A friends LBZ started knocking today (2006 with about 260K miles). He was driving it easy and started making noise and idling really rough and shaking the engine. It is putting out some black smoke at idle, and anytime you lean on the throttle to mildly accelerate. He stabbed it one time and it was pretty black. The knocking seems to go away during deceleration. Check engine light does not come on.
I checked the codes with a Tech II, and the only code was P2563 - Boost control position sensor, which he has had for a few months. There is no white smoke or excessive blow by when you remove the oil cap, and the way he drives (really, like Mrs. Daisy), I don't believe he hurt the engine mechanically. We have not done a compression test.
I tried to get the balance rates, but it idles too fast when in Park >1000. When it is started, it fires right up (knocking the whole time) and idles at about 650 rpm, then after about 30 seconds climbs up to the ~1000 (which is weird to me, as the idle according to B0701-Base Idle Speed, Cold should never go that high). When I put it in Drive, the idle drops to about 650 & is pretty rough, and the balance rates are mostly +/- 2.5, with a 3.5 and a 4.8, which seems OK in gear. Rail pressure at idle is close enough to desired ~5000 psi. We did check to make sure the grounds were tight.
Is this symptomatic of bad injector(s)? I'm kind of stumped with no codes. When I tried to command individual injectors off with EFILive, it did not seem to make any difference, but I have never tried that before...
Any help is appreciated. Thanx
I checked the codes with a Tech II, and the only code was P2563 - Boost control position sensor, which he has had for a few months. There is no white smoke or excessive blow by when you remove the oil cap, and the way he drives (really, like Mrs. Daisy), I don't believe he hurt the engine mechanically. We have not done a compression test.
I tried to get the balance rates, but it idles too fast when in Park >1000. When it is started, it fires right up (knocking the whole time) and idles at about 650 rpm, then after about 30 seconds climbs up to the ~1000 (which is weird to me, as the idle according to B0701-Base Idle Speed, Cold should never go that high). When I put it in Drive, the idle drops to about 650 & is pretty rough, and the balance rates are mostly +/- 2.5, with a 3.5 and a 4.8, which seems OK in gear. Rail pressure at idle is close enough to desired ~5000 psi. We did check to make sure the grounds were tight.
Is this symptomatic of bad injector(s)? I'm kind of stumped with no codes. When I tried to command individual injectors off with EFILive, it did not seem to make any difference, but I have never tried that before...
Any help is appreciated. Thanx
