Suction noise after catch can install

Dereck Haugen · January 28, 2016

So I installed an rx catch can on my 6.2l and now It has an suction sound that you can hear with hood closed is this normal?

MMC · January 28, 2016

Sounds like a vacuum leak, check to make sure the drain valve is closed, the drain has left hand threads IIRC.

Coach Hill · January 28, 2016

Mine did the same thing the first time I emptied. I think MMC is correct. Make sure your drain valve is closed tightly.

Dereck Haugen · January 28, 2016

That's what I thought also so took off the can and ran hoses into each other still have the sound.

GDI Tech · February 3, 2016

Can you post pictures of all connections, etc? I can help trouble shoot for you. Also, which can did you purchase? The genuine RX or the cheap China made knock-off?

Cheers!

brokesilverado · February 4, 2016

Look & see if the hose is collapsed any at all when the engine is running. I had to get some 350 psi hose that would not then the sucking noise went away.

southern_sierra · February 4, 2016

So I installed an rx catch can on my 6.2l and now It has an suction sound that you can hear with hood closed is this normal?

I had the same thing posted way back about it. I used fuel hose, then tried vacuum hose still had suction sound.The hotter it gets the hose gets softer. So I started squeezing the hoses just a little and the sound would change. I went to hydraulic hose and solved the problem no sound at all now. Hydraulic hose is wire reinforced and will not deform any to cause restriction. If you use it get the cloth coated hose its much more flexible than the rubber coated. Be sure to measure your old hoses and get the parts house to cut the Hydraulic hose for you if not you will have to cut it with a chop saw or hack saw because of the wire.

jrob56 · February 4, 2016

I had the same thing posted way back about it. I used fuel hose, then tried vacuum hose still had suction sound.The hotter it gets the hose gets softer. So I started squeezing the hoses just a little and the sound would change. I went to hydraulic hose and solved the problem no sound at all now. Hydraulic hose is wire reinforced and will not deform any to cause restriction. If you use it get the cloth coated hose its much more flexible than the rubber coated. Be sure to measure your old hoses and get the parts house to cut the Hydraulic hose for you if not you will have to cut it with a chop saw or hack saw because of the wire.

Going to try that, i have some ovaling on mine, where did you get it? Ace, Menards, Lowes carry that?

crushNchowda · February 4, 2016

Or...you could try not putting one of these contraptions on your engine, they can create problems, and become "useless" (not that I'm convinced in the slightest they're of any benefit to begin with) the first time you forget to empty it.

Alot of what you see in the can isn't actually oil per se either - its a frothy mix of water/vapor/oil condensation. Could (ie: SHOULD) void your warranty too if you have an issue down the road, not like the dealer can't see the hoses/lines/can and crap all up in there

southern_sierra · February 4, 2016

Or...you could try not putting one of these contraptions on your engine, they can create problems, and become "useless" (not that I'm convinced in the slightest they're of any benefit to begin with) the first time you forget to empty it.

Alot of what you see in the can isn't actually oil per se either - its a frothy mix of water/vapor/oil condensation. Could (ie: SHOULD) void your warranty too if you have an issue down the road, not like the dealer can't see the hoses/lines/can and crap all up in there

Mine has not caused any problems. I change my oil every 5k and empty the cam at 2500 miles and will only be about a 1/4 full. When I went in to my dealer to get the headlight bulb update at about 1200 miles (12k now) the tech asked me what the can was told him he said good idea also the shop foreman said good idea. These direct injection engines need all the help they can get since the valves are not washed anymore with gasoline. Notice the tail pipe on these trucks not clean like the older ones. Just my 2cents worth.

southern_sierra · February 4, 2016

Going to try that, i have some ovaling on mine, where did you get it? Ace, Menards, Lowes carry that?

Got my hose at a Case IH tractor dealer. I'am a farmer and live in a small farm town so the parts houses also keep the hoses. You could try a napa.

GDI Tech · February 4, 2016

Or...you could try not putting one of these contraptions on your engine, they can create problems, and become "useless" (not that I'm convinced in the slightest they're of any benefit to begin with) the first time you forget to empty it.

Alot of what you see in the can isn't actually oil per se either - its a frothy mix of water/vapor/oil condensation. Could (ie: SHOULD) void your warranty too if you have an issue down the road, not like the dealer can't see the hoses/lines/can and crap all up in there

Huh? A proper closed system can cannot by law have any effect on the warranty, but that is only the few that are designed and installed properly. As they prevent so many damaging issues, there is no downside.

The water/unburnt fuel/sulfuric acid/abrasive soot/carbon/ash all are what these are removing from the crankcase where it otherwise would settle and mix with the engine oil causing contamination and greater wear. These vehicles are mass produced and corners are always cut to be competitively priced. These are not $200-$500k supercars that DO run these systems from the factory.

Letting your engine ingest this mix (along with the oil mist) is not ever good in any way. It is something the automakers tolerate.

All great info in the other reply's. Fuel line is too soft of a sidewall and can collapse under vacuum. Emissions rated vapor hose, or hydraulic hose has a far stiffer sidewall.

15 Z71 · February 5, 2016

So what happens to these motors if you just change the oil and put gas in them? Their not going to last to long? After reading all this stuff I should have just kept my 2006 Silverado. 108,000 never one problem with the 5.3. Sure seems like a lot of headaches for a 45,000 dollar truck.

jrob56 · February 5, 2016

So what happens to these motors if you just change the oil and put gas in them? Their not going to last to long? After reading all this stuff I should have just kept my 2006 Silverado. 108,000 never one problem with the 5.3. Sure seems like a lot of headaches for a 45,000 dollar truck.

Itll still last till 150k+ probably without major issues but itll be down on power, idle rougher, and rough starts. Still need to do scheduled maintenance though.

GDI Tech · February 5, 2016

So what happens to these motors if you just change the oil and put gas in them? Their not going to last to long? After reading all this stuff I should have just kept my 2006 Silverado. 108,000 never one problem with the 5.3. Sure seems like a lot of headaches for a 45,000 dollar truck.

Port injection engines eliminated all intake valve coking the old carbureted engine used to experience, so you never had to deal with it in the past.

By 20-30k miles we are seeing intake valve guides already worn beyond acceptable tolerances and oil consumption rises. Unstable valves usually only become a problem at higher RPM.s

The money lost on the reduced fuel economy is a bummer, and over time as these hard crystalline deposits break loose, some of the smaller ones can be forced between the piston and cylinder wall causing scouring which compounds the issue allowing more blow-by.

After 50k or so miles chunks large enough to get trapped between the valve and seat can come loose, and if that occurs the pistion makes contact with the valve and bends it like this picture shows:

So overall longevity of the engine as a whole goes down. There are still examples of some with 100k miles and still running, but not well.

Clean the vales and put on a good separation system and then every 10-15k miles do your own CRC/Seafoam treatment for less than $10 and you will have as long of trouble free life as before. These dual evacuation suction systems also improve the function of your PCV system and your oil will remain clean far longer as well reducing wear.

Itll still last till 150k+ probably without major issues but itll be down on power, idle rougher, and rough starts. Still need to do scheduled maintenance though.

I think cared for these can go 200-300k miles, but not if neglected unlike the port injection engines that I have otrn down at 150-200k miles plus and not a spec on the valves:

There will be some though that still run good enough like you state.

On hose, look at any auto parts store for 3/8" transmission cooler hose. It is stiff wall.