Jump to content

Cylinder pressure out intake port


ChallengeDave

Recommended Posts

Have you inspected the valve stems yet? Valve spring pressure test? Sounds like a too tight valve guide or a weak spring. Or a combo. Maybe you'll find witness marks or heat distortion on the valve stem. If it's just hanging up a little after some good heat cycles maybe it's a faulty valve, bad forging or material.

Link to comment
Share on other sites

11 hours ago, ChallengeDave said:

I already pulled the cylinder head off last night. But before I did that I did check the valve set and they were spot on where I reset them after the head retorque after the initial run in. I pulled both valves out of the head and inspected them. Neither intake valves are burnt and the don't seem to bind in the guides at all. I spun them on a drill and they are both true. The seats seam to be intact. I reinstalled the valves and springs, then filled the intake port with break clean and it didn't come rushing out around the seats.

Do some people not read all the posts anymore!?  (Sorry Joey i had to delete the last post your responding too because I quoted the wrong one.)

Link to comment
Share on other sites

I get it...  no biggie...  I try to go back to the beginning if i feel i am off topic..  i have done it tonight on 2 threads..  it goes to show how we will go to any length to help these guys..  :)  

Link to comment
Share on other sites

yeah checking spring pressure in this case is a stretch..  The machine shop probably didnt check them either...  the engine is already taken down to a point where the issue may have been passed by, however, he has a large skillset and I expect he will find the issue...  I dont see where he test drove the truck to duplicate the issue, so I guess he is going on the driver's story...   jojo

Link to comment
Share on other sites

I read and reread the thread. If the cylinder pressure is coming out from the intake then you would think the obvious like a valve hanging open or something pushing down on it such as the engine brake. The only other thing I can think of right now is cam timing. 

  • Like 1
Link to comment
Share on other sites

Just now, Vmac3 said:

I read and reread the thread. If the cylinder pressure is coming out from the intake then you would think the obvious like a valve hanging open or something pushing down on it such as the engine brake. The only other thing I can think of right now is cam timing. 

💯

Link to comment
Share on other sites

3 minutes ago, Joey Mack said:

But how did it run good for 20-25 thousand miles til now??? poor cam timing should  be instantly noticed..  Please correct me, for I dont know..  

maybe some teeth on the cam gear need to be inspected? Maybe they broke or rounded over and jumped time?

Edited by Onyx610
  • Like 1
Link to comment
Share on other sites

I feel like anytime you have exhaust/compression going out the wrong valve it’s timing. That’s just what I learned. But I’m green and have learned a lot from a handful of you guys and you know who you are. 

Link to comment
Share on other sites

I don't think it's a cam because the intake valve would have excessive lash and he would of noticed it. Also the intake would not open all the way because the lobe is worn out. I wonder if the injectors have too much forward leakage (dribbling). 

  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...