KNOCK

[mhagie]

I tried this post on the 6.2 forum with little response so I'll try over here.
I have a Avant 6.5 reman W/DB2-4911 freshly installed ready for trial run however when I put it in gear a knock shows up under load.
You can blip the throttle and hear it rather well, loosen #7 inj line and it goes away. Thought it was injector checked it and noticed it was a reman so removed all injectors replaced with new DELPHI units, didn't help knock is still there.
upon removal of injectors it was observed that # 7 & # 8 were clean on bottom all others had a small build up of soot, So it tells me those two cyls aren't firing corectly but why? it was also observed that #7 follows #8 in the firing order is there a clue here?.
Pump is new reman also.
Torque converter bolts were torqued as per specs , inj lines look good no kinks.
Any and all ideas are appreciated, this is a high dollar performance reman and is very frustrating to diagnose :mad: :mad:
I thought I cut a fat hog is the a#$ but all I got was the smell.
Thanks, Merle

[GARY PAGE]

Did the engine ever run correctly?

[mhagie]

No,its brand new reman right out of the crate,thats why its so frustating, :mad:
Total distance driven 1.5 mi.scared all the way.
Idle knock free slighty rough, add load, KNOCK
Timing set at rebuild shop,ran in for 30 min or so.
Cold start produces rather loud diesel hammer so confident timing not retarded.
Set 10* at idle falling off to 5* at 1100

[catmandoo]

thats kinda weird with the 2 cyls together like that ,years ago i was drivin down the road with my 6.2 pickup and swear to god something went out the pan it knocked so hard pulled over,shut it off checked for massive oil leak,had none started it and no knock so took off had good oil pres and it didn't happen again for 2 weeks and did it again.so replaced inj's thought one sticking and 2 weeks later same thing,then got to thinking ever time it did it i had fuel from a certain station,so quit buying from them and no more problems,have you maybe tried switching inj's with other cyls to see what happens.and if you think it has a knock come on over to this side of the state and i'll show you an 82 sub with a banks thats knocked since a rebuilt motor 60,000 miles ago and i mean this baby knocks loud and only on one cyl ,had pan off checked brgs and pistons for cracks and nothing so said to heck with it i'll drive it til it drops, then i'll know what it is ,but i can see your point them engines aren't cheap by any means and a guy would expect nothing short of a great engine,whats avant say about it?

[mhagie]

Avant is scratching head as much as me.
Going to make an appointment next week with the IHC service center we have locally and get their opinion.
I do know that I WILL NOT drive this thing with a knock after spending the kind of money I spent on it, add the cost of a performance reman, add a new Banks Turbo and we're talking some serious money here. :mad: Dam dam double dam I knew I should have put a D/Max in it. :D
Wasn't sure I could fit it into a 80 silverado.
Anyway keep the Ideas coming guys I appreciate it.....Merle
Christ I hope I get this POC running for the 04 rendezvous I don't want to hear, Gee, like your truck,love your knock.
BTY, catmandoo this knock isn't just a run of the mill knock, this one is pronounced,like a squirril on steroids with a ball-peen hammer inside the block trying to beat his way out.

[ 11-16-2003, 06:27 AM: Message edited by: mhagie ]

[Jim P]

This is just a thought, but is it possible that the #7 and #8 injector lines are switched around on the pump? That would make it fire at the wrong time and possibly cause a knock.

[Randee of the Redwoods]

Hmmmmmmmm...this is a new one on me. And so close to home, too. What are the chances that the knock in my Ebay truck is caused by this? My pump has a green tag denoting a changed pump. Is it possible? Details here are my engine has great throttle response and a seeminly smooth idle(no shakes or rattles).