Is this normal??
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Le Mans Master
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From: Akron Ohio
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Is this normal??
I replaced the pass side crank case vent in the valve cover with this filter breather because the throttle body was sucking up too much oil. At idle with the hood open there is a bit of smoke that kind of trails out of the breather. Is this normal?? I cant smell anything when driving and I drove around hard in a vacant parking lot and no oil spilled out, so assuming its ok?
Le Mans Master
Joined: Aug 2000
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From: Australia
In the normal setup the pass side is the supply side of the PCV system feed from the TB port.This air is metered.
Running an open breather means the PCV air is not metered= vac leak.
Based on the fact you have visible fumes at idle ( normal ) but they are not being sucked into the engine (highest vac at idle) plus the fact that oil is going back up the inlet to the TB I suggest you check the PCV valve to see if it is actually working or there is vac on the line.
Running an open breather means the PCV air is not metered= vac leak.
Based on the fact you have visible fumes at idle ( normal ) but they are not being sucked into the engine (highest vac at idle) plus the fact that oil is going back up the inlet to the TB I suggest you check the PCV valve to see if it is actually working or there is vac on the line.
Last edited by rodj; May 5, 2009 at 08:31 PM.
Thread Starter
Le Mans Master
Joined: Oct 2007
Posts: 9,660
Likes: 3,359
From: Akron Ohio
2025 Corvette of the Year Finalist - Modified
2024 C5 of the Year Winner - Modified
2023 C5 of the Year Finalist - Modified
2022 C5 of the Year Finalist - Modified
St. Jude Donor '09-'10-'11
In the normal setup the pass side is the supply side of the PCV system feed from the TB port.This air is metered.
Running an open breather means the PCV air is not metered= vac leak.
Based on the fact you have visible fumes at idle ( normal ) but they are not being sucked into the engine (highest vac at idle) plus the fact that oil is going back up the inlet to the TB I suggest you check the PCV valve to see if it is actually working or there is vac on the line.
Running an open breather means the PCV air is not metered= vac leak.
Based on the fact you have visible fumes at idle ( normal ) but they are not being sucked into the engine (highest vac at idle) plus the fact that oil is going back up the inlet to the TB I suggest you check the PCV valve to see if it is actually working or there is vac on the line.
Having the breather just means I dont suck oil now when the crankcase vents.I will check the vacuum line going to the PCV. The idle does fluctuate from 1000-1200 sometimes so I will check for leaks.
Le Mans Master
Joined: Dec 2000
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From: San Diego, Ca
Breather side draws fresh air in from the TB (when hooked up correctly) and mixes it with fumes in the crankcase which are then metered into the intake via the PCV valve. With excessive blowby, it becomes a vent - and your seeing that. Make sure there isn't a hole in the PCV hose and that there's vacuum on the valve - put your finger over it and let go - it should pop back. You might also put a vacuum gage on the port - 15 inches would be minimum - make sure the needle is steady - make sure the port isn't plugged up.
If it's all working, change the oil and I'd run a compression check after you check the plugs - how many miles?
If it's all working, change the oil and I'd run a compression check after you check the plugs - how many miles?
Thread Starter
Le Mans Master
Joined: Oct 2007
Posts: 9,660
Likes: 3,359
From: Akron Ohio
2025 Corvette of the Year Finalist - Modified
2024 C5 of the Year Winner - Modified
2023 C5 of the Year Finalist - Modified
2022 C5 of the Year Finalist - Modified
St. Jude Donor '09-'10-'11
Breather side draws fresh air in from the TB (when hooked up correctly) and mixes it with fumes in the crankcase which are then metered into the intake via the PCV valve. With excessive blowby, it becomes a vent - and your seeing that. Make sure there isn't a hole in the PCV hose and that there's vacuum on the valve - put your finger over it and let go - it should pop back. You might also put a vacuum gage on the port - 15 inches would be minimum - make sure the needle is steady - make sure the port isn't plugged up.
If it's all working, change the oil and I'd run a compression check after you check the plugs - how many miles?
If it's all working, change the oil and I'd run a compression check after you check the plugs - how many miles?
My dads camaro had no PCV on his race motor and just breathers on both sides and it didnt smoke.
