a breather in each valve cover and it stops you know it is the PCV. But if the breathers are dripping oil down the valve covers you have a ring problem.
 

red hot71

Sr. Member
Joined
Nov 26, 2009
Messages
648
Loc.
kent wash.
I built a 390 years ago using all the so called tricks to make a strong and reliable longer lasting daily driver type. Well it also used 1 quart per hundred miles and I did everything you guy's have said to do and never could solve the oil consumption problem.
In the end the problem I came to was when I built this motor I set up the clearances to looser side of factory specs, plus FE's like oil pressure, so I used a high pressure oil pump.
These two things I figured were throwing so much oil out of the rods bearing and mains that the cylinder walls were being flooded with so much oil that the oil rings could not handle the oil and it burned that way. Far fetched but that was in the end all I could think of.
 

blubuckaroo

Grease Monkey
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Jun 11, 2007
Messages
11,795
Loc.
Ridgefield WA
Another thought.
Are you sure you're using the correct PCV valve?
You don't want too much flow at high vacuum.
The Valve sort of work inversely. Lower flow at higher vacuum.
 
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77RHINO

77RHINO

Full Member
Joined
Feb 22, 2011
Messages
308
Thank you for all the input guys, I didn't get to work on it last night as planned, but should tonight. What would be the best materials to make a temporary catch-can? I want to make something that can withstand the oil temps and not melt, but can also have a clear casing so I can see if its accumulating easily. I am currently running the '96 factory PCV valve, and it does drip oil. I do get oily mist spewing out the exhaust while its warming up, but that could also be condensation mixing with the soot in the exhaust pipe.
 

Broncobowsher

Total hack
Joined
Jun 4, 2002
Messages
34,835
Quick down and dirty, home Depot PVC. Mount it behind a headlight and it will stay cool enough. Just need it to be strong enough not to collapse with vacuum. Screw top lid lets you check the contents.

Fuel filter soaked in oil won't flow very good. Even a clean disposable fuel filter probably won't flow enough to keep up with a PCV.
 

Timmy390

Bronco Guru
Joined
Jan 1, 2011
Messages
5,609
Loc.
Conway, AR
Quick down and dirty, home Depot PVC. Mount it behind a headlight and it will stay cool enough. Just need it to be strong enough not to collapse with vacuum. Screw top lid lets you check the contents.

Fuel filter soaked in oil won't flow very good. Even a clean disposable fuel filter probably won't flow enough to keep up with a PCV.

It will show you if oil is passing through.....just a quick down and dirty test.....3/8 clear fuel filter will flow well I think....

It was just and idea to verify the issue....

Tim
 

pcf_mark

Bronco Guru
Joined
Jun 11, 2010
Messages
3,574
This guy went pretty serious

https://www.tacomaworld.com/threads/diy-oil-catch-can.244981/

I like the design but would stuff it with Brilo pads as a separator.

I want to clarify something I said earlier. If you have bad rings it can't get on the intake valves and up the intake runner. HOWEVER if you PCV is sucking all the junk out of the crankcase and feeding it to the base of the carb you will get that.

Check your valve stem seals and guides, intake manifold sealing and then it may be rings (assuming PCV is right). That is a ton of oil.

I'm trying to think of what happens when the oil rings are bad / installed wrong / wrong design. The oil will not get scraped off the walls so oil goes into the combustion chamber and should get burned and thrown out the tail pipe so you will use a lot and see it in the exhaust. It can't contribute to oil in the PCV. Only blow by from the compression rings would create a lot of crankcase vapors which need to be managed which will over work the PCV side.

Something is not adding up for me yet.
 

sykanr0ng

Bronco Guru
Joined
Aug 11, 2014
Messages
5,363
That much oil that quickly?
I would not rule out multiple points of failure.

Everybody wants it to be only one problem so it only needs one fix, but it isn't always that way.
 

broncnaz

Bronco Guru
Joined
May 22, 2003
Messages
24,341
quite odd to burn that much oil in a short amount of time and not foul out any spark plugs. Along that line Id say your running way to lean by looks of the plugs and if its burning that much oil. But Id say something is wrong with the rings. I think I would pull the engine and tear it down. You could then double check everything replace anything that is suspect. I look real close at your ring gaps and measure the cylinder bores. Maybe the machine work didn't quite hit its mark and is out of spec for the parts you used.
 

Skiddy

Bronco Guru
Joined
Oct 8, 2003
Messages
11,557
quite odd to burn that much oil in a short amount of time and not foul out any spark plugs. Along that line Id say your running way to lean by looks of the plugs and if its burning that much oil. But Id say something is wrong with the rings. I think I would pull the engine and tear it down. You could then double check everything replace anything that is suspect. I look real close at your ring gaps and measure the cylinder bores. Maybe the machine work didn't quite hit its mark and is out of spec for the parts you used.
exactly what I was thinking, even could have some broken oil rings
 
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77RHINO

77RHINO

Full Member
Joined
Feb 22, 2011
Messages
308
I turned the engine over by hand last night to check for coil binding, but I have plenty of clearance on my springs when the valves are fully open. That takes out the squishing umbrella seals option. I will make a catch-can and try that test, and look into a leak down test after that, since everything is still together right now. I've never performed a leak down test, so I have some research to do first. I really hope its not the rings, but it is starting to look that way.
 

Timmy390

Bronco Guru
Joined
Jan 1, 2011
Messages
5,609
Loc.
Conway, AR
Are you TRULY running "umbrella" style valve stem seals? Very OLD SCHOOL Or are you running "flex body" M-6571-A50 seals that are for GT-40 heads?

Tim
 
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77RHINO

77RHINO

Full Member
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Feb 22, 2011
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Timmy I am running the flex body ones, the factory replacements for those heads. I just used the term incorrectly.
 

Timmy390

Bronco Guru
Joined
Jan 1, 2011
Messages
5,609
Loc.
Conway, AR
Be careful doing the leakdown. You will be shocked at how little pressure it takes to spin over the engine and move the rig if not on perfect top dead center.

Went through this a year back when looking for a head gasket issue.

Tim
 

PaveBronco

Sr. Member
Joined
Oct 30, 2012
Messages
912
Been reading your thread and threads, seems this has been an issue for awhile, sucks and I feel your pain.
Not saying its this issue, but long time ago I pulled my heads, first time ever, to install a cam. Had lots of carbon on the pistons, I cant remember why but I pulled a piston out and found some of the rings were seized up because of the carbon build up, I wasn't using oil, or more than normal. Odd about your plugs, look too clean for a crummy stock coil and basic plugs. keep us posted on the leak down results, that's really the only way left to pinpoint your issue.
• Intake valve : Air whistling out of the intake, carburetor or throttle body indicates a leak at the intake valve.
• Exhaust valve : Air heard hissing out of the tailpipe, turbocharger or exhaust manifold means an exhaust valve leak.
• Piston rings : Whistling or hissing out of the PCV valve, oil filler cap hole or dipstick tube means the air is pushing past the rings. Suspect ring or cylinder wall wear.
• Head gasket : Air bubbles in engine coolant seen at the radiator filler cap could mean air escaping into the coolant past the head gasket.
• Cracked cylinder head : Bubbles in coolant or coolant being pushed up out of the radiator neck can also indicate cracks in the cylinder head or cylinder walls.
 

nvrstuk

Contributor
Just a Bronco driver for over 50 yrs!
Joined
Jul 31, 2001
Messages
8,615
Catch can for in line on the PCV is a simple cheap HF in line air filter for an air compressor. Works great, that's what I use and it's on the firewall...heats not an issue.

Clear plastic housing...

Like I mentioned earlier, if oil is on the intake valves it can only get there from above... of course there's other possibilities but...start there ...again...good luck
 

Broncobowsher

Total hack
Joined
Jun 4, 2002
Messages
34,835
Catch can for in line on the PCV is a simple cheap HF in line air filter for an air compressor. Works great, that's what I use and it's on the firewall...heats not an issue.

Clear plastic housing...

Like I mentioned earlier, if oil is on the intake valves it can only get there from above... of course there's other possibilities but...start there ...again...good luck

Not really. With the reverberations in an engine it's common to get chunks of a failed catalytic convertor in the intake manifold. I've seen engines on a dyno that hit a resonance and there will be a cloud of gas vapor above the carburator. Just because it should doesn't mean it does alwyas flow in one direction.
 
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