Jump to content
fjh

SO how is the "new" Common rail working out for Mack

Recommended Posts

Just asking for feed back purposes! We have quite a few running in our area now with few problems so far We have a small glitch with one running rough at the moment interment issue we think maybe a fuel rail regulator  may have connection problem, the plug looks iffy ,Not throwing up codes But we have heard rumors!  They have lots of stock on the little harness and the solenoid could be a good thing maybe a bad thing !  Any words? Kind or otherwise!

😅

Share this post


Link to post
Share on other sites

There is a service bulletin on the harness under the valve cover and the sensor on the fuel rail. I can’t remember if it’s the rail pressure sensor or the pressure regulator.  We have 2 common rail Mack’s in our fleet and both were repaired due to fault codes. The fault codes caused no performance issues. Other than that, any other issues we had were corrected with software updates . 

Share this post


Link to post
Share on other sites

“New” common rail? Did they come out with something besides that Mickey Mouse thing they call common rail?

  • Like 1

Share this post


Link to post
Share on other sites
1 hour ago, 1965 said:

“New” common rail? Did they come out with something besides that Mickey Mouse thing they call common rail?

Nope same old same old! Surprisingly enough the dollar store HP common rail seems to work fine ! Time will tell! C how it goes!  

Edited by fjh
  • Like 1

Share this post


Link to post
Share on other sites
1 hour ago, Mackpro said:

There is a service bulletin on the harness under the valve cover and the sensor on the fuel rail. I can’t remember if it’s the rail pressure sensor or the pressure regulator.  We have 2 common rail Mack’s in our fleet and both were repaired due to fault codes. The fault codes caused no performance issues. Other than that, any other issues we had were corrected with software updates . 

Thanx  Pro  got a E service going on it they have said to continue toward the two replacement items We do have a performance issue ! no codes  C how it plays out ! Lucky for us its snowing this week  so most dump truck  jobs will be shut down for a bit  give us time to get the fix tryed! 😅

Edited by fjh

Share this post


Link to post
Share on other sites

We have been playing with common rail engines for over a year now. We had them in the Volvos months before the Macks. Lots of pressure sensor failures under the valve cover. A few of the same harness and about half a dozen injector failures. A couple of the plunger injectors became quite noisy through the valve cover. Also issues with the AHI module that is now part of the fuel filter housing.  All in All, Mickey mouse design and an engineering step backwards. Can't upload any pics of the tear downs I have in my phone.

Wish the system was external with a high pressure pump.

  • Like 1

Share this post


Link to post
Share on other sites

So I'm fishing for info here we have  the afore mentioned truck  sits over night ,it starts clean then ten seconds or so into the run it starts missing and stumbling like its passing an air bubble past the injectors then cleans up  and runs Ok  No CODES ! Now the guy is quite fussy and is not happy with this anomaly that has started here  with in the last couple of days Is been cold here 5 or so below freezing not sure if this has anything to do with it however! not sure where the check valves would be on the system or if its loose its prime on the high side or the low side  of the system ,  the fix we thought might repair this the rail sensor and harness  did not correct this condition ! Having Zero experience with this  fuel system  its going to be  hard to nail this down ! Searching for clues to this issue if  anyone has ANY experiences feel free to pipe up!   Should we be Taking an oil sample to see if there maybe fuel in the oil ? using the pretense that where there is  Air there is likely a fuel leak???  No visible leaks on the outside!!!

  Reasonable Opinions?

Setting fire to it Is not an option At this point! 😁

Share this post


Link to post
Share on other sites

Any kind of "cold enrichment" type solenoid or transmitters in the system? If it's a consistent time before the symptom reveals it's appearance, the problem is usually something related to input sampling. Does the symptom show only after initial start and is gone till the next engine start several hours later, or if the engine is shut right off, will the symptom reappear again after restart? 

Share this post


Link to post
Share on other sites
1 hour ago, Rob said:

Any kind of "cold enrichment" type solenoid or transmitters in the system? If it's a consistent time before the symptom reveals it's appearance, the problem is usually something related to input sampling. Does the symptom show only after initial start and is gone till the next engine start several hours later, or if the engine is shut right off, will the symptom reappear again after restart? 

Rob These are definite questions to be worked thru  ! Because its so long between getting parts and trying stuff its hard to Gauge ! Seems to be an overnite or parked  a day or so anomaly at this point!  I have suggested getting an oil sample done at this point we will see if that suggestion get any action from the gurus! The sound is reminiscent of An air pocket on a normal fuel system! Seems to clear after a minute or so of running If We find a fix I will post it! .Macpro  Said above there is a rail reg and preasure  sensor !We changed out the reg and the harness to it as the  plug looked to be getting warm! He went to school on this system I how ever are on the outside looking in! 😥

Edited by fjh

Share this post


Link to post
Share on other sites
4 hours ago, fjh said:

So I'm fishing for info here we have  the afore mentioned truck  sits over night ,it starts clean then ten seconds or so into the run it starts missing and stumbling like its passing an air bubble past the injectors then cleans up  and runs Ok  No CODES ! Now the guy is quite fussy and is not happy with this anomaly that has started here  with in the last couple of days Is been cold here 5 or so below freezing not sure if this has anything to do with it however! not sure where the check valves would be on the system or if its loose its prime on the high side or the low side  of the system ,  the fix we thought might repair this the rail sensor and harness  did not correct this condition ! Having Zero experience with this  fuel system  its going to be  hard to nail this down ! Searching for clues to this issue if  anyone has ANY experiences feel free to pipe up!   Should we be Taking an oil sample to see if there maybe fuel in the oil ? using the pretense that where there is  Air there is likely a fuel leak???  No visible leaks on the outside!!!

  Reasonable Opinions?

Setting fire to it Is not an option At this point! 😁

We had several bad reman injectors that caused a similar issue. Truck would start and run fine for about 2 seconds and die. On a few we saw fuel in the oil , some we didn’t . We put 60 psi air pressure into the the fuel galley in the side of the head and capped off the pressure relief valve. Sprayed the injector plungers and body down with soapy water. We also bumped the engine over and re-checked with plungers up and down. This was on non common rail engines though. What’s last 6 of vin and model

Share this post


Link to post
Share on other sites

We've had some issues with the newer style fuel filter housings. A couple of strange diaphragm looking parts falling out with the removal of the fuel filter. 

Not related to this issue, we had a few cam lobes on the camshaft (which are now pressed on) turn out of time.

Share this post


Link to post
Share on other sites
2 hours ago, Macktech689 said:

What you are probably dealing with is high oil pressure in the rocker shaft causing  low compression when the oil is cold, usually cause by running 15W40 instead of 10W30. Next time you check it cold install the gauge set on the front of the head. rocker pressure should be below 120 kPa, if the pressure goes to 150 kPa report results to tech support.

Thanks for your response! A question to your response what is the higher oil pressure doing to cause lack of compression on start up only for 10 to fifteen seconds then clears up? as explained the miss sounds like air in the fuel if this were a normal fuel system! Your expectation could be correct as the engine starts Clean then the miss appears for a brief period after running for a few seconds possibly long enough for the pressure to effect the running not sure didn’t link the two at the time .and the sound is not like the engine brake coming on!

Edited by fjh

Share this post


Link to post
Share on other sites

Your problem sounds nearly identical to a common rail I had a couple of weeks ago, cold start misfire. Installing a different solenoid valve to lower the rocker pressure fixed that one. Higher than normal pressure was unseating the brake pistons far enough to slightly open the exhaust valves and lower compression causing the misfire. Just food for thought, take it for what it's worth.

Share this post


Link to post
Share on other sites

Ahh now I get where your going with this !🤔   Well if this is the case  this issue will probably disappear until the next cold snap we now have a little warmer weather we will see next week if it smartens up The comment about the oil May be part of the issue as well not sure what oil is being used  here, using a lower viscosity oil May affect this situation! What I don't Get is the situation is only momentary at start up  lasts as long as it would take to pass an air bubble thru a system after service! 10 - 30 seconds or so! One would think it would take longer run time than that, to change the viscosity of the oil to make that valve reduce the pressure! Your comment also begs the question When was the oil last changed? Another unasked / unanswered  question! 🙄

Thanx for the input 

Share this post


Link to post
Share on other sites
On 2/17/2019 at 9:36 AM, Macktech689 said:

Your problem sounds nearly identical to a common rail I had a couple of weeks ago, cold start misfire. Installing a different solenoid valve to lower the rocker pressure fixed that one. Higher than normal pressure was unseating the brake pistons far enough to slightly open the exhaust valves and lower compression causing the misfire. Just food for thought, take it for what it's worth.

 

On 2/16/2019 at 11:56 AM, Macktech689 said:

What you are probably dealing with is high oil pressure in the rocker shaft causing  low compression when the oil is cold, usually cause by running 15W40 instead of 10W30. Next time you check it cold install the gauge set on the front of the head. rocker pressure should be below 120 kPa, if the pressure goes to 150 kPa report results to tech support.

So  as we disgust!  after our little cold snap here this problem has disappeared!  Did some research and yes 15/40 is being used to service this engine! So were going to assume that this was the cause ! The engine started up clean once the weather warmed up .Were  going to assume once the oil pressure comes up the engine brake becomes partly en gauged till the warmer oil from the base  flows through the system ! ??? Maybe?🤔 The customer is a little put off now Because his older units all use 15/40 which he buys in bulk and this unit will require 10/30 ! 5 gallon pails I suppose! 😉

Thanx for the ideas !

  • Like 1

Share this post


Link to post
Share on other sites

Thread is a good read, I was perplexed first time I saw a truck that didn't use 15w40 for steering fluid, but older Mack trucks are all I'd driven to that point. Gotta use what the manufacturer tells you to use, doesn't matter if you bought something else in bulk for other trucks.

Share this post


Link to post
Share on other sites
16 hours ago, JoeH said:

Thread is a good read, I was perplexed first time I saw a truck that didn't use 15w40 for steering fluid, but older Mack trucks are all I'd driven to that point. Gotta use what the manufacturer tells you to use, doesn't matter if you bought something else in bulk for other trucks.

Yup You Are correct ! how ever If you are not privy to all the info you can be led on a wild goose chase like this one! And  WE would not have Thought of this scenario if it weren't happening  till it was brought to my attention by Macktech689! and being able to experiment with it first hand !   customer  has not had issues with using 15/40 up to this point 10/30 now the accepted norm for oil so we all have to adjust to this! Like everything we now have experience! This should be added to a (Rough running when cold )  A topic in Case base reasoning ! 😉  Right at the VERY TOP ! First Question !!!  Is your engine equipped with the proper Viscosity oil !🤔

Now that we are aware of the issue He can use this oil during the warmer weather and change over in winter if he needs to ,not a problem !

Comes down to experiences! 

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...