2020 V6 stalled and knocking at 162,000k

Hi Everyone,

My engine is knocking or tapping only when warm and loaded past 1300Rpm. Also stalled on the highway the other day. Dealer removed belt, still knocking. Dealer claims it's bank 1 but not sure, seems to want nothing to do with it for some reason unless I want to pay for them to "tear down" the engine?... No talk of a plan or any tests to run.

So I figured I'd try myself..
LP fuel pressure at startup sometimes pushes past 65psi but normally sits around 40psi(needle jiggles)

HP fuel pressure is acting very wierd imo but not too familiar with gasoline engines. On startup it slowly builds to ~3800psi sometimes taking 10 minutes then dumps down below 400 when in drive and loaded. Once driving around the command rail pressure and actual rail pressure vary dramatically and independently. Going to check the pressure sensor tomorrow.

I'm pretty sure my fuel economy has worsened also but not 100%

Pulled the surge air box off to take a look and found soot and oil ONLY on the driver's left bank, other bank is clean and dry, not sure if this is normal. PCV valve rattles loosely. Can partially blow air through the checked end if blowing gently, it locks up when blowing harder. Free flowing in the un-checked direction.

Truck has been dealer serviced every time and never late, all recommended service tasks performed by dealer. Sparks and coils changed at 93000

I've uploaded some oscilloscope readings. Let me know if you want more and I'll do my best.

Any help or idea is VERY MUCH APPRECIATED!!!!

 

Welcome to the forum

Sorry an issue has to be your first post.

 

Thanks Rusty!

Hey no worries, the truck has been fantastic up untill this, gotta be something small.. I hope

 

Do you fall under the fuel pump recall? That would be my first guess.

Here’s the original one with a lot of info
https://static.nhtsa.gov/odi/rcl/2020/RCMN-20V012-7781.pdf

they expanded it to cover some additional vehicles including 2020 model year
https://techinfo.toyota.com/techInf...echinfo/html/prelogin/docs/cp/20TB02tofaq.pdf

 

I would also look at what injection mode is commanded. In port mode a default value may be used so the numbers will look weird. Could possibly be a direct injector leaking down. Pull plugs on the bad bank and see what they look like.

 

Yes! And this is another thing that confuses me..

The dealer said it has already been done before I got the truck and is most likely unrelated BUT i found it shows up as not completed in the vehicle inquiry. I also believe the new part number is installed.

 

Clear, concise, pictures, I applaud you OP!

Have they determined it's not internal engine related and cylinder pressures are in spec?

Fuel pressure should remain quite constant.

 

Here is for the reference.

LP pump - should be ~60 psi throughout all engine speeds/loads.

This is normal behavior.

HP Pump. Pressure in MPa

 

Pulled the plugs on b1 just now and guess what, they're loose!! Looks like they been blowing by. Could tighten them with my pinky lol

Even better the middle plug tightens up to a stop on its way out

Dealer changed at 93,000

I really hope this is all it is. Going to snug them up and check the other bank then test it soon

 

People have reported loose plugs many times on here. It seems far more common than it should be.

 

Dealer quality of work strikes again

 

It has been almost 70,000 miles since the spark plugs were replaced, you are looking right at them, change them while it is still easy...

 

Yea your right I'll go pick some up and throw 5 of the 6 in that I can

 

You definitely found the problem, nice work

 

you can do them all, just loosen the bolt to the bracket and you got access to all 6

 

one of them is locking up halfway to removal while loosening. Not going to force it out. installed by dealer so ill let them deal with it.

 

checked gaps and changed 5 of 6, tightened properly, still knocking

also noticed it is much louder from the bottom of the truck..

Worried about the bottom end now

Here are the plugs from the driver's side bank. One is really bad.

 

Not sure if it's the quality of my obd reader but it's sensing up to 3800psi. It slowly climbs there on idle and drops when I put it into gear and drive.

 

i dont understand why there is so much oil on those plugs.

 

I would imagine the oil is mostly from the O ring seal around the plug hole in the valve cover. The engine looks like it's been burning extremely rich though with some oil included, normal for any FI engine is a very light tan.

I just did the ones in my Honda recently and after 50K from new, they were hard to tell from brand new. [tip/ceramic coloring]