engine vibration when slow step on the gas

throttle body cleaning? just a guess

 

Try cleaning the MAF sensor. It may not help, but it is easy to do, and it will not hurt.

Posted via the PriusChat mobile app.

 

When you get a specific cylinder misfire code, a good trick is to swap coils and plugs around, see if the misfire code follows, or not. If not, could be head gasket. Your cleaning efforts are good, but might be too late. Is the engine coolant level stable in the reservoir?

 

Keep driving until the damage is further It's already started and pretty much done I don't know if you're trying to save something or what's happening more than likely saving is not the issue at this point getting ready to get everything in place for the remedy or getting out of the car or the next points of interest probably

 

Why isn’t a leak down test sufficient to disprove head gasket failure?

 

Yes you need to track down if you have a miss or do you have a stumble Is the fire being put out or is the fire not in proper control.

 

Another thing that you can try is some Techron fuel system cleaner, add it to a full tank of gas and see if it helps.

I like bisco's idea of throttle body cleaning. If it has not been cleaned before, it is definitely due by 125k miles. If you clean the throttle body, you should disconnect the 12v battery for a few minutes so that the car can re-calibrate for the clean throttle body.

 

Are those OEM from the dealer?

 

HV?

 

Hybrid vehicle aka, start out in ev, then the engine fires up

 

Oem coil is one thing, what about Chinese spark plugs?

 

I had the exact same problem you had with a misfire on cylinder 1 instead of 4. I tried to do a coil swap but it still showed a misfire on 1. I also did a spark plug swap but same issue. I did a block test as well and the liquid was still blue.

I ended up replacing all the spark plugs with OEM ones and it stopped shaking. The misfire error code went away after a week or so. So after I thought it was fine, I noticed my oil getting slightly murky. I thought it was coolant leakage but my coolant loss seemed fine. I got an oil change and ALL of the oil turned out murky. They told me it was an engine problem but couldn't tell me what exactly.

At the moment, I'm debating whether or not I should try to get it serviced from the used dealership I bought it from or just a rebuilt engine from HybridPit. I haven't asked about the cost of the engine + labor but I'm dreading it.