My 87' sami is stock except for the exhaust and its been running great. The only thing that is weird is that after I drive for about 10 - 15 miles it starts making a loud clunking noise. Once it sits and cools down the noise is gone again. This noise is difficult to trace, it is coming from around the engine area. I do have a noisy throw out bearing but this noise is not like that, it is a heavier sound, almost like something bumping. Weird. Anyone else ever experienced a similar thing?