So today I went outside to start my 94 Olds 98 and check the fluids when I was looking at how I would have to go about replacing the TPS. It looks like its held in with two flat head screws which makes the angle tough, so I may have to remove the throttle body. Anyway, this is when I noticed an antifreeze puddle right beneath the throttle body. Any ideas on where that could be coming from in that area? How much does it cost to repair?
Its really a shame I want to keep this car it only has 71k original miles but the 20 years of age is starting to take its toll on my wallet.

Probably the lower intake manifold gasket has failed.

could be the upper as well both are pretty common failures, you can do it yourself for maybe 120 with the redesigned dorman upper set and aluminum lower gaskets, and lower aluminum coolant elbow. its pretty labor intensive though if you had to have it done i would think 500-750.

https://www.gmforum.com/mechanical-1...ts-l36-297702/
https://www.gmforum.com/mechanical-1...2005-a-304071/

I just did this job on mine, it is labor intensive, but as long as you keep yourself organised, it goes by really well. Plus I'm getting 20 mpg after the work. There are several great write ups on it, and if you have any questions I'm more than willing to help.

Or it could be the throttle body gasket....very common......old style was orange colored...then blue....latest I think is black.....

Check your oil, and check exhaust if you're leaking in one area, might be more. I've found though K.I.* (Keep It Simple) so it might be the throttle body gasket. Had you removed the throttle body previously?

No i haven't removed the throttle body but it might have been removed in the past. I was going to remove the throttle body and replace the TPS Sensor since it has flat head screws and its a bad angle to access it. How difficult is it to remove the throttle body? I'm hoping its pretty straight forward.

Simple....disconnect the accelerator and cruise cables, then remove the cables from the bracket......then three 10mm nuts.....there is a little bracket underneath you just have to slightly move to get the throttle body off(sometimes it easily pries out of the way(don't have to move it much), sometimes you have to loosen the bolt which is tough to get to)......

If the gasket was leaking, you will see traces of coolant on the bottom of the throttle body joint.....

There is the possibility it could be leaking between the UIM and LIM as well, and the coolant would be coming from between the two.

You should also be warned, that the parts most are referencing are for the Series 2, the L36. You have the series 1, the L27, a little bit different animal. The procedure will be pretty similar, but the parts will be different.

I think they make a screwdriver that bends 90*, and then another 90* for that very job. I cant think of what it is called however

But to get to the bracket isn't there an exhaust crossover pipe that blocks the bottom of the bracket?

I used one of those extendable magnet wands to hold the 10mm. nut in place, got it on with my fingertips, and finished the job with a small box wrench, if you can't get the bracket off, or don't want to risk rupturing that exhaust pipe. I found it fairly easy. If that helps