Dodge 5.9L Diesel Hesitates to Start

BlackGun

BlackGun

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As the title states my diesel isn’t starting right off as usual. Battery test at 12.9-13.0 volts. Output running is 14.6 volts. It’s starting at all temperatures as if it were 30 degrees. Hesitates before turning over like low battery but isn’t. 1991 Dodge 5.9L Intercooled turbo diesel. Starter changed in 2013. Brand new battery terminals and connectors (last month). Battery bought May 2020 and 810 CCA.

Internet diagnose it.
 
It's a diesel with only one battery???

Every factory diesel that I've ever owned had at least two batteries in series.

Have you tried putting a load test on the battery, or checking the voltage while cranking?
 
Hesitates like try’s to spin and then spins quickly? Or doesn’t engage at all for a second.

I’d lean towards the starter if it was a reman unit.
2nd guess would be the headgasket. Gasp! I know….common for cummins to start like that when the hg first fails and let’s a small amount of coolant into the cylinder.

Fingers crossed for the cheaper fix.
 
My guess is the starter.
A gas engine can make you think the battery is bad before the starter goes. My Honda just went thru the same type of deal. It was the starter. Check all cables and rule that out.

Sent from my SM-N970U using Tapatalk
 
hp468 said:
Checked the voltage drop when cranking?
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No
Scsmith42 said:
It's a diesel with only one battery???

Every factory diesel that I've ever owned had at least two batteries in series.

Have you tried putting a load test on the battery, or checking the voltage while cranking?
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One battery. No test on cranking but battery seems good.
Notacop said:
Test battery Check grounds
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Grounds solid. Mechanic put new terminals on per my request when doing brakes 4th time because it had the hesitation month ago.
Pogue said:
Hesitates like try’s to spin and then spins quickly? Or doesn’t engage at all for a second.

I’d lean towards the starter if it was a reman unit.
2nd guess would be the headgasket. Gasp! I know….common for cummins to start like that when the hg first fails and let’s a small amount of coolant into the cylinder.

Fingers crossed for the cheaper fix.
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Hesitates then spins fine. Could be gasket and for sure either the rear main is leaking or oil pan but my mechanic can’t lift the engine weight. Head gasket has never been changed.
 
.........im guessing starter........ If the head gasket was leaking, how would that create a hestitation in the starter spinning the engine?
 
A compression tester isnt expensive and should....tell you if a cylinder is leaking. A battery tester isnt expensive either and will tell you how may amps the battery has. Check it in a couple of hours later to see of the battery is holding a charge.

Swap out a relay and see if it makes a difference.......unlikely but possible.

If the above checks out......im still thinking starter.
 
It’s very odd that there’s only one battery. I don’t see one having enough cranking amps to really turn over reliably. I’d start looking for a second battery. Bad grounds make diesels do crazy things. Those would be my starting points

Is it just the initial start up or does it happen even when it’s hot?
 
BowWow said:
.........im guessing starter........ If the head gasket was leaking, how would that create a hestitation in the starter spinning the engine?
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Coolant doesn’t compress. Cummins rods are strong enough to push coolant back through the hg or around the valve seal in some cases without bending.
BowWow said:
A compression tester isnt expensive and should....tell you if a cylinder is leaking. A battery tester isnt expensive either and will tell you how may amps the battery has. Check it in a couple of hours later to see of the battery is holding a charge.

Swap out a relay and see if it makes a difference.......unlikely but possible.

If the above checks out......im still thinking starter.
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Gas compression testers maybe cheap, diesel testers not so much. Nor is it easy to do so. Being a 91 it IS slightly easier having external injector nozzles that can be removed for testing. Newer models have actual injectors under the rocker cover and require a much more expensive adapter and the need to replace one time use parts (injector feed tubes) just to check compression. Much easier thing to do would be to check for excessive tightness in the coolant hoses and find a shop that can do a chemical block test to check for combustion gases in the coolant.
 
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For the comments about this engine only having one battery… I believe the early Cummins were like this. I have a 1990 5.9L swapped into a old body style Chevy 1-ton, and it is set up for only a single battery. It worked fine with the lead acid battery that was in it when I bought it (a big one), and then as that battery got older, I replaced it with a big Odyssey battery. If the OP’s truck used to work fine with the single battery, but now does not, I wouldn’t expect that the fact it’s running a single battery is the root cause.
On my truck, I had starting issues because of the battery cable - actual corrosion in the cable itself that you couldn’t see it until you pulled back the insulation near the terminal. I would have never checked it since the terminal looked good and was factory bonded to the cable (not a replacement terminal) but my starter repair guy suggested it when I had the starter rebuilt. He said I had probably hurt the starter prematurely by continuing to try to use it with that bad cable.
But I agree with you, other diesel trucks I have seen had two batteries. My 1990 6.2L suburban has 2.
 
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Have batteries checked if you or dont have the tools then i would suspect starter or grid heater if it is just slow to start with no water in the oil or excessive smoking from a injector failure. Also most cummins had two batteries but it its a good one most 5.9s will start one of the best cold starting diesels I have been around.

Also check battery cables for dirty connections or bad cable.
 
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Pogue said:
Coolant doesn’t compress. Cummins rods are strong enough to push coolant back through the hg or around the valve seal in some cases without bending.

Gas compression testers maybe cheap, diesel testers not so much. Nor is it easy to do so. Being a 91 it IS slightly easier having external injector nozzles that can be removed for testing. Newer models have actual injectors under the rocker cover and require a much more expensive adapter and the need to replace one time use parts (injector feed tubes) just to check compression. Much easier thing to do would be to check for excessive tightness in the coolant hoses and find a shop that can do a chemical block test to check for combustion gases in the coolant.
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Thanks for pointing that out about the diesel differences.

Would a slight coolant leak be enough to cause this problem? Im thinking the coolant leak would have to terrible to cause any kind of hestiation. Like white smoke pouring out of the exhaust
if its the same for a diesel.
 
BowWow said:
Thanks for pointing that out about the diesel differences.

Would a slight coolant leak be enough to cause this problem? Im thinking the coolant leak would have to terrible to cause any kind of hestiation. Like white smoke pouring out of the exhaust
if its the same for a diesel.
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Doesn’t have to be much. There’s not a lot of volume in a combustion chamber when the pistons at tdc
 
DCGallim said:
It’s very odd that there’s only one battery. I don’t see one having enough cranking amps to really turn over reliably. I’d start looking for a second battery. Bad grounds make diesels do crazy things. Those would be my starting points
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I had an ‘89 D350…first year of the Cummins, before they added the intercooler. One battery. Had almost 250k miles when I bought it. Never had any issues with the single battery.
 
Sounds like the glow plugs are staying lit longer now that it's cooler. Maybe a sticking glow plug relay
 
As for testing HG issues Napa and the like have a combustion gas testing kit for $30ish
On Amazon

Does it smoke a little extra on start up....could be a leaking injector dripping fuel into the cylinder when shut off....see if turning the eng by hand first makes the hard start go away....if so this is likely the problem if no combustion gas is found in the coolant system.
 
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The first thing to do is run a load test on the battery. It could have a weak cell which would result in the problem that you describe. Put your multimeter on the battery terminals and have someone crank for 5-10 seconds. If the battery is fully charged and the voltage drops to 10 or below while cranking, you have a bad battery.

A weak cell can also damage the starter over time due to the increase in cranking amps pulled.
 
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this can help rule out your ignition wiring, connections etc
 
Scsmith42 said:
The first thing to do is run a load test on the battery. It could have a weak cell which would result in the problem that you describe. Put your multimeter on the battery terminals and have someone crank for 5-10 seconds. If the battery is fully charged and the voltage drops to 10 or below while cranking, you have a bad battery.

A weak cell can also damage the starter over time due to the increase in cranking amps pulled.
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Exactly, always rule out the simple stuff first.
 
I’ll check back in after the battery diagnostics. Walmart said it would be 2 hours. No time this morning. I’m still weeks behind from early August on jobs.
 
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Pogue said:
Hesitates like try’s to spin and then spins quickly? Or doesn’t engage at all for a second.

I’d lean towards the starter if it was a reman unit.
2nd guess would be the headgasket. Gasp! I know….common for cummins to start like that when the hg first fails and let’s a small amount of coolant into the cylinder.

Fingers crossed for the cheaper fix.
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Doesn’t engage for a second. By the way two places put it on their tester and everything passed like a new battery. I have the print tickets. 12.66 volts, 890 cca. And again there are one month old new battery terminals. 14.9v output from alternator.
 
I drove a ‘92 for ten years. Had a starter go out that I replaced, and it lasted for about two months before it quit. Replaced that starter and it was working when I sold the truck three years later. Bad rebuild I guess. Sounds like you’ve tried everything else. I don’t know if yours came with a block heater, but I plugged mine in any time the temperature at night dipped below 45 or so. I always felt like it started a lot easier on cold mornings like that. Hope you figure it out!
 
DangerRuss said:
I agree - that is my guess. If it has been tested by bypassing the ignition switch and still has this issue, it almost has got to be the starter at this point, right?
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I have a 2000 and was having the same issue, I was thinking it was the injector pump again, I was relieved when I was told it was just the starter.
 
You can pick up a rebuild kit for the starter from genos garage. That is a pretty common thing on those trucks to need service over the years and not that hard of process from what I understand after you get it off.
 
Jp8819 said:
You can pick up a rebuild kit for the starter from genos garage. That is a pretty common thing on those trucks to need service over the years and not that hard of process from what I understand after you get it off.
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I can’t mess with anymore for a week. I need to keep moving. I’ll update next week.
 
Truck starting went to death. Went to O’Reilly to get a battery so it would be new for the mechanic. Counter guy looks it up and tells me it has 2 batteries. Nope. Tells me it’s 810 cranking amps with a group 27 second battery. Nope. Tells me it has side terminals. Nope. So I lift the hood and show him no second battery and top terminals. This is why I cannot trust buying at these low end parts places.

I bought the biggest battery they had which was 810ca and 900cca. This may go dead but it proved the starter is solid. Cranking fine now with no hesitation. Two bench test at Walmart and Advance said it was good. My test indicated good battery, alternator, and voltage regulator. I asked about new cables but O’Reilly had nothing that size gauge. Not even close. Auto-zone didn’t have the cable size locally also. I’ll give it a couple weeks and see if it solves the issue. Any help with this model cable gauge would be appreciated. Unfortunately I was in need of a battery quickly so I took what they had but not what I would like in quality. Thank you all for replying. Again I learned a lot here.
 
If and when I have to replace cables. I use 1/0 welding cable and make my own.

You probably know this, but electricity actually runs on the outside of the strand of wire. I don't know how many individual strands are in that size cable but it's ALOT more that standard battery cables.

I made a set for a 99 ford diesel that was having issues like you described and never had an issue again.
BlackGun said:
Truck starting went to death. Went to O’Reilly to get a battery so it would be new for the mechanic. Counter guy looks it up and tells me it has 2 batteries. Nope. Tells me it’s 810 cranking amps with a group 27 second battery. Nope. Tells me it has side terminals. Nope. So I lift the hood and show him no second battery and top terminals. This is why I cannot trust buying at these low end parts places.

I bought the biggest battery they had which was 810ca and 900cca. This may go dead but it proved the starter is solid. Cranking fine now with no hesitation. Two bench test at Walmart and Advance said it was good. My test indicated good battery, alternator, and voltage regulator. I asked about new cables but O’Reilly had nothing that size gauge. Not even close. Auto-zone didn’t have the cable size locally also. I’ll give it a couple weeks and see if it solves the issue. Any help with this model cable gauge would be appreciated. Unfortunately I was in need of a battery quickly so I took what they had but not what I would like in quality. Thank you all for replying. Again I learned a lot here.
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