Make payments with PayPal - it's fast, free and secure! registry | CVN on Facebook | tech | news | email login Make payments with PayPal - it's fast, free and secure!

Welcome to CVN - Your Panther platform headquarters!

Custom Search

Topic Options
#4071284 - 07/20/20 07:27 PM Hey guys help me with the infamous hissing dash
TwiztidRat Offline

Registered: 06/10/12
Posts: 31
Loc: WI
Hey guys been a while since I been here but I acquired an 86 MGM box again so here I am. I am trying to fix the hissing noise that is pretty common on these cars. I know the remedies to fix it, but I'm having trouble finding where this vacuum line is located. Is it under the hood, or am I suppose to be looking inside the dash by the gas pedal cause between the pedals there is a white line but I didn't want to mess with this until I know what I'm doing and to be honest right now I don't feel like I am. If someone could send me a pic of where this line is it would help even more I feel like an idiot but under the hood ther's so much junk under there I can't tell where I'm suppose to be looking. Also the gear shifter requires a bit of force to get it to move my old GM had this same issue would it help to spray some lubricant inside the gear selector slot thing? Thanks guys.

#4071588 - 07/22/20 11:08 PM Re: Hey guys help me with the infamous hissing dash [Re: TwiztidRat]
a_d_a_m Offline
3 Orange Whips

Registered: 10/25/05
Posts: 26548
Loc: Cleveland, OH
'91 LTD Country Squire (POTM Mar. '19) | '03 Marauder (POTM Nov. '10, Jul. '20) | 2010 P7B

formerly: '02 MGM, '04 MGM, '04 MGM v2.0, '04 MM, '07 P71 (POTM Feb. '18), '04 CVLX (POTM Jun. '19), '03 SAP P71

#4071990 - 07/26/20 11:06 AM Re: Hey guys help me with the infamous hissing dash [Re: TwiztidRat]
BigMerc96 Offline
I know nothing
Posting Addict

Registered: 06/05/10
Posts: 19766
Loc: I can see Detroit from here!
I've always just disconnected and plugged the white vacuum line that comes thru the firewall and runs to the vacuum switch that is on the shifter linkage on the column. You could disconnect it at the parking brake, but then you still have vacuum at the vacuum switch which is potentially leaky, so just eliminate the vacuum supply for the whole thing. Did this to my buddy's '88 and '91, and I want to say I did this on an Aero too but honestly can't remember if it was one of mine or his, its the same basic system on any year that had it aside from the vacuum switch being different for the different columns ('79-'89, '90-'04, and '05+).

2006 Audi A6 ~132k miles, stock.
1998 Mercury Grand Marquis LS HPP ~100k miles, slowly acquiring modifications.
1997 Town Car Cartier ~145k miles, Ported Plenum, Gutted Airbox, Contour E-fan Retrofit, Dual exhaust with Magnaflows, cats deleted, MSD Ignition, KYB Gas-A-Justs, P71 front bar, air ride reinstated, Projector retrofit, Caddy 4-note horn retrofit, Wood rim steering wheel retrofit, holistic weight reduction as the parts fall off..
1996 Mercury Grand Marquis GS 117,485mi. R.I.P. 7/14/12 frown


Who's Online
2 registered (3fords1, MaxyK9), 53 Guests and 272 Spiders online.
Key: Admin, Global Mod, Mod
Email Login
EMail Login Name
 New users, sign up!
Top Posters (30 Days)
bluejay_32 192
BigMerc96 78
ClayBelt 75
Old_Guy_Stu 66
Ponyguy 61
TheCableGuy 58
a_d_a_m 57
Moby_Vic 57
Psxmoe 43
RF_Overlord 36
Member Spotlight
Member Since: 06/19/05
Posts: 5394

Copyright 2000-2015 by and Steve Spaulding. All Rights Reserved.
The photographs, graphics and data contained in this Web site are the properties of the contributors, or and may not be used without expressed written consent. is not affiliated with the Ford motor company.

Happily consuming the fuel saved by Prius owners!