Desperate for help on low engine oil light 2010 Tiguan

Question

In August 2019, someone hit and totaled my 2005 Toyota Corolla. I purchased a used 2010 Tiguan. From day 0 it has had issues. I drove the car home but as I got off the highway it screamed and flashed low oil pressure. I pulled over to check the oil but everything appeared fine. The light disappeared instantly with no recurrence. Nearer my home it happened again.

I contacted the dealership immediately and they sent a tow truck the next day and brought the vehicle to their garage. To my knowledge (just what they told me) they replaced a sensor and could not replicate the issue. The issue immediately reoccurred for me once I had the vehicle again. I contacted them again and they asked me to bring it to my local VW dealership and they would pay for the inspection. The VW dealership found no codes despite the incident happening within the last 24 hours.

Now, as Winter approached, the issue seemed to fade and my regular commute is very short (10 minutes) so the issue was not at the forefront of my mind. Even with the issue occurring rarely during this time period the vehicle drove fine. Now that it is back to the warmer months and the quarantine is lifting I’m having to make some longer trips again and the screaming and flashing light is appearing more and more often. I will describe when I have seen it most often and when it does not occur:

A few baselines:

• The oil is full
• VW said the pressure was fine in their tests and again no codes
• I also checked for codes within an hour of warnings - 0 codes found
• It never occurs at highway speeds
• It never appears within 20 minutes or so of driving if the car is cool
• I believe it is more likely to appear when my foot is off the accelerator not necessarily breaking
• Breaking seems to make it more likely to appear
• Taking sharper turns or going downhill make it more likely to appear
• It occurs more when hot

Currently it has 5w-30 in it which is in spec. I do not know if this is related because I do not know what was in it before it was last changed since I did not own it but it was still having issues then.

As an example, I drove to my parent's house a couple of days ago for my birthday and the vehicle was fine getting to the highway ~20 mins. Getting off one highway onto another on a 270deg ramp breaking it went off. No problems on that highway and then once off it went off very often at almost every slight slowdown. I pulled off into a parking lot to let it cool down for ~15 minutes to hopefully finish the rest of the way in peace. It went off once more after ~10 minutes more driving before I got where I was going.

It’s clear to me that whoever originally got rid of the vehicle must have had this issue. The carfax was immaculate. It was effectively a 1 owner car and they had taken it to the dealer for every 10k mile recommended maintenance. I would not have seen this during the test drive as I mentioned it takes some time and is more likely under certain conditions. I do not know what responsibility the dealer has to fix this issue. My understanding is the law is quite lax here and does not protect the buyer much if at all.

Pretty lousy situation for the first car I bought (the corolla was given to me. may she rest in peace.)

What should I do?

Answer 1

The items that suggest intermittent wire chafing to me are its occurrence intermittently, "when braking," and during "sharper turns or going downhill."

In each of these, the driveline and motor will move around on their mounts as the car goes from accelerate/steady state to braking's deceleration. Physical movement of stuff within the car body could easily cause a wire to move and intermittently make a connection.

I'd look specifically at the wire(s) to the oil sensor(s). I'm not familiar with the Tiguan motor. Oil sensors are typically located hear the motor's oil pump, which is usually low in the block, or screwed into the block where the sensor can "read" what's going on in an internal oil passage.