Oil Pressure Warning - 2012 VW Tiguan 2.0 TSI

This is true on newer vehicles. It certainly isn’t true on older models, and I prefer that the A/C not come on, unless I choose to turn it on. On a typical car from the 1980s to early 2000s, turning the HVAC to windshield or windshield/low level vents did nothing but move manually actuated dampers inside the dash, which direct airflow to the windshield and/or floor-directed vents.

It did not affect the temperature setting–which itself just controlled a manually-actuated blend door, and it certainly did not activate the A/C compressor.
Nowadays, turning the HVAC to those settings tells the BCM to move motorized dampers, and it also activates the A/C. As always, some people like the added convenience, others prefer the simpler more reliable design.

I would think this 2012 VW Tiguan has Auto Temp Control so the AC will be on at times even if the person does not know it.

But the real problem seems to be his reluctance to have this oil light problem looked at soon.

Agree the more simpler the better.

You should say some older models. Some did engage the AC when defrost was selected. I had a ‘72 Electra 225, it did that to ensure warm dry air was used to defrost/defogger the windshield.

1 Like

Maybe I oversimplify, but it is low oil pressure not level. Extra demand from kicking in ac causes the engine to work harder, oil flow is bad causing the low pressure when needed under higher demand.

1 Like

Good advice above. My guess, there is an actual low oil pressure problem, of undetermined cause. First step, make sure you’re using the correct oil spec. Second step, ask your shop to measure the engine oil pressure using their calibrated shop gauge.

Beyond a possible faulty oil pressure sensor — knock on wood — even though the oil warning light is associated w/turning the AC on, I doubt this is a simple electrical problem. The AC compressor loads the engine, and an increase in engine load will exasperate an existing low oil pressure problem. The oil pump’s job is to push oil through narrow passageways in bearings. If the bearings are like new, there’s a lot of resistance to oil flow, and the oil pressure is high. Bearing wear increases the size of those passageways. Which lowers the oil pressure.

2 Likes

Agree with Purebred, I’m pretty sure my 94 Saturn Sedan turned the AC on when I put it onto defrost.

Added convenience has nothing to do with it. The defroster is more effective with the A/C on so it dehumidifies the air.

2 Likes

On most cars I’ve seen there is a switch on the climate control panel that allows you to turn the AC off. This would stop the compressor. Also if you turn it off and then set it to defrost mode the AC is automatically re-engaged.

2 Likes

This thread has a Solved Check mark . As far as I can tell nothing has been solved here .

I really hope John 41 has this looked at by a shop or even see if the place he bought it from might take a look before he has serious damage to the engine.

1 Like

Something to keep in mind here. Just because the lack of oil pressure indicator light is off that does not mean for one second there is not a problem.

Oil pressure lights are designed to illuminate at very low pressures. Low or no oil pressure may turn on the lamp but just because the pressure is a shade above that minimum it is not enough to protect an engine or signify there is not a problem.
Given the widespread neglect going on I’m generally pessimistic on this kind of issue and my opinion is the oil type would make practically no difference be it 0/20 or 10/30. The heavier might make it a bit easier to douse the light but again; does not mean trouble free.

3 Likes

I always figured the only purpose for an oil pressure light is to tell you the reason your engine is shot. If I remember right, back in the 60’s and seventies the idiot light didn’t come on until the pressure got below 5 or 7 pounds.

There are a high number of oil pressure sensor failures for that vehicle. If the oil pressure value drops below 24 PSI @ 1500 RPMs or higher, the warning message will be displayed. Likely just high resistance in the sensor.

Especially since the OP’s own post about an obscure brand of oil is labeled as the “solution”.
Huh?

4 Likes

These engines had a lot of problems with the timing belt or timing chain tensioners wearing out. Also, turbo failures and I know a few people that had a lot of problems. This is the reason I no longer buy VW’s. I traded in a 2018 VW Tiguan that was total junk. Expensive money pits.

1 Like