So Close, But How Far (ThumpaThumpa)

[idi_econoline]

After head gaskets, injection parts and several weeks of work, my engine DOES start and run.

But, even while cranking with no fire yet, the engine lets out a wicked thumpathumpa.

Recorded a vid on my phone, which is a 3GP file, which is apparently useless outside the cell phone world.

Any thoughts?

 

[idi_econoline]

Was texting with Hydro-idi. He suggested timing was advanced, and it was. We brought it back as far as everything hooked on in back would let us, so its still advanced a bit ahead of the timing lines on the pump & housing.

And, FYI, I did mention in an earlier thread that, yes, we did torque down the lifters without having the timing at 11:00 per da Book.

 

[idi_econoline]

Don't know if this will work, here's an MP3 of startup and the thumping......

You must be registered for see images attach

 

[GOOSE]

Sounds like it could be the valve train to me.

 

[Dave Barbieri]

x2 Sounds a lot like an intake valve isn't seating.

Remove your air cleaner and see if the thumpa-thumpa is louder. If it sounds like it's coming from your intake horn, that's a pretty strong indication. A compression test will pinpoint the bad cylinder.

 

[idi_econoline]

Yeah, thanks, fellas. A bent valve was certainly possible, as I didn't have the timing lined up per da Book when I torqued the rockers.

My friendly head shop boss said he'll fix it for free, even if it was our fault. Of course, that means removing the head and taking it to him......

My buddy helping me is thinking more like crud between the valve & seat (on a freshly reconditioned head?), while a former 6.9-owner is thinking sticky valve guide.

I have a headache now.....

 

[idi_econoline]

Well, hydro-idi stopped by this evening. His theory, told to him by an oldtimer with tons of experience, was to run the engine, and the valve would seat itself.

Cautious me was already fearing bent valve. My buddy was psyching up for in-frame head removal. I've been a stressy mess this week.

I started up the beast for hydro-idi. It let out about 3 thumpas, then ran beautifully for 15-20 minutes of idling before I shut her down......

Thanks for the help, gentlemen, but I hopefully have a happy valve now..... WHEW!!!!!!!!!!!!!!!!!!

And thanks to that oldtimer, whereever he is....

 

[smitty429]

when ya crank on them without it firing it will do that out the intake . I think the lifters getbpumped up. Mine have done that before when cranking for a long time but clears up after it fires and runs for a few seconds

 

[Dave Barbieri]

I'm glad things turned out well. I love a story with a happy ending!!

Thanks HI for taking the effort to help a fellow IDI'er. Nice work!

 

[idi_econoline]

I'm glad things turned out well. I love a story with a happy ending!!

Thanks HI for taking the effort to help a fellow IDI'er. Nice work!

x2, Dave. Yeh, hydro-idi was/is my first buddy on OB, lives about 60 miles away, and is often in my neighborhood. We've helped each other back and forth with parts and advice over the past 4 months, and text back and forth several times a week.

 

['94IDITurbo7.3]

ya know, that sounds alot like the noise my engine puts out after sitting for a long time.

 

[Dave Barbieri]

Yup, I'm glad it was a lifter settling in. My thumpa-thumpa wasn't the lifter; it was the valve. This is definitely a happy ending!!

 

['94IDITurbo7.3]

even though i have the same sound, my engine has 212K miles on it. you'd think the valves have seated themselves by then lol

 

[hesutton]

even though i have the same sound, my engine has 212K miles on it. you'd think the valves have seated themselves by then lol

Better check those valve guides while the heads are off! Replace them now if they are worn. Otherwise, a valve could stick open and kiss the piston and she's DEAD.

Heath