PI Intake/Cam install problem

Discussion in 'SN95 4.6L Mustang Tech' started by Dusstbuster, Sep 24, 2006.


  1. Dusstbuster

    Dusstbuster I love meat more than anything! I just have a spec

    Joined:
    Jun 1, 2004
    Messages:
    1,692
    Likes Received:
    43
    Trophy Points:
    49
    Location:
    Moorhead, Minnesota
    Well we got everything bolted back together today and fired her up and it started smoking kinda, but we figured it was just some oil or something that'd spilled on the headers during the install. Turned it off, went in to eat, came back out and turned it on and the smoking had kinda subsided, so we backed it out and then it started popping out of the drivers side exhaust. Anytime we put it into gear it'd start popping and running pretty hard, especially on the drivers side, then we threw a p0300 "Multiple/Random misfire" code. Anytime it's in park it runs fine, put it into gear and it starts popping again...we checked all the plugs/wires/anything ignition related and it all was fine so we're thinking it might be leaking coolant into a cylinder or 3. Anyone want to confirm my fears? It was spitting out a decent amount of smoke from the exhaust after we drove it for a quick little drive out of the cul de sac and back, and anytime we'd give it gas or a load it'd pop like no tomorrow. We also pulled some plugs and one of the plugs looked a little darker colored than the others, although it wasn't easy to say if it was fouling or not. The plugs we pulled were on #1 cylinder and then the front and rear cylinders on the drivers side. The one that looked sorta iffy was the one on the front of the drivers side bank of cylinders, closest to the thermostat. I'll get some pictures uploaded of our gasket/RTV layout just to show you guys. Probably a coolant leak though?
  2. stangGT97

    stangGT97 New Member

    Joined:
    Dec 22, 2004
    Messages:
    1,405
    Likes Received:
    32
    Trophy Points:
    0
    Location:
    Boston area, MA
    Ok, so you didn't tamper with the head gaskets, right? As in, the heads never came off the car... so that would eliminate the possibility of head gasket failure (unless this is very coincidental that they just blew out right now, but thats unlikely). The more likely scenario is you either have a vacuum leak in the intake manifold, or you didnt seal the coolant ports correctly and they are leaking into the intake ports on the head. Then you would certainly be burning coolant and blowing smoke. What color is the smoke? Did you use NPI or PI gaskets? The reason this is important is if you used NPI gaskets, then coolant leakage from the water jacket is pretty much a non-issue (perfect seal) but the PI gaskets will leak if you did not use RTV in the correct spot. What about torque... did you follow the torque specifications and order as layed out in the Haynes manual? This is all i can think of right now..

    oh also, did you spill coolant into the plug wells? that will cause misfires for sure. And if your cams are not timed correctly, your car will run like sht as well


    Sponsored Ad

  3. Dusstbuster

    Dusstbuster I love meat more than anything! I just have a spec

    Joined:
    Jun 1, 2004
    Messages:
    1,692
    Likes Received:
    43
    Trophy Points:
    49
    Location:
    Moorhead, Minnesota
    Correct, the heads never came off the car. The smoke is whiteish, it was getting dark out at the time so if there was a blueish tint to it it would have been hard to see. Umm lets see here, I used NPI intake manifold gaskets and put RTV around the intake ports as well as a little on the coolant passages. They were all torqued down to spec, didn't use a haynes manual but used some image I found on ************. The plug wells were clean when we installed, and the cams should be timed correctly...i don't see how the timing could have changed at all during the swap, the gear/chain never changed position and the cams should be seated in the exact same position as the stock cams. We'll probably end up taking the manifold off tomorrow if it doesn't run correctly in the morning and re-rtv everything. When I get back home i'll upload pictures of the gasket/rtv layout we used before we put the manifold on.
  4. stangGT97

    stangGT97 New Member

    Joined:
    Dec 22, 2004
    Messages:
    1,405
    Likes Received:
    32
    Trophy Points:
    0
    Location:
    Boston area, MA
    with npi gaskets, you do not use RTV around the coolant ports... the gasket makes a perfect seal without it.
  5. Dusstbuster

    Dusstbuster I love meat more than anything! I just have a spec

    Joined:
    Jun 1, 2004
    Messages:
    1,692
    Likes Received:
    43
    Trophy Points:
    49
    Location:
    Moorhead, Minnesota
    Here are the pictures. The one with the yellow on it shows the plugs we checked and the one with red in the yellow was the plug that looked like it might be kinda funky. That one of the rear of that cylinder bank also looked like it might be kinda funky too...who knows. We'll probably be tearing it down tomorrow if it keeps running like crap when we fire it up again in the morning.

    [​IMG]
    [​IMG]

    What do you think could be causing this problem then?? I wish I could upload a video/audio of it but have no means of doing so.
  6. stangGT97

    stangGT97 New Member

    Joined:
    Dec 22, 2004
    Messages:
    1,405
    Likes Received:
    32
    Trophy Points:
    0
    Location:
    Boston area, MA
    nice shocker hahaha

    When I did my intake originally w/ the NPIs, put the gasket onto the manifold first, then sealed where the gasket missed. If you put it onto the head, there is no way of telling if you've used enough rtv to insure a good seal... either that or you use way too much. It is really hard to tell from those pictures, but it almost looks like you're trying to seal up the gaskets on the head, not where they miss on the intake. here is a picture of my intake when it was done..

    [​IMG]


    As you can see, the gaskets don't seal the port on the side facing the runners, so you just need rtv there, not all over the head. I almost guarantee you have a massive vacuum leak where your gaskets are not sealing the intake ports properly. Thats an easy enough fix, but I recommend using the PI gaskets this time though, and only using a dab of RTV where it doesn't seal the water jacket all the way.
  7. TGJ

    TGJ New Member

    Joined:
    Mar 31, 2005
    Messages:
    1,055
    Likes Received:
    1
    Trophy Points:
    0
    I have heard that before and when the issue was resolved, it was the cam gear that moved. How do you know a cam gear didn't move?

    First, I agree, replace the gaskets with the PI gaskets and RTV the coolant ports and try the car again.
  8. Dusstbuster

    Dusstbuster I love meat more than anything! I just have a spec

    Joined:
    Jun 1, 2004
    Messages:
    1,692
    Likes Received:
    43
    Trophy Points:
    49
    Location:
    Moorhead, Minnesota
    Here is what I don't get about that though. Ok...the gear and cam only mate 1 way. Throughout the install the gear and chain never left eachother, and I KNOW the chain didn't slip a tooth. Therefore, if we kept tension up, popped the old cam out and put the new one in, how could the timing be off if nothing ever changed position relative to the old positioning?
  9. Dusstbuster

    Dusstbuster I love meat more than anything! I just have a spec

    Joined:
    Jun 1, 2004
    Messages:
    1,692
    Likes Received:
    43
    Trophy Points:
    49
    Location:
    Moorhead, Minnesota
    Well we checked the timing with a timing light at it's fine...we're in the process of ripping the manifold off again.
    How long should you let the RTV cure before you start the car??
  10. COramprat

    COramprat Drone Driver Mod Dude

    Joined:
    Mar 3, 2003
    Messages:
    5,990
    Likes Received:
    90
    Trophy Points:
    98
    Location:
    Sea of Tranquility
    Timing light is useless on these cars. Run through the timing procedure located on the MD website if you don't get rid of the misfire checking the manifold.
  11. stangGT97

    stangGT97 New Member

    Joined:
    Dec 22, 2004
    Messages:
    1,405
    Likes Received:
    32
    Trophy Points:
    0
    Location:
    Boston area, MA
    rtv takes a full 24 hours to cure. I let my car sit a fully day before starting it, but I'm sure you could wait 12 hours if you just start it to let it idle for a few minutes
  12. Dusstbuster

    Dusstbuster I love meat more than anything! I just have a spec

    Joined:
    Jun 1, 2004
    Messages:
    1,692
    Likes Received:
    43
    Trophy Points:
    49
    Location:
    Moorhead, Minnesota
    So do you think the fact that we've only let the RTV cure for about 1-2 hours max before starting it could have anything to do with this? It's hit about 1500rpms too, and all within 2 hours of applying the RTV and torquing everything back down.
  13. Dusstbuster

    Dusstbuster I love meat more than anything! I just have a spec

    Joined:
    Jun 1, 2004
    Messages:
    1,692
    Likes Received:
    43
    Trophy Points:
    49
    Location:
    Moorhead, Minnesota
    anyone? If so i'm going to tear it down again tonight and re RTV it one last time tomorrow
  14. TGJ

    TGJ New Member

    Joined:
    Mar 31, 2005
    Messages:
    1,055
    Likes Received:
    1
    Trophy Points:
    0
    On my car, when I did the intake swap, we let the RTV cure about an hour. The car fired up and never leaked. I doubt your problem is in the gaskets.

    I am still inclined to think it is either in the cam timing or that something was not re-connected properly.
  15. Dusstbuster

    Dusstbuster I love meat more than anything! I just have a spec

    Joined:
    Jun 1, 2004
    Messages:
    1,692
    Likes Received:
    43
    Trophy Points:
    49
    Location:
    Moorhead, Minnesota
    I'm thinking it is the RTV....just pulled a plug and checked the cylinder closest to the thermostat and it looks like there is some green liquid in it. I'll start ripping it apart again tonight and we'll once again redo it tomorrow and let it cure for a full 24. If it still runs like crap after that i'll be more inclined to check out the cam timing.
  16. stangGT97

    stangGT97 New Member

    Joined:
    Dec 22, 2004
    Messages:
    1,405
    Likes Received:
    32
    Trophy Points:
    0
    Location:
    Boston area, MA
    You're still having problems after regasketing the intake? How did you do it this time? TGJ, you did the intake swap using the PI gaskets, right? If he used the NPI gaskets, there is a lot more rtv being used, I wonder if it is more of a matter of where he is applying the rtv which is causing a leak. I don't see how you could have coolant in the cylinders unless you have blown headgaskets or your intake is just dumping coolant in there somehow.

    Are you 100% sure the cam timing is correct?
  17. MisterCMK

    MisterCMK Member

    Joined:
    Oct 2, 2004
    Messages:
    206
    Likes Received:
    0
    Trophy Points:
    17
    Location:
    Fargo, ND
    The cam timing is correct. We kept tension on the chain the entire time. Its probably the RTV like people have been saying. Dustin is re-doing the intake tonight and hopefully that will take care of the problem.

    BTW, that was my shocker. :D
  18. TGJ

    TGJ New Member

    Joined:
    Mar 31, 2005
    Messages:
    1,055
    Likes Received:
    1
    Trophy Points:
    0
    My car was with NPI gaskets. I did mine not long after JL did his and at that time, the NPI gaskets were the way to do it. Never had issues with mine.
  19. Dusstbuster

    Dusstbuster I love meat more than anything! I just have a spec

    Joined:
    Jun 1, 2004
    Messages:
    1,692
    Likes Received:
    43
    Trophy Points:
    49
    Location:
    Moorhead, Minnesota
    I'm thinking that we haven't let the RTV cure long enough and then the added pressure of revving the engine so soon afterwards put too much stress on the fairly fresh RTV and blew some of it away. That probably allowed some to leak from the thermostat housing/coolant ports through the gasket and into the cylinder. Tomorrow we'll have it redone a 3rd time and the car will NOT be turned on for a full 24 hours. If the problem persists im shooting the car on the spot.
    Oh and the way we gasketed it this time was: cleaned up the head/gasket, RTV'd the lower part of the gasket that meets the head just for added seal around the head, then also did a small bead on the top of the gasket as well for added seal around the manifold. Then torqued it down to 89inch/lbs, around 1.5 hours later we started it up and it seemed to idle fine, put it in gear and it didn't pop or anything. Then we gave it a little gas/revved it up slightly and it felt like it started hesitating/missing there, reshifted it into reverse and the popping came back.
  20. stangGT97

    stangGT97 New Member

    Joined:
    Dec 22, 2004
    Messages:
    1,405
    Likes Received:
    32
    Trophy Points:
    0
    Location:
    Boston area, MA
    89 in-lb? its supposed to be 17-22 ft-lbs. 89in-lbs is only ~7.4ft-lbs, thats not enough pull to keep that manifold flush with the heads.

Share This Page