Valve starting to stick

CDX825 · Apr 27, 2018

I agree that its probably a lifter bleeding down. Your oil choice most likely doesn't have anything to do with it. You just have a bad lifter.

7.3s are also known for valve guide issues because they used tighter seals than the 6.9 did. So instead of using a bit of oil they wore valve guides out faster. Was done for emission reasons from what Ive been told.

riotwarrior · Apr 28, 2018

Chuff out exhaust indicates ex valve huff out intake ...take off air filter lid....indicates intake valve....

Thats easy check

IDIBRONCO · Apr 28, 2018

riotwarrior said:
Chuff out exhaust indicates ex valve huff out intake ...take off air filter lid....indicates intake valve....

Thats easy check

That's if the valve isn't seating. If it's not opening, like I'm guessing it is here, it's different. If the exhaust valve doesn't open, then the pressure of the piston rising will go back out of the intake when the intake valve opens. If the intake valve doesn't open, there probably won't be much noise coming out of the exhaust since there's no air getting into the cylinder since the intake valve isn't opening. There probably wouldn't be much extra noise in the exhaust. At least this is the way that I see it.

Thewespaul · Apr 28, 2018

Well said.

pastorjeep · Apr 30, 2018

I had a Jasper 7.3 that stuck a valve at 70thou and bent the push rod and collapsed the lifter. I had to beat the valve out with a mallet. It was doing the same as your for about 500 miles and then seized. The machine shop said the tolerances on all the guides were too tight.

Hydro-idi · Apr 30, 2018

pastorjeep said:
I had a Jasper 7.3 that stuck a valve at 70thou and bent the push rod and collapsed the lifter. I had to beat the valve out with a mallet. It was doing the same as your for about 500 miles and then seized. The machine shop said the tolerances on all the guides were too tight.

Sounds about right for a jasper rebuild unfortunately.

Joseph Davis · May 2, 2018

If a valve doesn't open start checking for metal in the oil pan or a loud clacking noise from valve covers. valves can get stuck open and usually big loss in power because cylinder will not fire. The ratting noise you are hearing most likely coming from IP at start up, because the gears can make a lot of noise when not timed right. I know because I ordered a Diesel Timing Meter and timed mine. there is no comparison to a properly timed motor. When I hear a lifter ticking check oil level first, and if needed I added Gunk Valve medic. Mechanical failures make a lot of noise and last for a long time, and hiccups good luck, could be any thing, only time will tell. But your first thought being the Valves do a compression test because that will never lie. Good Luck and I hope for the Best

Macrobb · May 2, 2018

IDIBRONCO said:
That's if the valve isn't seating. If it's not opening, like I'm guessing it is here, it's different. If the exhaust valve doesn't open, then the pressure of the piston rising will go back out of the intake when the intake valve opens. If the intake valve doesn't open, there probably won't be much noise coming out of the exhaust since there's no air getting into the cylinder since the intake valve isn't opening. There probably wouldn't be much extra noise in the exhaust. At least this is the way that I see it.

On the intake side, if the valve isn't "stuck" and just not being pushed down at the right time(collapsed lifter, loose rocker, bent pushrod) you'll get a loud thumping as the engine draws a vacuum hefore the valve finally opens and air rushes in.

IDIBRONCO · May 2, 2018

Never thought of that. I haven't seen this before and I can't really imagine what that would sound like. Hopefully, I never will.

crash-harris · May 2, 2018

Macrobb said:
On the intake side, if the valve isn't "stuck" and just not being pushed down at the right time(collapsed lifter, loose rocker, bent pushrod) you'll get a loud thumping as the engine draws a vacuum hefore the valve finally opens and air rushes in.

THIS is what I get most of the time.

Mike_42 · May 4, 2018

Well since I added the MMO it has done it a few more times, seems like its getting more common. Im thinking about just doing a flush of somesort and changing the oil again, what do you guys reccomend? Each times its done it its on one cylinder and does it like 3 times..

About to pull the valve cover what gasket should I get and where?

Mike_42 · May 4, 2018

It also makes this droning noise when idling I can hear on driver side and not passenger. Not sure if valve or exhaust leak or what. If it werent for being a DD id pull it and rebuild.

Where do you guys buy your lifters, pushrods, etc?

Mike_42 · May 4, 2018

IDIBRONCO said:
Never thought of that. I haven't seen this before and I can't really imagine what that would sound like. Hopefully, I never will.

Im surprised I have, I baby the hell out of this truck, alwaks kept on maintence, it only has 235k..

Macrobb · May 4, 2018

Mike_42 said:
Im surprised I have, I baby the hell out of this truck, alwaks kept on maintence, it only has 235k..

That babying may be your problem. Get out there, hook a trailer to it and romp on it. Get her hot! You've got to burn the carbon off once in a while.

pastorjeep · May 4, 2018

It still sounds like a sticking valve to me. I was able to get pushrod and lifter at a Ford dealership about two hours away, just went to my local dealership and had them check the network to see who had the stuff on the shelf.

Valve starting to stick

CDX825

filtration nut

riotwarrior

Supporting Member

IDIBRONCO

IDIBRONCO

Thewespaul

Supporting Member

pastorjeep

Full Access Member

Hydro-idi

Full Access Member

Joseph Davis

Full Access Member

Macrobb

Full Access Member

IDIBRONCO

IDIBRONCO

crash-harris

Breaker! Breaker!

Mike_42

Kid Mechanic

Mike_42

Kid Mechanic

Mike_42

Kid Mechanic

Macrobb

Full Access Member

pastorjeep

Full Access Member

Similar threads

Latest posts

Forum statistics

Members online

Share this page