When Im racing, or just driving a little harder than normal my "Overheat exh system" light pops up, and then turns off after a bit. What does this mean? Does it mean that Rosie needs a RB exhaust system?

 

it means what it says...and yes, i think she deserves the best.

 

The same thing was happening last year to my '84, and then I replaced the original catalytic converter, which was basically clogged. The light hasn't come on since. I have a stock exhaust, no mods yet.

 

mine comes on all the time, especially in the summer.
the sensor is located under the pasenger seat and is designed to monitor the temp of the main cat. I have no cat at all, but I did remove all the heat sheilding which is why mine gets triggered

 

yea, a clogged cat will do it, mine did. It's funny, when I installed my Rb system I thought it odd that I never saw a sensor or anything, a few weeks I started taking my project cars interior apart and found it sitting there on the body. I never would have thought it was there, strange...

 

I have racing beat exhaust, and that light comes on sometimes. seems like its mostly in the winter though...

maybe someday when im not so lazy ill tear that stupid sensor out...

 

Mine comes on when there's a cop within a 2 mile radius. My Phantom security is rigged to flash the exhaust temp overheat light .

 

I cant belive someone posted that about summer..... Would a difference of 40 degrees matter when we are talking around the 3k range I believe.. I am inclined to say the temp outside is irrelevant. That is like people saying they are overheating because of the temp outside which is full of it too. It's because thier cooling system is lacking. That is in the mid hundreds or so too...

 

Engine water temp is around 230 degrees, outside temperature is a huge factor on how hot or cool the engine runs.

 

Your airpump could be toast, allowing the cat to heat up. BUt prolly a cloged cat.

 

let me repeat, mine comes on all the time...especially durring the summer. What, did you think I was making that up??? oh, and btw, your exhaust is leaking.

 

3000 degrees!?

 

Isn't that the infamous Radar Jammer?

Are you saying that stuff works?

-Rich

 

Hmm....

My sensor must have been broken. My exhaust heated up to the point of complete explosion on the highway one day.

The car jumped like 4" off the ground when it happened, and I almost lost control, right next to a semi at 90mph.

Everything from the exhaust manifold back......KA-BOOM!

My cats must have been glowing a nice shade of red before I lost them.....

Now, they're all gone. HOORAY AREA WITH NO EMISSIONS TESTING!!!

 

Bwahahaaa! Holy buh-jeezis.... I would have sh*t my pants...

Edit: damn... I am the ZOMBIE THREAD MASTER!

 

Funny thing.

My exhaust never overheated until I a custom exhaust put in. I think it's the lack of heat shields, and the higher flow.

 

On the contrary, outside air temperature has a lot to do with heating/cooling problems with our cars.

Given that your oil system and antifreeze coolant systems rely heavily on the flow-through air from the front airdam, the temperature of that air is critical to maintaining a proper cooling system. The difference between 80deg F and 120deg F is considerable when you consider the ability for the outside air to ABSORB the heat energy from your hot oil and water cooling systems and remove this from the engine. With cooler air comes greater density and a greater ability to absorb heat as it passes through the radiator and oil cooler.

As you increase outside air temperature, air density goes down, along with the air's ability to take on more heat (out of your engine). Simple problem. As an extreme example, if the outside air temperature were 180 degrees, and your engine temp was also 180 degrees - then no cooling would take place, would it? The closer you get to normal water temperature (w/180d F thermostat), the less cooling effect you will get from the outside air flowing. At a certain point, the volume of air must overcome the air temp problem, and your car will overheat if you sit at a stoplight for too long (ask me, I know). Get it up on the freeway at 60mph and it quickly cools off.

The reason why a lot of people experience overheating issues in the summer is directly related to this fact about thermodynamics. Overheating probably won't be an issue in the wintertime when you have 20-30deg F air which has a very high ability for adiabatic cooling effect. As the engine heats up, there is just a lot of heat shed into the passing air, which is why some larger trucks have to have baffles installed in front of the radiator - to keep the engine temp UP with all that cold airflow.

To say that outside air temp has nothing to do with overheating is overlooking the obvious, IMO. Just like we recommend everybody replace caps and rotors for the beginning of winter, so should we all exhange coolant and oil, thermostat, pressure cap, etc. for the summertime. I even go so far as to change belts prior to summer, but that's mostly because I hate getting stranded in the 120deg F heat of the AZ desert... HTH,

 

What if the light can stay on (comes back on when the car is started) even if the car has been sitting for a few days? I spend more time driving around with that light on than with that light off, ... and I think the car's response to the light is to dump more fuel.

 

It's typically the precats that clog up, and these can be unclogged and reinstalled. As long as the air pump is hooked up the main cat (ie: the one that retails for $2500 U.S.) is usually quite durable. Their eventual failure mode is typically to split rather than clog. This can sometimes be welded, but auto shops will usually try to sell you an aftermarket or stock cat and keep the old one for the precious metals inside. Same goes for when (not if) your car fails emissions. They'll tell you it's the main cat whether this is true or not.