smoke out of the beather
 

question on my PVC system.

when the engine is cold I get air being pulling into the valve cover breather.
On the other side valve cover I have a new PVC that is connected to the back of the carb.
Once the engine reaches temp I get smoke coming out of the breather and oil dipstick when it's pulled.
I'm guessing that I'm getting blow by after the it warms up and tolerances open up a bit?
I'm also guessing this means I'm due for an engine build.
Any other thoughts or things to try first?
Thanks,
Mark

Re: smoke out of the beather
 

Sounds like simple blow by to me, I have the same problem, and believe me it gets progressively worse, haha. There are a number of things you can do to prolong the inevitable, such as additives that some people swear by, but it sounds like it is time for a valve job, a rebuild or a new engine.

Me, I am looking for a new engine. My blow by is so bad that I installed a road draft tube just so I can move it from place to place without filling the cab with smoke...

Re: smoke out of the beather
 

Look into doing a compression check on all cylinders. Blow-by is typically caused by worn rings and dry and wet compression checks will help determine if it is bad rings.

I think you are right in your assumption, but better to do the checks first. It could just be a bad PCV system, but smoke in the crank case (not just oil mist) is not a good sign.

Re: smoke out of the beather
 

Definitely do a compression check to determine what your issue is. ASS U ME anything is a fools game and can cost a lot of waisted dollars.


A couple of items:
- Simple first, pull the pcv valve and check that you have good suction to the carb.
-Do you have an aggressive cam? ie reduced manifold vacuum.

-Do a complete compression check to determine the status of your engine.
- if it is a ring issue, a) start saving money for a new engine
- you can try using thicker oil (ie 50W), but it won't help a lot on a long drive.
- you can vent into a catch device instead of your carb to reduce smoking etc and drain it back into your pan. Kind of a pain, but if you a blowing a ton of oil it works. I would only do this if you are fouling plugs every couple of weeks.

PS> I think GM uses a Positive Crankcase Ventilation system, not sure what a PVC is :-)

Re: smoke out of the beather
 

It’s a stock engine and tired so definitely due for a rebuild or replace I’m sure. Mileage unknown.
I’m going to do that next winter but wanted to drive it this summer.
I considered a hose to dump it below the cab.
My compressor tester quit reading but will pick up a new one do that test next.
I have good vaccum at back of carb hose.
So after engine gets hot blow by increases past what the vacuum can pull thus pressurizing the oil pan and pushing out the breather?
I did try a thick additive. Rilestone?
Already running 40 weight oil. She’s definitely due for a rebuild.
Thanks for all the info

Re: smoke out of the beather
 

I’ve used this stuff to keep a motor going.



https://autoplusmart.com/lubricants-...sl-400-ml.html

You could try a pcv like this.


http://mewagner.com/?p=444

Re: smoke out of the beather
 

During an oil comparison test it was determined that 10w40 caused rings to stick. This test was run by Oldsmobile Engineering. I worked there. So after that they recommended that you stop using 10w40 oil. I haven't run it since then. Now all of you people that swear by 10w40 can tell me that its great for your engine.

Re: smoke out of the beather
 

Run 15w40 diesel oil in almost all my motors and have no ring sticking issues. Diesels or gas.

OP. Some blow by is normal. Does it sellte down with the breather pulled for a few minutes? I ran into this on my truck recently. It would actually cause the valve covers to leak. Turned out that the aftermarket valve cover breather had clogged and just needed replaced. New breathers and issue solved. I do not have the carb connection for burning rhe vapors.

Re: smoke out of the beather
 

Sounds like your engine it beat, and blow by is your problem.

For others, something as simple as not having baffles in their new valve covers can make a mess.

Re: smoke out of the beather
 

Thanks for all the replies and info. Good stuff always here.
I’m gonna drive it this summer and see if she holds up.
Rebuild or replace the engine over the winter
Thanks!
Mark