Announcement

Collapse
No announcement yet.

Loosing vent under engine load

Collapse
X
Collapse
 
  • Page of 1
  • Filter
  • Time
  • Show
Clear All
new posts
Previous template Next
    #1

    Loosing vent under engine load

    Hey guys, I have a slight problem with my Grand Marq. Under heavy engine load (i.e. going up a hill on the highway in OD), I loose enough vaccum that the climate control begins to from vent to defrost, sometimes completely. Does anyone know where I could start looking for leaks? I sprayed all of the lines under the hood with starting fluid to no avail, and plugged my leaking parking brake release.

    Car: 1988 Grand Marquis wagon
    - No ATC
    -Only happens under heavy engine load.

    Thanks for you input!

    -Nick
    Nick
    88 Colony Park LS
    G-pa's old car, but he's cruisin around heaven in his 69 wagon now
    Future plans:Semi HO conversion, or Explorer motor swap, shift kit, PI springs and sway bars, KYB-GR2 shocks
    Tags: None
    #2
    What condition is your soup can in?
    1983 Grand Marquis 2Dr Sedan "Mercules"
    Tremec TKO conversion, hydraulic clutch, HURST equipped!

    Comment

      #3
      Soup can is also my first suspect, but the one-way check valve at the firewall vacuum tree can also leak internally, and cause this.

      And don't spray starting fluid around. That shit is real explosive. If you had a leaky plug wire, it could have literally blown up in your face.
      86 Lincoln Town Car (Galactica).
      5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley

      91 Lincoln Mark VII LSC grandpa spec white and cranberry

      1984 Lincoln Continental TurboDiesel - rolls coal

      Originally posted by phayzer5
      I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers

      Comment

        #4
        I was worried about the plug wires and the warm exhaust, personally I didn't feel that comfortable doing it but all of the guys at the shop I went to said it was fine so...oops. Soup can has a bit of surface rot but when I hit it with the fluid the idle didn't change. The firewall vaccum tree is the little white thing with like 3 lines coming out of it located smack dab in the middle of the firewall?
        Last edited by 88MercWagon; 07-18-2009, 01:31 PM.
        Nick
        88 Colony Park LS
        G-pa's old car, but he's cruisin around heaven in his 69 wagon now
        Future plans:Semi HO conversion, or Explorer motor swap, shift kit, PI springs and sway bars, KYB-GR2 shocks

        Comment

          #5
          Ya that's the tree. Keep using the starting fluid and you won't have to worry about any vac leaks.
          89 CV LX 225/60 x 16 tires, CC819 rear springs, Front & rear sway bar, trans & PS cooler from 90 cop car. KYB shocks, F-150 on rear. Dual Exhaust w/ H pipe. Dark brown door panels, carpet, steering wheel, trim parts from a 87 Mer GM. Power front buckets from 96 Jeep Cherokee. LED'S front & rear. 3G Alt from a 97 Taurus wagon 3.0. Electric fan. Rear axle from a 97 PI 3.27 with disk brakes. Headlight relays.

          Comment

            #6
            Use a vacuum pump to check for leaks, or if you're confident in your manliness, just put the hose in your mouth and suck. If it leaks, you'll find it.
            86 Lincoln Town Car (Galactica).
            5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley

            91 Lincoln Mark VII LSC grandpa spec white and cranberry

            1984 Lincoln Continental TurboDiesel - rolls coal

            Originally posted by phayzer5
            I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers

            Comment

              #7
              Originally posted by gadget73 View Post
              Use a vacuum pump to check for leaks, or if you're confident in your manliness, just put the hose in your mouth and suck. If it leaks, you'll find it.
              Originally posted by gadget73
              There is nothing more permanent than a temporary fix.
              91 Mercury CP, Lopo 302, AOD, 3.08LSD. 3g upgrade, Moog wagon coils up front, cc819s in the back. KYB GR-2 police shocks. Energy suspension control arm bushings. Smog deleted.
              93 F-150 XLT, 302, ZF 5-spd from 1-ton, 4wd.
              Daily--07 Civic Coupe. Bone stock with 25k miles
              Wife--14 Subaru Outback. 6-speed.
              95 Subaru Legacy Wagon--red--STOLEN 1/6/13

              Comment

                #8
                The soup can plasticish line is bad, or the can itself is rotted out. Mine broke, and whenever I accelerated the controls would revert to defrost.

                Comment

                Previous template Next
                Working...
                X