Intake valve build up - Pics Inside

kennerz · April 7, 2021

4 hours ago, HoosierZ said:

Over the weekend, I ran a can of CRC GDI valve cleaner thru my intake and it most definitely made the engine more responsive. I’ve had a catch can on my 2016 5.3L since around 5k mi and it just turned over 60k. I sprayed the cleaner through the line between the catch can and intake so the cleaner would take the same route as the PCV vapors do.

Would make sure to change the oil asap, that stuff gets past everything. I used a little on my cleaning exercise directly. The oil was absolutely filthy after the cleaning. Can dilute the oil...

kennerz · April 7, 2021

3 hours ago, Grumpy Bear said:

Here's my take on a can for whatever it is worth. My truck uses no measurable amount of oil between 5K OCI's and I use a lube with a NOACK under 6%. A can doesn't really make sense in this case.

My wife's SUV uses a quart in 10K or about 8 ounces between 2,500 mile OCI's. That's how often I have to change it to keep the rings free.

This one I would put a can on IF it had an external PCV system...which it does not. 2.4 Ecotec I4 is internal and uses a sized orifice instead of a valve. Really dumb design but point is...it uses enough oil to be a problem as I showed in an earlier post photo. And it consumes it via the intake manifold as that photo shows.

One of these days I might just plug that orifice and tap the cam cover and manifold for an external system I can trap.

That can would also be much larger that any commercial can I've seen to date. Most efficient ones I've seen are fabricated for race car systems and are about a 2 liters in size minimum. Some cans over a gallon.

Would agree it needs to be larger and have some type of trap/filter something to be more effective. What the small ones on the vettes/camaros actually accomplishes would be really surprising if it does anything meaningful. I've heard that same info about the DI ecotec (2.4) that they have a deficient PVC system, especially for performance applications.

Anyhow, the whole exercise here is just another data point. Don't know that I'm going to change anything about my program, I don't know with certainty what to change to get a better result. And to me a better result would be keeping the intake tract clean.

Another thing about the CDI cleaner if used the way they intend you too. You will inadvertently wash a bunch of garbage into your cylinders, some of it is on the harder side. If I did use a liquid chemical induction cleaner I would change the oil within the 1st 100mi. for sure.

HoosierZ · April 7, 2021

1 hour ago, kennerz said:

Would make sure to change the oil asap, that stuff gets past everything. I used a little on my cleaning exercise directly. The oil was absolutely filthy after the cleaning. Can dilute the oil...

The truck was due for an oil, so I changed it when I got back from driving it after the treatment. The can actually says to use the cleaner before every oil change. That seems excessive.

wingsaa · April 7, 2021

14 hours ago, kennerz said:

Would make sure to change the oil asap, that stuff gets past everything. I used a little on my cleaning exercise directly. The oil was absolutely filthy after the cleaning. Can dilute the oil...

Yep. I've used it twice now and as you mentioned, just before I'm changing the oil. Get it out asap and in with fresh. I'm not saying that stuff doesn't work... I'm sure it does to some degree. I don't believe it gets to all the ports effectively however.

That said, my next rodeo is to take the intake manifold off again sometime soon and clean the valves. I'll start with soaking with CRC and then cleaning and depending on the results may go ahead and walnut blast.

pokismoki · April 11, 2021

has anyone tried locking out the VVT solenoid on the cam and disabling the Vtec in the software? then do a long term intake-valve test with NO catch can. could the oil deposits be coming from inside the combustion chamber pushing oil mist back up into the intake, during V4 DoD and the cams Vtec cycling events?

Grumpy Bear · April 11, 2021

6 hours ago, pokismoki said:

has anyone tried locking out the VVT solenoid on the cam and disabling the Vtec in the software? then do a long term intake-valve test with NO catch can. could the oil deposits be coming from inside the combustion chamber pushing oil mist back up into the intake, during V4 DoD and the cams Vtec cycling events?

It's how passive EGR works sir.

kennerz · April 14, 2021

Just an FYI my DoD has been disabled for a long time, since like 30k mi, and I'm at 87k now.

pokismoki · April 14, 2021

On 4/11/2021 at 4:28 PM, Grumpy Bear said:

It's how passive EGR works sir.

I wonder where in the ECM's file I could find and Disable the passive EGR function? I'll have to call a tuner shop if no one on here knows...

Grumpy Bear · April 14, 2021

36 minutes ago, pokismoki said:

I wonder where in the ECM's file I could find and Disable the passive EGR function? I'll have to call a tuner shop if no one on here knows...

Might want to ask what EGR does in a gasoline motor. Not the same thing it does in a diesel. It isn't there for Nox reduction. It's there to keep the cats alive. Heat management.

pokismoki · April 16, 2021

On 4/14/2021 at 8:59 AM, Grumpy Bear said:

Might want to ask what EGR does in a gasoline motor. Not the same thing it does in a diesel. It isn't there for Nox reduction. It's there to keep the cats alive. Heat management.

i thought the cats where cooled during over temp, by the ecu dumping fuel into the motor?

Grumpy Bear · April 16, 2021

1 hour ago, pokismoki said:

i thought the cats where cooled during over temp, by the ecu dumping fuel into the motor?

Fuel to cool. I haven't heard that one in a few decades. Honestly I don't know how it responds to an "over' temp.

EGR 'moderates' the heat during normal operation. Remember the fire triangle? Heat, fuel, oxygen. (chemical reaction)

pokismoki · April 16, 2021

i never datalogged it to see if its true, just stuff heard on HPT forum, not sure those guys know what they're talking 'bout either sometimes

2 hours ago, Grumpy Bear said:

Fuel to cool. I haven't heard that one in a few decades. Honestly I don't know how it responds to an "over' temp.

EGR 'moderates' the heat during normal operation. Remember the fire triangle? Heat, fuel, oxygen. (chemical reaction)

Grumpy Bear · April 16, 2021

13 minutes ago, pokismoki said:

i never datalogged it to see if its true, just stuff heard on HPT forum, not sure those guys know what they're talking 'bout either sometimes

It would be interesting to know wouldn't it? There have been allot of different strategies employed over the decades. Has to be the right mix and at the right cat temperature. The difference in complexity between pretty darn good and zero is nuts.

I won't leave these up for very long as they fill up my attachments limits.