Hello All, I am new to this site, and also have only owned my 2000 Beetle TDI for a little over a year. I am from Jacksonville Florida, but I live in Guatemala Central America. I purchased my car in Alexandria, VA and drove it down to Guate. About 6 months ago my car went into the infamous "limpmode" for the first time. I was ascending a mountain at about 55 mph when a Semi puled out in front of me. I down shifted, dumped the clutch and hammered the brakes, at which time the turbo quit. The very next time I started the car the problem was gone. I have a very similar situation happen a few months later and after a hard down shift, and hard braking the car entered limpmode. In the following months my symptoms changed from occasional limpmode to constant low power with rough idling and rough acceleration up to about 1500 rpm's.
Since the above described incidents, I have replaced the N75 valve, cleaned and serviced the injectors and inter cooler. There was no change, so I took the car to a highly recommended "racer / mechanic", he scanned the car and reported only 4 lb of boost coming from the turbo and told me I needed a new turbo. I did not agree, so I removed and thoroughly cleaned the EGR, intake, EGR cooler (which were all almost totally clogged), and turbo (which also was very dirty, but after cleaning appeared in very good condition as per inspection by the same racer / mechanic). Upon removal of the turbo I found the VNT actuator had a hole rusted through it, and was replaced. I have also replaced all the vacuum lines (in this order).
This Sunday I finished re assembling the car. I also replaced all the required gaskets, and added some high temp silicone for good measure. Sunday the car ran better than ever, since I purchased it. It ran very strong, and the "check engine" light went out for the first time since I have owned the car. Turbo performed exceptionally well, and no rough idling or acceleration. I did notice something odd. After turning the car off I hear a low pitch buzz or hum that sounds like a closed valve leaking vacuum or pressure. The first time I can remember hearing this noise was the day I replaced the N75 valve. I have no idea where the sound is generating from because it only occurs for a few seconds and I can only hear it from inside the car. It is clearly coming from the engine compartment, but I do not know from where.
HOWEVER, Monday morning the car began to idle rough again, and rough acceleration up to 1500 RPM, and the check engine light has returned. The car is entering limpmode once again. The only component I have not replaced is the MAF sensor, because both mechanics who have worked on the car told me it was fine and did not need replacing. Can the MAF be tested? HELP!!!!
Since the above described incidents, I have replaced the N75 valve, cleaned and serviced the injectors and inter cooler. There was no change, so I took the car to a highly recommended "racer / mechanic", he scanned the car and reported only 4 lb of boost coming from the turbo and told me I needed a new turbo. I did not agree, so I removed and thoroughly cleaned the EGR, intake, EGR cooler (which were all almost totally clogged), and turbo (which also was very dirty, but after cleaning appeared in very good condition as per inspection by the same racer / mechanic). Upon removal of the turbo I found the VNT actuator had a hole rusted through it, and was replaced. I have also replaced all the vacuum lines (in this order).
This Sunday I finished re assembling the car. I also replaced all the required gaskets, and added some high temp silicone for good measure. Sunday the car ran better than ever, since I purchased it. It ran very strong, and the "check engine" light went out for the first time since I have owned the car. Turbo performed exceptionally well, and no rough idling or acceleration. I did notice something odd. After turning the car off I hear a low pitch buzz or hum that sounds like a closed valve leaking vacuum or pressure. The first time I can remember hearing this noise was the day I replaced the N75 valve. I have no idea where the sound is generating from because it only occurs for a few seconds and I can only hear it from inside the car. It is clearly coming from the engine compartment, but I do not know from where.
HOWEVER, Monday morning the car began to idle rough again, and rough acceleration up to 1500 RPM, and the check engine light has returned. The car is entering limpmode once again. The only component I have not replaced is the MAF sensor, because both mechanics who have worked on the car told me it was fine and did not need replacing. Can the MAF be tested? HELP!!!!
