Engine rotations (Cranking) to start has doubled since fuel filter change.

[PGR2007]

2020 3/4 6.7 diesel. Dealership changed oil filters. The 2nd time started (1st time by me) it took 10 to 12 seconds to start. After putting 1500 miles (within 10 days of fuel filter change) it still takes twice a long to start the engine as before the fuel filters were changed. Looking for some insight or reasons for problem before I return to the dealership.
Thank you in advance for helping with this matter.

 

[AH64ID]

Look at both filters and see if there is a leak, if there is a small leak under pressure you could lose prime and a long crank would ensue. It wouldn’t take much.

How long is it taking to start now? The CGI motors seem to crank a lot longer than older trucks, which is just software related but when you pay attention it takes a long time.

 

[PGR2007]

Look at both filters and see if there is a leak, if there is a small leak under pressure you could lose prime and a long crank would ensue. It wouldn’t take much.

How long is it taking to start now? The CGI motors seem to crank a lot longer than older trucks, which is just software related but when you pay attention it takes a long time.

Well it seems to be back to normal. Using my phone's stopwatch I started it when the engine started to crank over and stopped when it started. Remote start around 1 sec, in cab start 2 sec. which is faster than after the recent fuel filter change. I got under the truck and could not find any fuel or fluid leaks. I will check start times after driving several miles for an additional comparison. I will keep you posted and thank for your time, it is appreciated!

 

[Diesel85]

Well it seems to be back to normal. Using my phone's stopwatch I started it when the engine started to crank over and stopped when it started. Remote start around 1 sec, in cab start 2 sec. which is faster than after the recent fuel filter change. I got under the truck and could not find any fuel or fluid leaks. I will check start times after driving several miles for an additional comparison. I will keep you posted and thank for your time, it is appreciated!

Sometimes air gets trapped in the filter media, or the media takes a while to absorb the diesel fuel.

But it is good to keep an eye on little things like this.

 

[Ozymandias]

Everything over 3 seconds is excessive crank time.
Count slowly to 3 while cranking.

 

[Diesel85]

Everything over 3 seconds is excessive crank time.
Count slowly to 3 while cranking.

For sure! Especially now a days!

These new engines start the as fast as gas engines do for the most part.

 

[AH64ID]

Everything over 3 seconds is excessive crank time.
Count slowly to 3 while cranking.

For sure! Especially now a days!

These new engines start the as fast as gas engines do for the most part.

Actually, not really anymore. These new CGI engines are known for long cranks. Something with the software, and not always the same crank time.

I’ve gotten used to it, but the crank time on my 22 is probably twice as long as my 18… and normal.

None of my 6.7’s have started anywhere as fast as my built/tuned 5.9 did, that thing just started FAST.

 

[Ozymandias]

Actually, not really anymore. These new CGI engines are known for long cranks. Something with the software, and not always the same crank time.

I’ve gotten used to it, but the crank time on my 22 is probably twice as long as my 18… and normal.

None of my 6.7’s have started anywhere as fast as my built/tuned 5.9 did, that thing just started FAST.

Im pretty sure you don't have to crank them more then 3 seconds.
Please use a stop watch next time.

For sure a 12V only needs 0.25s of crank time.

 

[AH64ID]

Im pretty sure you don't have to crank them more then 3 seconds.
Please use a stop watch next time.

3 seconds has happened, there is no rhyme reason for how long these new trucks take to crank. 1-2 seconds is routine, 2-3 seconds has been reported. There are threads about the long cranking on other forums. Then sometimes it fires up like my 5.9. Computer is looking for something I guess.

I will agree that routine excess of 3 seconds is an issue, even on the newer trucks.

 

[Cummins12V98]

Im pretty sure you don't have to crank them more then 3 seconds.
Please use a stop watch next time.

For sure a 12V only needs 0.25s of crank time.

My 98 12V with light touch to the pedal fired instantly as does my 01 with no pedal. 15 I would guess one full second.

 

[Signal73]

My 19 lights off in 3 revolutions or less since new.

 

[Ozymandias]

My 98 12V with light touch to the pedal fired instantly as does my 01 with no pedal. 15 I would guess one full second.

Yeah, the old direct injected Diesels are a miracle for starting.
Just a "kick" with the starter is enough if the engine is in good shape.
Barely touching the starter contact let them fire right away.

 

[AH64ID]

My 19 lights off in 3 revolutions or less since new.

How do you track that?

 

[Signal73]

How do you track that?

3 ruh ruh ruh’s from the starter

 

[petersonj]

My 19 lights off in 3 revolutions or less since new.

How do you track that?

3 ruh ruh ruh’s from the starter

I am guessing each "ruh" you are hearing is a compression stroke. Since there is one compression stroke every 120 degrees of crankshaft rotation in a six cylinder engine, three "ruhs would equal one crankshaft rotation.

Just sayin'...

- John

 

[AH64ID]

I am guessing each "ruh" you are hearing is a compression stroke. Since there is one compression stroke every 120 degrees of crankshaft rotation in a six cylinder engine, three "ruhs would equal one crankshaft rotation.

Just sayin'...

- John

I’m not sure you could hear each compression stroke since there are likely over 10 compression strokes per second when cranking.

 

[Turbo Terry]

What’s a ruh ruh My truck doesn’t ruh ruh.

 

[AH64ID]

What’s a ruh ruh My truck doesn’t ruh ruh.

Sure it does, it’s the rhythmic sound a diesel makes when cranking. Unlike a small gas engine the bigger diesels don’t sound smooth when cranking.

 

[Signal73]

What’s a ruh ruh

It’s a technical term..

 

[crispyboy]

I think Scooby Doo must have made it up.......