Hello everyone; I'm a new member and making my first post.

I'm looking for advice about what parts to change on an older car with pretty low mileage.

A little over a month ago I bought a 1998 Bonneville SE; it'* a one-owner car and had 37,341 miles on it at the time of purchase. Mileage is currently 38,185.

The engine is the standard 3.8L V6 normally aspirated 3800 Series II.

Since it was driven so little I'm assuming the previous owner likely didn't do too much in the way of regular maintenance. I don't know anything about its maintenance history.

So far I've done the following to it:

1) Oil change

The oil was somewhat dirty looking to me so immediately after buying it I drove to a "quick-change" place and had the oil and filter changed.

2) New tires

The ones on the car looked a few notches above being bald so I replaced them.

3) Had the engine block, radiator and heater core flushed and a new thermostat put in.

The coolant that was in the car looked to be Dex-Cool or similiar based on color so I had it flushed out and replaced with mixes-with-any coolant.

4) Had the transmission pan dropped and serviced to include a new filter, gasket and fresh fluid. (No flushing with a machine.)

5) New air filter and a new complete PCV valve assembly.

I'm planning to do the following:

1) New plugs and wires

2) New fuel filter

3) Have the MAF sensor and throttle body cleaned.

3) New serpentine belt

The guy at the quick-change oil place said the belt is somewhat worn looking and suggested changing it pretty soon.

Is it necessary to replace parts like the oxygen sensor (which I understand is pretty pricey)?

I've seen that recommended here on the forum when doing a tune-up on a car in order to regain any lost mileage or horsepower.

In general, the car is running normally and the engine light has never come on. It'* my daily driver and I'm going to keep it stock (no mods, no aftermarket parts).

I simply want to keep it in good working order for as long as I own it and that'* what prompted me to post regarding the age/low-mileage issue.

Although the mileage is rather low, the car itself is still 11 years old and I'm very curious to know if there are any parts that should be replaced and/or maintenance services to be performed simply on the basis of age.

In closing, I lurked on the forum for a little while before registering and have found it to be very informative. Thanks to everyone for providing his knowledge and experiences about these great cars.

*** Moved from Performance ~ Kevin ***

Being nearly 12 years old and that low of mileage, I'd say save up. There'* nothing you are leaving undone....except the unexpected. Usually an older low mileage car will have a bunch of things to do once you put it into service.

My feeling is things have flat spotted, like bearings etc. Hang on a few weeks, it'll ask for something.

If you got the $$$ we got the time lol j/k

Your on the right track to replacing the regular maintenance parts that cause most normal problems. Id start with the new belts, plugs, wires filters *both air and fuel definately*, and clean the tb but BE CAREFUL around the MAF sensor wire, its fragile... other than that and with the o2 sensors, you can replace them if you want to just to make sure and to keep track of when it was all done when you got it, but if the cars running right with no SES Lights on, its not a necessity. That is why is called Preventative Mainenance tho, to prevent problems before they happen so its all up to you.

id check out the LIM & UIM gaskets since its a common problem with the series 2 motors. they leak coolant after a while

BillBoost: I was concerned about the scenario coming true. I guess I'll just have to keep my fingers crossed and see what happens.

TLSHEFF: I'd read about the MAF sensor wires being delicate. Will definitely keep that in mind. And like you said, outside of the basic maintenance items that need to be replaced/serviced as long as the engine light doesn't come on I'll take a wait-and-see approach to future repairs.

GEFORCE: I'm aware of the UIM/LIM issue and have been keeping an eye on the coolent level since having it flushed to see if it'* dropping rapidly.

This was the telltale sign on my father'* 99 SE that the LIM gaskets were shot and leaking coolant.

Is there a particular way to check the UIM/LIM gaskets as you suggest? I'm not aware of how to do that.

Thanks everyone for your advice.

from what i know these gaskets leak internally so im pretty sure you wont see anything leaking around the motor.
Id keep on eye on the level.
Have you checked the level when you bought the car? ... before you flushed the coolant.

Geforce, as best I recall the coolant level was normal but it looked like Dex-Cool. So I had it flushed on the logic that if the LIM gaskets aren't bad yet then at least the Dex is out and we'll see what happens down the road.

So far the coolant level looks to have remained normal over the last month.

Then its PROBABLY* safe to say the gaskets are fine... for now anyways

usually within days there will be a substantial drop, and it will be making a considerable amount of "condensation" spray out the exhaust, and in some rare, odd cases will mix with the oil a little and cause the milky effect. The typical effects are noticable so I wouldnt worry about them too much, they tend to go out on higher mileage cars so you SHOULD* be fine

* - waving all rights to Jinxings, "Its YOUR Fault'*", and "But YOU Said'*". Should anything happen I am not liable, just merely expressing my opinions lol

One problem I have seen with these at about 100K is the upper intake itself. If you start losing coolant it'* one of the first things to check. Unfortunately it almost takes removing the throttle body to see where they leak, which is around the egr pipe where it goes from lower to upper, watch for coolant seeping up around the pipe, Dorman has a good replacement that'* been modified to keep this from happening again.