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Knocking Noise 2007 Mercury Mariner Hybrid

Good Morning,
I am so scared right now. I am so stupid when it comes to cars. My husband used to take care of all the maintenance so never really learned the simple things that need to be done to keep a car running. Now that he’s not around it’s up to me and I just completely ruined my car. I was driving my daughter to school when the car started making a small knocking noise. It was accelerating weird too. I drove to the nearest gas station and googled. I checked my oil And it has 33% life, but when I physically checked it, there was a very tiny bit on the dip stick. You could barely see it. So I put 3 quarts in. Let it sit and then started it and drove home less than 5 miles and parked it. Now when I start it the knocking noise is louder and it accelerates weird. So I just parked it. I called a mechanic and they said I need a new engine and it will be a few thousand dollars. I’m literally in tears because I’m a single mother with 2 kids, I’ve been off of work due to emergency surgery and do not have a dime. I’m just reaching out to ask if anybody knows if this is what would happen and if an engine is really that much money. The check engine light is not on, would it be on if it was the engine? I’m so sorry for the stupid questions, but I am very ignorant when it comes to cars and car maintenance. I would appreciate any advice. Thank you.

Just to be clear, you’re saying that three quarts was needed to get the level back to the correct mark on the dipstick, correct? If so, I’m afraid that being three quarts low is indeed very likely to damage your engine and that that really is the rough price of a replacement engine. The check-engine light is for other things (generally emissions-related), so it normally wouldn’t come on in a situation like this. It sounds like you didn’t actually bring this car to the mechanic yet, so you really should do that as a next step to be sure.


I am very sorry for your plight both in regards to your car and circumstances. I don’t see how you are going to be able to fix or replace the car without money but if you do get another one here is my advice. Check your oil once a month, the first is easy to remember.

Find the maintenance schedule for your car, it will tell you when things need to be done. Try to find a good local mechanic, it isn’t always easy. Don’t ask for a tune up, there is no such thing anymore.

Stay away from any place that trys to sell you $100 miracle in a can, like fuel system cleaner. You don’t need fuel system service if your car is running fine and if you do need it , it is done by hooking up a machine and running solvents through the fuel system. The stuff the oil change places sell you is no better than the less than $10 bottle of Tefhron you can buy at the parts store or Walmart.

An engine replacement is pretty expensive, usually in the $3000 to $7000 range. For a hybrid configuration, replacing the gasoline engine part of that configuration is possibly more. There’s no way to tell via the internet if the engine needs replacing or not. Usually if the oil is still visible at the end of the dipstick there’s enough to keep everything lubed in city type driving. Freeway driving might be more of a problem. Beyond that, just speculation … going forward whatever path you decide, suggest to find you an independent repair shop that will ask you to bring it in on a regular basis, like every 6 months, in order keep your car in good repair. If you do that, then all you’ll have to do is check the oil on the dipstick every once in a while in between shop check, like whenever you buy gasoline.

I’ll add that if I owned that car and an engine replacement was needed, I’d probably just buy another car. Engine replacements tend to be problematic and time consuming for the car owner, something you probably don’t need. In any event, Best of luck…