mr.cody.daniel
Registered User
Hey y'all, first post to the forum. Has been an invaluable resource for me already!
I recently acquired a beautiful 1987 F-250 6.9 for the glorious price of $900. 4wd, 4spd, minor surface rust but very clean an intact. 200k miles.
Of course, the problem. Excessive blowback in the intake. Excessive acrid white smoke out the exhaust. Loosen the intake cover and a chugging noise as the pressure pumped the intake. Sort of a "chuff chuff noise"
After reading the forums, seemed likely that the valve guides had worn and allowed the valves to start rocking, destroying the valve seat and creating all the blowback. So I set to work with my ~100pc Craftsman set and a borrowed garage space and tore the heads off. Have a ton of experience with race bikes and gas engines, but first diesel. Took all the proper steps, read Mel's great article (http://www.thedieselstop.com/contents/getitems.php3?6.9L Gasket and Turbo Install), kept push rods and rockers sorted, and heave hauled with three guys to get the heads out of the bay (heavy suckers!)
Took them down to the machine shop and have the preliminary report back now. Exhaust valves have all started to tulip. One precup is loose. Guides are all in spec.
Current plan is to remachine the valve seats, replace all exhaust valves, rebuild.
The question I have is whether I should preemptively have new guides inserted to avoid any potential future woes, or trust the factory guides to last. Another question is how afraid I should be of the loose precup. And lastly, should I have anything else done to the heads while they're out now?
Thanks for taking the time to read! Looking forward to the forum.
I recently acquired a beautiful 1987 F-250 6.9 for the glorious price of $900. 4wd, 4spd, minor surface rust but very clean an intact. 200k miles.
Of course, the problem. Excessive blowback in the intake. Excessive acrid white smoke out the exhaust. Loosen the intake cover and a chugging noise as the pressure pumped the intake. Sort of a "chuff chuff noise"
After reading the forums, seemed likely that the valve guides had worn and allowed the valves to start rocking, destroying the valve seat and creating all the blowback. So I set to work with my ~100pc Craftsman set and a borrowed garage space and tore the heads off. Have a ton of experience with race bikes and gas engines, but first diesel. Took all the proper steps, read Mel's great article (http://www.thedieselstop.com/contents/getitems.php3?6.9L Gasket and Turbo Install), kept push rods and rockers sorted, and heave hauled with three guys to get the heads out of the bay (heavy suckers!)
Took them down to the machine shop and have the preliminary report back now. Exhaust valves have all started to tulip. One precup is loose. Guides are all in spec.
Current plan is to remachine the valve seats, replace all exhaust valves, rebuild.
The question I have is whether I should preemptively have new guides inserted to avoid any potential future woes, or trust the factory guides to last. Another question is how afraid I should be of the loose precup. And lastly, should I have anything else done to the heads while they're out now?
Thanks for taking the time to read! Looking forward to the forum.