Engine Mechanic Says Sticking Valve Guides

Discussion in 'Fox 5.0 Mustang Tech' started by JasinC19, Aug 26, 2013.

  1. I think the sequence from tf and edel was different. I never had issues with this one. From the service manual. I think I did it in three equal steps finishing at 17 ft lbs. On the final one I go through the sequence 3 or 4 more time until the bolts stop torquing. I've never had to heat cycle the engine and retorque it. Not that that is a bad idea.

  2. Actually you can see the torque sequence cut off at the top of the pic. I went lower cause of the aluminum heads. I think I did 18 ft. lbs.
  3. UPDATE:

    I dropped the heads off at the machine shop today. He pointed out right away that some of the valve stem tips had an uneven wear pattern on them. Like an X instead of an even dash.

    I had noticed this but didn't know if it was a bad sign. He said that is usually caused by floating valves. He'll have more info once he takes them apart and measures everything (spring rates, clearances, etc).

    I know that I've never revved the car past 4k since it hasn't been running that great.

    Anyone ever seen this? And could it be causing my issue?

    I'm excited that I might have actually found a real issue that I can finally fix.
  4. Hey guy, I've been following this thread to date. I can say that these types of issues can sometimes sound like complaints that you have with your body where you eventually go to a doctor. The doctor tells you one thing, and others that you ask express there own experiences. This is normal and sometimes you get a quick fix, but often you have to push forward with what you feel in you gut.

    I know you couldn't wait to get those heads off! I was wondering when you'd cave and just do it... Hopefully you will come back with a fix.

    For the record:
    I have heard some really good advice that gets at many symptoms like those that you are having' like the PCV valve issue and other vacuum checks.

    Funny, everything most of these guys would recommend, you would intelligently come back with a reply that you'd covered the process in some way. I was thinking to myself: "I'd be SOL if I were in your shoes. I guess that's why I read all this stuff, to get ahead on my future problems.

    So, I will certainly be interested in seeing if you find the smoking gun and come up with a fix.
  5. Haha, well... I got the heads back today and he confirmed that springs/valves/guides and all that are perfect. Kind of a bummer, but at least I have peace of mind that I can move on from there.

    I've got a Kirban FPR and a 2nd set of 24# rebuilt injectors in the garage that I'm going to install when I'm done cleaning up the engine. Who knows...

    One thing I noticed was a pretty healthy amount of carbon on top of the pistons, and some pistons were worse than others. I know for a time it was 'running' with stock length spark plugs and that could have been creating a dirty burn in the chambers. I'm not sure if a lot of carbon on the pistons could cause my issue, but I cleaned what I could off with some seafoam and a non abrassive scrubby.

    So no smoking gun yet... I am starting to think it might be the tune.
  6. Well, sorry you pulled the heads for nothing, but glad you found out it wasn't anything wrong with them as I suspected. From the valve wear I would double check the pushrod length again. Were the pistons carbon caked when you put the heads on last time or is this a new symptom? For plugs, either the Autolite 3924 or NGK FR5 will work.

    I would recommend you use the Felpro 9333 head gaskets with those aluminum heads.

    Let us know when you get it bolted back up.
  7. Thanks, I will double check the pushrods.

    They were new pistons last time i saw them so I'm not sure what exactly caused it. Using oe spark plugs for a while probably did something weird.

    And I'm good on the plugs now. The autolites you mentioned fixed the issue.

    I'll have the car back together hopefully this weekend. I'll post an update.
  8. Quick question: When installing the head bolts that pass through the cooling jackets, do i need to drain the block first?
  9. Yes it is best to drain the block down a little and try to clean those holes with a little brake Clean. Then I prefer permatex rtv over liquid Teflon on those threads

    Sent from my XT907 using Tapatalk 2
  10. Thanks..

    I unfortunately just snapped a head bolt into the block while torquing step 3 to 110. The torque wrench never clicked.

    All the alarms in my head were going off that it was getting too tight but I had my SnapOn TW calibrated and it is was fine. So I chose to trust my tool. Bad decision.

    I will probably need to have the car towed to the machine shop for them to drill it out because it doesn't look like something I can do.

    I would like to understand though how this happened...

    The engine is in the car. I had about 6" of extension on the wrench so that I could clear the head hardware. I was trying to keep it as square as possible.

    I don't know... now I am scared to ever torque anything again..
  11. 110 ft lbs? What bolts- stock, ARP, new, used... did you use oil or moly lube. ARP bolts should not snap at 110 although I remember the torque should be 90-100 with moly?
  12. ARP. Used once.

    Used the ARP teflon lube under the bolt head.

    The TFS instructions (assuming ARP bolts) say 100ft lbs for 1/2 inch head bolts, with an extra 10 on the long bolts.

    And I'm pretty sure it was a lot more than 110 ft lbs... I'm not sure if my torque wrench wacked out or what, but it never clicked. I just checked it at 110 on a lug nut and it clicked fine.

    BUT after messing with the bolt fragment, i was actually able to spin it out using a punch and 30 minutes of time. So... back to square 1.
  13. There's your problem you have 7/16" head bolts that go to 70ftlbs

    Sent from my XT907 using Tapatalk 2
  14. Really? The socket size is 1/2. Is it talking about the width of the bolt? That doesn't measure out to 7/16 either. Is the measurement taken with threads included or without?
  15. I feel extremely stupid
  16. much better! do i need the extra 10 ft lbs on the top bolts?
  17. Measure from outside of thread be about .4375"

    With a na motor like your combo IMO it is not needed to go 10ftlbs more on the longer bolts

    Sent from my XT907 using Tapatalk 2
  18. Another question: When putting the passenger head on I keep noticing that when the bolts get further down in the hole, they hit like a 'rough spot' during part of the turn.

    I notice that the head moves a mm or two when the bolts are loose, I suppose due to a dowel maybe not being a really tight fit.

    Is this normal? Will the bolts pull the head where it needs to be? Or do I need to mess with the dowel size?

  19. Make sure the dowels are seated properly in the recess... it is always a good practice to run a brush and a thread chaser through to clean the holes properly.

    Sent from my XT907 using Tapatalk 2
    JasinC19 likes this.
  20. It turns out some of the top bolts were actually slightly bent...

    I can only guess that this happened during the initial install a year ago. Probably when my engine snagged on the frame while pulling it out to reposition it and I unknowingly jacked the car up with the engine. (The crane was hooked to the back of the passenger head by an old head bolt)

    I'm not sure how else it could have happened. I'm not sure what kind of impact that would have on the operation of the engine, but it can't be good.

    I bought some new bolts and it fixed the issue. The heads are back on.

    Tomorrow I'll do the valvetrain and lower intake.

    When checking the rocker swipe on the valve stem tip, what is the acceptable width of the wear pattern?