Rough idle after oil change

[General Esdeath]

I recently changed my oil and had the bright idea to try 20,000 mile oil. Now 3 things changed with this new oil and filter: #1. I went from regular to full synthetic.
#2. I went from 10w40 to 5w30
#3 I went from a regular 3k-5k miles between change oil to 20k miles

Now the engine idles rough and wants to almost die upon start up and until it's really warmed up, especially when coming to a stop. I changed the air filter at the same time I did the oil change and I ran a full fuel system cleaner through which seemed to help some. Could switching my oil like this have caused this issue? The truck has run like a top until this last oil change. We drive this truck a LOT upwards of 700 miles a week which is why i wanted to try the long lasting oil. So everything is in good running order and i was having no issues before this. Any thoughts?

 

[EB4X]

Check your MAF wiring.... maybe you stressed them out when you changed your air filter ....gently push / pull / move those wires while idling and see if idle changes at all. Also air tube / inlet ...make sure you didn't inadvertently put a crack in it etc...unlikely on this but....

 

[Mbrooks420]

It’s not the oil. You almost surely disturbed something working, like mentioned above.

 

[Mbrooks420]

Also, if this is a SOHC stick to the short oil changes. The SOHC is NOT a candidate for long interval changes. It’s also a terrible choice for driving 40k a year.

 

[General Esdeath]

Check your MAF wiring.... maybe you stressed them out when you changed your air filter ....gently push / pull / move those wires while idling and see if idle changes at all. Also air tube / inlet ...make sure you didn't inadvertently put a crack in it etc...unlikely on this but....

I didn't think so but I've never used the stuff. I'll check the wiring and the harness on the sensor clipped into the intake. I did notice a loud hissing noise in the engine bay this morning taking my son to work, but I couldn't figure out where it was from in the 5 min I had before we left. I thought it might just be a bearing on the serpentine belt somewhere but maybe not.

 

[General Esdeath]

Also, if this is a SOHC stick to the short oil changes. The SOHC is NOT a candidate for long interval changes. It’s also a terrible choice for driving 40k a year.

Yeah, I've gone 4k on it already and I'm just going to switch back to the regular 10w40. It's not like I'm losing money on it i got 5qt and the filter for $42 so it'll just be another monthly oil change. Also I just noticed this morning that there's a loud hissing noise coming from the engine bay, I couldn't find it in the 5 min I had before taking my son to work, I thought it could be a worn bearing in the serpentine belt assembly somewhere but maybe it's an air pressure leak from somewhere because the check gas cap light came on but the cap is seated correctly

 

[General Esdeath]

I didn't think so but I've never used the stuff. I'll check the wiring and the harness on the sensor clipped into the intake. I did notice a loud hissing noise in the engine bay this morning taking my son to work, but I couldn't figure out where it was from in the 5 min I had before we left. I thought it might just be a bearing on the serpentine belt somewhere but maybe not.

The check gas cap light came on this morning but the cap is seated correctly maybe i have a vacuum leak somewhere? But I don't have any problem with acceleration or bogging down just the dropping below the normal 1200rpm idle and shuddering like it's trying to die on me.

 

[C420sailor]

You prob have a vacuum leak. Look at the vacuum line that feeds the EVAC purge solenoid

 

[mair_n]

I didn't think so but I've never used the stuff. I'll check the wiring and the harness on the sensor clipped into the intake. I did notice a loud hissing noise in the engine bay this morning taking my son to work, but I couldn't figure out where it was from in the 5 min I had before we left. I thought it might just be a bearing on the serpentine belt somewhere but maybe not.

Check all of your vacuum hoses for cracks or leaks and change your PCV valve and hose. Good luck!

 

[J_C]

Scan tool live data, look at long term fuel trims. It may have also set a trouble code. I too, suspect a vac leak.

 

[jr230]

I recently changed my oil and had the bright idea to try 20,000 mile oil. Now 3 things changed with this new oil and filter: #1. I went from regular to full synthetic.
#2. I went from 10w40 to 5w30
#3 I went from a regular 3k-5k miles between change oil to 20k miles

Now the engine idles rough and wants to almost die upon start up and until it's really warmed up, especially when coming to a stop. I changed the air filter at the same time I did the oil change and I ran a full fuel system cleaner through which seemed to help some. Could switching my oil like this have caused this issue? The truck has run like a top until this last oil change. We drive this truck a LOT upwards of 700 miles a week which is why i wanted to try the long lasting oil. So everything is in good running order and i was having no issues before this. Any thoughts?

pull codes

I didn't think so but I've never used the stuff. I'll check the wiring and the harness on the sensor clipped into the intake. I did notice a loud hissing noise in the engine bay this morning taking my son to work, but I couldn't figure out where it was from in the 5 min I had before we left. I thought it might just be a bearing on the serpentine belt somewhere but maybe not.

never spray the maf with anything but maf cleaner and remove it from car spray then let dry thoroughly and this is advice to every owner of a regular truck car suv don't go over 10k oil and filter synthetic. 7000 regular oil and newer than 2010 don't use oil weight unless specified in owners manual heavy trucks have gallons of oil not quarts . thats if you want more than a few years out of truck or car
and even trucks using oil changing at normal intervals slows consumption

 

[fast_dave]

Just sayin'

It's always a bad idea to go from a lifetime of straight Dino Oil to Full Synthetic on ANY engine.

Reason: The very high concentration of detergents in Synthetic Oil is likely to have loosened dino oil sludge and varnish and moved it on to the oil control rings, oil passages, timing chain rollers and bearings of your engine.

Even worse to leave the full synthetic - or any motor oil for that matter - in for 20,000 miles...

 

[J_C]

The check gas cap light came on this morning but the cap is seated correctly maybe i have a vacuum leak somewhere? But I don't have any problem with acceleration or bogging down just the dropping below the normal 1200rpm idle and shuddering like it's trying to die on me.

Check your EVAP system vac lines.

 

[Eesydog]

I recently changed my oil and had the bright idea to try 20,000 mile oil. Now 3 things changed with this new oil and filter: #1. I went from regular to full synthetic.
#2. I went from 10w40 to 5w30
#3 I went from a regular 3k-5k miles between change oil to 20k miles

Now the engine idles rough and wants to almost die upon start up and until it's really warmed up, especially when coming to a stop. I changed the air filter at the same time I did the oil change and I ran a full fuel system cleaner through which seemed to help some. Could switching my oil like this have caused this issue? The truck has run like a top until this last oil change. We drive this truck a LOT upwards of 700 miles a week which is why i wanted to try the long lasting oil. So everything is in good running order and i was having no issues before this. Any thoughts?

Well u went to a thinner oil which is not a good idea on a high milage vehicle. As the engine wears the bearings become loose and so you wood need a thicker oil to fill that gap not a thinner oil. If I were you, I would go back to the thicker oil but stick with the full cynthetic. Hopefully you didn't wear the bearings even more with the thinner oil.
I run full synthetic 10,000 miles and have had good luck with this. Just stick with the thicker oil and your engine will be your friend longer

 

[donalds]

ONLY USE 5/30
The 4.0 single overhead cam engine is very picky about oil
Never go Heavier oil
Your engine has a very durable bottom end

 

[Fix4Dirt]

ONLY USE 5/30
The 4.0 single overhead cam engine is very picky about oil
Never go Heavier oil
Your engine has a very durable bottom end

^^^^^^^^^^

 

[C420sailor]

Exactly. This isn’t a Harley.

Those tensioners need oil and they need it fast.

 

[Fix4Dirt]

Exactly. This isn’t a Harley.

Those tensioners need oil and they need it fast.

nor is this a boat, or a jet

 

[Stormin Norman]

I recently changed my oil and had the bright idea to try 20,000 mile oil. Now 3 things changed with this new oil and filter: #1. I went from regular to full synthetic.
#2. I went from 10w40 to 5w30
#3 I went from a regular 3k-5k miles between change oil to 20k miles

Now the engine idles rough and wants to almost die upon start up and until it's really warmed up, especially when coming to a stop. I changed the air filter at the same time I did the oil change and I ran a full fuel system cleaner through which seemed to help some. Could switching my oil like this have caused this issue? The truck has run like a top until this last oil change. We drive this truck a LOT upwards of 700 miles a week which is why i wanted to try the long lasting oil. So everything is in good running order and i was having no issues before this. Any thoughts?

 

[Stormin Norman]

Make sure your oil cap is on correctly or is not leaking. Check for any other potential vacuum leaks.