Hello, a friend who's not mechanically inclined owns a 2016 Hyundai accent with 120,000 miles on it and experienced a problem over the weekend. They left the car at a trusted shop and we're told today that one cylinder is down to 10 psi compression. I advised my friend to have the shop do a leak down test, scope the cylinder, and maybe do a wet compression test if the leak down test shows leakage into the pan.

My question is this: I know this is not nearly enough information to draw a conclusion, but I'm wondering if there is a known issue with this vehicle the commonly results in the sort of compression loss.

Thanks in advance!

 

Can you ask your friend if the vehicle overheated at any time?

 

She says "never".

 

As you have stated, now somebody has to dig a little deeper to determine exactly why that one cyl has low/no compression. Could be ring problem, or valve problem Agree ,
A leakdown test should tell which one, air into crankcase or intake or exhaust.