Misfire without code

Hi guys,

I bring my toyota tacoma 2009 with 215k km at the garage last week because between 40-60 the vehicule was shaking badly. I have done a couple test by myself to make sure it was not the drive shaft, the center bearing or the differential. It was none of them. I talk with a transmission garage and he said that sometimes the toque converter slip and makes the vehicule shaking. The mechanic at the garage said the truck misfire at the cylinder 1-3-5 but not all at the same time and that is what makes the truck shaking. What I found weird is that I do not have misfire code, I got o2 sensor b2s2 code only and on the transmission I got 1 time neutral switch on the transmission. I changed the 6 spark plug when the truck was around 200k km. The mechanic makes some test and test the spark plugs and they were good. He also test the coil and said they were also good. He also said that misfire can be cause by a clogged catalytic converter (remember that I have o2 b2s2 code), or the timing begin to slip some time. Now I don’t know where and what to check. Can you guys got the same problem or can help me?

 

Does your mechanic have a gauge to check exhaust backpressure?

 

Assuming the 1-3-5 misfire to be correct it would appear you have something common to the right side of the engine going on. I'd start with fuel delivery...

 

Misfiring severe enough to shake the truck at speed should definitely set the MIL and create a stack of misfire codes.

I could like the timing belt for this however... when was the last time it was changed?

 

I have the truck since 150k km and I have never change it. I am pretty sure it is a timing chain, but maybe I need to change it?

 

It’s a chain. And they don’t often fail.
Your B2S2 sensor is on the OPPOSITE side of the 1,3,5 cylinder. (Bank 1)

Just somethings to consider.

 

Thank you for the info, what did you suggest me to test?

 

Yep, sorry. Getting my responses mixed up.

 

Who and how is this misfire being determined? Would definitely get a dash light, probably flashing, if it's a misfire or anything in the engine. Maybe I missed it, I'll reread.

40-60 then it goes away? When's the last time your tires were balanced... that would shake the whole truck.


Edit: reread,
Mechanic said 1,3,5 misfire w no codes? Time for a new mechanic IMO

 

Im a DIYer.
But I’d probably monitor O2 and Fuel trim data when the problem is occurring.

And do as @b_r_o said. Check the cat

 

It does not matter what tire I have on the truck, it does the same with my winter tire with different wheel than my summer set with oem wheel. That is the point, with my experience in mechanic, it make no sense to me that there is misfire without a check engine code.

 

You can have a misfire with no codes.
There is a threshold numbers that needs to be exceeded to throw a code.
You can monitor live data a see “live” misfires.

 

How did the mechanic rule out a coil problem? Did he swap them all to the other bank?

Was this at a shop that offers "free diagnosis" ?

We can help you with this but you're going to need some tools. Like a handheld scan tool that can read basic data, a fuel pressure gauge and possibly a backpressure gauge.

It could still be a single faulty coil. Misfire detection isn't perfect and the computer often won't be able to code a specific cylinder. What kind of scan tool was used to check for codes? Any pending codes, any history codes?

 

No I pay for the diagnostic but they schedule me a short appointment and that is what they found. If I want the full diagnostic, I need to take another appointment, but I want to try to find the problem without going to the garage. I have no idea what kind of scan tool was use, the only history code was o2 b2s2.

 

That’s and odd way of doing diagnostics.
I’m not sure how much time the tech spent diagnosing the misfire.
But pulling codes isn’t usually a charge.

In my experience, you go in for a diagnostic.
1 of 2 things happen.

1. You get a call ,and they tell you what they found, and how much it is to fix it.
You will be charged for this diagnostic. Because the problem was diagnosed.

2. They call you back and tell you, they can’t find the problem without getting you to approve diagnostic time, or you approve that they can “open up” parts and look further. A good tech knows when to call it quits and ask for diagnostic time. This is basically where the tech decides how much time he is willing to give you “free”. And time isn’t cheap. You can deny the time and pick up the truck, or approve the time and pay for labor diagnosing it.

I’ve never seen anyone charged for a diagnostic without results.
Which is what it sounds like you got.

 

I belive that you can have misfires without codes but if driving under load to 40-60 km or mph and the truck is shaking those thresholds should have been met.

This coming from a guy that has never had this issue in a tacoma but have in other cars and trucks.

When all else fails, drive it till something breaks. Then you'll know for sure. - my dad

 

Before taking the appointment, I call the shop and explain the problem and the test I have done. The mechanic guy on the telephone told me it is maybe a transmission problem and take the truck for a diagnostic of the transmission. He makes some test and it was not the transmission that was faulty. When he was doing his test he saw on the scan tool that the cylinder 1-3-5 does misfire. Because my appointment was diagnostic for the transmission, he does some easy and quick test for the misfire until the time for my appointment was kinda expire.

 

Your dad sounds like my mother. “I’ve been hearing a noise”. Too bad that noise isn’t a problem until it IS a problem.

 

Im not sure what to tell you.
It sounds like the “phone “ mechanic thought it was the transmission. And it wasn’t.
If it were me, I would have told you it wasn’t the Transmission. I would not have charged you.
I would “maybe” then suggest you have an engine diagnostic. But explained to further diagnose the issue, I’d need to charge a fee.

Then again, there is probably a reason I’m not a mechanic. Nor have I ever made money repairing a vehicle. I’ve saved myself money, but never made money on repair a vehicle.


My advice is, call a reputable shop and explain your situation.
Tell them what you have done, and what you expect.
Trust me. Don’t be afraid to tell anyone what you expect.
It benefits both parties.

And most of all, don’t say “I just need you to tell me what’s wrong with my truck”
This can lead a shop to think you just need them for diagnostic, and you have no intentions of letting them do the work or labor. 99.9% you are getting charged in this case. (And should be)

Again, my advice is take it to a REPUTABLE shop.
If you don’t have the tools to diagnose the problem, you probably won’t come out head by the time you buy them.

I don’t do this stuff for a living, and I probably have $3,000 worth of tools
And even now, I still PAY someone else to do certain things on my vehicles.

 

Thank you for your advice!