I have a 92 RS/305 TBI with 135,000, all stock, my problem is that the exaust smells really bad, and the temp gauge reads into the red sometimes, especially in the summer. The single fan comes on like clock work at 240 degrees, or when the a/c is on. The exaust smell from the tail pipes and the cooling problem has been going on for about 2 years. The car never visually overheats, it's just the gauge that says its hot, and i believe the gauge is reading rite. I took a trip 800 miles on the freeway, it was 75 degrees at nite, and while on the freeway for hours the temp gauge stayed religiously at 210 degrees, and whenever i stopped for gas, the temp gauge would rise to about 245 degrees by the time i got back on the freeway, and then back to 210 degrees (with no fan) when back on the freeway. The air deflector is fine, and i have a new radiator, heater core, coolant temp sensor, all radiator & heater hoses, 50-50 mix, water pump, 195 thermostat, tune up, plug wires, serpentine belt, cooling system pressure test ok, o2 sensor, cat. converter, after all this, same problems, and if u stand near the back of the car outside while it's running, the exaust fumes will take your breath away. The car didn't have a cat. converter at first, and the exaust smell was bad, & after a new cat. converter it smells the same. The car runs great, there are no codes, but i know something's wrong, i now get 195 miles to a tankfull in the city. I passed Tx emissions barely. The car idles great, doesn't miss, it runs extremely smooth, that's why I am fresh outta guesses. I have been reading on this site for three days, and any help would be greatly appreciated. This is a great site by the way, I'm a new member.

 

Hmmm, that'll look good on a t-shirt

Anyways, it sounds like you did your homework and got all the major cooling system components checked out. It does seem to be running a little hot though. The only thing that comes to mind so far is to make sure you don't have any obstructions in front of the radiator. I'm really just reaching for anything though, since you seem to have checked everything and no reason stands out for your car to run hot.

As for the exhaust smell, you can buy a bottle of the stuff that makes it smell like coconut, vanilla, strawberries, or whatever else they have. Just kidding, don't do that. What does it smell like? Does it smoke at all? New exhaust parts usually have unpleasant smells to them. If you get any dark smoke or if the exhaust makes your eyes tear up easily it would likely be due to running too rich.

Well, I guess I haven't been a whole lot of help, but wanted to welcome you to the boards. Hopefully everybody will get this worked out for you soon.

MikeS

 

Moved, seemed better here than in the t-shirt Forum...

Actually I think the only thing I might be able to suggest is to have it checked with a computer, so you can see what is happening... that would be my first thing...

John

 

Do you have an air tube going to the cat from the smog pump?

The lack of cat makes me think that this car has had its emissions system ripped out. Hence the *** awful smell. A rich condition usually will make the plugs black as well, check the plugs first before blaming it on a rich condtion.

Another matter is you changed everything EXCEPT the fan switch on the passenger side block. That's what controls the operation of your fan. It's a 1 wire sensor/switch.

 

If the car doesn't visibly overheat, then..... it's not overheating. I'd be inclined to think your temp gauge is off. Next time you do a drain & flush on your cooling system or whenever else it's convenient, try a new temp sending unit, it's the one in the driver's side head between the #1 & #3 spark plugs.

As for the smell and poor fuel mileage, try a new oxygen sensor. It should be considered part of a tune-up but rarely gets attention. If it's telling the ECM that the exhaust is lean, then the ECM will be doing its best to richen it up; it will think that life is good and everything is working properly, and will throw no codes; but there will be way too much fuel. Very common problem actually.

 

thats true, I did not think of that, sometimes the O2 sensor gets "Lazy" its not bad enough to throw a code, but it will make it get bad gas milage, and smell funny, my 95 Riv smelled like Eggs... the O2 sensor took care of that...

John

 

OBTW - the coolant temp sensor is not associated with the gauge. The gauge has its own sending unit; the CTS is only hooked to the computer.

 

On my 87's

Temp sensor in the front of the intake is for the Computer (ECM).

The Right head temp sensor with the single (green) wire I think was for the fan

the Left head temp sensor was for the gage... If I remember right...

John

 

If you have put a lot of high perfomance parts, and did no adjust your fuel pressure regulator, than you're run very rich. GM's fuel pressure regulator can be modified to adjustable. GM hid this pretty good. I've heard the aftermarket one you can buy for $65, is nothing more than a stock one that has been modified. You can also get this stuff "Manhattan oils." You add it to fuel race/normal, and it comes in several flavors. It makes it smell better, but you should adjust fuel pressure regulator too. If dosen't work, or you can hear noise (before or after adjustment), it could be manifold leak or something to that effect.