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Not sure where to start with this as I’ve been on the forums A LOT lately and trying to diy as much as I could on my 06 is350 until finally I’m at a point where I don’t see anything or anyone on here experiencing what I have been. I also don’t really want to leave anything out so this might be pretty long but I just feel like I need to be thorough, apologies in advance for the long read.
So two weeks ago CEL came on and my car began hesitating to accelerate but with that hesitation it’d shake the car pretty rough. Being nervous about possibly breaking something in the engine I pulled off on the side of the freeway and at a stop the idle was pretty rough for awhile then leveled out and CEL went away so I kept driving home. Once I had gotten home I connected my OBDII since the engine light had came back on and I got the p0300 p0304 codes so being that my car is nearing 120k miles I figured I just needed to change out the spark plugs which I did and codes still appeared. Then I went to switch out the coil packs to see if the codes would follow the coil pack I switched to and nope still p0304. At this point I’m seeing on the forums that if it isn’t any of that it could be the fuel lines or intake manifold but I’m done with working on my car so I take it to a local mechanic who specializes in Toyota/Lexus and tell him everything I’ve done and what I’ve been experiencing with the car. After hearing me out he then tells me to start the engine for him so I do and immediately he tells me to cut it off and do it again so I cut off the engine a second time and step out of my car to hear that his conclusion from just listening to how my car cranks up is that one of my pistons has lost compression and that we could do a compression test to be sure but that if it is that I’d have to rebuild the engine or replace it and he suggests just replacing it. Now I’m definitely in no place to rebuild or replace an engine at this very moment ($$-wise) so I declined, thought I’d save myself the money and just drive it home which is where the overheating problem arises. I drove her home but right as I was about to get home (I had been driving maybe 20 miles) I noticed that my oil temp gauge was moving to the right a little too much until it started nearing the H so I pulled off into a parking lot and turned the engine off to save myself from further catastrophe, I thought, but now the car won’t turn at all or go into accessory mode so I don’t know what to do anymore. Sorry but another thing I’d like to include is the spark plug from cylinder 4 when I had moved the coil packs I noticed it was completely black on top like it was burnt and I saw that that means carbon fouling so I’m not sure how that fits into this whole situation or if it’s a factor or not.
If anyone needs me to provide any more details or clarification I’d be happy to answer anything just would like the opinions of those wayyy more knowledgeable than me. I’d appreciate any advice or suggestions those of you who took the time to read through this have to offer as well. Thank you!!
Where did you get the replacement plugs from? So only the one plug mentioned is carbon fouled?
I got them from autozone they’re the auto lite xp iridium 5325. Yea I pulled all the plugs to check their condition and it was only cylinder 4 that had the carbon fouling.
I know a lot of people on the forum say not to use those spark plugs and only run the denso oem plugs but I was in a tight spot when this happened so I felt like I had no choice with this being my only vehicle at the time. I have another car for now but I do want to fix this car still and at the moment it won’t start or go into accessory mode and my key fob doesn’t work either so at this point I do feel like an engine replacement is my only option I just don’t like that I don’t have any idea what went wrong with my engine. Here’s a picture of one of the spark plugs that I feel shows what happened to my car although the overheating and stall out happened with the spark plugs I put on.
It looks like it's running lean and using oil through that one hole. Like it has a significant fuel event starving it for fuel or a big air leak occured. Check MAF, and look for vacuum leaks. A couple of plugs were very hot.
Key ingredient is misfire codes are not absolute, its not always the ignition. It can fuel or compression. The 0300 was random among many cylinders. The P030X says hole 0X was not accelerated to the minimum velocity the ECM expected for those conditions and it triggered a misfire code.
It looks like it's running lean and using oil through that one hole. Like it has a significant fuel event starving it for fuel or a big air leak occured. Check MAF, and look for vacuum leaks. A couple of plugs were very hot.
Key ingredient is misfire codes are not absolute, it’s not always the ignition. It can fuel or compression. The 0300 was random among many cylinders. The P030X says hole 0X was not accelerated to the minimum velocity the ECM expected for those conditions and it triggered a misfire code.
Yea after everything I did I figured it wasn’t the ignition anymore but the fact that the engine overheated and now won’t turn on, that would make it more so a compression issue correct? I don’t know I guess I’m just wondering if my engine is truly done for since the last time I ran it I just saw the oil temp gauge rising and immediately shut the engine off before anymore damage could be caused and since it’s not wanting to turn anymore (acc mode and key fob are dead along with the push to start button) I’m guessing the engine probably is ***********. I was gonna get the engine compression tested as well but they were
going to charge me around $200 just for that and the mechanic, just from hearing the engine running, suggested I just get a used engine and replace it. So I felt like if he’s saying that why would I pay that money if I’m gonna have to replace this engine anyways. He basically told me the rebuild for the piston(s) that lost compression would be more costly than a replacement so I’m unsure of what to do 😓😓
Was thinking of doing the compression test and possibly tearing down the engine myself but definitely don’t have all the tools to do so. Guess for now I’ll be saving up for whatever option I go with I kind of just wanted to know more about what happened with my car before doing so but hate how expensive mechanics are nowadays
08-17-23, 09:38 PM
Can P0300/P0304 Code cause overheating? Reasons??
