3rd Gen . 4 Cylinder rough idle

Is it normal for the 2.7 4 Cylinder to idle a bit rough ?

 

How many miles .. idle low or high ? I had a 2.7 18 model sr and then I got a 21 sr5 v6 and now a 21 off road v6 . I put 55,000 on the 2.7 2wd and it never had a idle issue for me .. the issue I had was lack of power on the Highway and when you haul stuff in the bed with a full load .. so I upgraded to the v6 for more power and higher towing capacity.

 

Maybe a little bit rough? Certainly compared to a V6 or V8.

When I bought my 2012 with 120,000 one of the first things I did was check the spark plugs. They appeared to be original to the truck so I replaced them on general principal. It did make the idle maybe 30% smoother.

 

spark plugs if you havent changed them in a while. Also check your mass airflow sensor. It could cause a rough idle as well.

 

I have 48,000 miles on the clock..

Toyota service says normal… but there is quite a vibration when it sits there at idle for a while … shaking the cabin a bit …..

Perhaps I should compare it to another 19 sr5?

 

Have a 16 SR with about 105k on it, the idle has been a little rough at times recently, but I think it's been especially noticeable when stopped at a light and the AC kicks on. I know the spark plugs are due at 120k, might bump that up, and check the MAF at the same time.

 

Funny my A/C on smooths it out a bit ….

 

Hmm. I could be backwards. I'll have to pay a little closer attention next time. I wouldn't be surprised if they got clever and goosed it a bit when it kicks on the AC.

 

Goosing some revs in there

 

that guy with 1.3 million miles on the clock said his original spark plugs ran to 700k ..

Although that’s an older Tacoma
https://youtu.be/8glWcEuxw3U

 

For sure they do. Idk if the 4 cylinder is the same, but they even bump up the rpms with steering wheel input.

 

My idle very nice and even when you Cold start in the morning….. but when the rpm drops back to normal idle it vibrates

 

I had same issue hes having and spark plugs were the culprit. IDK if i believe that he ran spark plugs for 700k

 

Same as me?

 

yes same engine just in 2012. They haven't changed them since. He also went and said he changed them after 123k. I changed mine at 105k which its recommend to change and check at 100k

 

My 4 bang bang idles so smooth, that you can't tell it's running.

 

Could be excessive carbon build up, could be the MAF, and like others have stated, could be plugs.

Try some Archoil 9100. It cleans engines really well.

https://www.archoil.com/products/ar9100-oil-additive?variant=40925513166