Would the check engine light come on if your engine compression is low?

Answer 1

David…
The check engine light related to engine control and emissions alone.
If there is high temp, low oil pressure or any other mechanical issue, the light MAY illuminate, but only because it is related to an engine sensor that monitors the electronics of the engine.
Vehicles 1995 and earlier used s system of self-diagnostics that would illuminate the light if there were any system faulty that would interfere with the engine's control and operation (MAP sensors, throttle sensors, knock sensors etc)
Vehicles 1996 and later do pretty much the same thing with one major exception: ANYthing that has the potential to raise the vehicle emissions beyond acceptable limits will trigger the light. That now includes the sensors, which can cause emissions to be uncontrolled, as well as a loose fuel cap, poor Catalytic Converter performance, inoperative EGR valve etc.
It also includes engine misfire. If there is one cylinder or two with low compression, it could cause the crank sensor to register a misfire and trigger the light.
But the light won't illuminate merely because of low compression. Only the consequences of the low compression.
The thing you need to do here is to retrieve the Diagnostic Trouble Codes, and proceed from there.

Happy Motoring

Answer 2

When the check engine light is on, that means the computer has detected a problem with the fuel delivery system. The most common cause is a sensor problem. Take it to Auto Zone and have them run a code scan for you, it's free. If you drive it very much with the light on, you take a chance of ruining the catalytic converter. And that can get expensive. If it's running lean, you should detect a rotten egg smell. That will ruin the converter. Compression has nothing to do with the check engine light. Always have a qualified tech work on you car. The best ones are at the dealership. They've been trained and sent to school. Hope this helps. Master tech 40 yrs.

Answer 3

How To Check Engine Compression

Answer 4

It depends on how bad the compression is.

There are no sensors to detect low compression, but there are a lot of other things that will happen if you do have low compression to set off a check engine light.

Firstly the car will have a hard time starting at cold start. A lot of times once it warms up it will behave fine.

You will most likely get a check engine light.

Most common code for low compression / bad compression will be a misfire code on a cylinder that has bad / low compression.

Answer 5

Go with Ironhand,
Why the low compression won't cause a fault-- it can cause problem that can make it come on--- like an incomplete burn can cause the O2 sensor to be out of range, engine knock, plug a cad converter and cause excessive back pressure........ So have it checked out so you know what the problem is--then you can figure out if you want it fixed--may part stores have loaner scanners at no charge, and other will hook it up themselves and tell you for free.

Answer 6

Take the car to a mechanic and ask if they do free diagnostic checks. If they do, have them scan the car to see why the check engine light is on.

Answer 7

yes it would: low oil pressure, cracked or blown head gaskets, little or no oil all would set off sensors for the check engine light.

Answer 8

no,,it wont,,compression isn't one of the monitored things ,and there isn't a sensor for this either,but it wont set the check engine light,,on any car,good luck hope this help,s.

Answer 9

It depends on the car. They sell On board diagnostic testers at auto parts stores and walmart for around $100. Some repair shops will test it for you for free, and some will charge up to at least $100. I just bought my own and do my own repairs.