100K Service and Maintenance Suggestions

I have a 2004 V6, 3.4L Chevy Impala rolling up to 100K miles. The owner’s manual suggests I change the transmission fluid (I changed @ 60K miles along with the coolant fluid), the transmission fluid filter and replace the spark plugs. Any other suggestions of other services?

The major service intervals are normally 30k, 60k, 90k, 120k, and so on.
Tell us what you had done at 90k, and also tell us what your Owner’s Manual suggests for both 90k and 100k, and we will be better-able to advise you.

I have not done any services at the 90K milage mark. The owner’s manual doesn’t have any 90K service recommendations, only at 25K intervals. The 75K interval suggested fuel & exhaust system inspection, and engine air filter change. All done already. 100K service suggestion was the same at 75K plus transmission fluid & filter change, oil and oil filter change, and replace spark plugs. Any other suggestions at 100K miles?

I think you have answered your own question. The 100,000 miles interval should cover at least the 25,000 miles interval, and maybe more.

If this was my car I would flush the cooling system again, since those “lifetime” fluids are not really lifetime. If you have DEX Cool in your car replace it with the same GM fluid or COMPLETELY flush it clean and use a universal coolant such as Prestone. Might as well change the thermostat at time asd well.

Check all hoses and belts; at this mileage a number wil be weak and should be replaced.

The PCV valve should probably be replaced as well at this mileage; not a great expense.

Your car has a timing chain, and it may get noisy around 180,000 miles; replace it then.

When you repace the spark plugs, all wires, etc should be checked as well.

Congradulations for being so dilligent on your maintenance.

The one and only thing I would add to those listed in the owner’s manual for you would be the transmission change, which you seem to have done.