smokes when starting

Discussion in 'Fox 5.0 Mustang Tech' started by volvo5.0, Dec 29, 2003.

  1. Just finished rebuilding the engine on my '91 5.0.No machine work,just re-ringed the pistons,honed the cylinders,new rod & main bearings.The lower end is bone stock with stock cam.I added a set of Edelbrock performer heads(used),performer intake,65mm throttle body,73mm C&L mass,24# injectors,FRPP roller rockers,and 1 5/8" headers.The car runs great,but when started has a puff of smoke.After that no smoke and runs great.I suspect valve seals because I bought the heads used and like an idiot installed them without taking them apart and checking them.I pulled the plugs and found that #4 & #8 plugs had signs of oil on them.My question is before I spend an afternoon replacing valve seals,is there anything that would cause the rear plug on each side to get oil fouled or is this just a coincidence?
  2. valve seals are the only thing i know of to do that. not saying that is all it could be, just all i have ever heard of it being.

    BTW, if your user name is accurate, you should hook up with Michael Yount if you havent done so already. great guy, super knowledgeable and has a '82 242 with a "massaged" 5.0. ive learned a ton from him and he is a heckuva nice guy.
  3. i would bet it's the valve seals
  4. I would have to agree with everyone else on this thread, sounds like the valve seals hit the bed. Now, it smokes after initial start up? How long do you let the car sit for, a week a couple days or just a couple hours? If it smokes after initial start up after sitting for a little, that's normal because the oil settles on the valves but if it smokes after a day or so, thats not normal. I would say replace the valve seals or do a compression test and that will determine what one it is for sure!
  5. found the problem

    I decided to replace the valve stem seals.First step was to pull off the upper intake.Guess what I found?The intake was full of oil!!Come to find out ,the lower intake (where the pcv plugs in)has a metal plate(oil baffle) rivetted underneath.I bought the intake(edelbrock performer)used and it was never installed.Oil was being sucked through the pcv into the intake.Iremoved the intake and installed the baffle from the stock intake.Problem solved.
  6. Glad you got her figured out. :nice: I'm definitely in agreement with HISSIN50 though. Michael Yount consistently gives clear and thorough tech advice here. He'd be worth looking up just for that, plus the fact that he owns a Volvo with a 5.0, too.
  7. i was reading through this thread and i was going to mention that intake/pcv problem. i happened to me twice. i couldnt figure out the relationship between #4 and #8. i see you already figured it out so good job