Replace spark plugs on a 1999 montana - 1999 Pontiac Montana

https://www.700r4transmissionhq.com/p0303-pontiac-montana/

It is usually coming from the spark plug wires( leak spark). Spark to ground or piece of metal.
To find out exactly take an empty spray bottle fill her up with water and add 2 tablespoons of salt. With the engine running a light spray of the mix on spark plug wires you will see the spark leak and proof the spark plug wires have a defect. if so replace all spark plug wires that should solve your problem.

Hope it helps.

Missing is usually ignition problems

Backfiring-timing issues or possibly lack
of fuel

Repeated dead battery that is over 4 years old
you have to replace.


I would first change the spark plugs & then
suspect a timing chain issue

Just have to go over the entire engine, one item
at a time

You can not just shot gun the problem or expect
an internet guess

The vehicle has to be looked at & things tested

153624 or 143625

I have a '99 Montana Oil Drain Plug is M12- 1.75 Thread

The best way i've found is to remove the coil pack, it gives you enough room to get to them. Be sure to replace them with OEM plugs. Don't by cheap spark plugs or you'll be doing it again sooner than you want to.

No you have to jack it up and put it on blocks and get them from underneath the vehicle.

The three front ones are simple and the three back ones are challenging. There are two ways to replacing the rear spark plugs on the Montana.
1. If your arms are long enough and you have longs extensions with a spark plug socket with a swivel build in to it, you can get to the plugs from under the Montana.
2. You can get to the rear plugs buy disconnecting the two dog bone engine mounts in front of the engine and tilting the engine forward. You can do this by placing the parking brakes on and disconnecting the dog bone, once that is done. Place your foot on the brakes and take the parking brakes off and push the Montana forward till the engine tilts forward enough to give you the room you need to get your arms over the top of the engine with the extensions and spark plug socket. Make sure you place the parking brakes back on and put a block at the rear of the engine to ensure the Montana will not move back and cause you to loose your arm or head.
Note that you need to keep the transmission in park when tilting the engine and that your going to have to replace the spark plug wires and do everything by touch to replace the rear spark plugs.
Thank you for using Fixya and use platinum spark plugs to give you 100,000 miles of service. Good luck and be safe.

it is either a plug, plug wire, a coil, an injector, or a vacuum leak.......hope that helps

THE BEST WAY TO DO IT IS FROM THE UNDERSIDE OF THE VAN. I'M NOT SAYING THIS IS EASY BUT IT CAN BE DONE FASTER THIS WAY IF YOU HAVE A LIFT.

DON'T TRY THIS WHEN THE ENGINE IS HOT.