Starter grinds, engine won't start after driving

[Crunch]

Starter cranks, engine won't start after driving

I've been having this intermittent problem over the last month or so. The truck starts fine after sitting all night or all day. I drive it for about 10 miles or so, then it sits for about an hour. When I come back and turn the key the starter grinds, but the truck won't start or grinds a long time before starting. It may be coincidence, but it seems to happen when the temperature drops between starts. If I wait another hour to hour and a half it will start. When it starts it runs smooth as silk, the injectors are all working great and the Optima batteries are only about 3 months old. If it was a gas vehicle I'd be thinking that it was a stuck choke or electrical problem, but in the age of computerize diesels I'm not sure where to look. There are no loose electrical connections that I can see, and since it runs like new once it's started. Anyone know what the likely problem is, or where to look? There are no codes being thrown, so I've got no specific clues to follow up on.

 

[Tuesdak]

Get a scanner on it and watch rail pressure while cranking. Miles on injectors? Stock fuel filter system? Canister lift pump starting to fail?

 

[cerberusiam]

Based on the description, the obvious thing to start with would be the starter.

 

[Crunch]

Get a scanner on it and watch rail pressure while cranking. Miles on injectors? Stock fuel filter system? Canister lift pump starting to fail?

Stock fuel filter, and has 334K on the engine but like I said, the injectors run smooth, like they did when I drove it off the lot. I replaced the transfer pump several years ago, but my experience with the transfer pump is that it craps out while the engine is running. I don't know of anyone who had it quit working with the engine off, and taking place over a month's time.

Based on the description, the obvious thing to start with would be the starter.

I considered the starter, but it seems to crank just fine, and at the normal speed. Just nothing firing when I do. I've cranked it close to 10 seconds, and it sounds normal, and the batteries are still fully charged when I quit. Hour or so later it starts up like nothing was wrong. What is the specific mechanism on these engines that causes them to start when the ignition is turned on and key is turned, and turns off the engine when the ignition is turned off? For some reason I tend to link the problem with that. I should also mention that the housing around the key cylinder has loosened over the years. Sometimes when the engine is off and I turn the key back to ACC to listen to the radio the connection is lost unless I push the key cylinder all the way in toward the steering column.

 

[sag2]

You should change the title and your description. A grinding starter indicates a starter/ring gear problem. More appropriate might be "engine cranks over fine but will not fire".

If that is what you have the best course is as was mentioned, monitor the rail pressure when it does not start.

 

[Crunch]

You should change the title and your description. A grinding starter indicates a starter/ring gear problem. More appropriate might be "engine cranks over fine but will not fire".

If that is what you have the best course is as was mentioned, monitor the rail pressure when it does not start.

Good point, I edited the title. If it is rail pressure, that's going to be tough for me to track down. The problem is intermittent, and I don't have the equipment to monitor it myself. I have the feeling it will be one of those things that only happens when no one else is around...

 

[cerberusiam]

Hard start after it warms up is good indication of injector issues. You might try re-torqueing the cross over tubes and see if that helps but it is usually a band aid on the real problem. The truck is 15 years old and no matter the mileage if you have not updated the injectors and\or using enhanced fuel filtration the injectors are likely approaching failure mode.

 

[Crunch]

Hard start after it warms up is good indication of injector issues. You might try re-torqueing the cross over tubes and see if that helps but it is usually a band aid on the real problem. The truck is 15 years old and no matter the mileage if you have not updated the injectors and\or using enhanced fuel filtration the injectors are likely approaching failure mode.

Because injectors are frequently the go to problem with engine troubles here, I am generally wary of that. But given the miles on my truck and its age I certainly can't disagree with you or dismiss it out of hand. We have several days of rain ahead of us here, so I won't be able to check the crossover tubes for a few days, but that is something I'll definitely do. Injector replacement is right there in the worst nightmare category, and I suspect it runs between $2K and $3K no matter where you get it done. Is it common for injectors to be responsible for hard starts, yet work perfectly when the engine is running? I would think there would be signs such as rough running or decreased fuel economy when they start to fail, yet the engine still runs perfectly, does not want for power and the fuel economy is still what it has always been.

 

[Tuesdak]

I can't say on the Cummins transfer/lift pump, but, intermittent operation has drove me NUTS on other lift pumps. Simply put if the lift pump isn't working it stops you. Don't throw parts at it. When you key on you should be able to hear the lift pump run: Something to listen for before each start. Is it still canister mounted or the in tank style?

Wouldn't hurt to pull the fuel filter and inspect it and check fuel condition for water or gasoline smell.

High pressure fuel system leaks will not allow the system to reach minimum pressure to fire the injectors. Sure worn injectors are common leak points, but, so is the FPR and the list goes on. Without tools you may take to a local diesel shop and have them do a return test on the injectors.

At some point you need to decide if you can afford injectors or park/sell/trade it. You just don't want to push injectors past failure because they can melt a piston. When my injectors finally gave it up I had a hard miss on #2 and extreme return rates on another injector that was still working. Annoying that they were tested not so many miles ago with an engine replacement. $3200 for BBI, Labor around $600, tune... And still cheaper than a year of new truck payments.

 

[Crunch]

I can't say on the Cummins transfer/lift pump, but, intermittent operation has drove me NUTS on other lift pumps. Simply put if the lift pump isn't working it stops you. Don't throw parts at it. When you key on you should be able to hear the lift pump run: Something to listen for before each start. Is it still canister mounted or the in tank style?

I might be using the wrong terminology, but the canister that sits behind the engine is what I call the transfer pump, and see lift pumps as the in-tank pumps. I changed the canister myself at about 110K. The replacement still works, and I do listen for the sound whenever I turn the key. It's usually a very brief sound, with the long run time occurring after a fuel filter change.

Wouldn't hurt to pull the fuel filter and inspect it and check fuel condition for water or gasoline smell.

Fuel filter gets changed every other oil change, i.e. every 10K miles. Last time it was changed was between Thanksgiving and Christmas. I've never noticed even a drop of water when I drain the canister for the fuel filter.

High pressure fuel system leaks will not allow the system to reach minimum pressure to fire the injectors. Sure worn injectors are common leak points, but, so is the FPR and the list goes on.

That definitely makes sense, and as soon as the rain passes I'll check the connections on the rail system from the pump to the injectors.

Without tools you may take to a local diesel shop and have them do a return test on the injectors.

At some point you need to decide if you can afford injectors or park/sell/trade it. You just don't want to push injectors past failure because they can melt a piston. When my injectors finally gave it up I had a hard miss on #2 and extreme return rates on another injector that was still working. Annoying that they were tested not so many miles ago with an engine replacement. $3200 for BBI, Labor around $600, tune... And still cheaper than a year of new truck payments.

Definitely can't afford a new truck, plus I really don't want to have to get used to a cat and running DEF after flying naked for so many years. Plus, I think the 5.9 Cummins is probably the best diesel engine in history for pickup trucks. I guess that means I'm spoiled. So if I have to go the new injector route, so be it, though I would probably stick with the OEM injectors. Other than 1 transfer pump and 2 APPS replacements, this engine has been trouble free and met all of my expectations. This has been the most trouble free vehicle I've ever owned.

 

[Crunch]

High pressure fuel system leaks will not allow the system to reach minimum pressure to fire the injectors. Sure worn injectors are common leak points, but, so is the FPR and the list goes on.

This seems to hold some promise. We had a break in the rain today so I started the truck and got it up to temperature. Ran some errands and the truck started fine all day. I did notice a diesel smell a few times while stopped at lights. When I got home I popped the hood and checked the crossover tubes. The tube nearest the firewall had a lot of greasy crud around it, and also appeared to be damp at the connection closest to the block. All the connections on the common rail were clean and dry. So once the rain is gone I'm going to see about tightening the connection near the firewall. The downside is that's the connection that is hardest to reach. A few years ago a friend of mine who has the same year truck noticed diesel dripping from his engine and took it to a diesel shop. They tightened a connection and commented that tube is notorious for loosening. They seemed to know exactly which one was loose when he described the problem, though he never had any trouble starting. It would be nice if the problem is just a loose connection. I really don't want to spend a few grand on injectors right now. Thanks for the help, everyone.

 

[Crunch]

You might try re-torqueing the cross over tubes and see if that helps but it is usually a band aid on the real problem.

Took the truck in to a diesel shop recommended by the local Cummins Southern Plains shop today. I had them replace the O-rings and torque down the connector tubes, and that definitely seems to have been the problem. The start time dropped from about a 2 second crank to almost immediately, and it may be all in my head, but it the truck appears to have a bit more power coming off a dead stop. They did tell me that two of the tubes didn't seem to be seated well in the injector, so they popped off the valve cover, loosened the injector and reseated them. The majority of starting problems I had were when I would travel to church in the late afternoon, and the truck sat for about 90 minutes or so while the outside temperature dropped. So this weekend will be the big test to see if the re-torquing worked, but based on the shorter crank time I'm pretty sure it did. Thanks for recommending this, cerberusiam. That's not something I would have thought of on my own. Based on my experience with this shop, and the recommendation of the Cummins Southern Plains shop, this is the place where I will take my truck when the time does come to replace the injectors.

 

[cerberusiam]

Yeah, if the caught the fact the tubes did not appear seated correctly and went to the trouble of installing them by loosening the injector they at least know the correct process and what to look for. That is a bonus anymore.