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turckster

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Posts posted by turckster

  1. On 1/6/2021 at 1:07 PM, John3406 said:

    Have a couple questions for you guys. Working on a inframe on a e7 350 mechanical. Do you guys recommend replacing head bolts and rod bolts? Also the cam looks good no flaking etc. What are your thoughts on replacing the cam? Im kind of new to mack motors but rebuilt plenty of deere, cat and cummins. Thanks 

    I reuse head bolts unless they have pitting or heavy rust. I replace rod bolts on E6/E7/Etech engines, never reuse, that's our company policy. Just a note, main bearings are the same on #2,3,5&6. #1 looks the same but it is not, the tang is slightly offset. If you mix that bearing then you loose all crank thrust. Seen many tech's scratch their heads trying to figure out why there is no crank thrust after replacing main bearings. Good luck

     

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  2. 5 hours ago, alex g said:

    I'll check centramax filter. If it's the oil pump do they just get noisy or should I replace it?

    I had overhauled an E7 some time ago and it had a hum right where the oil pump was located. We contacted Mack reman center and was told to not worry about it, known issue. Since then I have noticed it more often but never seen an oil pressure issue related to the noise.

  3. The puff limiter is to limit rack travel to limit smoke. As manifold pressure builds the bimba valve(on inj. pump) allows more rack travel. As long as you have the correct reversing relay and the bimba valve is correctly shimmed, the engine should run just fine. The engine will get full rack travel until the park brake valve is pushed in to aid start-up. On an engine with a LDA, the rack is mechanically restricted until manifold pressure overcomes the LDA allowing full rack travel. 

  4. When priming the fuel system is fuel leaking around the primer pump (little plastic cap next to pump handle)? If so, the o-ring below the plastic cap has eroded allowing it to suck air. The plastic cap can be replaced. Mack/Volvo should be able to get that part. 

     

  5. A fault like this could be many things. The fault's possible cause is listed as def quality and/or dosing too low but could be many things such as bad nox sensor(s), egr flow, plugged egr cooler, intake/exh. leak, injector cups, bad injector(s), turbo, egr diff. psi sensor and so on. Check def quality with refractometer. Remove def doser valve and check for excessive build up of dried def inside dpf outlet and flow test def doser valve if possible. Make sure def pump is building and maintaining 128-132 psi. If all looks ok then it's a matter of elimination by checking above mentioned items. The PDF below is step by step testing for 4094 w/FMI 18 and 5394 FMI 17, the fault you have w/FMI 1 is basically the same. If everything checks out ok, check the part numbers on both nox sensors and if they are not current, replace them. 

    snm 13- 022 archive spn5394 fmi17 diagnostic.pdf

  6. Right off the top of my head, (1)- possible EGR valve stuck open-- remove the egr cross tube (over valve cover) and try to start the engine. If it starts the egr valve is stuck wide open choking the engine w/exhaust. Normally they would start, just run like crap, but you never know.  (2) DPF plugged to max. Have seen a DPF plugged and it wouldn't let an engine start. Remove the flex pipe at the DPF inlet and try to start the engine. (3) Bad engine brake solenoid- it will cause full engine oil psi to rocker shaft causing exh. rocker pistons to hold exh valves open.  Usually while cranking it sounds like the engine has no compression when the valve goes bad. (4) Bad Injector(s) or badly leaking injector cup(s) can cause a no start. Seen this a lot as well. Loosen the fuel return regulator, prime fuel system until fuel flows out fitting and then try to start the engine (fitting loose). If it starts it will run horrible. With the engine running, take a flashlight and look inside the fuel tanks at the fuel return port/pipe (the top one). If there is a lot of bubbles coming out the return pipe you have bad injector cups. Compression is blowing the fuel out of the galleys and the only proper fix is replacement of all inejctor/cups. 

     

  7. Years ago we had customers that had the same issues, mostly heavy duty oil field application. The truck felt like something was holding it back then it would start to pull ok or drop out in high upper rpm's. Our forman would call Mack tech support and explain issue, they would usually tell us to flash both eecu and vecu, DO NOT save customer parameters and program w/new datafiles. I would print out customer parameters and manually enter them back. I think it was called heavy haul file or something like that. Been a while and slept since then. 

  8. If the eecu wasn't powering up the the engine wouldn't crank over since the eecu provides ground for the starter relay. Loosen the fuel return regulator valve at the front of the head, pump the fuel hand pump and verify you have fuel coming out around the fitting. Try starting the engine then, should have fuel psi while cranking. Could possibly be cam timing, easy check, Remove plug on bottom of flywheel housing and rotate engine until "0" lines up with bump in hole. The cam tdc mark should be between lines on #1 cam cap. If its on the edges or outside the marks then cam timing is an issue, but it being on the edges it should still run, just not so good. Do you have access to software to read faults? That would be helpful.

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  9. There is an inconsistent signal between the cam and engine position sensors. The most likely cause is the flywheel ring has moved. You should be able to unplug one or the other sensor and the engine should run, may take some cranking to start though. There is a procedure to check if the notched position has moved on the flywheel but right now I can't find it. 

  10. The IMT (intake manifold temp)sensor are on pins J2 80 and 61. The sensor you are checking is the  aftercooler outlet temp sensor (pins J2 84 and 67). The IMT sensor is located in the intake near the center (next to the VGT control valve). Knowing the fmi will help in what direction you need to perform diagnostics. 

  11. Could possibly be a cracked injector cup at the body to tip area, seen that many times. Could also be a leaking egr cooler, worst case could be cracked head. I don't think a bad water pump would cause pushing coolant unless the engine overheated and cracked the head or damaged the egr cooler. 

    If the upper radiator hose is hot to touch and the lower radiator hose is cold the you may have a water pump issue(vanes spinning on w/p shaft). Even if the water pump is determined to be bad its not the reason for pushing coolant. 

  12. When replacing injector(s) you should program their calibration codes and perform a learned data reset. That way the engine ecu relearns idle characteristics and so forth to adjust for a smooth idle. Or, let the engine idle for a while with all accessories turned off so it can re-adjust/learn accordingly. 

  13. 41 minutes ago, bbigrig said:

    Yes...about 60lbft coming out on the hold downs is about right. 

    When you torque the inj. hold downs to 15 ft/lb, 180 deg, back off to 7-8 ft/lb, torque to 18 ft/lb and torque turn to 90 deg that averages 45-50 ft/lb. Therefore there is no way when backing off a bolt that you are going to get 60 ft/lbs. Several years ago there was a recall that require retorque/check of MP8 injector hold downs and the torque spec was 45 ft/lbs.

    It may be that is the problem, not tight enough. But, what do I know, I'm not an engineer, just a dude that fixes their mess ups. 

    • Like 2
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