Oil vapor...is this normal?

[c2computer]

I have what seems like a lot of oil vapor coming out of my breather hose on my driver side. Is this normal? It is a newly rebuilt engine from the block up. I had it before in my old engine also but I figured I would ask. Any ideas would be much appreciated.<br><br>I am running 302, 289 heads, 10w30 valvoline, high volume Milodin oil pump

 

[76Broncofromhell]

10w-30 is waaaaay too light for a 302 in California. Chances are you went to Kragens and they told you to run that. I would use 20w-50. As far as the vapor, do you have a PCV valve hooked up? That will usually get rid of that.

 

[c2computer]

I have always used 10w30, what do you recommend 20w50? <br><br>As far as the PCV valve, I don't want to run that to the carb... I run a breather straight out to the front of the truck. What about replacing the breather with the pcv valve and still letting it out to the corner? I am smog exempt and don't want that vapor getting the carb dirty.

 

[JMurray]

If your engine is BRAND new it could be blowby, which will go away once the rings seat. Usually in 500 miles.<br>Another thing, if youre not using stock valve covers, the covers might not have baffles in them.<br>Is there oil actually dripping out or is it just vapor comming out?<br>Jerry

 

[wildbill]

:-U :-U :-U Hook up your PCV valve it wont hurt the carb. it go's in the bottom of it and is like a good thing keeps the crap from staying in the motor and 10/30 will work on a new motor with no problems . but as was said it is hard to do the new motor recmand 5/30 oil and you will have some blow by on a new and old motor good luck. ;D ;D ;D Bill 8) :

 

[c2computer]

Thanks. I have Edelbrock valve covers, they have the baffles in them. It seems like almost water like, mixed with oil. I ran straight 30 in it to break it in and changed to 10w30 now. <br><br>wildbill, you recommend running the pcv valve back to the carb? I originally did this and the pressure in the system made a lot of oil come out of the dip stick tube since it doesn't seal well.

 

[Guest]

The PVC valve should be hooked up to the large vacume port and no breather cap should be used.

 

[c2computer]

Ok, so like I had it before, to the large port on the front of the carb?

 

[Yellow75]

Yup that's where I have mine run to..

 

[c2computer]

Does it hurt to run it out to the corner of the truck, just like a breather cap?

 

[JMurray]

I guess I didnt see the message about your lack of a PCV valve. You are better off using the valve as it removes combustion "leftovers" in the crankcase. One of those leftovers is raw fuel & it can thin your oil prematurely, which would cause more wear. Of course you could change oil more often.<br>The vapors go into the intake manifold under the carb so it will not get it dirty. I would keep the valve, my 2 cents. <br>Jerry

 

[c2computer]

Ok, so you don't stick it into the carb at the bottom of it? It seems to pressurize the system a lot.

 

[alex69eb]

Don't run a breather with the pcv hooked up! I'm starting to get confused also now. the pcv hose should be hooked to the large vacuum port on the carb.

 

[c2computer]

Yeah, I have one breather on the passenger side routed out to the ground. The other is also doing the same. It seems to run fine this way but the vapor is a little annoying. If the vapor is not a bad thing why not leave it this way. <br><br>I see what you are saying though, run a pcv valve with the hose going to the carb. What do you do with your othe side?

 

[Rustytruck]

Hook pvc valve in one valve cover and run the hose to the base of the carb. go to the other valve cover and hook a hose to it and run it to the air cleaner on the filtered air side. Enging vacuum sucks through PVC valve and draws spent blowby gass and hot vapor into intake to be burned. fresh filtered air enters crankcase to relive vacuum pressure and create an air flow path. If you dont do this the moisture in the air condences in the oil and turns to an acid base which is hard on bearings. as engine warms up water is turned into steam and is sucked through the PVC system and burned in the combustion chamber. Venting into the air will not remove the water vapor and also leaves a path for grit and dust from the roads to grind up your engine from the inside. Race cars dont use PVC systems because of the minor HP loss but they change their oil all the time and their engines dont last 150,000 miles.

 

[c2computer]

Thanks. Well here is my real problem. I had that hooked up that way but it seems to pressurize the system too much. I mean, I have oil spooing out the dipstick and it appears out the back somewhere near the rear main seal. I know this sounds crazy but I drove to 7-11 yesterday and when I came out I had a puddle of oil under my truck. Not to mention it was covering the bottom of my truck. Do you have any ideas on why this is? I did not have this problem with my other engine. Thanks.

 

[JMurray]

Man, for the life of me I cant figure hou you have pressure comming out of the PCV connection at the base of the carb. Do this, pull off the hose at the PCV & put your finger over it, is it sucking or blowing. If you have air comming out of that hose then it is not hooked up right.<br>Jerry

 

[Rustytruck]

Does this engine back fire the only way that you can get pressure in an intake is if something is broken or out of time. Are you useing the right dipstick for your engine? maybe over filling the oil system? This is a confusing problem as it doesn't make sence. Something is wrong and you will have to back track everything you have done with this engine to solve it.

 

[Mikey]

Hate to get involved this late in the game but...I built a 68 Cougar and my 74 Bronco. I like the fancy valve covers with the open element air cleaners. Both vehicles have this. Here's the trick....put a breather on the drivers side and hook up the PCV valve up to the passenger side and to the base of the carb. The trick? You MUST use a PCV valve for a 66 Mustang! ;D<br><br>74 stock PCV valve wants to see one side at the base of the carb and the other attached to the filtered air cleaner. When you go to the system I mentioned above, the PCV valve is now out of calibration for that and you get oil vapor everywhere. Give it a try, it works! And, it's cheap!!!

 

[c2computer]

Yeah I know this problem is strange, belive me I know. Yes, the hose coming from the pcv valve from the driver side valve cover does blow out vapor. I was told to hook this up to the base of the carb and the other side to the air cleaner. I did this and oil came out of my dipstick and the pan, trans, etc. was covered in oil. Maybe I am missing something but this is a brand newly rebuilt engine and I did not have this problem before. I am taking it back to the engine builder today and he is going to look at it. <br><br>I have heard of the trick with the Mustang PCV Valve, at this point, 5 months messing with a new engine I will try anything. Thanks.