ES250 Engine Problem
About 3 weeks ago the engine started running really rough. Felt like it wasn't firing on all cylinders. It wasn't constant and this happens at idle, in park, neutral, accelerating and running. It seems to have a little less power but at high RPM I still have pretty good acceleration. It has gotten progressively worse. It started as a short term problem, after a couple of miles the car ran fine and now it seems to be pretty constant problem.
This came on suddenly. Engine was running fine. I thought it might be something with the transmission because it felt like there was a jerk forward (like more power coming on) then back to the rough run or idle, but it seems to run fine in all gears.
I have run regular gas in it, premium and even used an octane booster. It still happens.
I did have the timing belt and water pump changed several months ago and it ran fine up to about 3 weeks ago. It seemed to coincide with the time I put octane booster in. I do smell a little gas in the exhaust at start up so it might be running rich at start but I do not smell it after the car warms up.
Any ideas?
I was looking around the engine compartment today and found that all of the vacuum hoses were not connected to the BVCVs. The ES250 has two of these valves with 2 vacuum lines each. All of the connection points are broken on the valves. Could this cause the misfiring, really rough idle and drive?
I am taking the car into the shop today to have the plugs, wires, distibutor and rotor replaced, throotle valve and injectors cleand and timing/ignition checked. They are also going to try to change out the vacuum control valves although these things are something Lexus cornered the market on and are hard to find other than through Lexus. All of this for about $500-$600 (I don't know if this is a good price, but it doesn't sound unreasonable).
I filled my tank with 93 octane this morning and the engine seemed to be running fine again, at least no bucking and it seemed much smoother with more power. It sounds like all cylinders are firing again. This happened before. At about 2/3 full it started missing and bucking and I would not have expected that to change this time. Hopefully the tune help will prove me wrong.
I do not see any smoke out the tail pipe but today of all days I did see a little out of the engine compartment (after I filled the tank). I am thinking (hoping) maybe the other cylinders were not previously firing are smoking slightly as they get back into the game.
Quick update: Took the car in and had new plugs, wires, distributor and rotor put in. Oil change also. Seems to be running great at the moment. We'll see what happens when I reach 2/3 tank.
I have to change out the BVSVs and hope that might help even more. The car still seems to run hot (mid-way up the temp guage). Maybe the new BVSVs will help.
Any thoughts?











