Q: I have a 1999 Dodge ¾-ton diesel that’s going through starters ever month or so. The batteries and all the cables have been replaced. Not long ago the fuel injector pump also was replaced to the tune of about $2,500. Within a week or two of the new starter being installed, my truck starts fine in the morning but after two or three stops during errands around town, it starts to take an unusual amount of “cranking” to start. It eventually fails altogether after a few days of this pattern. It still sounds like it’s turning over adequately, but just doesn’t start.
A: I’m confused! If the engine is still cranking over “adequately,” why is the starter motor suspect? Unless you have to crank the engine for so long to get it restarted that the starter motor is overheating and failing, I don’t see the direct link between the starter and the no restart.
Ask the dealer to check to see if the ECM (electronic control module) in your vehicle has been reprogrammed with updated software as per TSB # 18-015-00 Rev. A dated December 2000. The ECM recalibration specifically focuses on hot/warm restart issues.
If the starter motor is somehow the issue, it can be tested for electrical current draw. This 3.6-horsepower electric motor should draw 450 to 700 amperes while cranking the warm engine.
If the issue is a failure of the starter pinion gear to engage or stay engaged to the flywheel/flexplate ring gear, the issue might be damaged teeth on the ring gear.
Q: After a half-hour of running, the low-oil warning alarm on my 2009 GM 6-liter pickup with 109,000 miles goes off and the oil-pressure gauge reads below 10psi. The sending unit, oil pump and oil screen have been replaced with little or no correction. I have found a lot of chatter on the Internet about this, but no solution for my issue. Also, I am over on miles but under on time for warranty; does your experience tell you GM might do something for this problem and is there any place the public can find manufacture’s service bulletins?
A: Many public libraries offer access to the ALLDATA automotive database that lists specifications, repair information, service bulletins and recall data for modern cars and trucks. It is also available as a subscription online for personal or professional use. According to the GM data in ALLDATA, minimum hot oil pressure specs on this engine are: 6psi@1000rpm, 18psi@2000rpm and 24psi@4000rpm.
I did see “a lot of chatter” on the Internet about this issue, but didn’t find solutions, nor did I find any specific service bulletins or recalls.
Having replaced the oil pump, screen and sending unit, make sure that the oil filter is correct for this engine and scan the ECM for DTC fault codes relating to the oil pressure sensor circuit — P0521/22/23. I also would suggest installing, even on a temporary basis, a mechanical oil-pressure gauge to confirm accurate oil-pressure numbers.
If oil pressure is lower than spec, it might be due to engine bearing wear, a sticky oil-pump pressure regulator valve, a faulty oil pump o-ring, a missing oil gallery plug or a broken valve lifter. If you don’t find an obvious cause and the engine is not making any knocking, taping, rattling-type “low oil pressure” sounds, you could try treating the symptom with a heavier viscosity oil like a 10W-40.
Will GM “do something” to help? The only way to know is to ask nicely.