Suddenly getting misfires on all four cylinders

Clearly the diagnosis has to be made first before doing much more than shotgunning some new parts, which is the common first step we hear about. But plugs, coils and injectors can get expensive unless it is clear they are at fault.

Typically one misfire will report as many on these engines so the diagnosis of a bad part based on codes alone is tricky. Counterfeit plugs are a known issue but it is unusual they fail so quickly. Oem plugs routinely make their 120k mile interval and often are trouble free through 200k.

A recent South Main Auto video shows a borescope procedure on a gen3. In that case it had progressed to obvious coolant loss and was not an early case that sometimes goes weeks or months between events. There seems to be evidence early hg leaks can bypass the gasket and quickly seal as the cylinder heats up. These leaks often respond to sealers for one to twelve months.

The pros often do a short block because it provides new pistons and rings, a Toyota acknowledged flaw in 2010-mid 2014 gen3s. It also eliminates bent connecting rods as a possibility which has happened when a hg leak was allowed to progress significantly. The rods have been known to break even after a hg repair because they were slightly bent due to hydrolock and or misfires. Again the short block option is the high end, 150,000 or greater mile solution. Others simply replace the pistons and rings, still others only replace the rings.

A recent Gasketmasters (California oufit with mobile service) engine replacement I heard about was a ring job with rebuilt head and gaskets. Specifically a Felpro head gasket, new J&D rings and rod bearings. The swapped engine included a cleaned EGR cooler, new PCV valve & hoses, a cleaned intake manifold, new spark plugs, oil and antifreeze. Plus a three year parts and labor warranty, all at the low end of engine replacement pricing. Actually their engine pricing is less than many shops charge for a head gasket. Hybrid Pit in Socal also has a good reputation with reasonable prices.

 

Leak down test is also good. Simplest approach would be to have a competent shop do it, requires compressed air and a special gauge set. And some know how. Individual cylinders are brought to TDC on compression stroke and tested.

 

These cars are junk..... all gas savings gone and lots of mental fatigue......... only vehicle I've had that's blown a head gasket.... plus the brakes, inveter and traction battery.......

 

You can do a compression check with techstream

Please post screenshots of the histeresis

 

Nowhere near the junk that was our 1998 Dodge Grand Caravan. By 30,000 miles it had everything but a replacement engine block.

 

OEM coil on plugs are $100 each for a G2 maybe more for a G3. But These engines make quite a racket like the motor is blown when a cop fails though.

The traveling misfires are usually caused by one thing and that's subsonic vibration. So much so that the pg waveforms on the cam and crank sensors get distorted the engine ecu cannot decode those distorted waveform's and runs home to mama and throws a missfire. Lots of them.

So either you have a bad HG or you are not timed properly. Get under the car and listen while the engine is running. Is it making a low thudding noise? Does it sound timed? Have someone put the car in gear while holding the brake and see what it sounds like with a load on it. While holding the brake and e brake on give it a little gas in gear.

Good luck be careful.

 

You could always take it back to the guy who did the head gasket and throw a fit. Seriously I would first wait until it repeats, maybe you drive the car until it does.

I would start with the borescope as the other techniques won't help on an occasional fault or simply do the sealant which is diagnostic in itself when the problem quickly goes away.

 

This is supposed to be toyota quality...... and a lot newer than 90's dodge technology.....
The cars are JUNK.....................

 

That hasn’t been our experience with our 2012 v Five, but that’s where statistical variance in components, build, usage and maintenance creep in.

 

Check out my post it's slightly similar, the thing is there is an inverter recall. I have a very funny feeling that the EV battery is running more efficiently due to me cleaning the Battery fan filter scrim under the rear right seat, after getting a "maintenance battery parts go to dealer" error, so I'm thinking something has surged some system and has caused the firing sequence to fire incorrectly or not at all; The 12V battery is given 12V by the inverter, and the inverters on these cars are being recalled because they cannot go into a safe mode/stall the car at any moment on the freeway, sometimes causing accidents (Fatal. Deaths have occurred). The recall is supposed to have a finalization of some sort in early 2023, unpaid/not under warranty until then but they advise to tow to Toyota if you are stranded, nevermind the coffin and 6 foot dig order we also need.

Anyways just a thought, and I found some green crap in my throttle body months previous, was having more strained initial starts, like 2-5 piston rotations thud then smooth running. What I mean by thud is it jumps a little hard for 1/2 - 3/4 second then it was smooth. I also sit in a parking lot for 9 hours per day with it cycling on and off every 5-10, 15 minutes or so.

Read the thread I created, it goes into much detail. Putting it in Toyota on Monday or Tuesday we'll find out for sure.

Solve yours yet?

Cheers

Studdering misfire on startup after cleaning Battery cooling fan air filter | PriusChat

 

He did the HG himself.

 

Check this out Wrench:

 

Go in with your eyes open, and keep a tight grip on your wallet. Especially if they propose the coils-and-plugs parts-cannon.

 

Or Dodge Journey: transmission overheats from highway driving
or Chyrsler 3.6: needle bearings on drivers head lifter disintegrate
Chrysler 3.8: piston rings crumble to pieces
Chrysler Concorde: What doesn't break
Chrysler LeBaron/K Car/etc: 50k mi car lol

 

I recently posted some info in another thread that might help you pin down the conditions where misfires are likeliest to occur.

 

Check first link in my signature, there’s info and tips.