midwestmx

Several signs suggest head gasket, but I'm not 100% convinced due to a couple of the symptoms below...

Car: 2002 ES300 with 190k miles.

Symptoms: Rough/low idle, very low power (some cylinders definitely not doing their job), shifts rough, some smoke (can't tell color), lurching and noisy at 3.5k or so rpm. If you reeaaally baby it, just ease on throttle, it will run sort of OK and smoothly reach cruising speeds. Any abrupt throttle at all causes chaos.

Lights: Engine, TRAC, VSC

Codes: PO300, PO302, PO306, PO430

Other observations: Bank 2 plugs are very black, Bank 1 plugs look OK, compression test is just over 180 psi on all Bank 2 cylinders, I tested Bank 1 Cylinder 1 and got just over 200 psi. I believe range is 145-213.

What is NOT happening: Bubbles in coolant, coolant on plugs, any of the Bank 2 plugs showing any signs of coolant (i.e., they are very black)

Stuff done: New ignition coils on Bank 2, new plugs, new a/f sensor (i.e., pre cat) on Bank 2, new MAF sensor, cleaned throttle body, new air filter.

Any ideas? The misfiring on 2 and 6 with the multiple misfiring readings, cat-related code and smoke (again, if I had to guess I'd say it's white, but not sure) definitely suggest head gasket, but the black plugs (look spray painted black after just short drive; replaced them just yesterday), in-spec compression readings and lack of bubbles in coolant indicate it might be something else.

I thought it might be oil blowing past pistons, but would they all go on Bank 2 at once? Same with an oil passage leak into cylinder...odd that it is happening on all three cylinders. Plus, all Bank 2 cylinders are right above 180 (probably closer to 185). Wouldn't the compression test be out of spec if an oil passage leak past head gasket or worn pistons were the case?

Is there something other than a head gasket that would cause a really rich condition on Bank 2, but not Bank 1, and not push Bank 2 compression out of spec?

Suggestions please? Luckily, all the symptoms are on Bank 2, and I would tackle the head gasket on that side without hesitation if I knew for sure that was the problem.

Oro

Sorry to be abrupt but I have a little time. Google oil control valve.

Another option is a broken cat given the 0430 and lack of 0304, which would generally accompany an OCV issue on bank 2 with your other codes.

Without abuse, a headgasket issue on these engines would be extremely unusual.

midwestmx

Thanks for the reply.

Could a clogged cat be the cause rather than a symptom of the rich conditions in bank 2?

I drove the car again this evening. It's so low on power, my guess is neither 2 or 6 are firing. There also is very little exhaust pressure reaching the end of the tailpipe.

I'll look into the oil control valve.

Thanks, again.

midwestmx

I pulled the Bank 2 OCV this morning. It "looked" clean, and when I jumped it on the battery, it operated smoothly and quickly.

Also, last night I pulled off the cat heat shields with the plan to remove that today. I also spayed down the bolts with PB Blaster. I started the car after putting the OCV back in and was staring at the cat while the PB Blaster evaporated off. That's when I noticed a spot of moisture build around one of the seams on the cat, so I guess there's a busted weld. Nothing helpful, really, since I know the cat is plugged or busted anyway.

Now I'm thinking it's narrowed down to either plugged injectors on 2 and 6 or the clogged cat is causing all this...

PFB

A clogged or damaged Catalytic converter is almost always caused by some external reason. Some such reasons could include the following:

1) Rich/Lean condition
2) Coolant or oil in the exhaust
3) Overuse, Abuse, or Misuse of fuel additives and cleaners.

So if you discover that your Catalytic Converter is indeed blocked, than you should look for one of the above reasons, and remedy the problem BEFORE installing a new Catalytic Converter, If not, a new Catalytic converter will experience the same problem in a short time.

Phil

midwestmx

Hi, Phil. Thanks for the response.

Yes, that is my concern -- that the clogged cat is a symptom and not the cause. However, one thought (hope?) is all the other stuff I did (ignition coils, bank 2 a/f sensor, MAF sensor) have corrected the condition that destroyed the cat in the first place.

Speaking of the catalytic converter, I just got it off (bank 2 cat/manifold) and it's trash, not just clogged, but the cat material inside is reduced to broken up chunks.

midwestmx

Just to close out this thread for anything stumbling on it, the clogged cat was the source of the rich conditions on bank 2, the misfires on 2 and 6 and everything else. Fitting a free flowing cat vs the clogged one fixed everything.

PFB

Nice of you to update this post. It helps other members experiencing the same symptoms.

some members ask for advise, members reply, and than the original poster is never heard from again.

Glad you found the solution to your problem.

Phil

midwestmx

Since the bank 2 cat is so easy to remove and visually inspect, it's probably a good rule of thumb to remove and fully examine the cat before spending much money chasing any bank 2/cylinder 2, 4 or 6 codes. It might be a case like mine where the exhaust is physically blocked by sideways chunks of cat material and no amount of cleaning or sensor replacement can fix. Wish I had done that.