98 Blazer-Service Engine Light

I have a 98 Blazer the service engine light comes on intermittenly. It has only come on when diriving on the highway 70-80 mph. The light will blink several times then stay on for a couple days then turn off. Each time it has happpened I have be climbing a hill. Is this something to worry about or have checked out? I have aprox 136,000 miles on the vehical.

A blinking check engine light is telling you that you have a engine cylinder miss.
Yes it needs to be checked and fixed.
A engine miss can cause engine and cat damage if not fixed.
Also I would get the code or codes and post back code no.

Has it ever had a tune up?
Plugs and fuel filter and check plug wires and codes is a good place to start.
MT

Does it matter that the light will turn off after a day and not reappear until it is under the same conditions, under load at 70-80 mph?

A blinking check engine light is a cylinder miss fire.
Read codes and see what codes it has.


Tune Up?
You did not answer the tune up questions.
The more info you give the more we can help.
MT