2012 Toyota Tacoma Engine Knocking


#1

Hi, my 2012 Toyota Tacoma’s engine knocks around 1500 rpm, going up hill and does it 100% of the time in the summer. This I attribute running the Air Conditioning, but don’t know for sure. The vehicle manual states on page 569 that the vehicle can take 87 octane gas. Also on the same page, there is a statement that says: “You may occasionally notice a light knocking for a short time while accelerating or driving uphill. This is normal and there is no need for concern.” This seems very strange to me, engine knocking normal? I don’t get it. Any ideas? Does anyone have any more info on this situation and any ideas on recourse? Thanks


#2

Put in a tank full of premium and see if that fixes it.


#3

You might want to downshift. 1500 rpm going up a hill is nutso.


#4

How many miles on the truck and what type of driving is usually done; short hop, etc?

This sounds like a pre-ignition rattle and that is usually caused by gasoline octane too low, knock sensor fault, carboned up engine, or an EGR system fault. The reason for asking about the type of driving is that a lot of short hop stuff can lead to clogged up EGR ports.
The truck is a bit young for a clogged EGR, but…

Whether it’s normal and acceptable is debateble but if severe enough and allowed to continue for long enough it can cause engine damage or outright destruction.


#5

I had this happen on my Corolla and it turned out to be the spark plug gap had increased beyond spec. New spark plugs fixed it straight away.

As mentioned above, it could be other things too. Besides the above, check to see if the ignition timing is too far advanced. Or if the valve timing is off. Might be a good time to bring it to a shop for a basic tune-up. From your description, it sounds excessive.


#6

Thanks all. I could try premium, but if the vehicle is suppose to take 87 octane, then I would think the knocking should not occur. The hills I am talking about here are not very steep, so 1500 rpm is possible. Thanks for the other ideas. The spark plug gap is an interesting one. I had never thought of that one. Time to take it to the shop. Thanks.


#7

Your comment that Toyota considers a light knocking during acceleration normal and acceptable dismays me.

I hope this will end up being like dieseling was in the early '70s. Manufacturers just told the customers it was normal and acceptable until they finally figured out how to stop it. It never really was acceptable to the customers… but it sure was normal.


#8

@the same mountainbike–Unfortunately, the “it’s normal” mantra did not end in the '70s!
Even though the Owner’s Manual for my '81 Chevy Citation stated that “light knocking on upgrades and when accelerating is normal”, I was never able to accept GM’s reality.
And, unfortunately, I was also never able to correct the problem.

That being said, I am astounded that a car manufacturer is still making statements like that nowadays.


#9

Statements like that keep their owners from attacking the corporate citadel. I wouldn’t worry about very brief knocking occasionally, but doing it every time you hit that hill is not good and I doubt is what Toyota meant by that statement. Good luck with finding the solution. I suspect it is something simple.