AIR question.
AIR question. So I gather that this system helps the cats do their job at cold start. What's going on here? I'm guessing that at cold start a solenoid allows hot gas to be sucked into the TB from the exhaust manifold? I might just delete that item when I get some LT headers.
And another thing. My car ticks a little but only when the engine is cold. After a few minutes I hear a click (Maybe it's the AIR system closing?) and then the ticking stops. Perhaps my ticking is actually just the check valve in the AIR system and not the valve train making the tick sound. The rythem of the ticking sounds a bit like a horse galloping. (The ticking maybe on-time with the exhaust event on just one cylinder?)
I think I'll disable the AIR and see if the ticking goes away. Wouldn't that be nice!
Any thoughts on Shev's rambling of the day?
GO PATRIOTS!!!!!
And another thing. My car ticks a little but only when the engine is cold. After a few minutes I hear a click (Maybe it's the AIR system closing?) and then the ticking stops. Perhaps my ticking is actually just the check valve in the AIR system and not the valve train making the tick sound. The rythem of the ticking sounds a bit like a horse galloping. (The ticking maybe on-time with the exhaust event on just one cylinder?)
I think I'll disable the AIR and see if the ticking goes away. Wouldn't that be nice!
Any thoughts on Shev's rambling of the day?
GO PATRIOTS!!!!!
Last edited by ShevrolayZ28; Nov 13, 2005 at 12:23 PM.
Joined: Nov 2001
Posts: 34,632
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From: Schiller Park, ILL Member: #317
AIR = Air Injection Reation.
There is a fresh air pump loacted towards the front of the engine bay (under the driver's side headlight) that pumps fresh, outside air directly into the exhaust system (pre-cat). The AIR pump lines connect to the exhaust system via the manifolds, and there is a one way valve (check valve) just above the connection point (AIR line to manifold) on each bank of the motor (one per mainfold) that prevents hot exhaust gas from the engine from escaping into the AIR lines. Only fresh air passes though these lines, on it's way to the exhaust stream.
The point of this system is to provide fresh oxygen into the exhaust system (pre-cat) to cause the converters to heat up faster after engine startup. More oxygen = hotter cats, hotter cats = better filtering ability. The system usually cuts off after a few seconds, longer if the motor is cold. The pump normally makes a high pitched whine as it operates.
Lots of things can cause ticking. If the check valves are failing, they may in fact be ticking (fluttering), but it would be more likely to hear it under throttle (driving) than at idle.
There is a fresh air pump loacted towards the front of the engine bay (under the driver's side headlight) that pumps fresh, outside air directly into the exhaust system (pre-cat). The AIR pump lines connect to the exhaust system via the manifolds, and there is a one way valve (check valve) just above the connection point (AIR line to manifold) on each bank of the motor (one per mainfold) that prevents hot exhaust gas from the engine from escaping into the AIR lines. Only fresh air passes though these lines, on it's way to the exhaust stream.
The point of this system is to provide fresh oxygen into the exhaust system (pre-cat) to cause the converters to heat up faster after engine startup. More oxygen = hotter cats, hotter cats = better filtering ability. The system usually cuts off after a few seconds, longer if the motor is cold. The pump normally makes a high pitched whine as it operates.
Lots of things can cause ticking. If the check valves are failing, they may in fact be ticking (fluttering), but it would be more likely to hear it under throttle (driving) than at idle.
