misfitflt

History - The RX300 has 160,000 on it. I am sorry to admit we had not replaced the plugs. We do change the oil regularly and I had the timing belt replaced about 100K. The normal stop and go highway commute was doing 19MPG.

We were goign to take the RX300 on a 3,000 mile trip. The oil was changed. I replaced the air filter. I was told the power steering fluid needed to be replaced, so I siphoned out about 10 ounces and refilled with ATF as instructed.

On the morning we left, the check engine light came on. Then tne VCS light. Then the CEL started flashing. We were about 25 miles from home. We drove to rent a car. Home to switch all the luggage and I dropped the car at my mechanic. The mechanic is a high school friend and I have him do all my work.

Side NOTE: The rental was a Camry that got almost 40 MPG, we figure that over the trip we almost broke even on the cost of the rental vs the savings on gas.

The mechanic said it had codes P0301 and P0302. And other codes that were probably caused by the misfires. He replaced all plugs and coils in Cyl 1 and 2. But it was still throwing P0302 errors.

He added Sea Foam and told me as I picked it up to try running it above 3000 RPM for about an hour to see if the error goes away.

It did not. I have done the IACV procedure. I also swapped coils from Cyl2 and Cyl 4. Still trhowing error P0302. And at one point it was tossing P0300 (Random Misfires).

Is a compression test the next step?

salimshah

You are lucky that you are dealing with #2.

It can be bad injector/bad gas. Compression test should be easy,

I am not a fan of Seafoam, but there are lots of happy users.

I could not understand your logic about the IACV cleanup.

Finally, trust your buddy mechanic ... he does this for living ... right?

Salim

misfitflt

Compression test indicated a major issue. It only reached 30 PSI and I guess it is supposed to be 120. We used an air compressor to determine that an exhaust valve is stuck, cracked or otherwise defective in some way.

My buddy recommmends continuing to add SeaFoam to the crankcase. He also said alternate with Lucas Oil additive. And maybe it will eventually work itself out.

Now up until the compression test, I was only seeing P0302 (and occasionally P0300). On the way home after the test I started seeing P1130 and P1150.

Any suggestions would be happily accepted.

jolomo

What did the #2 plug look like when your mechanic changed the plugs? Was is oil fouled? During the compression test, did you add some oil to the #2 cylinder to see if the compression came up?

kalali

Cylinder compression does not drop from 120+ to 30 PSI overnight. If the compression is indeed 30 PSI on that cylinder then the next logical options are 1) drive the car as is or rebuild the engine. Not much of a gray area.

misfitflt

Yes, it was black with carbon deposits.


No. What does that do?

misfitflt

Well. I am hoping the exhaust valve got stuck. With some luck it will free up again. A used or rebuilt engine will cost $3000 or more. So the drive as is, may be the logical choice.

jolomo

If you add oil to the cylinder during the compression test and the compression increases, that means you have bad rings also.

A month ago, I was going through the exact same situation you are experiencing with your #2 cylinder (oil fouled plug, low compression, leaking through the exhaust valve, etc). Tried Seafoam and spray car cleaner. The compression only got worse. My 2001 RX was barely drivable but it would never pass the emission test here in Texas. It's in the shop now getting the engine rebuilt.

misfitflt

I am really sorry to hear that. Please let me know what the final damages were and where you are having the work done.

I feel sick about my Lexus.