Hello Scotty I have a 2012 VW beetle base model with 113000 miles on it. I have been fighting with some problems since I finally paid off the car. I was driving one day and all of a sudden the EPC light and check engine light came on and it wouldn't go over 40 MPH. I took it to a local mechanic who works on exotics and VW and he said it was a bad throttle body and engine speed sensor. At the time he gave me a choice between an OEM throttle body for $800 and wait 2 weeks to come in or for $290 he could put in a third party one and it would be 2 days. So he put in a third party one in and it ran fine for a while, but then started stalling. It is a random stall usually at low RPM like coming to a stop or idling. The crazy thing I'd there is no error code or check engine light when it does that and what I have to do is put the shifter I'm park then turn off the key and restart the car. The electric systems still work whenever it does this. I took it to a local VW authorized repair dealership called New Motors (who did a factory recall repair so they are VW approved) and they had the car for 14 days and replaced 2 relays on a hunch but said they weren't sure why it was stalling. I then took it to a local mechanic who works on BMW, VW, and Exotics only. He told me he thinks the third party Throttle body wasn't communicating with the Computer in the car so that's why he thinks it's stalling. My dad and I bought an OEM Throttle body and put it on and then found out my battery was shot. We put in the new battery and Throttle body and it worked great for Maybe 8 months and now it's starting to stall and lag again. I am not sure what it is or anyone else who looks at it has no clue. Is this a normal thing with VW and if so is there any way to fix it
Is that a 2.5L? Those are known for having fuel pressure issues (usually the pump or it’s filter)
Change the filter fuel if it’s easily accessible. (They usually are on cars with VW’s 2.5L engines)
Go go a VW mechanic that can check if the fuel pressure is ok.
Additionally, I’d drive with live data and look if there’s anything weird that drastically chances when you’re coming to a stop.
It is an 2.5 L 5 cylinder with an automatic transmission. I have a new fuel filter just need to get it on. Thank you. I know one of the three hoses that holds it on was very hard and I couldn't get it off. But I will try that. Need to find someone local with a computer to check the pressure tho.
I changed the fuel pump completely. It was an easy fix right under the back seat. In the old pump it had a filter built in that looked blocked
I didn't think a Gremlin could fit under the hood of a Beetle!
Aside from that, unfortunately VWs in the U.S. have a reputation for developing serious electrical problems. Moderator @dan is very knowledgeable about European cars and might have some specifics.
Thank you. I did have the wire harness checked and the electrical system checked by a local Battery and Alternator place and they said it looked fine and they couldn't find any shorts. So I'm still scratching my head.
Also check your alternator output to see if it's within specifications.
"Unexplainable" old engines´ stalling at idle could well be due to some device, driven by the engine, being simply worn out. The AC compressor, the alternator, the coolant pump... Frequently, several such devices on older cars have high grades of wear simultaneously.
Each such device constitutes a certain resistance to the engine rotation. As the device ages, this resistance increases. As several devices age, their increased resistances pile up.
The ECU program has a certain range or window, within which this added resistance can be compensated for by adjusting the engine idling parameters.
However on older engines the _sum_ of such resistances, constituted by the abovementioned devices, could well get outside of this window, causing the engine to stall.
P.S. It is like the ECU would say: "No way an engine I am supposed to control would require so much fuel for just idling. It is not supposed to. I´m shutting the engine off."
In some cases, but not necessarily, the ECU may then show / store an error code saying that the idling parameters went off spec, or similar. It may be complaining about virtually any of the mixture-relevant parameters being bad. But in this case nothing is wrong with the parameters themselves - it is that it is physically impossible to keep the engine running while staying within the max and min limits of those parameters, contained in the ECU program.
Example: the ECU may throw a code that the air throttle valve (or the idle-control air valve) is bad. But it is not that this valve is really bad in this case. It is that to still keep the handicapped engine running one would have to inject much more fuel, than normal; and to properly combust this fuel one would have to add much more air through the air valve, than normal, and the ECU notices that the air quantities get messed up (leave their acceptable range) and thinks that it is the valve(s) fault.