Blackstone tested my sample same day. (Thanks for the incredible service!). So, the plot thickens...here is the summation of my test.

Thanks for the notes. You're wondering about coolant contamination, and no such contamination turned up in this sample. If there were any coolant here, it would show up as high potassium and sodium, but both elements were low. The only element that was high enough to mark was silicon, which would show abrasive dirt or a harmless sealer. Check the airfilter/intake just to be safe. Metals look good, so we don't see any explanation for the troubles you mentioned. Maybe it's exiting with the exhaust? Universal averages are based on~5,000 miles on the oil.

Thoughts?

 

Hmmm
You lost a good bit of coolant in a short period of time
The SIB implies with a broken bolt it will go into the oil and raise the level
Perplexed because no coolant in the oil and no white exhaust?
Gotta be going some where

I filled mine up to the point I started measuring
It took 3 oz to raise 3 mm so 1oz /mm
I used a measuring cup
An inch would be 25 oz or more since the tank squares off below the middle level

 

IIRC having pulled 42 oz of coolant out with a turkey baster in the past I think it's safer to say that I lost a min of 12 oz. Still, I'm puzzled. The test showed 0.0% water. ToXic may be on to something also. I did just start it up for the first time since. A very loud and prolonged cold start bark (unusual in my experience) followed by a somewhat stumbling idle with little "rev factor." It's so puzzling that the coolant loss coincided with the massive misfiring.

 

I hope he is correct and it is an easy fix

 

Could be two separate issues....a coolant leak and a separate problem related to the misfires.

 

Yeah, anything is possible at this point. I was going to do plugs and O2 sensors in 5k miles anyway so I just ordered them. I was surprised at the (good) price of the OE Bosch upstream sensors, $176 for the pair from Rock Auto. OE NGK plugs were $83 for eight from Amazon. If this solves the misfire then I'll start driving the car locally and see what happens with coolant levels. The amazing thing to me is that this car had never thrown a code until now.

 

That's good news. I was expecting the worst.

Change the plugs and O2's like you planned and keep an eye on the coolant level.

 

I read back through a number of threads on the P03XX codes. It seem that the instant drop off in power essentially renders the vehicle undriveable. I mean, I barely got into the garage. Why design a system that is fine one moment and massively disabled the next? What changed in that microsecond? Why disable a car so dangerously if an item sends out a slightly off-calibration signal? Makes no sense to me...

 

I think the car is trying to save itself from catastrophic failure. Just my thinking though and not sure if that is accurate.

 

So you can pull over and have it towed rather than let it grenade and lock up...

 

Weekend update: I installed new OE NGK plugs today. All Bank 1 plugs were black and wet-fouled, although the plug themselves looked to be in great shape with no visible erosion whatsoever on grounds or electrodes. Bank 2 plugs looked perfect, a light coffee w/ cream in color. All plugs broke loose with even torque but four - one on Bank 1 and three on Bank 2 - had (wet) oil on the threads, on average half-way up. I know others here who have changed plugs have found this oil also but still, it puzzles me a little. The color of Bank 2 plugs confirms that a cooler plug is not necessary with my setup.

Tomorrow the O2 sensors go in. I did replenish the lost coolant today. After sitting a week it seemed the coolant level had risen a hair. I ended up adding exactly 10 oz to bring it back to the mark. I cleared the codes...my plan is not to start it until after the new 02 sensors are in. If it runs OK then I'll stay close to home and drive it an hour or two a day and see what happens.

 

If it were my engine, I'd run a compression check on all 8 cylinders, especially on the bank with the wet spark plugs.

 

O2 sensors on these cars should be a service item. Car runs closed loop it needs perfectly functioning sensors.

Headers seem to destroy the O2 sensors quicker.

 

I got the car up in the front and slid underneath to tackle the 02 sensor replacement on the Bank 1 side. Even with a beefy 22mm wrench I couldn't break the old one loose. The one tool I needed - my old 3# lead-head hammer - "walked" after I loaned it to a friend so I had nothing to bang the sensor loose with. I might have to flatbed it to shop to have it put on a lift. I decided to start it with the new plugs though, but it still ran rough, not revving freely at all. On the bright side, I surprisingly found all four wheels were firmly frozen to the hubs despite only having been put on three months ago, so it was good to give them a little clean up and anti-seize.

 

hi mate

once you change out the oxy sensors your car will run like normal trust me

before my last change my car wouldnt even run it was running on 4 cyc
i couldnt even drive in my estate

once you get the new ones in you will be very surprised

 

Good to hear...that gets me excited!

 

I have the exact same problem.. cannot get the damn sensors off. I have a breaker bar, but cannot get enough clearance to use it with jacks, I need to find a lift.. My still runs okay, but I know the secondary O2 passenger side is failing (voltages on the sensors should fluctuate while the car is on, that one is solidly at the same voltage).

 

Update?

 

+1 on a compression test just to be safe.

 

A minor update...I have this 3# dead blow hammer coming via eBay, perhaps as soon as Sat:

http://www.ebay.com/itm/271362907528

As jvan states there's little room underneath the car to muscle tools around w/o it being on a lift. In the past I found my old lead hammer invaluable while working under a car so when the replacement gets here I'll give the 02 sensors another whack, literally.

And thanks about the compression test suggestions. I have a compression tester but don't really want to do the plugs again at this juncture. If I get the sensors off/on and everything is not OK then I'll compression-test before the flatbed comes.

 

My guess is an automotive engineer (but not a mechanic!) is that it's not the coolant at all.
The coolant level will rise and fall. You are checking the level in the expansion tank. It will change.
As long as it's in the min-max range, don't worry about it -- unless you see other symptoms.
The limp home wouldn't be triggered by low coolant. If the coolant were low, the overheated engine light would come on. You would be able to keep driving normally -- although you definitely shouldn't!!

 

His concern is that the m156 has a documented issue with the headbolts
If they fail coolant seeps into the oil and cylinders
In the cylinders it causes a misfire and sets codes amd limp mode

The level will vary with temperature but if measured on level ground at the same temp it should be fairly constant, mine is within a mm or 2
Over time a few oz may be lost
Mine lost 2-3 in 7000 miles of 80 mph extended cruising

 

Before going to town with the dead blow, use PB, and maybe after driving it hard to heat up and expand the sensor socket a little. If you just wail on the wrench holding the O2 sensor, you might break the sensor off and have half a sensor stuck in there.. or you might destroy the threads the O2 sensor goes into...

 

did not read all the post in this thread but if you are just trying to diagnose if the 02 sensor is working why dont you use STAR DAS and it will plot the voltages of all sensors on a graph when the car is running

 

Have you ever used a hammer like this? I have this (now, just came today) plus two hammers with double urethane and hard rubber faces, one on each side. I only use a steel hammer for driving nails now. Aside from the obvious benefit of no surface marring to the tool you're striking, IMO it's the best tool for separating joints like this, especially when you have little room for a large-arc hit. It's very easy to "feed in the power" of multiple hits when you don't have room for much of a swing as in this case. A dead blow hammer functions like an utterly safe impact driver if you have any feel at all for doing your own wrenching. I think I'd snap the body of an 02 sensor with a high-effort two-handed pull on a wrench long before a controlled strike with a dead blow hammer. BTW, I think it's clear that I shouldn't/can't drive the car in this condition, not even around the block a few times.