I have a 1996 T5. I have a weird problem. On start-up in the morning when the car is completely cold, I get this weird groaning/whining noise coming from the engine bay that goes up and down with the rpms. After about 5 minutes, it goes away. The colder the weather, the longer it stays around. I usually start off easy in the morning but if I drive more aggressively, it goes away quicker. So it definitely has something to do with engine bay temp. I run Mobil 1 5/30 oil. It's pretty loud too so it's sounds like something major. Could it be something to with the trans, turbo, ...?

Also, I installed the IPD exhaust and TME ECU. I was expecting a little more boost - I get about 13 lbs. Anyway, I'm happy considering I dropped almost a second off my 0-60 & 1/4 mile times. Here's the other weird thing. If I floor it from a stop in the first 5 minutes of running, it really seems to struggle off the line until about 4K rpms and then it takes off like a rocket. This is more than turbo lag. It almost misses (or just plain bogs) until the rpms get into the 4000 range. After the car warms up, it's fine. Again, the colder the weather the worst it is. Any idea what this could be? Are the groaning/whining and the bogging related?

IPD is stumped. Any ideas?

Thanks.

Dave.