Transmission Jerking Badly in ECO Mode

Thanks. I will do the manifold next. I am suspecting may be there was existing carbon in the pipe coming from exhaust and connecting to the cooler. I hope it has not blocked the cooler again.

 

While awaiting weekend for further disassembly of Intake, I decided to add Seafoam in the gas tank with the hope that Seafoam may following the EGR cooler passage as well. I drove about 15 miles in stop n go traffic and the highway and so far it didn't misfire.

 

Definitely the intake is on top of the list for this weekend's project. Picked up manifold gasket from the dealer.

For Seafoam, I added it to the gas tank. Since then I have driven the car twice, mixed pattern - no issues so far. Interestingly, I tried ECO mode as well - no problems here either. ECO mode was the scariest one - I tried from full stop multiple times - not even a glitch. This modes used to be the worst one. I will drive to work tomorrow and hopefully Prius behaves well.

 

Update 22 May: After adding Seafoam to the gas, it drove fine for 2 days, about 150 miles, until this morning as I was going to the dealership to pickup PCV valve. It again acted up. Anyway, I opened the intake manifold - did not see blockage of the EGR ports, however, I did good cleanup of the manifold. All the ports on the engine block intake were dirty, especially, the first cylinder. i also changed the PCV valve. Just test drove it and has been OK so far. Just lost trust in the car though as the behavior is very unpredictable.

 

During the test drive, it glitched again once in a stop n go traffic 15 miles roundtrip - warm 85 degrees outside. The problem is still there which just manifests under some unknown conditions at this point. I drove two days ago while it was 92 degrees outside and no issues.

 

The problem continues to pop up once in a while during my driving trips. Any ideas for next steps? I heard about head gasket sealants, however, that will ruin everything..

Checked on gasket replacement - was told it was over $2k. I am checking around used engine replacement costs.

Strangely enough, there is no white smoke in the exhaust - may be it will be the next stage as the gasket further deteriorates.

Any ideas?

 

Any further ideas? I called around various shops and they don't want to change the engine because of being hybrid, although it looks exactly similar to Toyota 1.8 engine.

 

Thanks for your guidance. The mechanics are asking too much ($3000) for head gasket rebuilt (first they don't even want to touch it) and result might be iffy because of the number of things that will be coming out. Engine replacement by shop $3,500. If my own engine $1500 labor.

 

In a given trip the problem sometimes shows up multiple times and sometime not even once. I can observe slow coolant loss, not much but noticeable and I can hear coolant rush every time engine starts when the level is low. Oil level remains unchanged.

Yesterday I drove about 250 miles - mixed. On one local trip the issue happened multiple times.

My theory is that when the engine stops with cylinder 1 being the first first cylinder to fire up during the start up, the startup cycle gets messed up until other engine gains momentum with the help of the cylinders. The issue, when happens both at cold starts and while engine is hot.

My next step is to conduct compression test (will need to figure out how).

One last option I my considering is disable cylinder 1 fuel, remove the spark plug and let it run on 3 cylinders, at least it would risk of rod coming out?

I really do not intend to spend the rip-off money on the repairs which exceed the price of the car at this mileage - while I may upcoming expenses.

 

Thanks. I am suspecting when the engine is stopped on traffic light for a longer duration and Cylinder 1 is the candidate for firing, it loses compression to a point where cylinder 1 would not fire up and hence rattling. Same thing during cold starts (all other cylinders I am assuming retain sufficient level of compression and/or can build quickly if their turn). I will study on Techstream.