Q: Low engine compression

asked by on May 01, 2017

I had an engine compression test done today. Three cylinders are at 75 psi and one is at 165. The car does not misfire though and no check engine lights. It seems to drive fine at the moment. Another shop who checked my transmission last week and test drive didn't mention it either. I realize the engine could fail at any moment but it seems to be running pretty well for being so poor. Trying to figure what to make of this.

My car has 159000 miles.
My car has an automatic transmission.

Hello, thank you for writing in. There are several components that wear down and can cause low compression. Considering three out of four cylinders have low compression, you may have worn piston rings and need a major overhal. Other main causes of low compression are worn exhaust and intake valves, a blown head gasket. With that being said, you can check for coolant mixing with your oil in the case of the blown head gasket. If the engine does need a major overhaul, consider the cost of the vehicle and the price of a new engine to compare the to cost of an overhaul. For more help with repairs, contact our service department to schedule an appointment.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

2006 Honda Pilot EXL-Navigation; 100K miles.

Hi there. In general, the parts for these services you're looking for can be purchased for around $500 (as long as you don't go to the dealership). However, I would recommend not purchasing them from E-Bay or Amazon. If you...

My car does not go past 40 kmph while driving

This is a common problem that can be caused by a clogged catalytic converter. If the converter is clogged or partially clogged, the exhaust gasses cannot escape the engine as fast as they should and this chokes the engine. Typically,...

Water leaking out from side of engine

The freeze plugs are on the side of the engine block and in other areas of the engine that will corrode and rust out over time and may start to leak. You will need to have the cooling system pressure...

Related articles

The Best Used Cars to Buy For a Graduation Gift
Your Your little bundle of joy has grown up and on the cusp of entering adulthood. Graduating is a milestone, and you want to reward their hard work and show how proud you are. Buying a used car is a...
The Best Used Cars to Buy If You're a Dog Trainer
If If you are a dog trainer, you expect a lot from your vehicle. You want a ride that is safe, roomy, and of course, dog friendly, since your training operation will often mean that you need to transport the...
The Best Used Cars to Buy If You're a Doctor Who Makes House Calls
If If you are a doctor who makes house calls, reliability is likely to be at the forefront of your mind when it comes to choosing a used car. You also expect a certain level of comfort. We have...