2018 3.6 Pentastar exhaust smoke on cold start

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

WarHawk_52

Junior Member
Joined
Dec 3, 2024
Posts
7
Reaction score
5
Location
Sacramento, CA
Ram Year
2018
Engine
3.6L V6
Hello all,

New to the site and been researching and trying to look up what my issue could be.

I have a 2018 Ram 1500 4wd 3.6 Pentastar with 80k.

I know with it being cold out there’s bound to be some condensation in the air on start up and initial drive. But this has got me worried a bit and trying to narrow down possible issues. When I start up at night and about 40° out, and 50° daytime, there is no initial smoke coming out. As soon as I drive away it poofs out something fierce for a solid 2-3 minutes and goes away. Then after only at idle does it come back, but normally a heavy whispy smoke. Should also point out that I’ve seen a drop of 1 MPG, but that also could be winter conditions. Doesn’t seem to have a certain smell and has a white tint to it. I’ve performed an oil change and did a combustion leak test and am seeing no coolant issue or leaks. Operating temps are normal. So my next stop is replacing spark plugs and pcv valve. Any thoughts or inputs are appreciated.
 

Attachments

  • IMG_0443.jpeg
    IMG_0443.jpeg
    74.8 KB · Views: 28
  • IMG_0444.jpeg
    IMG_0444.jpeg
    16.4 KB · Views: 29
Last edited:
OP
OP
WarHawk_52

WarHawk_52

Junior Member
Joined
Dec 3, 2024
Posts
7
Reaction score
5
Location
Sacramento, CA
Ram Year
2018
Engine
3.6L V6
Oil was clean and full when I did the most reset oil change only 100 miles ago.
 
OP
OP
WarHawk_52

WarHawk_52

Junior Member
Joined
Dec 3, 2024
Posts
7
Reaction score
5
Location
Sacramento, CA
Ram Year
2018
Engine
3.6L V6
I’d say about 9 miles in 20 minutes with pretty much stoplights and 40mph traffic.
 
Last edited:

Fast69Mopar

Senior Member
Joined
May 10, 2019
Posts
2,453
Reaction score
2,694
Location
Texas
Ram Year
2006
Engine
5.7 HEMI
I’d say about 9 miles in 20 minutes with pretty much stoplights and 40mph traffic.
This seems like normal, cool/cold weather operation to me. It's normal for a hot exhaust to generate condensation on the inside of the exhaust while the pipes and cats cool down. On the next startup you may not see anything coming from the exhaust until it starts to warm up and even after it warms up it can take quite some time for all of the condensation to burn off and evaporate while driving.

If you are not loosing any coolant and your oil level is being maintained throughout your normal oil change cycle then it I can be safe to assume that you are only seeing the condensation being burned off as the engine and exhaust warm up to its normal operating temperatures.

When you get a chance to operate the truck for a longer period of time I bet you will see the exhaust clear up. The short drives do not get the exhaust very hot. Put this thing through its paces and get out on the big road and get the exhaust hit and it will burn off the condensation that is lingering in the bottom of the muffler and the tailpipe.
 

Bigskyroadglide

Moderator
Staff member
Member Relations Specialist
Moderator Supporting Member
Joined
Nov 9, 2016
Posts
2,783
Reaction score
5,944
Location
Montana, officially RETIRED
Ram Year
2014
Engine
Hemi 5.7, supercharged
Op, I don't have a penstar in my Ram but have a hemi. My truck started smoking on cold start after sitting for several hours and I went through about a week of h.e.l.l. before I found the issue.

I did everything you mentioned, leak down test, head gasket test. Replace pcv valve, plugs and at this point it is where I found my issue.

Upon removing the most difficult to reach plug, found it was covered in oil.

Turns out, it was the plug tube gasket on the valve cover allowing oil to leak into the plug tube.

I never had low oil on dipstick, never had an oil leak and would never have thought about a plug valve cover tube seal.

My experience, never had a penstar apart but look at this video.

 
Last edited:
OP
OP
WarHawk_52

WarHawk_52

Junior Member
Joined
Dec 3, 2024
Posts
7
Reaction score
5
Location
Sacramento, CA
Ram Year
2018
Engine
3.6L V6
Somewhat of an update.

Went to change my spark plugs and with the intake manifold off, noticed oil in the throttle body. So that led me to change the PCV Valve also. Hoping after a couple of long drives the residual oil burns off and we are good to go. Thanks for all your input.
 

farout75

Senior Member
Joined
Apr 27, 2020
Posts
330
Reaction score
312
Location
Laurie, MO
Ram Year
2019 Limited
Engine
5.7 L
Hello all,

New to the site and been researching and trying to look up what my issue could be.

I have a 2018 Ram 1500 4wd 3.6 Pentastar with 80k.

I know with it being cold out there’s bound to be some condensation in the air on start up and initial drive. But this has got me worried a bit and trying to narrow down possible issues. When I start up at night and about 40° out, and 50° daytime, there is no initial smoke coming out. As soon as I drive away it poofs out something fierce for a solid 2-3 minutes and goes away. Then after only at idle does it come back, but normally a heavy whispy smoke. Should also point out that I’ve seen a drop of 1 MPG, but that also could be winter conditions. Doesn’t seem to have a certain smell and has a white tint to it. I’ve performed an oil change and did a combustion leak test and am seeing no coolant issue or leaks. Operating temps are normal. So my next stop is replacing spark plugs and pcv valve. Any thoughts or inputs are appreciated.
Good chance its valve guides.
 
OP
OP
WarHawk_52

WarHawk_52

Junior Member
Joined
Dec 3, 2024
Posts
7
Reaction score
5
Location
Sacramento, CA
Ram Year
2018
Engine
3.6L V6
Possibly. Leak Down Test to confirm? Also noticed some oil sitting in the valley most likely from the oil cooler. Could that also be why my truck is burning some oil at startup and first 1-2 minutes of driving? And what are some of your guys' thoughts on OEM vs an aluminum cooler to replace?
 

BenchTest

Senior Member
Joined
Nov 7, 2023
Posts
792
Reaction score
1,650
Location
Midwest
Ram Year
2018
Engine
3.6
Possibly. Leak Down Test to confirm? Also noticed some oil sitting in the valley most likely from the oil cooler. Could that also be why my truck is burning some oil at startup and first 1-2 minutes of driving? And what are some of your guys' thoughts on OEM vs an aluminum cooler to replace?
Having done several, I recommend the aluminum one. Don't go cheap (knock-off E-Bay or Amazon units). Don't use the supplied o-rings that come with any of them as they all seem to be hot garbage. Use either Mopar o-rings or FelPro.
 

BenchTest

Senior Member
Joined
Nov 7, 2023
Posts
792
Reaction score
1,650
Location
Midwest
Ram Year
2018
Engine
3.6
Get the aluminum version. Oem will crack again. Been no consistent reports of issues or problems with the aluminum version
+1 on this. There have been several revisions to the OEM, but I'm still reluctant to trust them since they couldn't get it right the first several times. I've used the Dorman units with success.
 

Wild one

Senior Member
Joined
Jan 17, 2016
Posts
23,882
Reaction score
54,976
Ram Year
14 Sport
Engine
5.7
Op, I don't have a penstar in my Ram but have a hemi. My truck started smoking on cold start after sitting for several hours and I went through about a week of h.e.l.l. before I found the issue.

I did everything you mentioned, leak down test, head gasket test. Replace pcv valve, plugs and at this point it is where I found my issue.

Upon removing the most difficult to reach plug, found it was covered in oil.

Turns out, it was the plug tube gasket on the valve cover allowing oil to leak into the plug tube.

I never had low oil on dipstick, never had an oil leak and would never have thought about a plug valve cover tube seal.

My experience, never had a penstar apart but look at this video.

I had a similiar issue after we did my cam,but it leaked oil into the plug tube,nothing a new set of valve cover and plug tube O-rings didn't fix. I think any time you pull the valve covers if they've been on for awhile,you should probably replace the valve cover O-rings at the same time.
 
OP
OP
WarHawk_52

WarHawk_52

Junior Member
Joined
Dec 3, 2024
Posts
7
Reaction score
5
Location
Sacramento, CA
Ram Year
2018
Engine
3.6L V6
Op, I don't have a penstar in my Ram but have a hemi. My truck started smoking on cold start after sitting for several hours and I went through about a week of h.e.l.l. before I found the issue.

I did everything you mentioned, leak down test, head gasket test. Replace pcv valve, plugs and at this point it is where I found my issue.

Upon removing the most difficult to reach plug, found it was covered in oil.

Turns out, it was the plug tube gasket on the valve cover allowing oil to leak into the plug tube.

I never had low oil on dipstick, never had an oil leak and would never have thought about a plug valve cover tube seal.

My experience, never had a penstar apart but look at this video.

Think this would also cause a P0305 Code? Did a random OBD2 check this morning and found the pending code that cleared after truck was warmed up. Check Engine Light isn't on. Finally getting around to the Oil Cooler this weekend. Prolly end up taking the valve cover off to check cams and lifters since Im already that far into it. Also get some new Valve Cover Gaskets and Plug Tube Gaskets like you mentioned.
 

Bigskyroadglide

Moderator
Staff member
Member Relations Specialist
Moderator Supporting Member
Joined
Nov 9, 2016
Posts
2,783
Reaction score
5,944
Location
Montana, officially RETIRED
Ram Year
2014
Engine
Hemi 5.7, supercharged
Think this would also cause a P0305 Code? Did a random OBD2 check this morning and found the pending code that cleared after truck was warmed up. Check Engine Light isn't on. Finally getting around to the Oil Cooler this weekend. Prolly end up taking the valve cover off to check cams and lifters since Im already that far into it. Also get some new Valve Cover Gaskets and Plug Tube Gaskets like you mentioned.

The P0305 code indicates that the powertrain control module (PCM) has detected a misfire in cylinder 5 of your car's engine.
 
OP
OP
WarHawk_52

WarHawk_52

Junior Member
Joined
Dec 3, 2024
Posts
7
Reaction score
5
Location
Sacramento, CA
Ram Year
2018
Engine
3.6L V6
The P0305 code indicates that the powertrain control module (PCM) has detected a misfire in cylinder 5 of your car's engine.
Guess I could have made it known I knew what it was. lol Just trying to see if anyone would have possible causes. I replaced spark plugs 2 weeks ago, didn't do coils this time as they appeared in good condition still. But if the cylinder is misfiring, and I believe that this original post about smoke might be a factor as it is spitting out even in 55-degree weather. Combustion Leak Test showed nothing, might test that again. And still losing no oil and looks clean. did a coolant flush last weekend and didn't have any discoloration.

So, a P0305 at cold start along with what I believe somewhat excessive exhaust smoke is what I'm asking around to see if anyone has any ideas. One of my next stops is injectors. Or a Vacuum Leak?
 

Lee Peterson

Senior Member
Joined
Dec 22, 2017
Posts
233
Reaction score
166
Location
Hamilton ON Canada
Ram Year
2016
Engine
3.6 Pentastar
Do you have any ticking or tapping noise like a bad cam rocker arm? Was it misfiring before you changed plugs? It's real cold up here -11C. I drove for one hour on the highway and when I got home and idled my 3.6 ram for 2 mins both tail pipes had left a good wet spot on the ground just like the AC leaves in the summer. It smokes like crazy too but not loosing coolant or oil, just hot air meeting cold air.

it could be a dirty or sticky injector. It could even be a weak coil. Injectors you could just swap 5 with 3 and see if mis follows it , maybe swap coil 5 with coil 1. Are you sure a valve cover seal isn't leaking oil into the spark plug tube?
 
Last edited:

tron67j

Senior Member
Joined
Oct 14, 2019
Posts
4,105
Reaction score
5,425
Location
Maryland
Ram Year
2018
Engine
6.4 Hemi
Does the smoke linger behind your vehicle or quickly disappear after exiting your vehicle? The former is oil, the latter is coolant (since you appear to have ruled out normal condensation upon initial running).
 
Back
Top