What would happen if…….
Thread Starter
Racer
Joined: Feb 2005
Posts: 332
Likes: 22
From: Georgia
What would happen if…….
What would happen if one were to remove the PCV system and incorrectly install a catch can and effectively cap off all other ventilation of valve covers with plugs? If a mechanic did this after a heads, cam and intake job and then ran the engine for a prolonged period of time while tuning, including several trips out road tuning, would there almost certainly be damage to the rear main seal or front seal? What if it was known that several quarts of oil disappeared in the process, only a few ounces of which ended up on the garage floor? Certain damage? I saw that there was a problem when the tuner was revving the engine in the garage trying to get it to idle correctly. A very small amount of oil was spitting from the dipstick tube, around the dipstick. A small puddle, maybe about six ounces, was then found under the car. The tuner then indicated that the low oil level had shown. With the new 2 quart oil cooler, there was a total of 8.5 quarts in the system and it took almost three to bring it back up to proper level. It’s apparent that the car was run with essentially zero ventilation and puked a LOT of oil out. Just trying to get my head around what the likely repercussions are from the mechanic’s oversight. Would like to hear opinions. Thanks.
Safety Car
Joined: Jan 2012
Posts: 3,956
Likes: 520
From: Da U.P.
If it didn't starve for oil, then you shouldn't be sitting on a time bomb. And if this wasn't a new build, then ring seal should be OK. I can't speak to your seals though, running it that way would also cause it to burn a lot of oil. How's the clutch? I puked enough out a rear main once to wipe out a clutch. Those are the first things that come to mind. It'll make more power once properly vented.
Thread Starter
Racer
Joined: Feb 2005
Posts: 332
Likes: 22
From: Georgia
If it didn't starve for oil, then you shouldn't be sitting on a time bomb. And if this wasn't a new build, then ring seal should be OK. I can't speak to your seals though, running it that way would also cause it to burn a lot of oil. How's the clutch? I puked enough out a rear main once to wipe out a clutch. Those are the first things that come to mind. It'll make more power once properly vented.
As for the clutch, I hadn’t even thought about that, and I haven’t driven it since it went into the shop. It’s a McCleod twin disk with very low mileage. I hope it wasn’t washed in oil…….
Safety Car
Joined: Jan 2012
Posts: 3,956
Likes: 520
From: Da U.P.
It's definitely worth a conversation with the guy, do you have an idea of where he stands on this? I'm guessing he screwed up the catch can setup in the first place. Is it fixed now? You need to see if all the oil blew out before, but is good now or not. If no harm/no foul then case closed. I've seen a backwards setup catch can in the past end up causing no damage, so it's not unreasonable to think nothing will come of this.
Thread Starter
Racer
Joined: Feb 2005
Posts: 332
Likes: 22
From: Georgia
It's definitely worth a conversation with the guy, do you have an idea of where he stands on this? I'm guessing he screwed up the catch can setup in the first place. Is it fixed now? You need to see if all the oil blew out before, but is good now or not. If no harm/no foul then case closed. I've seen a backwards setup catch can in the past end up causing no damage, so it's not unreasonable to think nothing will come of this.
Race Director
Joined: Oct 2004
Posts: 12,864
Likes: 4,667
I eliminated the PCV long ago, by venting to the atmosphere via a catch bottle, and it works fine. BUT-You can not plug every escape route for blowby gasses, because even gapless rings have some blowby. If you do, you'll end up with just what you've discovered, a possibly damaged seal, or two!! The pressure will build up just like inflating a tire until it explodes! Those gasses have to have an escape route, whether thru PCV, or vent tubes. If they don't, the weakest point in the engine will let go, and the gas will vent where you don't want it to. Whoever posted that the engine will run better once the PCV, or other means of venting, are in place is 100% correct. WOW......This is so basic, it's hard to believe someone who is employed as a mechanic would do such a thing. This could even possibly cause an accident if it blew enough oil out all at once to make an oil slick on the pavement. Sheesh......
Thread Starter
Racer
Joined: Feb 2005
Posts: 332
Likes: 22
From: Georgia
I eliminated the PCV long ago, by venting to the atmosphere via a catch bottle, and it works fine. BUT-You can not plug every escape route for blowby gasses, because even gapless rings have some blowby. If you do, you'll end up with just what you've discovered, a possibly damaged seal, or two!! The pressure will build up just like inflating a tire until it explodes! Those gasses have to have an escape route, whether thru PCV, or vent tubes. If they don't, the weakest point in the engine will let go, and the gas will vent where you don't want it to. Whoever posted that the engine will run better once the PCV, or other means of venting, are in place is 100% correct. WOW......This is so basic, it's hard to believe someone who is employed as a mechanic would do such a thing. This could even possibly cause an accident if it blew enough oil out all at once to make an oil slick on the pavement. Sheesh......
Race Director
Joined: Oct 2004
Posts: 12,864
Likes: 4,667
My thoughts exactly, or even a fire with oil spraying over hot headers. When I saw the way the catch can had been plumbed at the same time seeing the oil on the ground and sputtering out of the dipstick, essentially sealing the engine ventilation in the catch can with nowhere to escape, I was filled with dread. I’m betting that, at a minimum, I’m going to be dealing with either a leaky rear main seal, leaking front cover seal, or both. Is there anything I’m missing, failing to understand about other possible damage that’s possibly lurking beyond what may now be an obvious leak, etc?
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