My new summit carb works great, but my old PCV valve now whistles loudly. I replaced it and the no change , but slightly different tone.

I clamped both ends of the hose... no change.

I can pull the valve out of the tight fitting grommit, plug it with my thumb and it stops.

I can't believe that the grommit might leak because it's so tight.

Has anyone had air suck in from around the valve cover before?

 

if the noise stops when you plug the pvc not installed in your valve cover, probably not suckin in thru the v/cover, besides , valve covers only keep oil from going all over the place, the internals of the engine are not sealed. I vote pvc. was your 2nd pvc used also?

 

Both the old and new pvc make the sound.

I too, have a hard time thinking that the valve cover would whistle like that, but I'm running out of options.

It is a pretty loud tone, and hard to track down. The motor is also very loud anyway.
I may try putting a piece of pvc pipe next to my ear to try and track it down.

Thanks

 

So, what is it that you are trying to tell us? You switched to a new carb, made no other changes, and now the pcv valve whistles? That's pretty weird, man. Have you checked what your manifold vacuum is? Is it different with the new carb, maybe? Might need some carb adjustments. if your manifold vacuum is different, it will be drawing on the pcv valve differently. How about, just for giggles, play with the idle screws until vacuum goes down a couple inches, and see if that has an effect on the sound from the pcv? It's not a fix, but it might give us some info we can work with.

That's about all I can come up with, I know it's kind of a stretch, but, hey, it's worth checking on unless someone else can come up with something better, right?


Keep the shiny side up!
Scott

 

The motor runs much better with the new carb. I am happy with the performance. It just sounds like a turbo winding down after I shut it off.

It must be air being pulled in somehow, but I'm pretty sure the system is leak free.

I was hoping it had happened with someone else.

I don't have a vacuum gauge but the pull from the PCV is significant.

I'll try the idle mix screws. thanks

 

Is the other valve cover vented?

 

I also have a whistling pvc valve, more of a clicking/fluttering sound.
Car runs great, no vacuum leaks, have tried 3 different brand of pvc's with some success in reducing the noice.

Drivers side cover is vented and pvc is in pass side , just putting finger over pvc inlet stops the noise. Getting 19-20 of vacuum.

 

Too big of opening at the PCV fitting at the carb base, too much flow. If you look at the online cataloges there is a fitting that screws into the carb base for a 63 corvette with a 1/8 inch hole that the hose hooks to. Reduces the flow but still functional.

 

I had a horrible noise almost a bearing squeal when the motor warmed up, removed all belts, still had the noise. Removed the air cleaner and heard the noise from a small hose coming from the drivers side PCV valve, grabbed the hose and the noise stopped. Also checked the hose to the base of the carb, soft and cracked. Replace both hoses, $4.00, and the noises stopped.

 

This is wrong... the engines rotation makes for a semi vacuum pump, ,,, so that the passenger side will more often than not have a negative pressure, where as the drivers side will go positive. The PCV valve is made to look at the pressure difference between the vacuum in the manifold and the pressure in the crank case.. when there is both enough pressure and vacuum then the valve opens and lets the oil fumes to be sucked into the intake manifold and out the tail pipe.

No the problem... on a stock engine the vacuum and pressure have been measured and thus fitted with the proper PCV valve.
BUT once we start modifying our engines the PCV valve we have no longer is correct... Thus the reason for an aftermarket unit like the one in the link below...
If you run the wrong PCV valve you will eat oil like it is gas!


http://mewagner.com



Benefits:
• Fully tuneable to your engine combination
• Adjustable flow rate can be tailored to your engine’s setup, allows controlled incremental flow rate changes
• Adjustable vacuum transition level can be tuned to your engine’s unique vacuum profile
• Properly ventilates crankcase, resulting in cleaner oil and cleaner engine internals
• Reduces crankcase pressure, which is often the cause of oil leaks
• Eliminates in-car oil smell while driving
• Works well with air-oil separators
• Reduces emissions
• Reduces moisture and acidic vapors in your engine’s crankcase
• Vacuum gauge tuning method ensures PCV system is set properly for your combination

 

Hey pauldana, I never did see the results on that PCV that you got. So it solved the oil consumption problem I'm guessing?
Must be pleased with it if you are recommending it.

Do you think it is worth the money for a modded engine even if oil consumption is not a problem?

 

I agree with the concept of reducing the opening to reduce flow, but in other cases why cant we just select a valve with the smaller opening?

Like from a 4 or 6 cyl car...Yes I have heard of the variable valves

 

I actually just put it on 2 weeks ago, and yes, so far oil consumption seems to be almost gone. I will have a better review on this in 2 months, as I feel this is a proper amount of time for this test.. but beyond this, the engine seems to run smoother at idle and cruse....

I can see why this is needed...

pricy? yes... would I buy it again? yes now... ask me again in 4 weeks.

 

Thanks.
Lets us know what you think in a couple of months. I'm intrigued by the design, just not enough to lay down the coin if there is little for me to gain.

 

Have to ask again if anybody has had luck using an off the shelf PCV to cure oil consumption or better idling. Especially with a bigger cam than stock!

 

I bought the Wagner PCV valve 4 years ago, I always had a problem with oil seeping around oil pan, valve covers, front and rear seals. Since installing it and setting according to the instructions I have not had a drop off oil anywhere and no more oil consumption problems.

Worth every penny that it cost!

 

Another believer and owner of this PCV to control air flow.