PCV Catch Can - keeps your engine clean, which helps gas mileage in the long run.

[suspendedhatch]

No alteration to the PCV system will save you from having to periodically remove and clean out the EGR ports. The hot exhaust gases cool rapidly on their way to the intake forming carbon deposits.

The PCV catch can in this thread will only catch a small portion of the residue. To be effective, you need to build a baffled catch can with a decent filter element. Steel wool is commonly used in these DIYs but it turns out that it's not an effective filter element. Neither are fuel filters.

You'll still need to periodically remove and clean the throttle body and intake manifold. Also, a lot of that mess coating your intake actually comes through your air filter and from your Evap purge.

Burning oil vapors effectively lowers the octane rating of the fuel in the combustion chamber.

[theholycow]

I wonder if cleaning the EGR ports, throttle body, and intake manifold is listed in maintenance schedules. Is it something I should do on my 180,000 mile old GMC?

[bowtieguy]

holycow,

i'm not a mechanic, but i typically do those things as part of routine maintenance(every 1 to 2 years).

just an experience...

i had a saturn throw an EGR code once. after pricing them, i decided to pull it off and clean it. put in a good fuel system cleaner as well, and never saw the code again(drove it for more than a year before trading it).

[suspendedhatch]

No, it's not listed. I can't speak to GM engines but I would say that if it's not too much trouble you should take off your intake tube, prop the throttle open, and peer into your intake manifold with a flashlight, maybe reach around inside with a white glove LOL.

On a Honda it makes a big difference. You need to change the gaskets, remove the injectors and clean out their ports, clean off the IAT, clean out the MAP port, the IACV and it's ports, the PCV valve, the Evap port (leaves a grease hill on your throttle body mating surface), and clean the throttle blade. Then you take the intake manifold to a place that has a parts cleaner. After 15 years those runners are coated in thick deposits of yummy black gravy.

[Daveedo]

I completely rebuilt an eagle talon motor last year and it had about 1/8" thick crud on the throttle body and close to 3/8" inside the intake. It looked and felt like that dirty caked oil you get on leaky old motors...but it was INSIDE the intake I can definitely see how this buildup over time can affect air flow, atomization(spray pattern of the injectors), and possibly power/mileage. I suppose if someone had a really crusted up intake/throttle body they could check mileage then clean it and check mileage again. Provided testing procedures were identical it would give us an idea of any difference that may occur. VERY small sample size for only one person to do it so it'd be nice to see several experiments.

btw, a motor that is in good shape should not be blowing/sucking hardly any oil through the pvc valve. If it is then a catch can is an option. Alot of guys with DSMs put them in their cars too.

[suspendedhatch]

That sounds just like every Honda that I have ever owned. Surprisingly most of the deposits are formed by particles that pass through your air filter.

I don't know if you'll see a significant change in FE but it does effect your emissions measurably.

[GasSavers_justing]

I have a 1993 Honda civic 1.5L. I already have a PCV filter and am not sure where to put it. I tried the tube coming off of the valve cover but after weeks of use I got absolutely no oil. I have not tried it anywhere else tho. does it need to be in between the charcoal canister and the throttle body?

[Ryanrpm]

Guys......I've been thinking about doing this trick also.

Tell me what you think and if it will work....



I am purposefully using water in this system in order to capture some water vapor. The metal screen is used to allow the gases to escape whenever it freezes. Then, during winter months, it acts like a catch can....just without the steel balls. But then.....the ice will condensate the oils won't it? And in short order, it will melt, giving me the water 'filter' effect again + water vapor injection.

[pat63]

pcv catch is very important part of a car.. it can make your car run rough or stall if it gets clogged. its very cheap and easy to replace.. just assure that you should replace the valve-cover head gasket, especially if you see oil on top of the engine..

[schuylkill]

I installed a catch can that I made in the sheet metal shop where I work (with the significant help of my welder friend John) and have about 500 miles on it and I checked it tonight to see how it might be working and found a small amount of oil. I also found a small amount of pressure when I removed the drain plug at the bottom of the can. I modified the pcv elbow valve into a straight valve when I did the setup and one hose (used 3/8 ID fuel line hose) with a tight bend is slightly disformed but not at all collapsed may be the cause of the pressure or is it normal to have some pressure in the can?