'90 TSi AWD runs like pooh

[BOOSTIN21]

so i was taking my friend for a ride in my car which is all stock with only 59k on it (the whole car) and after i spooled up the turbo a few times through 4 gears i noticed going into fifth i had lost a great deal of power and when i turned i downshifted and it chugged and the car shuddered as i accelerated around a corner i took it home and it felt like a GEO METRO would walk me in a race, boost is only at 7-8 psi when gas is all the way down and car is at 4500-5000 rpm's and it doesn't spike

i ran a compression check and got 160 psi on all 4 cylinders, i ran a multimeter test on the coil and it seemed fine the car is running rich really rich, i did put on my friends intake that day to see if the turbo would spool up louder or faster (the car was running great then) he has a 91 TSi AWD, i changed plugs and plug wires and PCV valve i am in the process of changing the oil with Mobil 1 15W-50 (for turbo motors), i put in an engine tune-up liquid and let it run through for 5 minutes and i ran injector cleaner through for 5 minutes, my one friend says it may be the MAS, O2 sensor, oe even the ECU. what do you guys think

oh yeah the car was sitting for about a year or more before i bought it and i have owned it for 2 months and put 300 miles on it if that and the oil is complete shit, i dont know if this will help

 

[TSi90Awd]

Uh yeah, change the oil. Also check your plugs and plug wires. If it's been sitting it could need some plugs. Also may be a boost leak somewhere.

 

[sphillips91]

"i am in the process of changing the oil with Mobil 1 15W-50 (for turbo motors)"

I dont think thats a good idea.

 

[TSi90Awd]

Yeah, too heavy. Your lifters won't appreciate that oil, tick city. Try 5W-20 or something along those lines.

 

[BOOSTIN21]

are you sure the oil is too thick it says it is for turbo and supercharged motors but i'll take the oil back i was thinking it was too thick, and i changed the plugs and wires and i also changed the coil. but now the oil filter is so corroded that it won't come off the housing, i tried a filter wrench, lock jaw and the screwdriver method (all that did was mangle the hell out of the filter) i had me and my friend using the lockjaw at the sametime it still won't come off. any suggestions? but could the problem be with the wastegate solenoid or how about the wastegate flapper like is the flapper not closing or is it the MAS. damn this sucks

 

[crankbender]

did you replace the timing belt. It may be that you slipped a tooth (would match symptoms).

what exactly does the car do in the lower gears now?

 

[sphillips91]

are you sure the oil is too thick it says it is for turbo and supercharged motors but i'll take the oil back i was thinking it was too thick, and i changed the plugs and wires and i also changed the coil. but now the oil filter is so corroded that it won't come off the housing, i tried a filter wrench, lock jaw and the screwdriver method (all that did was mangle the hell out of the filter) i had me and my friend using the lockjaw at the sametime it still won't come off. any suggestions? but could the problem be with the wastegate solenoid or how about the wastegate flapper like is the flapper not closing or is it the MAS. damn this sucks

Its too thick for a motor modified like yours. IE: My uncle has a 67 chevelle with a blown 502. Thats the kind of oil he uses.

 

[Hooptytalon]

Do a boost leak test
http://www.vfaq.com/mods/ICtester.html




edit: it's messy but to remove the oil filter you could drain the pan and then punch the side of the filter with a screwdriver and turn the filter with the screwdriver handle. To prevent this condition I put a dab of grease around the o ring of the new filter.

 

[adam355]

Your wastegate isn't stuck open is it? Check the actuator arm.

 

[BOOSTIN21]

like i said i already used the screwdriver method it only mangled the filter and your supposed to put oil on the o-ring of the new filter, i have the o2 housing unbolted it is just stuck on, to get the filter off i am taking the housing off with the filter

 

[BOOSTIN21]

well i got the filter off i took off the housing put the filter in a vice and used a crowbar against my work bench to twist it off it was a beoch. as for the cond. of my car i unplugged the o2 sensor and it still ran the same way so i guess it's the o2 sensor i will change it tomm. does anyone have a good way to to change those, it looks like its in a bad spot will it come off with an open end or do i have to take anything off like any accessories or the o2 housing