I just bought an '04 TL 6spd manual, and took it up to my cabin in WI (ultra fun to drive!). But, it turned out the plow guy didn't come like he was supposed to, and the driveway was a bit snowy. Trying to get out, I may have hit some high RPMs on the way (but not redlining), and it exhausted nasty smelling white smoke. Later, when I went to shovel, I noticed drips of coolant in the snow. On the way home I also noticed a 15-20% power loss going down the freeway. After I got home, let it sit a night or two, I fired it up to take it to the shop, and my check engine light came on with error code P2195 - Bank 1 sensor 1 (O2) stuck/biased lean. I also noticed a strong, seeping air noise near the head/intake manifold area that was not there before (usually a super quiet engine). The coolant level was lower than before, but still enough (75% full between min and max fill lines).

Anyway, I took it to the dealership where I bought it, told them all of this, they did a pressure test on the coolant circuit, only to tell me that they didn't see any leaks and that the car is fine (bunch of incompetent fools). I got fed up with their lousy service, and I now plan to take it to a real, friend-recommended mechanic.

I'm guessing the intake manifold gasket or head gasket are going bad (oil and coolant seem to be uncontaminated at this point).

Has anyone had this happen to them before, or have any advice on the matter? Any help is appreciated. Thank you.

 

Vacuum leak causing your lean, given away by the "seeping air noise". Use a propane torch (with no flame!) to find out exactly where it's coming from and replace that gasket.

Dripping coolant?? You'd better find where it was dripping from before it gets worse. That's probably why it's lower. Keep in mind that it get pressurized, so when you measure coolant levels, always do so at the same temp (cold).

 

Are you saying this coolant came out of the exhaust? Are you sure it was not normal condensation? Condensation builds up in the exhaust especially while it's idling and heavy throttle will blow it out.

If the 02 is stuck lean I can only assume the ECU is trying to richen it up so that will cause more condensation out of the exhaust than normal.

I would keep an eye on coolant levels and see if it has actually dropped. You'll have a higher level when hot than when cold and everything in between. If both times you looked at it, it was a different temperature, the level will be different without anything being wrong with the car.

One other thing to keep in mind is coolant will destroy 02 sensors. I doubt yours is actually burning coolant but it's something to check out if the level looks like it's dropping. Many TLs leak coolant from the little hose that connects the overflow to the radiator. Mine did it when it was brand new. I solved the problem with a couple small zipties. This will not show up on a coolant pressure test as this is not the pressure side of the system. I ran into the dealership incompetence when my fiancee's Murano was losing coolant. It was under warranty and I didn't feel like messing with it so I took it in. They could find no problem and said they had pressure tested it and it passed so it was good. With them right there I asked if they tested the low pressure side since the high pressure side passed. I got blank looks. I popped the shroud off of the radiator and there it was, a coolant leak in the same place I described in the TL.

How cold was the engine when you were trying to get it out of the driveway?

 

I hate cars,

First: Love the screen name

Second: Thank you for the insight,I didn't know that about exhaust condesation, coolant's effect on O2 sensors, or the overflow tube problem. I'm definitely going to check my overflow-radiator connection.

However, the sheer magnitude of the power loss is what's leading me to believe there is a bad gasket, as well as the seeping noise near the head/intake manifold, which is most prevalent on the side opposite of the air intake.

Vlad,

Good call on the propane torch trick, I'll tell the guys to give it a try. Also, the dealership filled the coolant to max (before purchase), and the "25% below max fill line" reading I took was cold. The only thing is, I'm not sure if the coolant was lost during normal operation, or the high-load situations.

But time will tell, thanks again for the help guys. If this situation sounds familiar to anyone else, please post.

 

I would definitely be looking for a vacuum leak. There are two covers or access holes on the end of the intake manifold on the passenger side that have leaked on mine. I usually just use water spray on suspect areas and listen for changes in the idle.

If the 02 says is stuck lean it is probably adding a ton of fuel to try and richen it up. This could be the power loss. Theres also the chance you have a plugged catalytic converter. This would explain the noise, the lean code, and the power loss.

I have a couple questions though. Does the noise increase with more throttle, rpm, or both? Does the power loss (especially at full throttle) seem worse at low rpm or high rpm? Does it idle normal?

If you have an IR thermometer you can shoot the temp of both catalytic converters to determine if there's a problem and on what side of the engine it's on.

About the vacuum leak, if it's on just one cylinder you can get a lean code. If it's in the common area like the intake manifold plenum it's not likely to cause a lean condition.

If the dealer filled it to 25% from the top when cold it's overfilled. Depending on how high it was it could overflow when it gets hot and it will look lower the next time it cools off. The level in the tank doesn't matter a whole lot unless it gets low enough to uncover the hose and suck air or unless it's getting lower.

If the dealer filled it to the max line when hot it's fine and 25% below that would be about right when cold.

 

Does the noise increase with more throttle, rpm, or both?
-Not sure, I didn't test it. Would have been a good test though.

Does the power loss (especially at full throttle) seem worse at low rpm or high rpm?
-Also, not sure. Didn't stress it when I drove it home from the cabin. Haven't driven it much since (been in the shop).

Does it idle normal?
-Yes, for the most part. The day after I got home from the cabin, I started it up to move it for my roommate. The light went on and the idle sounded slightly rough. The light actually went off on my way to bring it back to the dealership and hasen't come back on. But it came on consistently when I started it while it was sitting in my driveway for two days (before I brought it back).

 

Sorry, forgot you didn't have it in your posession anymore.

I asked about the idle to eliminate a stuck EGR because if it was bad enough to cause power loss at part throttle the engine would barely idle. If the noise got better with heavy throttle, it's 99% for sure a vacuum leak. Make sure to let us know what they find, I'm curious.

 

Will do, thanks again for the help.

Also, just out of curiosity. How accurate is a pressure test when looking for a head gasket leak. I know that they only pressurize it to apprx one atm (gauge), and the car isn't running when they do it. When looking at a gasket leak between the coolant orifice and cylinder orifice, I'm sure the differential pressure would be much greater if the test was done when the car is running, and would increase with an increase in RPMs (Bernoulli's principle), which would lead to a test more reflective of real-world conditions, right?

 

Just heard from the non-dealership mechanic. No head gasket/intake manifold gasket crack!

-Air seeping noise was a leak in the vacuum line for the rear motor mount (which caused the lean check engine light and power loss).

-Leaking coolant probably came out overflow during high rpms while getting out of snow. Absolutely no signs of leaking coolant anywhere else.

-White smoke probably came from high snow level on driveway coming right up to my exhaust pipe (but wasn't over). This close, low temp heat sink condensed the exhaust H2O in the pipe during idling, which was vaporized and then ejected upon engine reving (trying to get unstuck).

 

if coolant came out of your overflow tank, spend the $20 and get a new rad cap.

 

The coolant was probably from when the dealer overfilled it when it was cold but as it was mentioned, if high rpms made water come out and your headgasket is fine, replace the radiator cap.

The motor mount theory is interesting. I just tested the actuator to see how it works. It's only active when the engine is at idle and rpms under 1,000. The amount of vacuum it flows even when you pull the vacuum line off the mount is tiny. When I pulled mine off I couldn't hear anything, I had to put my finger over the hole to make sure it had vacuum. If the line came off at the intake manifold, you can hear it slightly.

Where the dealership's theory is full of holes is saying this caused the lean condition. A leak in the plenum which is what this is will not cause a lean condition, especially being that small. It's impossible. I wouldn't get your hopes up about this problem going away. The only hope is if it somehow set when the rpms were high on a cold engine and resetting gets rid of it permanently. I hope its gone for good though.

 

^ he should know for sure when he pulls his plugs. One or more of them will be messed up... (he did mention rough idle, loss of power at high rpm)