Ok all, this is my first Volvo. My dad is letting me borrow it while I look for a new vehicle. I'm a Jeep person so I'm not used to these vehicles in any way, shape, or form.

First off-check engine light. I got the code read at Advance Auto and they told me it was a misfire on cylinder 1. It's sluggish when I accelerate. I was going to start with spark plugs and go to the coil pack if that doesn't work. Any other input?

Second matter-the exhaust. The check engine light had previously been on and I'm not positive that it caused the issue. I drove it to work fine. Then drove it to the farm to take care of my horse. I started it back up after being there for a half hour and it sounded like there was a hole blown in the cat or muffler. It sounds like a 73 Chevelle (I WISH it was one!). This has been for about two weeks because I haven't had a chance to climb underneath it and take a look. Just the other day it started to sound like a bat was stuck in it (high pitched squeak) only when I accelerate. It's not constant, and mainly when I'm going uphill, which it struggles because of the misfire. Almost sounds like a lifter tick, but again, not constant. Any ideas? I'm thinking the whole exhaust could have just become unattached. I'm going to try to take a look this upcoming weekend. I always check fluid levels and it's not low on anything.

Third matter-my dad has never maintained any vehicle, so this poor car hasn't had it's oil changed in quite some time. Possibly 10,000 miles ago. I'm planning on doing it this weekend, and want to use an additive to help clean the engine a bit more and get rid of any sludge. I have a quart of Marvel Mystery Oil on hand. I'm not sure how sensitive foreign engines are so I want some advice on weather to use this or not.

Thank you all in advance!!

 

plugs then coils sounds like a good start for the misfire code. For the exhaust, I'd start by looking around the flex pipe in the front. They do creak and break over time. If you decide to add detergent to the oil (ie the "seafoam" treatment, just beware that while you may remove sludge, you may also send sludge into the PCV system which can clog. A good way to determine if you should consider an oil/flush is to look inside the oil fill cap. If you only see some discoloration (ie brownish color but no gunk that can be scraped off), you should probably just change the oil and go from there.