Well, this may be it, the last failure. P0301... Blown rings/motor

[TopherSho]

During hard acceleration it sputtered/backfired-ish right at the 2nd gear shift... and threw that code after i let off for the 2nd gear shift to finish.   now is missing for sure on two cylinders.

Either i fouled the plugs (but two at the *exact same time* seems unlikely)
Or it smashed the valves..
Or it backfired and killed a turbo and sucked it through the block..

UPDATE:  or a fuel injector #2 dumped fuel during my on ramp run and physics kindly/explosively placed my rings in the pan ... /eyeroll/

2/3 odds this car is now beyond repair .. i cannot afford a new engine right now.. or any time soon.

/ugh/

expecting the worst on this one.

[SHOdded]

Sorry to hear   Sounds like compression loss or fuel injectors.  If compression loss, could be multiple reasons, but a nused block is the practical solution.  Injectors - not too bad to replace.

Could be 2 plugs failed, may not be common, but there is always an exception.  What plugs are you running?

[TopherSho]

Oem plugs..

[4sfed]

Compression test time!


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[TopherSho]

Two adjacent plugs are wet with oil and gas. (rear back passenger and middle) not a good sign.  all the plugs are out,  off to get 7 sp-534's and drop them back and and cross my fingers.

all remaining plugs were perfect as far as i could tell.  no impact damage from debris so turbos are not scattered which was my 1st horror show thought.

this leaves 'fouled on backfire with meth',  or 'bad head gasket'. 

question, if the cylinder smashed the valves would the plugs be intact?

[TopherSho]

verdict == bad.  new plugs, issue same.

So bad gasket from some sort of over pressurization issue when it backfired and stumbled.  if it were valves I imagine it would backfire under light load,  which it does not do or spit crap out the exhaust.. 

but the presence of oil  on the plug concerns me.  I have a fear we cracked a sleeve as a worst case scenario. 

off to the worst dealership i have ever seen.

[4sfed]

off to the worst dealership i have ever seen.

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[SHOdded]

Fuel should only be a leaky injector, oil is likely from blowby unless the intercooler is filled with crud (has happened). Oil could be leaky turbos also, simple enough to pull the hoses and check.  Air flow for bank 1 does not have the same characteristics as bank 2, plus bank 1 runs hotter anyway due to location.  Fingers crossed it is a combo of injector and PCV/intercooler, probably the simplest/cheapest fixes. 

[TopherSho]

It would have to be 2 injectors failing side by side at the exact same time .. so I'm not so hopeful. 

I do live out here in Oregon so gunk in the intercooler is pretty common that might explain the oil.. but in not convinced.  it was more than a spattering.. it was a solid dark film.

I'm pretty confident it's a head gasket with the side by side bad plugs, but there could be more going on in those cylinders.  *one* of them for sure had some extreme pressure issues. 

i will check on the costs of replacing the gasket .. but since this is the rear bank i just don't see fixing it any time soon.  i imagine the engine will need to come out and i am not capable of this depth of work. 

[Sabtaj1]

Find someone to swap the coils off of and try.  There has been issues with coils failing from time to time and that would cause a missfire.  I would start there.  I just had the p0300 but that was my fault because I forgot to plug a connector in on the trans side of the engine after changing the water pump and timing chain.  All was well after plugging back in.

[TopherSho]

Sadly I did swap the coils around,. Same two cylinders come back fuel soaked and oily. 🤤

[lamrith]

Before you do anything else at all do a compression check it will tell you more than guess work that is being done sofar.  With the symptoms and things you have said I would do compression and leakdown before I spent a single dime on plugs or anything else.

That car is killin you bro, stop throwing parts $ at it, $ on tools like compression tester are well spent for any future cars.  plus you should be able to borrow one from Orielly's for free.

Crossin fingers for you man

[ZSHO]

I was curious where did you install the Check valve for Meth! 
Keep your chin up Bro! Z

[SHOdded]

May or may not help, but could be timing related
https://shoforum.com/index.php?threads/2016-non-pp-random-misfire-issues-check-engine-light-help-please.138623/page-2#post-1506213

or have carbon buildup on the intake valves causing them to stick.  Kinda goes along with Z's thinking about the meth injection, and maybe not enough spray reaching those cylinders.  Yea, long shot, I know.

[TopherSho]

The Forum is being super slow and not loading on my phone or pc,  so i will reply here an not with the reply-qoute buttons

We will do a compression check prior to pulling the motor.  I am taking it to my old mechanic and there going to do the job 1500$ cheaper *IF* it is just a gasket. So we will do a compression check, and if it fails as expected we will go from there and pull the motor.

I had the valves cleaned prior to meth installation at around 50k miles.   I saw numerous valve caking complaints so i did have them blasted once.  car has 20k more miles now, about 15k with plenty of meth.

The check valve is in the last 24 inches of hose,  right before the nozzel, it is a #5 devils own, about 700ml flow, nets me .80 stft readings on hard acceleration.

spark plugs looked amazing,  i had to change them at 60k due to the one step colder being a issue,  the ones i pulled that were the replacements were super clean front and back except for the two wet/oiled ones.

gasket questions.  what gasket am i going to use? is there a better gasket than the oem replacement to go with?  Rockauto had a few .. but it has been years (or 20) since i have done headwork (nova/mustang days)