offdensen Posted May 18, 2017 Share Posted May 18, 2017 My pcv valve is rattling on my 63 with a 401 and I was wondering what others have experienced with this? I am using one I got from oreillys. The one that was on the car was the same and I replaced it because it rattled too. At that point I assumed it was normal but now I got some time on my hands so I figured I would see if there was anything I could do about it. If the rattle is avoidable I would like to ask what part number or brand you are using? And yes, it is installed correctly. It only does it at idle. Link to comment Share on other sites More sharing options...
RivNut Posted May 18, 2017 Share Posted May 18, 2017 It's supposed to rattle until some vacuum is applied to it. That's how you check to see if they're good. Link to comment Share on other sites More sharing options...
Seafoam65 Posted May 18, 2017 Share Posted May 18, 2017 (edited) Try replacing the vacuum hose that goes to the pcv valve with a new one and report back. A restricted hose that is coming apart internally can cause this rattle. As a matter of fact I had one in my shop last week that was rattling and a new hose fixed it. Edited May 18, 2017 by Seafoam65 (see edit history) Link to comment Share on other sites More sharing options...
offdensen Posted May 18, 2017 Author Share Posted May 18, 2017 1 minute ago, RivNut said: It's supposed to rattle until some vacuum is applied to it. That's how you check to see if they're good. So it's normal? Just seemed pretty loud. Link to comment Share on other sites More sharing options...
RivNut Posted May 18, 2017 Share Posted May 18, 2017 It should only "rattle" when you're shaking it, now when it's on the car. Link to comment Share on other sites More sharing options...
offdensen Posted May 18, 2017 Author Share Posted May 18, 2017 (edited) 52 minutes ago, Seafoam65 said: Try replacing the vacuum hose that goes to the pcv valve with a new one and report back. A restricted hose that is coming apart internally can cause this rattle. As a matter of fact I had one in my shop last week that was rattling and a new hose fixed it. I will stop by a parts store on the way home and try this out. Will report back my experience later tonight. I also have cruise control and there is a t in the line between the valve and the carb base, so I guess I will replace everything. Can't hurt. And to clarify, yes this is a problem when the car is running at idle. Edited May 18, 2017 by offdensen (see edit history) Link to comment Share on other sites More sharing options...
Seafoam65 Posted May 18, 2017 Share Posted May 18, 2017 Basically, the PCV valve needs a very large strong vacuum to work properly, If you take the valve off the end of the vacuum hose you should feel an extremely strong suction. If you don't, that is your problem. When the vacuum is restricted or weak, the valve will "chatter" at idle. Is this "T" in your vacuum line a factory setup? Generally it is not advisable to siphon off any vacuum from the PCV line. They usually have their own designated hose from the factory with no "t" anywhere. Link to comment Share on other sites More sharing options...
telriv Posted May 19, 2017 Share Posted May 19, 2017 On most "Nails" there is a T off the back of the carb. for the PCV valve & the pwr. brake booster, but once the booster is full of vacuum it is NO LONGER robbing vacuum from the PCV valve. The rattling could be caused by a vacuum leak, a carb. not adjusted properly, idle speed too low, timing not correct & a host of other problems. Tom T. Link to comment Share on other sites More sharing options...
offdensen Posted May 19, 2017 Author Share Posted May 19, 2017 That is how mine looks. My brake booster connects to the front of the engine where is says Nut 100-150. I put new hoses on everything touching the T connecting to the pcv. I can go to the store tomorrow and buy more hoses for the brake booster and vacuum resovior. Idle is at 480rpm. Link to comment Share on other sites More sharing options...
RivNut Posted May 19, 2017 Share Posted May 19, 2017 On the 63, there is a port in the front of the intake that supplies vacuum for the power booster and the a/c. It's been a long time since I've been under the hood of my 63 so I'm other sure where the other hose coming off the T goes. It may have been too long gone, I may be completely wrong. Link to comment Share on other sites More sharing options...
1965rivgs Posted May 19, 2017 Share Posted May 19, 2017 (edited) The first time I came across the cruise "teed" into the PCV vacuum hose I was sure someone had done some rearranging as I would personally not arrange the vacuum lines in that manner. I was accustomed to working on the dual quad setup which has the cruise connected directly to the carb base. But after running across a second car with the cruise "teed" into the PCV line I checked the shop manual and found the illustration pictured in this thread. This is factory correct, I have seen it many times since on original cars, Tom Edited May 19, 2017 by 1965rivgs (see edit history) Link to comment Share on other sites More sharing options...
offdensen Posted May 20, 2017 Author Share Posted May 20, 2017 Replacing all hoses significantly reduced the rattle. Thanks all. Still curious as to what valve everyone uses, though. Link to comment Share on other sites More sharing options...
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