[bmatt777]

I have a FBO 2019 SS that has been leaking oil for the past year. The first time I took it in, it was the front main seal. Got that fixed, then discovered the rear main seal was gone as well (second time). Just recently had the rear main seal fixed and also had to have my oil pan resealed. Both were done together last week (4/18 - 4/22). I drove it over the weekend and noticed I was still smelling oil but thought it may have been residual oil just burning off after the repairs. I merged onto the interstate Tuesday night (4/26) and noticed a trail of smoke coming from my car in my rear view. I immediately took the next exit and as soon as I stopped I noticed smoke coming up from under the hood and a potent oil smell, I almost thought the car was on fire actually. I parked the car and opened the hood and (no fire lol) there was lots of smoke. I looked under the car and she was pissing oil from the rear side of the engine.

Part of this is me ranting because I'm extremely fed up with this oil problem but I'm also looking for answers/suggestions because this seems ridiculous for a car that's only FBO pushing ~465whp. There are Camaros pushing way more power and I don't ever hear about seal issues or even oil issues for that fact. Maybe I'm just ignorant?

I'm not 100% sure that the real seal just blew again but I'm about 99.9% sure it did given the dramatic events that took place Tuesday night. I have a mighty mouse wild catch can (8AN 800hp) on the way to relieve the crank case pressure. This is the only remedy I can think of for now.

My questions are:

1. Why? Why on earth is my car being so malfunctional? I mean I JUST got the seal replaced and it seems to have blown again in < 1 week.
2. Will the mighty mouse alleviate this from reoccurring?
3. Is there an upgraded version of the rear main seal like the LS3 front main seal upgrade?

Any advice/suggestions/recommendations are very much welcomed. For the love of all things holy and sane, I want this problem fixed.

Thank you in advance.

[cjperformance]

Might look into what could be causing high crankcase pressure in the first place. Excessive blowby, etc... I dont have exp with this specific engine, but from past exp it could also be the recess for the seal is out of round, or maybe the crank is nicked and destroying the seal.

Some shops dont look for root causes and only fix the symptoms.... which leads to recurrence. Given the number of similar but different issues, might be worth doing a compression and/or leakdown cyl test.

[Mark114]

What he said. The LT1 has a small ring gap. If the tune is too lean the extra heat can cause the rings to expand to the point that they close the gap and damage the piston. Excessive crankcase pressure can be an indication of ring and piston damage. You will want to do a compression check. This is a more common problem with boosted LT1 engines and there are numerous threads where others have run into this problem with the LT1.

[SomeGeoffGuy]

I was going to say the same thing - something is cranking up the crankcase pressure. Running compression and leakdown is the logical next step. You can run compression yourself with a $20 gauge. I would also look at the PCV system - something might be plugged up.

-Geoff

[ctrlz]

Originally Posted by SomeGeoffGuy

I would also look at the PCV system - something might be plugged up.

-Geoff

I agree.
I would look at the hose that connects the oil separator to the air cleaner duct. This hose should be letting clean air in. It should not be filled with oily residue. It sounds to me like your PCV valve may be stuck, and your crankcase blowby gases are being rerouted in such a way you are drawing blowby and oil into the intake stream, rather than having them sucked through the PCV valve.
Higher crankcase pressure will result, and force oil into places it should not go, particularly at higher rpms.

Leaking oil seal does not account for oily exhaust fumes.

Also, I assume you are losing oil. Can you say how much?

And I would not install any aftermarket gizmos that change the PCV plumbing until you have this sorted. Dealer may say your catch can CAUSED the problem.

[95 imp]

Originally Posted by Mark114

What he said. The LT1 has a small ring gap. If the tune is too lean the extra heat can cause the rings to expand to the point that they close the gap and damage the piston. Excessive crankcase pressure can be an indication of ring and piston damage. You will want to do a compression check. This is a more common problem with boosted LT1 engines and there are numerous threads where others have run into this problem with the LT1.

It has nothing to do with ring gap. Especially in a N/A motor. Otherwise, ALL our motors would be doing this.

Detonation might have damaged something. Leak down test is the way to go.

[ctrlz]

Here's the official description of the PCV system, with a separate section for the LT1.
This bit here is working backwards, I think:
"Filtered fresh air is routed from
upstream of the throttle plate to the external PCV oil separator tank. From there it is passed to both
engine rocker arm covers."

DESCRIPTION AND OPERATION > CRANKCASE VENTILATION SYSTEM
DESCRIPTION
A positive crankcase ventilation system is used in order to provide a more complete scavenging of
crankcase vapors. Filtered air from the air induction system duct is supplied to the crankcase, mixed
with blow-by vapors, and passes through a crankcase ventilation metering device before entering the
intake manifold. The primary component in the positive crankcase ventilation (PCV) system is the PCV
flow metering device (valve or orifice). Vacuum changes within the intake manifold assembly result in
flow variations of the blow-by vapors. If abnormal operating conditions occur, the design of the PCV
system permits excessive amounts of blow-by vapors to back flow through the crankcase vent tube and
into the engine induction system to be consumed during normal combustion. This engine ventilation
system design minimizes oil consumption and significantly reduces the potential for oil ingestion during
vehicle limit handling maneuvers.
LT1 Engine
The LT1 engine utilizes an integral positive crankcase ventilation (PCV) system which is located in the
Valve Lifter Oil Manifold Assembly beneath the Intake Manifold Assembly. The Valve Lifter Oil Manifold
Assembly contains composite oil separating baffles and PCV plumbing. Filtered fresh air is routed from
upstream of the throttle plate to the external PCV oil separator tank. From there it is passed to both
engine rocker arm covers. The rocker arm covers' design shields rocker arm oil spray, thereby reducing
the potential for oil being drawn back into the tank during backflow of the ventilation system. If oil is
drawn back into the tank it will drain down to the oil pan, which further reduces oil consumption. Blow-by
vapors are routed from the valve lifter oil manifold assembly through a fixed orifice (7.5 mm) within a
steel PCV tube, then into the Intake Manifold Assembly.

EDIT: This is the tube I think you should pull and check for oil. Red rectangle is where it connects to the intake. On the left side of the photo (right side of car) is the connection to the center fitting on the oil separator. The other fittings go to left and right rocker covers. As an aside, this guy's coolant reservoir is not filled properly.
https://www.camaro6.com/forums/showp...02&postcount=1

[bmatt777]

Thank you guys for all the insight so far. I really appreciate it!


Quick update:

I have the car in the shop, and they said they were going to run a compression test on it and then inspect using dye again. The tech said he couldn't see a problem when it was idling so I'm assuming by the way they explained things, they'll be putting the engine under load while it's on the lift to see what's going on.

If this yields no results then it seems like the leakdown test and a PCV system check is the next best step based on what I'm reading from you guys.

I'm praying this is not a deeper issue and maybe just something that was overlooked or isn't inside of the engine. If it is inside the engine, then I guess the silver lining is heads, cam, and forged pistons are going in haha. She'll be ready for boost at that point.

[bmatt777]

Originally Posted by ctrlz

I agree.
I would look at the hose that connects the oil separator to the air cleaner duct. This hose should be letting clean air in. It should not be filled with oily residue. It sounds to me like your PCV valve may be stuck, and your crankcase blowby gases are being rerouted in such a way you are drawing blowby and oil into the intake stream, rather than having them sucked through the PCV valve.
Higher crankcase pressure will result, and force oil into places it should not go, particularly at higher rpms.

Leaking oil seal does not account for oily exhaust fumes.

Also, I assume you are losing oil. Can you say how much?

And I would not install any aftermarket gizmos that change the PCV plumbing until you have this sorted. Dealer may say your catch can CAUSED the problem.

So I just remembered something as I was reading this. I have an LT2 intake and the PCV hose that attaches to it is in an awkward position. I had to sort of fabricate my own hose by attaching a longer hose to the quick release clamps because the OEM hose doesn't reach the intake mani. The issue I was then running into was that the hose I installed was rubbing against the hood because of the arch thats in it was too high. I need a 90 degree quick release to solve that issue but never got around to it. (see pic for reference)

Could this have anything to do with the issue?

[ctrlz]

This thread mentions possible problem of PCV hose getting kinked when you close the hood:
https://www.camaro6.com/forums/showthread.php?t=587617


If you still had the car I would suggest putting a dollop of shaving cream on top of that PCV hose and closing the hood. If you see a smeary mess on your hood liner you know the hood touched the hose and pushed it. The shave cream should be easy to clean off.

my guess is this car may work just fine in the shop with the hood open.

More posts commenting how the LT2 basically touches the hood liner when closed, and you have to modify the PCV fitting to prevent kinking of the hose:
https://www.camaro6.com/forums/showt...558640&page=19

[Tim Trempz]

Seems like the exact same issue I've been having on mine. I posted a thread on here as well that explains the exact same problem and it seems you have the same setup as me as far as the LT2 intake and what not. Interested in seeing the results and hope it's just some dumb easy to fix issue.

[ctrlz]

I agree the oil leak is most likely due to increased crankcase pressure. Since you are not running forced induction, the most likely cause is inadequate venting on the oil separator side (right) of the pcv, or blocked suction lines on the side with the pcv valve (left). If the right side is clogged or kinked anywhere, it can impact the pcv system in both the vacuum and non-vacuum states. In the vacuum state, the right side tubing lets air in to the crankcase. At low (or no) vacuum, it lets excess pressure out of the crankcase and it gets pushed into the intake tube between the MAF and the throttle body.

You do not want to put a cone filter in the middle position of the oil separator. The inside will eventually get coated with oily residue clogging up the filter.

[Andre27]

Generally speaking, oil leaks can be caused by a really large number of reasons. And if you don't take action in time, you can say goodbye to your engine. My Ford F-250 Superduty had a leak once. It turned out the problem was in the oil filter. I just saved money and bought a cheaper filter. I have tried many filters, but the best oil filter for 7.3 Powerstroke is from the brand K&N. It was the only one that fixed the problem. I had a lot of trouble at the time. I read your problem and remembered my own:(((

[TheWildJarvi]

Was this issue ever resolved? I have a 2018 camaro SS h/c/i that keeps blowing the rear main seal as well.