Blow BY???

[h2odrx]

ok what is it? is it compression in the crank? if so, it is pressure getting by the rings? if so new rings would fix it? is this right or am i
thanks

 

[Roland_Jenkins]

Bob The Oil Guy knows

 

[LUCKY_LARUE60]

Blow by can be bad rings, bad valve guides, wore cyl walls, cracked piston. Just a number of things and yes compression is getting into the oil pan.

 

[Agnem]

It's the nature of the beast. I don't think there is an engine made that doesn't have blow by. The reason it's called blow by, is that it is the compression getting past the rings, or blowing (due to compression) by. Even the best rings will not seal 100%, since all rings are not a complete circle, and that opening in them is going to pass something, even if they don't let any gasses squeeze by in the ring to piston and wall sealing area.

 

[ericboutin]

I got a stupid question to ask since this has been brought up...Where do you see the blowby? I hear people talk about the dipstick tube or is it where you fill with oil or am I just

 

[argve]

Eric,

You can see it when you open up the oil fill. You will see it more so with a RDT set up like I had on The E or with Mel's Moose Truck.

You will be able to see in from any opening leading to the oil crank case - might not see it from the oil dipstick tube unless the blow by is excessive or something else is restricted not letting it out via another opening... Like say if your CDR is slammed shut for whatever reason then you would see it pretty good out the dipstick tube when you yank the stick.

 

[yARIC008]

Right after I installed my new engine I had zero blow by, well at least non that i could detect coming out the oil fill tube. After 40,000 miles or so, i have just a slight hint of some out the oil fill tube. You can only see if at night when you shine a flash light across the fill hole.

As for them all having blow by. I bet new engines don't hardly have any. Their rings are cut out by plasma lasers or something so they're perfect. I'm not sure how close they come together though, like the little gap in the rings, dunno how big.

One of my diesel mechanic friends said when he used to rebuild CAT engines if you didn't replace the rings alot of times and just installed the old rings, they'd for some reason work themselves all aligned so the gaps in all the rings would line up. Then you'd get no compression in that cylinder and would have to take it all apart again.

 

[h2odrx]

so little is good more is bad and make sure you have a rdt!!
does any one have a reclaim type setup for the rdt?

 

[yARIC008]

does any one have a reclaim type setup for the rdt?

Sure, we all do orginally from the factory, it's called a CDR :Sly

 

[Exekiel69]

If you want to do the rdt setup you can order the ip gear cover adapter from Banks $29.something with shipping and 1" hose to route it out. There is a post about this already that you can read, I will try and install something that will route those gasses through the exhaust.

 

[zigg]

Sure, we all do orginally from the factory, it's called a CDR

Is this the point where I get up on my soapbox and start to ramble as usual about my thoughts on the purpose of the CDR?

Many of us believe this thing has absolutely NO capacity to condense oil back down into the engine. Sure, it does get all oily because the oily blowby passes through it, but the volume of blowby is so huge in an old worn engine like mine, there's no way that little can does much to solve the problem.
Guys are cleaning them, and buying new ones, but that's just throwing money into the hole treating the symptom, not the problem.

Blowby is a normal common symptom of a wearing/worn engine.

There is actually a set of rings that can be had which have the ends overlap unlike the usual where there is a gap at the ends, but I haven't heard a lot of good things about their use in diesels.

If you really want to see how much blow-by your engine has, pull the fill cap, and at the same time reach down into the intake and cover the opening from the CDR valve and then all the blow-by will come out the fill cap. It can be pretty impressive.

I once tried to run a RDT, but my engine's got more blowby coming out than an old steam locomotive, and I just got tired of people yelling at me "your trucks on fire!!"

Zigg

 

[h2odrx]

ok, if i turn the CDR into a loop like a jug thing then back to the intake it should work? i had a 1.9 with real bad blowby that pushed oil out thru the breather, i added a jug and looped it back, after a few days i would unhook the jug and reuse the oil. so if i can do something like this would it work?

 

[Diesel JD]

Why fool with it..., either just use the factory CDR system, or use a RDT if other people's comments or environmental concerns don't bother you. The other option is to buya racor CCV. They are quite pricey and I don't remember the part #. I wouldn't even worry about blowby too much unless it is very excessive like puffing 3 feet in the air when you take the oil filler cap off or puffing in tune to one or more cylinders more than their brothers. I'm not trying to squahs creativity and feel free to ignore everything I say, I have just seen people cause more frustration and oil leaks than anything else by messing with it. What works for sure is
1) a straight RDT
2) the Racor CCV system
3) Factory CDR

 

[zigg]

i added a jug and looped it back,

What JD says is true. I've done the loop system with various collection systems from just a jug to 9ft of 3/4 tubing in front of the Rad(as a condenser) and it works a bit, but mostly you just create more leaks, and it's not addressing the problem, just trying to treat the symptom. My engine still uses oil regardless, and oil is a lot cheaper to buy than a rebuild...

Zigg