I see cars in terrible condition every week and just when I think I’ve seen it all, I realize that I truly haven't.
This week's contestant was a VW CC equipped with a TSI 2.0T CCTA engine suffering from low oil pressure. This issue made itself known after the installation of a fresh engine from an independent shop that told the customer everything had tested O-K. An engine with less than 25 pounds of pressure is not OK. A vehicle that flashes a low oil pressure light that tells you to shut off the engine shouldn’t be ignored, but it was.
If your low pressure light is steady or appears intermittently, do yourself a favor and just shut off your engine, get your car towed, and count your blessings. A tow is always cheaper than another engine swap.
So, what is low oil pressure? To put it simply, it's when the engine is not producing sufficient oil pressure to lubricate rotating components. This is an extremely volatile condition because a lack of oil pressure can and will result in contact between metal components within the engine. Metal-on-metal contact is can include rod knock, bearing failure, crank wear, and other damage. Your engine will very quickly wear itself to the point of being inoperable.
You may be asking yourself what DIY steps you can perform before sending your vehicle to the professionals. First, check your oil level and then verify that you actually have low oil pressure. A pressure switch is not an expensive item to replace, so if the fault lies here, consider yourself lucky. This diagnosis isn't likely if you have a later model vehicle, but some older model vehicles have oil pressure switches notoriously prone to failure (think 80’s-90’s Benz’s). We offer a simple to use gauge, the CTA 2001, that can be installed in less than 5 minutes.
Locate the pressure switch, on most modern cars it is on the oil filter housing module.
Disconnect the electrical connector
Remove the pressure switch/sensor using the appropriate socket. On this CCTA engine, it was a 24mm deep socket.
Next, screw your pressure gauge into the pressure port on the engine. Be sure to use the correct fitting with the proper thread size; the last thing you want to do is use an inappropriate NPT fitting on a Metric thread. You won't realize your error until you attempt to reinstall your pressure sensor and find that you've mangled your threads.
Place the gauge somewhere visible and read the pressure after starting the engine. If you are below the manufacturer specification, shut off the engine immediately.
Common reasons for low oil pressure:
Low oil level - If you own a late model turbocharged Audi or VW, t’s not uncommon to burn a quart or oil or more in two months. Consider checking your oil level every other gas fill-up.
Blocked sump screen - Drop the oil pan and verify that you don’t have anything clogging your mesh screen. If your oil pickup tube cannot siphon a sufficient volume of oil, it can’t pressurize it. If you're dropping the pan, consider picking up one of our kits that includes the correct sealant and oil pan bolts.
Increased bearing clearances due to age or bearing failure - While some designs allow for easy access to engine bearings, others require significant effort to access the bearings (ie: transmission removal to access the upper pan). Consult a factory service manual to determine if this is a DIY procedure or something to leave to the professionals.
I can’t stress enough how important it is to heed the warning signs. On the vehicle featured in this article, I drained the oil and it came out of the pan looking like metallic paint.
Be proactive and consider using some of the tools we offer to diagnose your situation. If you are unable to locate the correct specification for your engine, don’t hesitate to email the team at email@example.com.
While we always encourage our customers to wrench on their own cars, it's important to realize your limitations so that you don't end up over your head with your car apart in the garage. If something is outside of your skillset, always seek the help of a professional.
Kyle is the Mercedes Catalog Manager at FCP Euro and has been with the company since 2014.