Ok my dad owns a used 92' Miata(bought it 4 years ago) with a 5 speed manual transmission, just below a 100,000 miles. The Miata has two big problems which have been worrying my dad and me for a while. The car overheats a lot, particular when it stops at a light or just sitting in traffic; basically anytime when the engine is on and the car isn't moving. This has been happening for a while now but just now has it start to really pickup because of the summer weather. Alright for one yes the radiator fluid levels are fine and all just to get that out the way. The problem seems to be with the 2 radiator cooling fans. As far as I know one of the fans is supposed to be on all the time while the second runs only when the AC is turned on or when the engine temperature begins to rise. We have started the car up and one fan will turn on and stay on; then we turn on the AC and second fan will turn on. Unforunately while my dad or me are on the road the second fan will not always turn on when the engine temperature begins to rise and for that matter the first fan sometimes just seems to stop. When the temperature reaches a little more than halfway on the gauge we usually turn on the heat and the temperatues drops back to normal or at least below the halfway mark. Normal operating temperature for the car is slightly farther than the 1/4 mark on the gauge. My dad had a real bad scare today when he just when down the street from his work to a Chic-fila; while waiting in line the temperature rose all the way to the maximum spot on the gauge, any farther and it would have pinned it. So if you have any suggestion of this matter it would be greatly appreciated.

Ok 2nd problem, not as worrying as the first but still noticeable. Alright for sometime now the gearbox(my guess) has been making a rattling noise(noise is coming from the rear of the car) and displacing some resistance to the movement of the car. I only notice it when the car is decelerating and the RPM's drop to just below the 2000 mark while in gear. The noise and resistance procedes until about the 1850 RPM mark. From then on the car behaves normally. My dad says he notices more often than that and it is not just based on the RPM's. Well for me I notice it happening during than interval of time repeatedly so thats what I am basing this off of. My dad noticed this problem a while ago(6 + months) and took the car into the shop. They said his differential was probably the cause of the problem, so they rebuilt it. After about 6 days of work the Miata came back and little behold the problem occurred as if nothing had be done to the car. When my dad took it back they told him it was probably his tranmission too. Well my dad said forget that and is just going to get rid of the car. I want the car though (sooo fun to drive!!), so help me out here. Any ideas or suggestions would be greatly appreciated as I know little about Miatas and cars for that matter.

Thanks, Jesse

On the overheat problem it sounds like the cooling fan relay is bad,that or the fan sensor. Also remove the small bypass hoses and clean them out. They are famous for collecting slag from the cyl head maching after a few years. I would have to hear the noise before i could tell you on the rearend. I would get my money back on the diff overhaul if it did'nt fix it.

Well I doubt the fan relay has gone bad already because that was replaced last year. I will check the fan sensor. I read that the main belt could also be affecting the overheating problem by being slightly loose thus not giving enough power to the water pump. I think last time the belt was changed was around 70,000 miles.
When you mention the bypass hoses, what exactly are you talking about it anyway? Or better yet do you know where the hoses would be located?

More info on the noise from the back, talked with my dad and he said it also makes the noise during acceleration. I never noticed the noise because it occurs to a lesser degree and I have only been driving the car since the beginning of may so it seemed normal to me. Anyway the noise occurs if say you were going like 30 mph and were in 4th gear; in this instance the RPM's are pretty low and thus the torque is really low so for a short period of time you would hear noise. I will try to get a sound byte or something of the noise but for now thats the best I can do.

If just the relay were replaced and the cause of it going bad was'nt fixed then the relay is where i would start.

Well my dad took the Miata in for an inspection and had the guy check the car over and told him about the sound coming from the back. The guy drains the transmission fluid and low and behold there is water in the tranny. So apparently the water has been corriding something for a period of time and just now it started to make noise.

With that straight, anyone know any good places to buy a rebuilt or used tranny for a 92' Miata, manual of course.