Volkswagen Passat Forum banner

02 Passat 1.8T No power when temp above 80 degrees

827 views 4 replies 5 participants last post by  ExtremePowerHouse 
#1 ·
Hows it going guys? This is my first post here. Awhile back I bought an 02 1.8T Passat from a coworker for cheap. I needed wheels & he had too many cars. The car has 431K on the clock but it seemed pretty sound so I bought it. The work I have done on it so far has kept me pretty busy. Unplugged heater core, new brakes all around, plugs & coils, Tiptronic repair, valve cover gasket, chain tensioner gasket replacement, and timing belt & water pump. I'm sure I forgot some but you get the picture. When I replaced the timing belt yesterday I found that the last belt put on was installed a tooth off. This would explain the sluggishness on take off that the guy that sold it to me called turbo lag. I didnt buy it but never got around to diagnosing it either. So anyway, after replacing the belt the car ran better than ever. Almost perfect. Smooth, good acceleration, power to spare. I was happy. Now let me back up a little bit. Last week when it got over 80 degrees I noticed the car was sluggish and lacked power pretty bad. Fire it up the next morning, good to go. Today it was 93 degrees out. When I left work to go home it ran great. As it warmed up the performance degraded to the point of ridiculous. I plugged my scanner in once at home and found no codes hence no freeze frame records to look over. ( I forgot to mention I am a 36 year veteran technician Master ASE certified) After fixing everyone elses cars all day I find little joy in having to fix my own so I am hoping this is something simple. Have any of you run across this condition? If so what was the fix? I have a full schedule two weeks out so I'll have little time to dink with this.
 
See less See more
#3 ·
Only thing I can think of that would cause your 1.8T to go from "it ran great" to "...accel. degraded to the point of ridiculous" would be one of the boost hoses between the compressor outlet (near airbox) and the throttle body.

There are only seven separate points (hose connections between compressor outlet and throttle body) that can leak boost. Can be difficult to find these types of leaks, thus not a "simple fix". It'd probably be a good idea to check the most suspect hose: The one connected to the compressor outlet with one leg of the Diverter (bypass) Valve (DV). This hose has the tee section for the DV grafted in during construction and is most subject to stress failure near or at the point where the DV inserts (look for fresh oil on the hose near the tee as an indicator).

Good Luck :beer:
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top