Oil out of exhaust on my 2006 4.0?

Whenever I wash my truck I notice a great deal of black ( I'm assuming oil) on my rear quarter panel just above the exhaust. This has prompted me whenever I am in parking lots to look at other Tacomas and I also notice that they to have this same oil spotting on their passenger side rear quarter-panel above the exhaust.

Do you any of you have this problem? Is this something I should be concerned about?

Thanks...

 

This does not happen on my truck.

Ted

 

I do not have this either.

Depending on the area that you live in, it is possible that there is an additive in the fuel that is not burning completely. That would cause a "soot like" emission that would cause an oily haze on your paint just above the exhaust pipe.

Just a theory.

 

I dont think i have this buildup, but my truck is black so i dont know if i could tell either way...

 

I am not completely sure I followed your question, but here is my answer to what I think you are asking.

Oil is heavier than air, and even in particulate form, say when shot out of an exhaust because of blow-by in the engine, it still stays relatively low, and stays in specks and droplet form, it would also be incredibly difficult to wash (read as scrub) off.

I suspect what you are refering to is more of a uniform coating of black soot, something more similar to brake dust. So if I have read your question correctly you quarter pannel looks more like your front rims, than looking like a kid took a black marker and put dots on your truck.

007 might be right and it might be a fuel addative that is not burning completely, so you could try changing brand or grade of gas. Failing that, here is my theory.

I have not noticed it on my quarter pannel, but have noticed a little bit of carbon on my tail pipe. I believe this to be because the 4.0 engine are notorious for running rich, so not all the fuel is being completely burned, and therefor what you are getting is esentially the remnants of un-burned fuel. I would further suspect that others who have it on the quarter pannel wind up stuck in more stop and go traffic on a daily basis, where as those that don't notice it as much, or like myself only notice it on the tail pipe are not stuck in as much traffic, so that when the truck is moving, the exhaust it being thrown further out from the truck, and the truck is moving away from the cloud as well. Based on my theory that would also explain why there is this film of soot on the nose of my camper.

As far as what to do about it short of the URD maf calibrator to correct the mixture, I don't know.

Disclaimer:
I have no facts to back this up, this is just my theory, and I may be completely wrong.

 

This is true on my 2.7L as well.

 

black stuff above the tail pipe means your running rich to much fuel not enough air. throw some weights in the back and get on the highway and open it up. burn that carbon out. I know the Diesel Generators I work on get BAD carbon build up if ran without a load applied. like Mavrick said I have SOME facts to back this up, this is just my theory, and I may be completely wrong.

 

You said on the quarter panel but you didnt mention residue in or on the exhaust itelf? My concern is it may not be the exhaust, I have seen transmission/engine seals that have slowly leaked, and the air directed the oil under the body to the quarter panels and even on the bumper. but it was ingrained with road and brake dust so it was deceptive and neglected. They didnt figure it out until it was too late......but the consensus is that tacos run rich so maybe its that simple. best wishes.

 

I have not noticed this on my 06(6spd) that I bought in Oct of 06. However, if in fact the engine is running rich, then that means the computer is not doing its job and needs a good Taco tech person to investigate and make sure all of yourengine/fuel parameters are set to the correct spec's. Keep the TW informed of what you find out.

Jeff
06, 6sspd SR5, 4x4 Brilliant Red bone stock( so far)

 

Well, actually, the Tacoma is set to run rich from the factory.

 

Like 007 said, they are set to run rich from the factory due to a wide acceptable variance (plus or minus 15%) in the MAF sensors. That is how the URD maf calibrator can do what it does, because it give you the ability to correct the air fuel map to your individual truck and your individual sensor, and your individual altitude, and your individual mods.

Toyota sets the trucks to run rich, because running rich only affects your fuel mileage, and makes a mess, but it will not harm your engine, where as if they set it leaner and one of the maf sensors was at the extreme end of the acceptable varience then the engine could lean out too much and cause damage. They chose to save money by accepting the wide sensor varience, and run the truck rich to protect themselves against warranty claims.

 

If it really is oil; I would suspect a mainseal leak.

 

Actually, if it really is oil, I would suspect bad oil control rings, or valve guide seals. A rear main seal leak wouldn't collect only in the one spot on the right rear quarter....it would be leaking out of the bell housing, down the bottom side of the transmission, and ALL OVER the underside of the truck. Oil concentracted in one spot at the exhaust pipe would indicate more of an internal engine problem than a rear main....

 

I've got a white 06 and mine does it. Looks like soot; probably is not burning all the fuel. My driving is 75% city which is probably the culprit. Doesn't seem to do it as bad running on the interstate.