Strange "pheww" sound when I step on the gas pedal

[rsturek]

Need help on this fellow Wagoneer owners. I have a 1990 Grand Wagoneer post multi year complete nut and bolt restoration, remanufactured AMC 360 , TBI from team Grandwagoneer, (Howell) rebuilt EVERYTHING! But I have a frustrating oil leak from what I see as the valve covers, which are new from team grand wagoneer. I keep torquing to spec and each 20 mile drive , I have oil dripping from the bottom of the bell housing coming from the driver side. Now today I started hear with the windows down a strange "phewwww" sound when I step on the gas pedal. I am also seeing some hesitation during excelleration. The sound seems like air being sucked in or out during acceleration for a very short 1 or 2 seconds.Any ideas are much appreciated!

[letank]

pffffewww vacuum leak... comes to mind

as for valve cover leak... if you torque too much the cover is deformed and it will lead to more leaks... time to take a mirror or a scope and look what is between the engine and the firewall as leaks... Also oil travels along the engine top, the leaky gasket could be come from the front and moves toward the rear of the engine.

[Yeller]

Could just be the air making noise on the throttle blade as it cracks open. TBI’s are notorious for making some sucking noises at small throttle opening. I’ve had the idle air control valves make noise too. Not something I’d be concerned about beyond double checking all of the vacuum ports are either connected or capped. Usually a noisy vacuum leak that is bad does the opposite, noisier when you close the throttle, not when accelerating.

Had a lot of TBI motors they all made some sort of weird noise. Part of the reason there were air baffles in the OEM air filter housings and piping. I did TBI swaps on everything for over 20 years, starting in 1989, finally quit about 10 years ago and have done nothing but LS or MPI swaps since.

[tgreese]

Original factory 360 air cleaner, or an open element aftermarket type?

Among its other functions, the factory air cleaner muffles the sucking noise from the throttle plates.

[rsturek]

Thanks for the ideas guys, FYI this noise is new, just started yesterday and I do have an after market K&N air filter. My first thought was Vacum also. I have heard the TBI noise when the hood is up and filter is off, but never while driving. I did an initial look, but guess I am going to dive in deeper on vacuum lines & connections today.

As for the valve cover leak, wondering if the "Jeep" logged covers I purchased from Team Grand Wagoneer are Chinese nock-offs and not fitting correctly. I recently pulled them and found the mechanic who assembled the motor for me over torqued the rocker arm brackets and bent one on each side of the motor empeding rocker movement, after replacing all rocker arms and push rods motor performance and power was much improved. I found No unusual ware on either Rocker arms nor push rods as i have maybe a 1k miles on this reman motor. I put new valve cover gaskets on and when torquing the covers down discovered those valve cover bolts are a 10mm bolts and 2 days after reinstalling them they were loose again yesterday. I definitely have a slow oil leak from the driver side back valve cover. Wondering if I should start looking for a better quality valve cover? Any suggestions? Also I am finding conflicting torque specs for valve cover bolts, anyone know what it should be?

[tgreese]

If I did not need the bling, I would use the factory valve covers. The valve cover flanges are sometimes bent around the bolt holes, and can be straightened. Should be fine - no leaks - if installed properly and not over-tightened. Really no advantage to the originals over similar steel replacements; indeed, the OEM stuff will be better quality than anything you can buy today.

Torque spec is in the TSM last I looked. Table at the end of the engine chapter. Ca 40in-lb or something like that. Not much. I use a 1/4" palm ratchet and my calibrated forearm.

Cast aluminum covers or stamped steel? Possible your over-zealous mechanic also over-tightened the valve covers. Pressed steel covers will leak if tightened more than the factory spec. They then must be straightened with some hammer and dolly action before installation. Lots of old posts discuss this here and on any Jeep site, if you search.