Stock air filter cover?

[RICKYRJ1]

Sorry guys I wasn't sure how to title my question. I bought my car w/ the Vortex air filter system already installed. As per everybodies comments I removed it and installed the stock one. MY Q. is the blk. plastic shroud that the filter housing lays on then scewed down w/the 3 round fasteners has a big hole cut out of it from the Vortex system. Is this a problem? Should a new shroud be installed? I also have one of the stock air filter housing that has been modified to make it a open system w/ K&N filter totally exposed. Should I use that one instead? Again sorry for the maybe not so clear Q.

[Demps]

I personally would seal the radiator shroud--or change it. It will potentially let debris and moisture in the engine compartment. I have a cut lid and K&N on two of my cars. Some people say it doesn't help. I just like it. One thing that I have noticed--a K&N filter in a ZR-1 will make the idle hang up slightly at a stop. GM put out a notice that the oil from the filter will contaminate a sensor for the automatic shift of a tranny. I'm suspecting it somehow interferes with the coast-down idle on a ZR-1 and the speed density system (either IAC valve or MAF sensor). Ted

[Locobob]

I wouldn't worry about it. I've got the same deal as you and it's been like that for over two years without a problem. On my car the hole for the Vortex is entirely covered by the factory air filter housing.

[RICKYRJ1]

The air filter housing does cover the hole. Is it a big job to install a new shroud? Are they still available?

[Tom]

A speed density system like on a ZR-1 does not have a MAF (Mass Air Flow Sensor) to get coated with the oil from a K&N filter and give faulty readings. It uses a MAP (Manifold Air Pressure Sensor) which on a ZR-1 is located at the back of the engine. The MAP sensor and connections do sometimes get engine oil into them which causes erratic readings, softens the rubber parts of the connections, and makes it much easier for the connections to be forced off if you have the ZR-1 starting backfire caused by not holding the key in the start position long enough.

The K&N filter oil could possibly get in the IAC area but it is easy to remove and clean.

[Demps]

Oops, typo. I'm fairly familiar with the speed density system. I chased an idle issue for about three years. I've now come to the conclusion that a K&N filter is causing it.

The radiator shroud is aggravating to change. If I remember correctly, Ricky, your car has about 4,000 miles. That is why I would change it/fix it. The correct one with the stickers will be hard to come by new.

Ted

[Tom]

My car had an idle problem from the day I bought it that got progressively worse. It finally got to the point where the car would die fairly often in stop and go traffic. After checking numerous items and finding no problems I finally gave up and took it to Guldstrand and they found that my MAP sensor was giving erratic readings that were at the very edge of the acceptable range. No codes would set since the readings were just inside the value where a code would be set. There was also engine oil in the line to the MAP sensor and the sensor itself. They replaced the sensor and line and the car was better than when I first bought it.

[RICKYRJ1]

Originally Posted by Demps

Oops, typo. I'm fairly familiar with the speed density system. I chased an idle issue for about three years. I've now come to the conclusion that a K&N filter is causing it.

The radiator shroud is aggravating to change. If I remember correctly, Ricky, your car has about 4,000 miles. That is why I would change it/fix it. The correct one with the stickers will be hard to come by new.

Ted

Ted, don't you have 5 of them? I only need 1! Should I install a stock GM filter instead of the K&N? The car does have only 4k miles so it is very important to me to replace the shroud. Any and all help in finding one would be greatly appreciated. Thanks Rick