Dan107 Posted January 19, 2022 Share Posted January 19, 2022 Evening everyone. I have a 2012 Pinnacle CXU613, MP8. I was unloading my pneumatic trailer yesterday and noticed the engine began making excessive noise. I initially thought something internal was about to fail. The noise quieted down somewhat, and on the way back home, I only noticed it when the truck was at idle. I put the computer on it today and there was an inactive injector code related to a bad signal. Through diagnostics, (cylinder balance reset, and compression test) I found that #1 and #6 cylinders are outside of normal (big red bars on the graph) with #1 being the worse of the two. I ran an overhead on it, and did another compression test with the same results. My question is; does this mean I need to do an in-frame? Is there any other tests that I could run to help me determine if this is needed? Any help would be greatly appreciated. Quote Link to comment https://www.bigmacktrucks.com/topic/69080-bad-signal-from-injector/ Share on other sites More sharing options...
Onyx610 Posted January 19, 2022 Share Posted January 19, 2022 I look forward to this one, I hope you get plenty of info on this… Quote Link to comment https://www.bigmacktrucks.com/topic/69080-bad-signal-from-injector/#findComment-487377 Share on other sites More sharing options...
63BMack Posted January 19, 2022 Share Posted January 19, 2022 Injector cups ???, how many miles are on it. Quote Link to comment https://www.bigmacktrucks.com/topic/69080-bad-signal-from-injector/#findComment-487379 Share on other sites More sharing options...
Dan107 Posted January 19, 2022 Author Share Posted January 19, 2022 950000. Replaced injectors and cups about 500000 miles back. Quote Link to comment https://www.bigmacktrucks.com/topic/69080-bad-signal-from-injector/#findComment-487380 Share on other sites More sharing options...
Mackpro Posted January 19, 2022 Share Posted January 19, 2022 I have seen the engine brake plunger/pistons unscrew themselves causing this issue. Also with that high of miles I’d really look for broken valve springs and for the intake and exhaust valves to start wearing up into the valve seats. Especially check this if the engine has been deleted. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69080-bad-signal-from-injector/#findComment-487395 Share on other sites More sharing options...
Mackpro Posted January 19, 2022 Share Posted January 19, 2022 https://static.nhtsa.gov/odi/tsbs/2017/SB-10090649-6903.pdf Quote Link to comment https://www.bigmacktrucks.com/topic/69080-bad-signal-from-injector/#findComment-487396 Share on other sites More sharing options...
Dan107 Posted January 19, 2022 Author Share Posted January 19, 2022 I forgot to add, the head was rebuilt last year at this time with all the seats, guides and valves replaced. #2 liner cracked and I had to replace it. Also, there is no smoke, or oil consumption from the engine. I did check the springs yesterday, and they all look good. Quote Link to comment https://www.bigmacktrucks.com/topic/69080-bad-signal-from-injector/#findComment-487401 Share on other sites More sharing options...
R.E.D Posted January 19, 2022 Share Posted January 19, 2022 13 hours ago, Dan107 said: Evening everyone. I have a 2012 Pinnacle CXU613, MP8. I was unloading my pneumatic trailer yesterday and noticed the engine began making excessive noise. I initially thought something internal was about to fail. The noise quieted down somewhat, and on the way back home, I only noticed it when the truck was at idle. I put the computer on it today and there was an inactive injector code related to a bad signal. Through diagnostics, (cylinder balance reset, and compression test) I found that #1 and #6 cylinders are outside of normal (big red bars on the graph) with #1 being the worse of the two. I ran an overhead on it, and did another compression test with the same results. My question is; does this mean I need to do an in-frame? Is there any other tests that I could run to help me determine if this is needed? Any help would be greatly appreciated. I'm not to educated on mp engines but if they are like any other diesel engine, I would assume that a cylinder balance or contribution test with failed compression will cause the engine to speed up where the compression stroke happens in the dead cylinder , it's an audible speed change when cranking.did you test compression with a known good analog gauge or just electronically? 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69080-bad-signal-from-injector/#findComment-487411 Share on other sites More sharing options...
R.E.D Posted January 19, 2022 Share Posted January 19, 2022 #1 and #6 are on the same Tdc stroke,just something to note Quote Link to comment https://www.bigmacktrucks.com/topic/69080-bad-signal-from-injector/#findComment-487412 Share on other sites More sharing options...
fjh Posted January 19, 2022 Share Posted January 19, 2022 (edited) 4 hours ago, Dan107 said: I forgot to add, the head was rebuilt last year at this time with all the seats, guides and valves replaced. #2 liner cracked and I had to replace it. Also, there is no smoke, or oil consumption from the engine. I did check the springs yesterday, and they all look good. Mack pros got a point! To the un trained eye I the engine brake slaves would not be easily noticed! You claimed to of done a valve set did you adjust much on the 1-6 we usually catch this issue when doing a valve set It shows up as a real tight engine brake set on the offending cyls! Also it is possible you got some pin fretting or rotten wire on those two injectors causing the codes ! possibly unrelated to the noise! Just sayin Edited January 19, 2022 by fjh 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69080-bad-signal-from-injector/#findComment-487416 Share on other sites More sharing options...
Dan107 Posted January 19, 2022 Author Share Posted January 19, 2022 1 hour ago, fjh said: Mack pros got a point! To the un trained eye I the engine brake slaves would not be easily noticed! You claimed to of done a valve set did you adjust much on the 1-6 we usually catch this issue when doing a valve set It shows up as a real tight engine brake set on the offending cyls! Also it is possible you got some pin fretting or rotten wire on those two injectors causing the codes ! possibly unrelated to the noise! Just sayin Thanks for the help everyone! To answer this, yes 1 and 6 were tight and there is also cracked wire shielding as well. I'm going to address these two issues and try again. Quote Link to comment https://www.bigmacktrucks.com/topic/69080-bad-signal-from-injector/#findComment-487419 Share on other sites More sharing options...
fjh Posted January 19, 2022 Share Posted January 19, 2022 The rocker arm assembly must be removed check them ALL! There is a special tool made to hold the slave While repairing it however you can get by with some aluminum soft jaws in a vice! Quote Link to comment https://www.bigmacktrucks.com/topic/69080-bad-signal-from-injector/#findComment-487425 Share on other sites More sharing options...
Dan107 Posted January 19, 2022 Author Share Posted January 19, 2022 (edited) Okay, so I'm also replacing the two injector cups while I'm here. I pulled the #1 cup and the injector hole filled with coolant. I don't recall this happening when I originally replaced the sleeves and injectors. Do I have something else going on? Head gasket??? Edited January 19, 2022 by Dan107 Quote Link to comment https://www.bigmacktrucks.com/topic/69080-bad-signal-from-injector/#findComment-487428 Share on other sites More sharing options...
Mackpro Posted January 19, 2022 Share Posted January 19, 2022 There is coolant around the cup so if you don’t drain the coolant before you remove the cup then it will fill up with coolant. Quote Link to comment https://www.bigmacktrucks.com/topic/69080-bad-signal-from-injector/#findComment-487429 Share on other sites More sharing options...
Dan107 Posted January 19, 2022 Author Share Posted January 19, 2022 Okay, good deal...I'm just showing my ignorance! Quote Link to comment https://www.bigmacktrucks.com/topic/69080-bad-signal-from-injector/#findComment-487430 Share on other sites More sharing options...
Dan107 Posted January 20, 2022 Author Share Posted January 20, 2022 New injector cups installed on #1 and #6. Cleaned and serviced the plungers. Put it back together and the injector harness cracked and frayed to the point it is beyond repair. The connectors on some are coming apart! $1484.82 for a new harness because Mack/Volvo doesn't think it practical for a connection and separate injector harness! Turbo in December, now this! Quote Link to comment https://www.bigmacktrucks.com/topic/69080-bad-signal-from-injector/#findComment-487525 Share on other sites More sharing options...
Mark T Posted January 20, 2022 Share Posted January 20, 2022 Pretty common issue with those harnesses. On the bright side ???? likely avoiding some other harness related issue that wasn't too far away from showing up. Quote Link to comment https://www.bigmacktrucks.com/topic/69080-bad-signal-from-injector/#findComment-487526 Share on other sites More sharing options...
fjh Posted January 21, 2022 Share Posted January 21, 2022 14 hours ago, Dan107 said: New injector cups installed on #1 and #6. Cleaned and serviced the plungers. Put it back together and the injector harness cracked and frayed to the point it is beyond repair. The connectors on some are coming apart! $1484.82 for a new harness because Mack/Volvo doesn't think it practical for a connection and separate injector harness! Turbo in December, now this! Yup you have to by a new truck if you want a new practical connection! Quote Link to comment https://www.bigmacktrucks.com/topic/69080-bad-signal-from-injector/#findComment-487550 Share on other sites More sharing options...
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