| ![]() | ||||||||||||
| |||||||||||||
|
|||||||
![]() |
|
|
|
LinkBack (1) | Thread Tools |
|
|
#1
|
|
Regular
Join Date: Mar 2007
Location: Orange County, CA
Posts: 53
![]() iTrader: 0 reviews
|
Pressure in my valve cover!?
Anybody know why Id get a ton of pressure buildup at higher rpms in my Valve cover (PCV side)? Doesnt happen on the other side, and my PCV is new and check out ok. Could this be rings that arent sealing and at high revs the pressure gets too high? It blows out my valve cover gasket and you hear a "whistling sound" until it idles again. Gets some oil on my intake too. The other side has a breather and seams to be ok. Im stumped.
__________________
1964 Falcon Sprint 4 speed 1965 347 Cyclone 4 speed, B/FX clone 1993 Mustang Cobra (red/grey cloth) |
|
| Sponsored Links | |||
Advertisement | |||
|
|
#2 |
|
MM Fanatic
Join Date: May 2007
Location: Bloomington, IL
Posts: 4,737
![]() ![]() ![]() iTrader: 0 reviews
|
get a new breather
__________________
88 GT CHI headed 351w 10.8 @ 125 - still figuring it out. 03 Cobra 2.3 whipple 10.7 @ 129 - sold it 04 Mach 1 12.7 @ 109 mostly stock - sold it 89 LX procharged 302 515 hp 497 ftlbs 10.7 @130 mph - sold it
|
|
|
|
#3 |
|
Regular
Join Date: Mar 2007
Location: Orange County, CA
Posts: 53
![]() iTrader: 0 reviews
|
breather tests fine. Any other ideas?
__________________
1964 Falcon Sprint 4 speed 1965 347 Cyclone 4 speed, B/FX clone 1993 Mustang Cobra (red/grey cloth) |
|
|
|
#4 |
|
MM Fanatic
Join Date: May 2007
Location: Bloomington, IL
Posts: 4,737
![]() ![]() ![]() iTrader: 0 reviews
|
If your breather works fine, then you have no pressure under the valve cover.
__________________
88 GT CHI headed 351w 10.8 @ 125 - still figuring it out. 03 Cobra 2.3 whipple 10.7 @ 129 - sold it 04 Mach 1 12.7 @ 109 mostly stock - sold it 89 LX procharged 302 515 hp 497 ftlbs 10.7 @130 mph - sold it
|
|
|
|
#5 |
|
Enthusiast
1989 Mustang LX
10.98@126.7 NA
Join Date: Feb 2008
Location: N.E. Ohio
Posts: 698
![]() iTrader: 0 reviews
|
Crankcase and inside of valve covers (both sides) are in common atmosphere. Pressure is the same. Ring blow by comes out the bottom of the cylinder into the crankcase.
__________________
Never fast enough.
|
|
|
|
#6 |
|
MM Fanatic
|
sounds like valve blow by.... take a compression reading of the problem bank.
|
|
|
|
#7 |
|
MM Fanatic
Join Date: May 2007
Location: Bloomington, IL
Posts: 4,737
![]() ![]() ![]() iTrader: 0 reviews
|
IF you had enough blow by, either from rings or valve seals, that a valve cover breather wasn't enough to vent (figure more than 200 cfm), then you would have more serious problems than a leaking valve cover gasket. Like burning 2 quarts of oil a day.
__________________
88 GT CHI headed 351w 10.8 @ 125 - still figuring it out. 03 Cobra 2.3 whipple 10.7 @ 129 - sold it 04 Mach 1 12.7 @ 109 mostly stock - sold it 89 LX procharged 302 515 hp 497 ftlbs 10.7 @130 mph - sold it
|
|
|
|
#8 |
|
MM Fanatic
Join Date: May 2007
Location: Bloomington, IL
Posts: 4,737
![]() ![]() ![]() iTrader: 0 reviews
|
In this case, he has breathers and a PCV, so everything should be at atmospheric pressure or slightly below. The only way to have positive pressure would be if there was so much blow by that the breathers couldn't vent it, if that was the case, there would be a serious problem with more symptoms.
__________________
88 GT CHI headed 351w 10.8 @ 125 - still figuring it out. 03 Cobra 2.3 whipple 10.7 @ 129 - sold it 04 Mach 1 12.7 @ 109 mostly stock - sold it 89 LX procharged 302 515 hp 497 ftlbs 10.7 @130 mph - sold it
|
|
|
|
#9 |
|
MM Fanatic
|
are you sure your motor isnt constipated?
|
|
|
|
#10 |
|
Regular
Join Date: Mar 2007
Location: Orange County, CA
Posts: 53
![]() iTrader: 0 reviews
|
I think I found it. I had my aircleaner off that day and the ram air was going directly into the carb unrestricted. At higher speeds, the airpressure was enough that it stopped or disrupted the flow from the PCV valve and caused that bank valve cover to load up with pressure.
And to the smartass who wants to know if my motor is constipated?....No, but I am. To much whiskey and Fritos
__________________
1964 Falcon Sprint 4 speed 1965 347 Cyclone 4 speed, B/FX clone 1993 Mustang Cobra (red/grey cloth) |
|
| Sponsored Links | |
Advertisement | |
![]() |
| Thread Tools | |
|
|
LinkBacks (?)
LinkBack to this Thread: http://www.moddedmustangs.com/forums/5-0-mustangs/70173-pressure-my-valve-cover.html
|
||||
| Posted By | For | Type | Date | |
| Pressure in my valve cover!? | This thread | Refback | May 9th, 2008 11:19 PM | |
Threads Similar to: Pressure in my valve cover!?
|
||||
| Thread | Thread Starter | Forum | Replies | Last Post |
| Valve cover ? | 88mysticgt | 5.0 Mustangs | 3 | April 5th, 2008 10:00 AM |
| Valve Cover | mustang1072 | V6 Mustangs | 15 | March 23rd, 2008 09:30 PM |
| valve cover painting | KenDogg | 2005 - 2010 | 20 | March 10th, 2008 09:46 AM |
| Valve cover options | caintcatchmyGT | 96-98 | 21 | October 24th, 2007 06:20 PM |
| leaky valve cover | raceruler03 | 99-04 | 4 | February 18th, 2007 02:33 PM |