Odd timing question

[Klymptof]

My 98 6.5TD was having intermittent issues of stalling, and after extensive research seemed like it might be the injection pump. Purchased a rebuilt one, began tearing the engine down and noticed there were no nuts holding the pump in place, that it was being held in place by the three bolts on the gear and the eight injection lines on the back, just resting on the studs.
Next, I went to unbolt the bolts from the gear through the oil fill tube, and the gear turned.
So, fearing the worst, I pulled the water pump plate (there is a special place in a hot pit for whoever engineered this mess), and found the bolt on the camshaft was loose, as in I could spin it with my fingers, and it can still be tightened.
My question is this: where do I go from here?

[Robyn]

Interesting ....

I would check the cam and gears for damage due to the bolts being loose. (Check the key in the cam as well as the keyway in the top sprocket)

If the parts are in good order I would clean the bolt holes with Brakleen to remove all oil residue and blow dry. (CAM RETAINER BOLT AND PUMP GEAR)

Install new bolts using BLUE Loctite..... (If bolts are in good order they may be fine)

Blue loctite is a MUST DO on these bolts....if a bolt drops out and goes through the gears/chain the carnage is major..... DO NOT USE RED.... Blue will allow easy removal but keep things where they belong...

Install the proper nuts on the IP to retain it to the front cover.

Get the engine started and clear any codes present.

Warm up the engine and see how things work.

If you get a timing code then its likely that the pump is off just enough that the electronics can't adjust the timing enough and the pump nuts loosened and the pump moved a bit ( 1/32"- 1/16" at a time) and then re-tighten the nuts and see what happens...

A Tech 2 scan tool is really the proper way to do the settings, and to get the TDC OFFSET proper (-1.5) is a good spot... but you can fudge things and once you get the pump back within the range that the ECM can adjust the timing to what it wants it will not complain

I have been around a lot of 6.5 but have never seen a pump left without the nuts.... and the gears loose.

Yessssss...the arrangement up front is a bit hinky...


JUST AN FYI

I would be sure to check the timing marks on the sprockets and be sure they are aligned correctly.

Also be sure the pump gear and the cam gear timing marks are correct too.

With as many things messed up a good snoop through is in order...

[Klymptof]

Thank you for the info. Will see about pulling the harmonic balancer and bottom cover off next and check those other items. May as well change the timing set while I am this far in since I have no clue as to if or when it was ever changed.

[Robyn]

Sounds good.

With the front end apart fully you can get a real good visual on the cam snout, the key and how things fit after being run loose.

Generally only a fresh chain is needed to get things snug again.

Look the sprockets over really good and if you don't see any odd wear (hooked teeth) I would drop in a fresh chain.

Be sure the gear and sprocket on the cam fit well and have not wobbled the cam snout or the gear/sprocket bores.

Be sure the key is good and the gears do not slop on the key.

Most important is that the key is not loose in the cam.

If the key shows wear on the part where the gear/sprocket fit DO PLACE THE KEY.

Another good idea is to replace the Crank position sensor while the cover is off.

These can stick in the bore and can be a bitch to get out and if they break....then the cover needs to come back off later.

Clean the sensor bore in the cover and make sure any buildup of crud is gone.... Grease the new sensor well before stuffing it back in....

I like never seaze myself.

When you get ready to reinstall the the cover...

Clean all the old silicone off the cover where it meets the pan.

DO NOT LOOSEN THE PAN ITSELF...ONLY REMOVE THE BOLTS THAT GO INTO THE COVER.

I like a gasket between the cover and the block.....Smear hi temp silicone on the cover and fit the gasket and align all holes, then allow silicone to cure.
DO NOT PILE THE SILICONE ON THE GASKET...JUST A THIN FILM TO GET IT STUCK GOOD...

Goop the front pan flange with the silicone 1/8" or a bit more and add a bit of a fillet to the covers where the pan/block/cover join...

Goop the block side of the cover gasket and then carefully worry it in and onto the dowel pins.

Use silicone on the gasket that seals the water pump back plate to the cover.

Make sure the plate does not have cavitation erosion on the pump impeller side.

If the plate is badly eroded it can spring a leak through into the timing cover...

Once the cover is on the dowels get a couple midline bolts snug to hold things.

Be sure to blue loctite the bolts that are inside the cover behind the gear/sprocket.

Install the 3 inner bolts and snug down.

Add the other bolts and the pan rail ones too and tighten the entire bunch.

Tighten from center up and down from side to side to get a nice even fit...

Replace the crank seal while the cover is off too.

[arveetek]

I purchased an '86 K10 one time with a freshly built 6.2L. It left me stranded one day, and it turned out that the bolt on the camshaft gear was not torqued properly. It caused the key to shear on the camshaft, so it stopped turning the injection pump. A new key with a properly torqued camshaft bolt and Blue Loctite fixed me up.

I've never seen an engine with no IP mounting bolts; that's weird for sure. I would think there would be resulting damage due to the IP moving around.....

Casey

[Robyn]

The studs were there he said...just the flange headed nuts were missing.

Between the studs, the pump being piloted into the cover and the fuel lines all snugged up the pump can stay fairly rigid in there.

[arveetek]

The studs were there he said...just the flange headed nuts were missing.

Between the studs, the pump being piloted into the cover and the fuel lines all snugged up the pump can stay fairly rigid in there.

I meant to say mounting nuts, not bolts, but it can still move around a bit, especially with the engine gears rotating it. Just seems to me that over time some damage would occur.

Casey