I'm wondering how hot the exhaust air should be out of the tail pipe after a long drive at normal freeway speeds of 60-70mph. I drove ~150 one way, 300 total in the day (car was off for 10+ hours inbetween) all in 'economy' and w/ very moderate acceleration and while my car was idleing when I got home and was removing everything from the wagon I noticed the exhaust air was very hot, it would definetly burn you if you touched the pipe.... is that anything to worry about?

 

Usually, the exhaust gas leaving the tail pipe shouldn't be that hot, more like lukewarm. Next time see if the catalytic converter is getting red-hot. If so, you may have A/F mixture problem.


JPN

 

The normal exhaust gas temperature (EGT) of a N/A engine is somewhere around between 700-750C (and probably another 100C+ higher if the engine is running lean) while the EGT of a turbo engine could be as high as 900C, depending on how hard the vehicle has been driven. Also keep in mind the internal working temperature of the catalytic converter is well over 1000C.

A portion of all that heat is absorbed by the metal exhaust system and consequently it does not surprise me your exhaust pipe was hot enough to burn you after a 150 mile drive.

 

That is HOT! The air coming out of the tailpipe is hot like steam, so it sounds like I'm alright. The engine is also a turbo.

Thanks for the replies.

 

It still wouldn't hurt to take a quick look at the converter after a semi long drive, but I think you are ok

 

I'm not sure what you want oldvovo to look for.

A quick look at the converter would be just that - a quick look at the converter or are you suggesting oldvovo should look for any signs of the converter being physically damaged or burnt through?

 

Psaboic, do you mean to check to see if it is actually 'red hot' like JPN suggested?

 

I remembered that one member said his cat was physically "red-hot". I myself have never heard the spent gas being so hot but as multiple members say it is ok, it probably is a normal condition for the 850. However, theoretically the spent gas on turbo engine should not be that hot, as the heat and pressure is used to turn the turbine in the turbocharger (160,000 plus/minus RPM). However, after a long drive and the engine at idle (turbocharger not in use) it could be a normal phenomenon. I need to study further[8D].

JPN

 

I have never noticed my exhaust being hot like steam coming out the back of the car. Then again I don't really check it either, but that sounds unusual to have it be that hot, in my opinion.

 

I will mention it next time the car is being checked out by a mechanic and see what they think.