2002 7.3 making tapping/knocking sound as rpms go up

jtgf250 · May 15, 2015

Buddy dropped his truck off for me to look at. Said he was driving down the road and the tapping/knocking sound just came out of no where. I ran a contribution test with AE and had a fault for injector #3 &#8. Pulled valve covers and checked uvch connections. Unplugged each injector while running and no change it the tapping noise. Nothing standing out on the valves, rockers, or rods. Ran contribution test again after messing with harnesses and the faults cleared but noise still present. Plan on pulling back apart in the next day or so and checking condition of glowplugs and push rods and such.

Icp was reading around 520-530 at idle and would go up to about 2600 getting on it going up the road. Icp % at about 9-10 at idle. Unplug icp and goes to default 750. Kinda scratching my head at this point. Seems like a mechanical issue at this point to me. No smoke while idling or driving. Had a little white/blue haze at first start this morning but cleared right away.

Any help or ideas welcome.
Thanks

mandkole · May 15, 2015

Where do you think its coming from? valve train? top of engine? lower? front?

Ron's Power Stroke · May 15, 2015

if its a tapping sound that seems to get louder check the EBPS tube....

jtgf250 · May 15, 2015

Ron it does get louder with the rpm increase. I'll check the tube, cant hurt. Its hard to tell exactly where its coming from. Haven't had anyone around to rev it up for me while I'm under the hood. Also gonna swap cps just to rule it out. Looks to be original and truck only has 125k on it.

Thanks guys

lincolnlocker · May 15, 2015

bent pushrod....

live life full throttle

jtgf250 · May 16, 2015

Already plan on pulling them if cps and ebps/tube check out ok. They looked good from what I could see but may go ahead and pull them to be certain.

lincolnlocker · May 16, 2015

jtgf250 said:
Already plan on pulling them if cps and ebps/tube check out ok. They looked good from what I could see but may go ahead and pull them to be certain.

if you can get overhead enough to look directly down the pr hole, you will see the hg tore from the bent rod rubbing on it..

i bent 8 pr's in my dually.. you would be surprised at how little of a bend can make your truck run like complete chit... also the other way around.. truck ran fine,so i thought, but had a wierd sound kinda like a piece of paper flopping in a windstorm... yup, bent pr... pull them all out and roll them on a flat surface.. if there is so much as a wobble, replace it...

live life full throttle

KYpatriot · May 16, 2015

How do pushrods get bent like That?

lincolnlocker · May 16, 2015

plays wack-a-mole with the piston

live life full throttle

KYpatriot · May 16, 2015

Right, but why? too many rpms? Overfueling, bad programming with too agressive timing?

Jst wondering what the usual cause is, if there is one. Mostly so i dont do it lol.

Rideracelivemx7 · May 16, 2015

Weak valve springs and winding it out on a tune will bent a push rod. I had a tick I couldn't quite put my finger on a month back for 3 weeks or so. One wrong day and full throttle showed me right quick what my tick was. Snapped a pushrod in half and found 6 other bent pushrods

TyCorr · May 16, 2015

Pussy valvesprings...

jtgf250 · May 16, 2015

Yeah this truck is all stock beside a ****ty intake.(Told the owner he needed to ditch it) The ones up front looked good from above but will get back on it when I come off night shift Tuesday morning. Had a little time before going into work this evening and cleaned up the engine so I'm not shoulder deep in oil and crap again.

lincolnlocker · May 16, 2015

KYpatriot said:
Right, but why? too many rpms? Overfueling, bad programming with too agressive timing?

Jst wondering what the usual cause is, if there is one. Mostly so i dont do it lol.

bone stock stock trucks have bent push rods just driving down the road.. my cousin that used to work at ford changed a bunch of them.. old granpa driving styles too..

Rideracelivemx7 said:
Weak valve springs and winding it out on a tune will bent a push rod. I had a tick I couldn't quite put my finger on a month back for 3 weeks or so. One wrong day and full throttle showed me right quick what my tick was. Snapped a pushrod in half and found 6 other bent pushrods

i bent one with the cruise set at 65 once... not even hammering on it.

live life full throttle

TyCorr · May 16, 2015

You can still have weak valvesprings bending one with the cruise set.

You using the standard smith bros or the thick wall?

I don't think the standard smith bros are worth the time. And id be veeeery intetested to see what a comp cams spring seat pressure is after 20 or 30k are put on them. I dont trust those springs for something modded that gets lots of miles put on it.

If you run a beehive spring and heavy duty pr whats the next danger? Busting a stock rocker arm?

lincolnlocker · May 16, 2015

TyCorr said:
You can still have weak valvesprings bending one with the cruise set.

You using the standard smith bros or the thick wall?

I don't think the standard smith bros are worth the time. And id be veeeery intetested to see what a comp cams spring seat pressure is after 20 or 30k are put on them. I dont trust those springs for something modded that gets lots of miles put on it.

If you run a beehive spring and heavy duty pr whats the next danger? Busting a stock rocker arm?

or bending the valve

live life full throttle

TyCorr · May 16, 2015

Yea? Never heard of that. I would think a rocker would break but I am not an engine builder. You seen/heard of bent valves in a 7.3?

TyCorr · May 16, 2015

I bent a smith bros pr 2k miles out with my original, used 250/200s. Got a replacement and sold the springs/arp studs/pr to Mick Miller. I wanna get stg1 springs from swamps, h11 studs and hd pushrods.