Toyota Nation Forum banner

5sfe engine blows air out oil fill cap?

15812 Views 5 Replies 3 Participants Last post by  snoopmo
Got a 92 camry with 260,000 miles on it and when it idles I took the oil fill cap off and it blew air out of there, not smoke or anything just clean air. It made me wonder so I did a quick compression test and came up with 180psi on all cylinders and it doesn't appear as though it burns oil. I've only drivin it about 50 miles. I got it with a bad tranny, rebuilt that and just got her going tonight. Does this seem like something I should be concerned with? It seems to run just fine and idle smooth, just the air blowing out of the fill cap seems odd. I work on mostly v8 engines and they don't do that.
1 - 6 of 6 Posts

· I work on euros.
96 Toy Camry Sport
Joined
·
207 Posts
that air is aptly called...blowby. means the rings aren't doing 100% of the sealing, which is normal. the VOLUME of air coming out tells you how bad it is, but if you got good compression on all cylinders, you really should just make sure you've got a new pcv valve and the breather line is clear of blockages. If you work on mostly older v8's, they have breathers on each valve cover to vent the gases to atmosphere. we don't do that because then you're venting gas fumes from the blowby, and hydrocarbon pollution is socially irresponsible. now we put it back into the intake for the environment and the mpg bump, mostly the environment tho.

anyway, if you only have a little blowby, no biggie. if you can set a hat over it and it floats, it's bad. if the car runs smooth, hey, just make sure it vents back to the intake and forget about it. no biggie!
 

· Registered
Joined
·
56 Posts
Discussion Starter · #3 ·
o.k. ya most of the time "blowby" as I would call it would put out kinda a white smoke to it from the compression gasses getting into the crankcase. I work on mostly all v8 engines and what not. I know all about breathers. When I overhaul a engine I always check them. All of them have non. Even most high mileage engines doen't have any, or very low amount with pcv valve out and valve cover hole pluged and looking through other valve cover hole. This thing seems to have a lot. No a hat wouldn't float on it, but I'd consider it a healthy amount. More than any worn v8 i've ever seen. Thing is I work at a shop and work on these things all the time and it seems like i see a lot of them like that. I was just wondering if it's a common thing or not? maybe it's in the design of the engine that as the pistons move up and down it creats a pulse in the crankcase, where something about the crankcase design of a v8 doesn't create that kinda turbulance. I guess I'm not worried about it to much, just curious if it's a common 4 cylinder thing or something? The more I can learn the better. Thanks guys!!!!:clap:
 

· I work on euros.
96 Toy Camry Sport
Joined
·
207 Posts
smaller crankcase volume means it's easier to notice, there shouldn't really be any pulse in the volume of the crankcase. there is a pulse to the blowby, but that's from the peak cylinder pressure versus times between compression strokes. It seems to be fairly common to the S block motors, and I don't think it causes any problems.
 

· Registered
Joined
·
3 Posts
Hey BL, I saw your old post concerning the blowby in a 4 cylinder Camry. did the car keep running for you? I just noticed the same thing on my 93 camry, no other problems, lots of air pressure out of the oil cap.
 
1 - 6 of 6 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top