Hey i have a 98 1.8t base manual with no mods just well maintained, a few days ago it started hesitating under hard acceleration in all gears, between 2000 and 3000 Rpms, and when at idle, the rpms move around 900 and 1000 which it wasn't doing before, also makes a noise like farting from the exhaust, this is a lot more evident when the a/c is on and its really hot outside, right now in Miami we're on an av. of 92f that feels like 105f.

I tried cleaning/changing the sparks, the coils, the injectors, air filter and today i took apart the Throttle body, what i found surprised me, there was oil in the inter-cooler/TB pipe, and also in the inter-cooler, I've had a bit of oil disappear between oil changes since like forever but i blamed it on a bad oil pan gasket that I've been procrasturbating on, i just don't know how it could be the same oil and if this might be what is causing the hesitation, oil in the TB, these is my daily driven car and i take good care of it, just need a hand once in a while, I've been reading a lot here just never posted before, any help is appreciated

 

oil in the pipes could be your turbo starting to show signs of it's age.... but your issue might be something as simple as a vac leak, is your car still holding pressure?......

 

I could get the vacuum pressure gauge but I've checked all the pipes and connections and everything looks solid, unless there's a puncture in one of the pipes which seems unlikely, i had an incident with one of them coming out while i was driving because i didn't tightened it and that same day i checked all the connections and double checked them today, i think your right about the turbo tho, i have been thinking of an upgrade whenever i have the cash for it

 

also there's no codes which in my way of thinking eliminates any electrical/sensor problem right??