6.2 knock

[86c20]

https://www.youtube.com/watch?v=A6tEVpHC9xs

new pump new injectors starter. pump was replaced due to a leak and hard starting injectors where after the knock started. after the pump was done the knock started 30 after starting. any one have a guess to what it is?

[craig113]

I would have to say that the timing is set wrong when you installed the new pump

[Oldriginal86]

There is a special tool that slides in the injection pump bore and engages the timing gear. This tool is torqued in the proper direction to remove slack from the timing chain. On top of the tool is a pin that re-stamps the timing mark on the front cover. I used the tool on a few engines before but never saw one with excessive slop in the timing chain. If it was mine, I would loosen the three mounting nuts and move the pump a few degrees and tighten down one nut. Start up and see if the knock changes. If it doesn't move the pump again until the noise goes away. Good luck.

[86c20]

ok i like where this is going.
now when i did this pump no one said anything about tools or timing even when i asked all said out and in and line up the marks on the block and pump. now how would i have gotten it off? is it like a dizzy and one tooth or??

[craig113]

If you download the military Tech manual TM 9-2320-289-34 (PDF File) and on page 147 it will tell you how. I do think your off one tooth.

[Oldriginal86]

If the pump was removed and the engine not turned over the timing should be ok. There is no way for the chain to disengage from the gear, not enough room. If the pin in the hub was installed in the slotted hole and all three bolts went in, you should be fine.

[craig113]

There is no chain for the injector pump it is gear to gear..
Crank to cam is chain
cam to injector is gear to gear
It is possible that when the injector was pulled out that the gear picked up slightly and then dropped down on another tooth. Retime the engine and make sure that the marks are in line and it should be fine. Crack all lines before the injectors to bleed the air out.

https://images.search.yahoo.com/imag...&type=blfnt_f2

[86c20]

ok now here is my problem with the timing stuff. if the timing was of would it not run like crap? hard start? i mean she starts like she did before the pump and when hot just tuch the key and she fires.

i am not saying you are wrong in any way just trying to get a better understanding here. one thing i can say so far is i hate 6.2 gm diesel. i wish i had the money for the detroit 453t that i want to put in.

[craig113]

If your sure the timing is correct, then you still have air in the system.

https://www.youtube.com/watch?v=OJBNlX_PXFg

[hatzie]

Leaky Injector nozzles can cause a knocking noise. A mechanics' stethoscope can isolate a nailing injector. If they all appear to be doing it then I'd suspect timing. It'd have to be off quite a bit to cause serious knocking.
Rebuild quality depends on what parts your rebuilder used in the injectors and how careful they were to balance the pop pressures. Just like Diesel Starters... The Injector nozzle market has been poisoned with cheap Asian and Indian parts that don't hold up well and don't conform to tolerances. Never let your original German Bosch housings out of your sight just like you never let that original AC Delco 27MT or 28MT starter out of your sight. The Asian/Indian garbage is just that.
I've rebuilt and pressure balanced dozens of these Bosch injectors for my VW and GM diesels over the last 35 years. I use a bottle jack pop tester with a fairly expensive precision pressure gauge. It's very fussy precise work but not really that difficult. I hand-load rifle and pistol target ammunition and it's on par with that. The major problem in the last 5 years or so has been to source decent quality nozzle sets and to cull out the Asian housings.

[Edahall]

Could also be a bad injector. Use the stethoscope to identify which injector. Then swap it with another and see if the knock moves.

[86c20]

bad injecter with 2 sets?? didnt even change after new ones but will see if i can swap with some one with known good ones. if there is air where would it be and how do i get it out? still have to play with the timing to rule that out too. thanks guys

[mrolds88]

I would start it up and crack the injector lines one at a time. The offending injector should stop making noise when there isn't enough pressure going to it. And if it is air in that line it should work out.

[86c20]

i have done that many times still knocking???

[mrolds88]

OK so ts not the air in the lines then. What do your glow plugs look like? Had them out? Maybe a tip rolling around in one of the cylinders? Also can you hear it if you unplug the IP and crank it?

[86c20]

can not here it when cranking. gp are all new and have been checked a few times. i am on my last week of work so have not had time to start runing the list of thing you guys are saying to check other then what i have already done, still need to play with the timing and get a scope to hear where it is. is there anyway its a push rod or lifter? read that some where and i know in my gas motors lifters tick not knock. just a thought but i dont know 6.2 well yet lol