Hello all. I am not an expert with the VWs but I need some honest (or at least not sales-motivated) advice if it can be had. I have a friend with a 96 jetta (2.0 - GL I think). She is not a car person or mechanically inclined, so she's been scouring the Atlanta area for a reliable mechanic.
The last mechanic she visited told her that the crankcase vent tube was broken and needed replacing, so she had him do it. She says that on the way home from the mechanic, three times, the RPM dropped suddenly and the car lurched, then went back to normal behavior.
This is totally new behavior for this car, and commenced immediately after the part replacement. Mechanic doesn't seem interested in checking his work, so she'll probably need to try the next mech on her list - but before she gets to that, is there anything simple she can check? Any likely causes for engine "lurching" (her word!) behavior that would have anything to do with the recent work? I am not too familiar with the layout of that engine, what's near that part, etc.
Any suggestions, ideas, pointers, whatever will be greatly appreciated.
Crankcase ventilation is something that overall is pretty non-critical. If the crankcase vent is completely plugged up you could have issues, but otherwise the worst that will happen is you might spit some oil onto the engine. The vent forces excess pressure in the engine back into the air-intake. The air going into the intake is filtered and metered, so it shouldn't make any substantial impact one way or the other, if the hose is damaged.
Assuming all he did was replace a hose it seems unlikely the problem she is having now is related. However, why did she visit the mechanic in the first place? Someone who is not mechanically inclined is unlikely to notice or care about a broken crankcase vent hose, so did he do other work?
Lurching like she is describing could be caused by bad engine mounts (assuming she is accellerating or decellerating) but depending on the extent of the lurching may be completely normal considering what the engine did. Possible problems that could have caused the rpm to drop include: bad fuel pump relay, bad ignition switch, bad wiring, bad distributor, bad coil (I think the power stage is built into the coil on that car), bad coil wire, and bad computer. Was the Malfunction Indicator Light tripped? There are a variety of ways to test this if the problem is repeats but there are so many possibilities its hard to describe everything.
Thanks for your response. There was some vibration in the car that the previous mechanic said was because of bent rims. The vibration suddenly appeared when that previous mechanic did some work (replacing AC compressor), and they were pretty evasive about answering why the car would be riding fine when they got it, and bouncing up a storm when they gave it back. So she was visiting the new mechanic partially as a "first interview" so to speak, and partially to check into the vibration issue.
The fact that it wasn't happening before and suddenly is (or was, I haven't checked back in since I first heard about this) is waht made me suspicious that it was related.
that's all he officially did. I was thinking that maybe he knocked something nearby around accidentally, or maybe did not attach the new one totally correctly.
I just remembered that he did a overall check of the car for her. Maybe he knocked something loose in the process of that. I didn't ask specifically what he poked around at.
Thanks, will keep thosep possibilities in mind...
I don't believe so, but I'll check. On a side note, just about the whole ignition chain on the car has been replaced in the last year or 2 by previous mechanics hunting down a problem that turned out to be leftover error codes in the computer that were confusing it badly...
understood.
Your reply and input are very much appreciated, thank you.
You are going to get all kinds of "expert" advice which will really blow your mind and could be hot or cold. I would look at the basics first. You don't need to be an expert with that. Do you use automotive tools personally?
Automatic transmission? If so, I fear that it might need a flush and have the flash reset once all the maintenance below has been done. I would find a local mechanic that can prove they worked on VWs. Do not go to PepBoys, K-Mart, Walmart, Sears, NTW, STS or any other chain. Look at the cars in the garage lot and see if they do european models like Volvo, Saab, VW, etc.
Maintenance, maintenance, maintenance. This happens when you drive it and let all the issues build up and then the mechanic will have a list of things to do. This is not the way to drive a vehicle.
The lurching sounds like the throttle sensor position going out of spec. Try taking apart the ribbed hose from the throttle body and get throttle body cleaner, clean the throttle body. You also want to check the ICV which is the idle control valve and clean that with throttle body cleaner. Change the spark plugs. They are probably the originals IMHO. Women can destroy a vehicle without realizing it. Most do not beat the crap out of the car like men do. Never buy a used cream puff that was owned by an old lady. :-) You also want to check the MIL codes for free at Autozone and write them down.
Replace the sparkplug wires, rotor and distributor if the 1996 doesn't have coil-packs.
Take the MAF mass air flow sensor and get some good electronic cleaning spray. Spray the sensor component real good and let it dry.
Get a new air filter.
Change the oil and filter. That helps with the smoothness in the engine. I would also change the fuel filter. I would worry about the pump unless you have trouble starting the car. Intermittant starts could also be the ignition key.
Sometimes the intake manifold gaskets leak outside air in and they could screw up the air to fuel mixture for the sensors and computer.
Does the AC work? That's another story.
Do a google search about hesistaion and lurching and you might read some good results instead of getting the shot gun answers which are really hit and miss.
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