2000 RX300 w/AWD - No Navigation

I have had, what most people refer to as a sludge problem, where oil is passing by the valve guide/seal on the #2 cylinder. Now, after an incident where I lent it to someone, they used regular fuel which lead to more than normal oil passing thru..

Now, I replaced the spark plug with the #4 plug & coil, put another plug into the #4 cyl along with the #2 coil, and the #2 cylinder still does not fire. Tested by removing the connection on the #4 coil, which resulted in a worsened firing situation, then after replacing the #4 connection, I removed the #2 connection which had no change result. The Only trouble code is: "P0302, Misfire detected in Cyl #2"

Would this be an ECM situation, as there may have been an electrode to ground short due to excessive oil build up on the plug?... OR??? After resetting the ECM, OD works till the code comes back on, then no OD

 

Well, it doesn't sound like the classic coil problem. Did you switch the wires also (if they reach)?

Why do you think regular gas would worsen the sludge issue?

 

I wonder if you have a clogged fuel injector.?

 

I have read on this forum that this is normal, i.e., no OverDrive when CEL Light is on.

 

I'm thinking the regular gas may cause the oil to run thru the seals, perhaps because of the burning temperature? I have no idea, but thats the only thing different that has happened to it.

The wires are too short to switch them as such.. I wonder if its the injector as well.. Will have to check to see if fuel is coming into the cylinder.

 

I have had an opportunity to do some diagnosing on the RX300..

I took out the coil, and attached a spark tester. There IS a spark, and a healthy looking one too.

So, the next step was to take out the new plug, see whats happening in there. It showed some fuel, as well it had smelled like it as such. Fuel injectors working..

Next, i did a compression test. First result was ~70psi. retested, ~65psi. Tested the #4 cyl for a control. Its results were ~160psi. Retested #2 for another time, and resulted with ~65psi again..

conclusion is that the oil contamination within cylinder #2 has, is some way, jeopardized the compression integrity within the cylinder, and has resulted in a low compression & misfire.

IF this is a result of rings sticking, which is my thinking, what would you recommend I use to 'wash' out the cylinder?

 

Regular gas won't cause that. The worse it would do is retard spark and reduce performance.

Do a leakdown test to see where the compression is being lost.

It's either going out thru the valves or into the crankcase.