Doffer Posted July 27, 2012 Share Posted July 27, 2012 I have been running a 2003 Mack MR688S the past month or so since the windmill jobs have been done, and I'm having some issues with my truck I was hoping you guys could point me in the right direction.I remember before I posted a topic about the 1994 Mack MR688S I was running and asked about the oil pressure, and you guys said that it was OK being where it was.Now on the 2003, the oil pressure is running when the engine is hot below 30 PSi at idle. Is this Okay?Also, sometimes when driving up hills the turbo sounds like it stops spooling as fast as normal. I actually loose speed because the turbo quits working. I do not notice any smoke, and the engine RPM are usually steady between 1600 - 1800 RPM. What would cause the turbo to do this?Finally, every once in a while my truck takes forever to start up, It usually happens when the engine is hot, but i've had it happen when its completely cold as well. I actually recorded a video and from the overall length it took about 6 seconds of constant cranking for it to start. I know these have the plastic bosche fuel pumps, do you think the pump could be getting weak and loosing the prime?? That would make sense to me, but it doesnt have any problems Revving up to while operating on the job, which kind of is throwing me off because when I had a fuel pump go bad, it started to sputter real bad, and this truck once it starts doesnt skip a beat besides the turbo while driving engine hours are 13565.3, 133133 miles when i fueled up todayheres a video of it starting: I really appreciate the help / comments so far, and would appreciate some help on the few issues im having currently.Thanks,Brandon Quote Link to comment https://www.bigmacktrucks.com/topic/26458-questions-about-2003-mack-mr688s/ Share on other sites More sharing options...
hatcity Posted July 27, 2012 Share Posted July 27, 2012 Oil pressure is OKTurbo-don't knowStarting- position sensor could be going. Happens once in a while with mine. Not often enough to worry for me Quote Success is only a stones throw away.................................................................for a Palestinian Link to comment https://www.bigmacktrucks.com/topic/26458-questions-about-2003-mack-mr688s/#findComment-130587 Share on other sites More sharing options...
Doffer Posted July 27, 2012 Author Share Posted July 27, 2012 Okay, thanks for the information! Quote Link to comment https://www.bigmacktrucks.com/topic/26458-questions-about-2003-mack-mr688s/#findComment-130752 Share on other sites More sharing options...
Chigozie Posted September 7, 2021 Share Posted September 7, 2021 Pls am seeing white smoke from my exhaust of my 1997 MR688S pls could u have to know what the problems is Quote Link to comment https://www.bigmacktrucks.com/topic/26458-questions-about-2003-mack-mr688s/#findComment-479535 Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.