rfc
New member
Brand new member of the forum and I have an issue I hope someone here can help me solve. I quickly consulted the FAQ's and did not see the problem listed there.
I have a 2003 Jetta 5 spd TDI which has had some significant performance problems for a few years. Initially, the vehicle would have noticable lag in acceleration climbing hills from time to time. As a decarb of the engine had improved performance previously, I did this again a few times, even though it was much earlier than expected for reaccumulation of carbon. I started adding fuel treatment during fill-ups also. The car would perform better for a short period of time, only to again have the same issues. Subsequently, the mass air flow sensors were changed twice. We have also had the pressure converter valve and the turbo assembly replaced. Each of these things have resulted in the vehicle performing properly for a time, only to once again start to have the same problems.
Interestingly, the vehicle has also had intermittent electrical issues that occur for no good reason. The key fob will lock only three doors sometimes. It will sometimes fail to unlock the vehicle. The sunroof will sometimes bounce right back to open when attempting to close it using the overhead control switch - this despite the fact there is nothing blocking the closing path of the unit. I have had to replace the headlight bulbs frequently because the bulb in just one of the units frequently burns out. The cruise control will occasionally fail to re-engage when the resume button is pressed on the steering wheel. If I simply turn the vehicle off and on, all of these problems will sometimes correct themselves. Other times, I just have to wait until the misbehaving component decides to start working again. Finally, we have had at least one time where the VW dealer found a 3.5 amp draw from the alternator. I have wondered if this plethora of electrical issues might be manifesting itself in the computer controlling the engine mechanism. Unfortunately, my ignorance about the vehicle doesn't allow me to be specific when expressing my concerns to a mechanic. I read somewhere that the Engine Control Module ground connection might be faulty - is this a reasonable issue to bring up with a qualified technician looking at the vehicle?
Just yesterday, my wife was merging into traffic while climbing a hill on a country highway when she noted sudden and profound loss of acceleration. She noted the vehicle speed had dropped to less than 20 km/h climbing the hill and she saw a large black plume of exhaust. This had her terrified because large trucks frequently travel at speeds greater than 100 km/h on this section of highway.
Having spent a fair bit of money on "solutions" that were clearly not the answer, I would REALLY like to be able to direct the mechanic to a potential problem that could explain all of these issues. Sorry for the essay, but I thought including all of this might twig something in the brain of one of the forum members. Any brilliant insights from the folks here would be greatly appreciated.
I have a 2003 Jetta 5 spd TDI which has had some significant performance problems for a few years. Initially, the vehicle would have noticable lag in acceleration climbing hills from time to time. As a decarb of the engine had improved performance previously, I did this again a few times, even though it was much earlier than expected for reaccumulation of carbon. I started adding fuel treatment during fill-ups also. The car would perform better for a short period of time, only to again have the same issues. Subsequently, the mass air flow sensors were changed twice. We have also had the pressure converter valve and the turbo assembly replaced. Each of these things have resulted in the vehicle performing properly for a time, only to once again start to have the same problems.
Interestingly, the vehicle has also had intermittent electrical issues that occur for no good reason. The key fob will lock only three doors sometimes. It will sometimes fail to unlock the vehicle. The sunroof will sometimes bounce right back to open when attempting to close it using the overhead control switch - this despite the fact there is nothing blocking the closing path of the unit. I have had to replace the headlight bulbs frequently because the bulb in just one of the units frequently burns out. The cruise control will occasionally fail to re-engage when the resume button is pressed on the steering wheel. If I simply turn the vehicle off and on, all of these problems will sometimes correct themselves. Other times, I just have to wait until the misbehaving component decides to start working again. Finally, we have had at least one time where the VW dealer found a 3.5 amp draw from the alternator. I have wondered if this plethora of electrical issues might be manifesting itself in the computer controlling the engine mechanism. Unfortunately, my ignorance about the vehicle doesn't allow me to be specific when expressing my concerns to a mechanic. I read somewhere that the Engine Control Module ground connection might be faulty - is this a reasonable issue to bring up with a qualified technician looking at the vehicle?
Just yesterday, my wife was merging into traffic while climbing a hill on a country highway when she noted sudden and profound loss of acceleration. She noted the vehicle speed had dropped to less than 20 km/h climbing the hill and she saw a large black plume of exhaust. This had her terrified because large trucks frequently travel at speeds greater than 100 km/h on this section of highway.
Having spent a fair bit of money on "solutions" that were clearly not the answer, I would REALLY like to be able to direct the mechanic to a potential problem that could explain all of these issues. Sorry for the essay, but I thought including all of this might twig something in the brain of one of the forum members. Any brilliant insights from the folks here would be greatly appreciated.