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View Full Version : 6.5 w/Supercharger Knock/Ping/Tap in #7 &#8



tt4ctis3
07-08-2004, 09:06
Hi all Chip here from New Orleans,
I have a 95 hummer with a Diesel Depot replacement engine. I added everything available for the motor including 18:1 pistons, main bearing girdle strap, high pop injectors, 350 hp injection pump, geared timing, align ported everything, ceremic coating on the exhaust ports, cylinder heads and piston tops and balanced the whole rotating assembly. When I installed all the components and the whipple supercharger there was an immediate Knock/ping/tap seamingly comming from the rear of the engine. After pulling #7 and #8 glow plugs I noticed the tips were broken off so I replaced them. I pulled injectors and replaced them but nothing seemed to have an effect on the noise. I've driven the truck with the noise for several hundred miles hopeing either it would resolve itself or the problem would become evident. I've sence reinspected the injectors and the tips were burnt blunt on 7 and 8. I replaced the pump and all injectors and tired my best to adjust the timeing to no avail. Can someone please help me

AndyL
07-08-2004, 09:15
Are you running the high volume water pump and dual T-stats? I believe the older coolant setup was known to run as much as 20+ degrees hotter on the 7 and 8 cylinders. I would think the coated pistons/heads would help prevent detonation even with the higher temps but maybe there is simply too much boost with the wipple.

How much boost do you run (low and high rpm) and what is your timing set at?

Does it knock when the engine is cold?

grape
07-08-2004, 09:45
sounds like some injector lines are crossed on the back of the pump, and as a result the timing is waaaaaaaayyyyy off somewhere.

tt4ctis3
07-08-2004, 10:06
Thanks for the quick responses.

I am running a HV waterpump but because of the whipple I needed to use the one provided by them so I'm not running the dual t-stat. It dosen't seem to make the Knock/Ping/Tap upon start up but shortly thereafter. I'm running at idle 1.5 - 2.0 lbs of boost and high 3200 rpm's about 15 lbs.

tt4ctis3
07-08-2004, 10:07
How do I know what the timing is set at -

AndyL
07-08-2004, 11:05
I think grape has hit it, double and triple check that the lines are correct. If the 7 and 8 were crossed it would do exactly what you describe.

tt4ctis3
07-08-2004, 11:59
cool -- something to try -- thanks grape

would you happen to know the order -- don't know if firing order is correct term
for a diesel

patrick m.
07-08-2004, 16:10
pic gone

[ 07-09-2004, 02:57 PM: Message edited by: Patrick m. ]

patrick m.
07-08-2004, 16:12
sorry, dodnt know it was going to be so big.
as soon as i know it has been viewed, i'll edit it out.

whatnot
07-08-2004, 16:37
Is anything touching an injector line? Mine was touching the pipe to the heater pipe and it was a noticable knock inside the truck.

cudaaa
07-08-2004, 19:13
Did you get the pieces of the glow plug tips removed? cudaaa

tt4ctis3
07-09-2004, 05:58
Thanks to all for your input. I will check the timing this weekend and let you all know the outcome on Monday --
Thanks again

diesel joe
07-12-2004, 12:35
When the glow plug tips are burned off, it is highly unlikely that they went out the exhaust valve.They more often than not are stuck in the crown of the pistons and slamming against the cyl head after the piston starts to swell when warming up. If the engine is not missing, and no white smoke out the tail pipe the injector lines are probably not crossed.
So what caused the glow pllugs to burn off in the first place?

tt4ctis3
07-14-2004, 08:48
It is in fact running rough and smoking -- do you think it's the crossed lines? As far as the pieces of glow plug, the knock does not weaver at all it's there almost imedeiatly after starting --I have to chack the injection lines...everything seems to be pointing at that --
Thanks for the reply -- i'll keep those interested posted --