I boosted a d15b in my 94 hatch for ***** a giggles and noticed there a little white smoke coming out of the breather filter on the valve cover. Is this normal on a boosted car? It seems to only do it at idle, not much smoke though. It doesn't smell like oil or antifreeze burning and I have been checking my fluids everytime I drive it and nothing is moving. It almost smell like gasoline, like it's running rich, but I can't figure out why it's coming out of the valve cover breather. My guess are my rings are starting to go out so I'm getting blow by, or maybe my pcv valve is fubared. Any info is greatly appreciated. The set up is a d15 with a t3/t4 50 trim on 8 pounds. I know I know, I am anticipating blowing the motor up, but she's still running strong, I'ma try to do a compression check tonight on it and see if maybe the bad ring theory's there. Let me know what you guys think.

 

bump

 

Ringlands

 

if its not alot i wouldnt worry about it. if it get strong smelling and smokes more then ya.. somtimes a comp test wont tell if u have a problem .. but its a place to start

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by turbovt &raquo;</TD></TR><TR><TD CLASS="quote">Ringlands </TD></TR></TABLE>
x2, happened to my last turbo'ed motor

 

My H23 puts out a little smoke. I think it's normal unless it's like really white.

Video:



That is from my crappy catch can....

 

1. get rid of that filter cause its a restriciton - theres should never be smoke out the valve cover, never during idle.
2. its probably too late as your crankase is getting pressurized - piston seals.

 

For the most part i am guessing its blowby. My car did kinda the same thing and it got worse and worse. When i pulled the motor it hade 3 cracked pistons.

 

so take the breather filter off and just run nothing there?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by turbovt &raquo;</TD></TR><TR><TD CLASS="quote">Ringlands </TD></TR></TABLE>that's what happened to my d15b

 

First off do you have a catch can set up? If not then this may be the cause of the smoke and it may be too late. Off the top of my head i can say that a Cylinder Leak down test would narrow it down quite a bit. Compression test is fine too, just harder to find out when your loosing the compression at??

 

The only thing a catch can will do when compaired to open breather filters is 'catch' the unburnt oil/fuel vapors and condense them before they hit the atmosphere. 2 lines going to a can with a filter will not magically create suction. Its the fact that catch cans usually use that pcv/black box hole and a slashcut that makes them work. You could run a line from the black box and/or valve cover breather to a slashcut and get the same effect.

Anyways, as mentioned, its most definately blowby caused by bad ring seal and/or cracked ringlands. The smell of fuel in the vapors is the air/fuel mixture leaking out of the cylinders as they compress the charge. I always forget exactly how the valve in the pcv valve works, but I believe that the pcv valve is mostly closed under high vacuum (idle), meaning anything besides idle will open that valve, and let the pressure escape through the valve into the intake.

 

Ok we're talking only a "little" smoke here. If the motor is built for boost, then chances are you have slightly bigger ring gaps then stock. For example my top ring is .019" and second ring is around .021"... I forgot the stock gaps but I know they are smaller. This is to allow a little more blow by then normal so pressure does not build up too much between rings.

Having said that, and assuming my statements are correct, the small amount of visible vapors from the catch can breather should be ok.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by turbosi03 &raquo;</TD></TR><TR><TD CLASS="quote">Ok we're talking only a "little" smoke here. If the motor is built for boost, then chances are you have slightly bigger ring gaps then stock. For example my top ring is .019" and second ring is around .021"... I forgot the stock gaps but I know they are smaller. This is to allow a little more blow by then normal so pressure does not build up too much between rings.

Having said that, and assuming my statements are correct, the small amount of visible vapors from the catch can breather should be ok. </TD></TR></TABLE>

Bingo. I don't know why everyone on this board has the misconception that a little smoke out the breather is a bad thing. That means the breather is doing its job. Now, if the smoke is excessive, then you may have a problem. My D16 has looser piston-to-cylinder wall clearances for boost and it has been smoking from the breather a little for years and it is perfectly fine.

 

This is a pretty sure sign of damaged ringlands.... it should not smoke at idle at all, maybe some at WOT, but smoke at idle is a pretty sure sign of busted ringlands....however, the car should still drive and might actually last for quite a while. My b16 smoked like a chimmney at idle and i boosted the hell outta it for another 2 months b4 she finally went boom. start looking for pistons/rods/bearings

 

its the rings or headgasket.

 

Those saying any smoke at idle is bad. Have you ever removed an oil cap from a car after it has been running for a while? There is going to be steam or oil vapor coming out the oil fill hole. As long as you are not getting any more smoke out of your breather then you do on a stock honda after it is hot then you do not have problems.


Modified by sp00led at 2:12 PM 3/9/2007

 

Smoke and steam or oil vapor are different things. If its clearly visible smoke. Your ringlands are going, it'll get worse, just wait. If its almost clear air being pushed out, thats completely normal on any motor.

Some guy measured all this stuff before. And its like +.25psi at idle, some vacuum at partial throttle driving, and I thnk postivie pressure at WOT. Anyways, he measured both crankcase and valve cover, I'll see if I can find it, but its completely normal for positive pressure to come out the valve cover.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sp00led &raquo;</TD></TR><TR><TD CLASS="quote">Those saying any smoke at idle is bad. Have you ever removed an oil cap from a car after it has been running for a while? There is going to be steam or oil vapor coming out the valve cover hole. As long as you are not getting any more smoke out of your breather then you do on a stock honda after it is hot then you do not have problems.</TD></TR></TABLE>

whether its ok or not, crankcase is getting pressurized and theres blowby. it is what it is, and it might work for a while but if its major blowby and major oil loss i'd be worried about contamination of engine parts.

one way to extend the life of the engine is to get additional valve cover vents cause it will help reduce the pressure. after rebuild, it would smoke slightly under high rpm + wot.. but it stopped after adding additional vents.

very little of that would matter on stock cars, they run stock hp, daily driven and don't see the type of pressure that you do on a boosted honda.

 

Same thing happened on my Z6.....Ringlands FTL

 

ha I got you guys all fooled. So here's the deal, I guess i neglected to mention some things cause I thought they weren't related. When I bought the car, it had a broken timing belt. So I had an extra timing belt laying around and we put it on and the car started right up, perfect right? Wrong, on the number one cylinder the lash was a little loose compared to the rest and we didn't think anything of it besides it was just typical honda loose lash. Well, I did my compression check tonight, and guess which cylinder only gave me a compression of 70 psi. Good old number 1. My guess is that the valves are a hair bent and not fully seating. This could be the reason I am having the blow by. All the other cylinders read 150 psi. So this is my theory. Any takers that beleive my idea lol?

 

rings buddy had that problem oil started to hit his headers in the back and his car caught on fire

 

I appreciate all the responses to my problem. Thanks a ton. I am gonna end up swapping my sohc zv non v-tec head that I just got back from the machine shop on it and see how she does. milled, port and polish, reseated, sshould help spool that big turbo a little faster lol. Thanks for the input guys.