adriver

iTrader: (1)

I'm running a AEM CAI. I've been cleaning my air filter / maf / tb roughly the first time I get a backfire, or every couple of years. I have 257K and last cleaned it 8 months and 5K miles ago, and its already backfiring again. I think the dusty off pavement in AZ and TX are a big contributor. The last time I cleaned it, the intake manifold looked like black 30 grit sandpaper. I could wipe a thick layer of gunk off with my finger, but was too worried about dropping some of that in to really make an effort at it. I'm certain the intake manifold has just gotten too dirty. Either way, I think that's something I need to do just because it seems like a cheaper fix, and a good place to start with.

I recently changed spark plugs, and found some oil on the threads from cylinder #5. Everything else looked as it should. Thinking that the rings could be causing blowby and that might be why it got dirty bad all of a sudden. Hoping its just a dirty intake.

I have a 2002 with a 4.8L. I eventually plan on swapping it to something larger, but for now would like to keep it running on a budget, and only interested in any mods that will transfer over to the new engine after a swap.

The only thing I have done to the engine is plugs, oil, and cleaned the TB. I plan on removing the intake manifold to clean it out. It seems easy enough with this video I found on 1aauto.com.
How to Replace Intake Manifold Gaskets 1999-07 Chevy Silverado | 1A Auto
Another big reason is just to get a little deeper experience into working on an engine before I go bigger.

I'm only planning on cleaning the manifold and using a new gasket.
Searching has led me to learn about the PCV valve. I am going to replace that ($3).
I think its time to add a catch-can. I see em from $30 to $150. The only thing I wanted to make sure it had was some type of window to see how full it gets.

Can anyone offer anything on any reason to or not to pull the intake manifold to just clean it, anything else that I should replace while I'm going this, or any thing you might be able to offer that I am not aware of? Thanks.

wretched73

iTrader: (1)

If you have grit in your intake manifold, I'd go back to a stock filter. Start there.

adriver

iTrader: (1)

I wouldn't call it grit, its just a dirty dusty fine powder that has built up to the point its starting to look like popcorn ceiling. In 257K miles I have never cleaned it. I have been running the filter for over 150K miles, and a lot of that is off pavement, dusty dirty roads.

MikeGyver

iTrader: (5)

This is the worst product endorsement ever. It sounds like they paid you to say how great their CAI is, but it's a POS. "It only lets dirt into the engine when there is dirt where I drive" lol "I only have to remove and clean the intake manifold every 5000 miles" lol "Other than ruining my engine, this CAI is great"

adriver

iTrader: (1)

That's not even close to what I said.

A lot of my miles include off pavement and in dust storms in Arizona. The dust is like talc and is said to be 1 micron in size. K&N filters are rated at 3 microns, all other filters are rated a percentage for 1 or 2 microns. After a dust storm there is a thick layer left behind on everything, and it will linger in the air afterwards. There is no warning when it happens, other than one when it is physically seen, and that provides less than an hour. It gets to where you can't see hazard lights 10 feet in front of you, and many people pull over to wait it out, even in the lanes of traffic. I would clean my filter afterwards, but Its still in the air afterwards. Even now Texas is experiencing the annual Saharan dust. Not sure if that's the only contributor, but I think it's a big part of it.

MikeGyver

iTrader: (5)

K&Ns might be rated at 3 microns, but it seems like they let a lot bigger particles than that.
You are thinking on the right track about trying to reduce the amount of oil that your PCV is introducing into the manifold.
On the other hand, the oil is catching some of the dirt that's passing the air filter.
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tjmath

I have lived in AZ my entre life and never had a problem with dust in my intake. I had a dry filtered K&N CAI on my truck for damn near 60k miles, been through multiple dust storms, driven off road through tons of dust and when I pulled the manifold to swap it, there was a small amount of oil in the manifold and on the back side of the TB but zero dust or any particulates of any kind inside. When I did the fiberglass fenders I eliminated the inner fender and swapped to a S&B CAI with a box to keep the filter a little more protected. Even on my 99 when I pulled the intake to do the cam swap at 183k miles there was no particulates in the intake and I'd had an open element CAI on it for close to 100k miles.

I would be pretty concerned about how the particulates are entering the intake. Because if they are in the intake, then are in the cylinders and could be doing some damage to the cylinder walls.

adriver

iTrader: (1)

I think how I drive has something to do with it too. I have the 4.8L with a 5spd. Its half the power below 4K rpm, and I rev it out ALWAYS. I drive it like a teenager in a honda, and have been for the last 10 years and 170K miles. I may have 257K, but I'll bet my rotating assembly has put in twice the work as most everyone else with the same mileage.

I have a boroscope. Not sure if there would be a way for me to inspect them by only doing the manifold.

03sierraslt

iTrader: (22)

none of this explains why you have grit in the intake.

shakenfake

Kick the K&N and your intake manifold and get a Hi-Ram for the cool factor