ROUGH starts on cold starts?

[Juli_hoop]

My rebel did this over the weekend. Went camping so it sat for 2 days. Went to start it and it started very rough for about 3 seconds. Puttered/almost died until it finally got going. Can anyone else who’s having this issue tell me what your idle RPM is? Mine is barely above 500rpm and I can feel it rumbling/rough idle. I think it might be related.

 

[Jpw]

So my truck had been doing this for a week now. Started at 1000 miles. Starts rough with popping and surging sounds for 30-40 seconds. Runs fine once it gets out of it. What is the exact TSB for this?

 

[RamCares]

Hi @Jpw,

We're sorry to hear you are experiencing these concerns with your Ram. If you send us a PM with your VIN, I can certainly look into any applicable TSBs for you.

Darlene
Ram Social Care Specialist

 

[M. Scarn]

RAM Stalls

Here is a recent video of this ongoing problem - first two days flat our stall, 3rd day an almost stall tach drops from 1100 to 200 before recovering and then it progressivley gets better and better where only a little dip in the tach is noticed. This usuallys happen over a period of couple of weeks, then dissappears for months and months before becoming an issue again. Usaully with the change of seasons. It's like something is in the line, it affects the fuel injectorss for a few days and then either works it's way out or receeds back into the line. Of course each time I get it to the dealer the issue does not present itself and throws no codes. So on and on we go.

 

[RamCares]

RAM Stalls

Here is a recent video of this ongoing problem - first two days flat our stall, 3rd day an almost stall tach drops from 1100 to 200 before recovering and then it progressivley gets better and better where only a little dip in the tach is noticed. This usuallys happen over a period of couple of weeks, then dissappears for months and months before becoming an issue again. Usaully with the change of seasons. It's like something is in the line, it affects the fuel injectorss for a few days and then either works it's way out or receeds back into the line. Of course each time I get it to the dealer the issue does not present itself and throws no codes. So on and on we go.

Hi M. Scarn,

I certainly understand why this would be concerning. If you end up trying to address this with your dealer again, please let us know via private message. We would be happy to have your concerns formally documented and so that we may connect you with a case specialist for an additional layer of support as you work with your dealer.

Mark
RamCares

 

[cotonymopar]

if it is towards freexzing, it will shake the throttle body flap, to de-ice it...

 

[J4U]

Mine has done this on a few occasions. Narrowed it down to where I purchased gas. Staying with known good brand from now on. Corrected every time I went back.

 

[Gman]

Seems to me almost like a hydraulic lifter issue. Fuel is fine. Seems to be worse if I let the truck sit for a few days.

 

[Rockystock]

Hey everyone - Just registered here to offer some thoughts on the rough cold start issue. I've been running and tuning a 2016 392 Hemi in a 2008 Jeep Wrangler, using a 2010 Dodge Challenger PCM. The engine has a Ram 5.7 timing cover and intake manifold, with a throttle body adapter that adds enough intake volume to make it comparable to a 6.4 Hemi Ram intake manifold. It's a clean and tidy package, but definitely a franken-hemi combo haha. Anyway, I've seen the exact same problem with cold starts: very rough, wildly fluctuating RPM from about 1 second after firing up, with near-stalling. Aside from the older PCM and intake, the engine is stock.

I've been logging cold starts using the AEM 30-0300 X-Series wide band O2 sensor and all of the other relevant vehicle data. It's clear that most of the startup/warmup settings in the stock tunes are inadequate to prevent a seriously lean condition that coincides with the rough running while in open-loop. The engine needs a lot more fuel in the first seconds after startup, before going into closed loop when the narrow band O2 sensors / fuel trims take over. The Hemis up to at least 2016 use two major levers to influence startup/warmup fueling: "Fuel-Air Cold Enrich" and "VE-ECT Multipliers."

The FA Cold Enrich is a table that adds varying amounts of fuel to the base commanded fuel-air ratio according to the startup engine coolant temperature. This table is only active for the first eight seconds or so, and tapers to zero in that time.

The VE-ECT Multiplier and VE-ECT Factor tables are a correction to the base volumetric efficiency table. The VE-ECT Multiplier table is active all the time (even at normal operating temperature) and varies according to engine RPM and manifold absolute pressure. The VE-ECT Factor table applies a multiplier to the VE-ECT Multiplier table and the Factor varies by engine coolant temperature. Generally, the Factor table has higher values at low temperature, making the VE-ECT Multiplier table have a larger effect at low temperature. (confusing much?) Basically, these two tables (along with the FA Cold Enrich Table) can also be adjusted to "correct" the volumetric effficiency, so the computer can adjust fueling based on a more correct amount of calculated air in the cylinders.

If you've gone round with a dealership and eliminated the other possibilities (bad fuel injectors, sensors, maybe even a re-flash) and still have the problem, I'd recommend finding a local aftermarket Hemi tuning shop that can adjust those startup tables. The more I've studied stock 5.7, 6.1, 6.2, and 6.4 Hemi stock tunes and played with the tune on my setup, the more it seems like the Mopar software engineers cut corners and half-*** these tunes. Alternatively, you could purchase your own tuning package (I'm using HP Tuners but there are others that can make these adjustments). Either way, you (or the shop) would also be able to correct other annoying quirks with the tune.

 

[A-TEAM]

So mine has 12k on it never an issue until I let a buddy drive it home from a trip about 300 miles, towing a trailer/atv and loaded up pretty good. He drives faster than I do probably avg 85 mph most of the way. Happened the next morning after that trip, real rough start, rough idle. Then it went away after that for a few weeks, but it’s done it 2 or 3 times again recently. I always run 89, and it runs great otherwise, quiet, smooth and powerful. Going to try and run some sea foam in the tank to see if that helps clean the fuel system. My current solution is just mash the gas pedal a bit to rev it up and blow it out if it starts poor. Seems to be fine after a quick rev. The “coming and going” problem tells me it’s likely computer related, more specifically buggy software.

 

[PowerJrod]

I've experienced very rough starts the last three mornings (at least) when heading to work.
I start the pickup using the remote start usually so it was possibly (see: probably) doing this before and I just didn't wasn't outside to notice it.
The truck acts like it doesn't want to start (but does) and the tachometer is all over the place all the way from near zero to 4K+ revving and nearly dying.
The truck sputters repeatedly and idles VERY rough with what i can only assume is non-standard noise coming from under the hood.
This usually lasts ~10 seconds before it seems to even out and has only been doing this on cold starts but I can't see this as being okay.
Anyone heard of other cases of this?

2019 - Ram - 1500 - Lonestar - 4x4 - 5.7 w/o e-torque - 3.21 gears - less than 2K miles -

Almost sounds like an EGR valve issue. But funny thing about these new vehicles...a problem like that could be anything from the gas you use to something in the electronics. Hope they find out what it is

 

[PowerJrod]

Had my oil & filter changed Saturday morning at 2,400 miles and it's potentially resolved my issue (haven't noticed the issue anymore, but it's only been 2 days). I'll monitor and report back if it's still having rough starts... and we'll see how it performs once it really gets cold in the coming months.

Oh, and turns out RAM care is only free for high end trims in Texas. Thanks RAM - glad I bought a $66K MSRP truck and 4 free oil changes was too much to ask for.

I wonder when spending $66k stopped being considered high end...smh.

 

[RamCares]

So mine has 12k on it never an issue until I let a buddy drive it home from a trip about 300 miles, towing a trailer/atv and loaded up pretty good. He drives faster than I do probably avg 85 mph most of the way. Happened the next morning after that trip, real rough start, rough idle. Then it went away after that for a few weeks, but it’s done it 2 or 3 times again recently. I always run 89, and it runs great otherwise, quiet, smooth and powerful. Going to try and run some sea foam in the tank to see if that helps clean the fuel system. My current solution is just mash the gas pedal a bit to rev it up and blow it out if it starts poor. Seems to be fine after a quick rev. The “coming and going” problem tells me it’s likely computer related, more specifically buggy software.

Hi @A-TEAM - I apologize for the trouble. Should you need to address this with your dealer, our team is just a private message away and we are more than willing to escalate a case on your behalf for further support through that process.

Mark
RamCares

 

[Dusty1948]

At my last service visit I complained about a rough idle after a cold start that would last for about 5-7 seconds. The technician performed a PCM flash per TSB 21-009-20. This resolved the problem completely.

Best regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33 gallon fuel tank, factory dual exhaust, 18” wheels. Build date: 03 June 2018. Now at: 037458 miles.

 

[Roquispier]

I am also having the erratic idle upon start up. I took it to my dealer with whom I purchased the vehicle and they said they could not replicate it and i would just have to wait for it to get worse??? How is it that I can find info about this problem with one easy internet search but my dealer who should have some answers on a vehicle that they produce is all shoulders and tell me its not a big deal. This is a new truck at least to me and is still under warranty. I'd like it to run dependably when you spend as much as I have for this vehicle. So I've started taking videos of start up and wouldn't you know it anytime I remember to record it, it doesn't do it!!! Lol So far I got it behaving badly once but I am determined to get more on tape and have them look again

 

[RamCares]

I am also having the erratic idle upon start up. I took it to my dealer with whom I purchased the vehicle and they said they could not replicate it and i would just have to wait for it to get worse??? How is it that I can find info about this problem with one easy internet search but my dealer who should have some answers on a vehicle that they produce is all shoulders and tell me its not a big deal. This is a new truck at least to me and is still under warranty. I'd like it to run dependably when you spend as much as I have for this vehicle. So I've started taking videos of start up and wouldn't you know it anytime I remember to record it, it doesn't do it!!! Lol So far I got it behaving badly once but I am determined to get more on tape and have them look again

Thank you for taking the time to share your situation here, @Roquispier. I apologize for the trouble! Please know that our team is just a private message away and we would be more than willing to escalate a case on your behalf for further support as you work with your dealer on this.

Mark
RamCares

 

[QMAN]

I have a 2020 Ram Rebel with just under 5,000 miles. I have also experienced an erratic idle upon cold start up. The first time it happened was a month ago while on a camping trip in the mountains. I then experienced it again about 2 weeks ago. It happened again today. It seems to happen when there is colder weather. It is very upsetting to have this occur with a new vehicle. The reason I bought this truck was to use it in the mountains and in the cold. Has anyone had their issue resolved at a dealer? I am going to call mine today and see if they can find the issue.

 

[User_3336]

SPECIFICALLY, what does your service order say? I looked at that TSB, it covers a lot of concerns. I don't see "rough idle after cold start"......

At my last service visit I complained about a rough idle after a cold start that would last for about 5-7 seconds. The technician performed a PCM flash per TSB 21-009-20. This resolved the problem completely.

Best regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33 gallon fuel tank, factory dual exhaust, 18” wheels. Build date: 03 June 2018. Now at: 037458 miles.

 

[Dusty1948]

SPECIFICALLY, what does your service order say? I looked at that TSB, it covers a lot of concerns. I don't see "rough idle after cold start"......

See enclosed.

Best regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33 gallon fuel tank, factory dual exhaust, 18” wheels. Build date: 03 June 2018. Now at: 039706 miles.

 

[User_3336]

Awesome. Thanks for posting.

Did you take the TSB #/printout in with you when you brought it to their attention "rough idle on cold start".

or

Did the tech find the TSB based off the concern?

I mentioned something about this before, but I didn't have an appointment. service advisor was unwilling to look up anything related.

See enclosed.

Best regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33 gallon fuel tank, factory dual exhaust, 18” wheels. Build date: 03 June 2018. Now at: 039706 miles.