99 Malibu

I have 99 Malibu with about 90,000 miles. I don’t know if I have a transmission, fuel or spark problem. The car runs pretty good except when at highway speed. While maintaining speed it is fine, but if I go up even a small hill the car will buck and stumble. Also if I push the gas pedal more than a small amount while on flat road it will buck and stumble. I have scan tool and points to a check engine light and it points to #3 cylinders intermittent but the light comes and goes but the problem is always remains. Any ideas?
Thanks
Greg

 

Sounds like a lack of spark or clogged fuel injector. 90K puts you in range for a major tune up i.e. all fluids changed, all filters replaced, lube job, all ignition components replaced. Look in your owners manual.

Good luck, post with results, and any other details to problem.

 

Yup, at least replace the plugs, wires and fuel filter. That should take car of the concern you mentioned. Being close to the 100,000 mile mark, I also agree the above post . These transmissions have an average life expectany of about 85,000miles, so a trans flush and trans filter is a good idea.

 

Word of caution from one Malibu owner to another.
Use OEM plugs and wires or you'll create extra performance problems. TRUST ME I know!
Go the Chevy dealer and buy your plugs and wires.
They are only a little bit more money but these modern cars are very sophisticated and need the OEM parts.
Not like the old days going out to Pep Boys and buying a universal set of wires then trimming them down.....nope those days are gone.
And it's not a fun job getting out the plugs on the fire wall side. You only want to do this once! (Knuckle Buster)
If you're flushing coolant use the original brand ( the brown stuff) because it reacts badly with the green stuff and can cause intake manaifold gasket to fail.

 

Mackey is right, go OEM on the plugs and wires. We constantly get cars in the shop with misfires due to aftermarket plugs and wires. The cutomers get upset because they just put new plugs and wires on and we tell them they are junk. You get what you pay for.

 

P.S
My 2001 Malibu just turned 179,000 miles old and is still going strong!