100k maintenance items?

[jasonp99]

Hi all. I have a '97 WS6 Trans-Am with 101k miles on it. The car is stock except for a K&N air filter. The stock spark plugs are due to be changed but I'd also like any opinions on other items to service. I've come up with this list:

Spark plugs
Inspect spark plug wires
Lube chassis components (suspensions components too?)
Check manual trans. fluid
Check rear limited slip diff. fluid
Inspect brakes

Here's what been done in the recent past:

5/24/04 Resurface flywheel, replace clutch, fuel filter
6/21/04 Replace rad hoses, coolant sensor, thermostat
8/27/04 Replace front disc pads, resurface front rotors, machine rear rotors, renew rear disc pads, replace battery, replace radiator
6/17/05 Clean fuel injectors/throttle
11/17/05 Replace coolant resevoir/hose
10/20/06 Replace EGR valve, replace serpentine belt
2/26/07 Replace water pump/thermostat, serpentine belt

I normally have the oil changed every 6k-8k miles with Mobil 1 (10w30). The oil was recently changed so that's not on the 100k list. The manual transmission and rear diff. fluids have never been changed. The last time I had a major servical interval work done was at 36k. Suprisingly there is not much in the owner's manual for 90k/100k different than any other interval except for the spark plugs.

Issues:
- fuel pump doesn't put out enough pressure. I only really notice this on cold starts, usually takes two turns of the key to get the car started. Warm starts it starts immediately. My shop says about $1000 for this repair so I'm not going to change the fuel pump unless there's a more serious problem.

- Shifting. Clutch has only 30k miles, but I've recently noticed that it's not shifting as smooth as before. Not all the time, but sometimes at the end of a shift movement I can feel/hear resistance. Not like the gears are being grinded, it's much more subtle.

- Only getting 22 mpg on the highway. Possibly due to stock plugs or fuel pump?

I've read on these forums that lots of folks prefer the MSD spark plug wires and NGK plugs. Since I've gotten 101k from the current plugs my plan is to replace them with the same type. I wouldn't mind using the MSD wires but since I'm not doing the work myself I don't know if the shop would install them for me since they are larger than stock.

Anything else? I love this car so I plan to keep it until it completely dies.

Thanks!

[Injuneer]

K&N Filter - Clean and oil if not done in last 25K miles.

Spark plugs - REPLACE (NGK TR-55 Iridium)

Inspect spark plug wires - REPLACE (MSD 8.5's are the best, but a tight fit in stock clips and looms)

Lube chassis components (suspensions components too?) - There are no lube points. Check suspension bushings for wear and cracking.

Check manual trans. fluid - CHANGE (Dexron III ATF or equivalent)

Check rear limited slip diff. fluid - CHANGE (GL5 80W-90 + GM LSD additive) Should have been changed at 5K miles.

Inspect brakes - FLUSH and REPLACE BRAKE FLUID. Inspect hydraulic lines for leaks, ballooning.

PCV Valve - INSPECT and REPLACE if needed

Here's what been done in the recent past:

I normally have the oil changed every 6k-8k miles with Mobil 1 (10w30). The oil was recently changed so that's not on the 100k list. - Sounds like you are changing them about once a year. That may not be a good idea. Low miles produce crankcase dilutants like water. I'd change it at least every 6 months, or 6K miles.

Issues:
- fuel pump doesn't put out enough pressure. I only really notice this on cold starts, usually takes two turns of the key to get the car started. Warm starts it starts immediately. My shop says about $1000 for this repair so I'm not going to change the fuel pump unless there's a more serious problem. - GIVE US SOME NUMBERS - What does the fuel pressure read 1) at idle with the vacuum line off the FPR 2) At idle with the vacuum line reconnected. 3) At WOT/max RPM?

- Only getting 22 mpg on the highway. Possibly due to stock plugs or fuel pump? - Also, HAVE THE O2 Sensors ever been changed?

I've read on these forums that lots of folks prefer the MSD spark plug wires and NGK plugs. Since I've gotten 101k from the current plugs my plan is to replace them with the same type. - YOU MAY BE SURPRISED when you pull the stock AC/Delco plugs. Check the gaps on all of them. If they are greater then 0.070" they have lost at least one of the little platinum pucks... a common problem with the AC/Delco platinums. Might be the cause of poor mileage. (not that its so bad.... with "commuting" type highway driving, that seems normal. I could get 30 MPG under very steady state, long range highway driving, but not in daily commuting.

I wouldn't mind using the MSD wires but since I'm not doing the work myself I don't know if the shop would install them for me since they are larger than stock. - WHY NOT DO THE WORK YOURSELF. Its time to learn, and save a BUNDLE of money while doing it

OTHER SUGGESTIONS:

*Check all vacuum lines for cracks.

* Inspect U-joints on driveshaft.

*Inspect pinion shaft seal on differential

*Inspect tranny output shaft seal for leakage.

*Jack the front end up and check the front steering for wear - ball joints, A-arm bushings, wheel bearings, tie rod ends.

*Inspect power steering components for leakage

*Inspect valve cover gaskets, oil pan gasket, rear intake manifold "gasket", and rear main crank seal for leakage.

*Inspect E-brake cable for wear

[jasonp99]

Thanks for the helpful advice Injuneer. I briefly considered doing the spark plugs myself but after reading about the lengthy procedure decided against it. If the new plugs last another 80k-100k then it's doubtful I'll have to change them again. I looked at NGK's site, they recommend these:

TR55
TR55GP
TR55IX ($9.87 on autopartswarehouse.com, fair price?)
IZTR5B-11

I'm guessing the ones you recommend are the TR55IX's? No data on plug life is given on the site. How many miles do you usually get out of these?

I have the oil changed about every 9 months. Good advice on the oil changes, I'll switch to every 6 months. Is it worth it using Mobil 1 synthetic if I change that often (6 mo's would be about 5k miles for me)? The main reason I use Mobil 1 is not to have to change the oil every 3k miles.

I have the fuel pump data at home, I'll post that later. The O2 sensors have never been changed.

I had the power steering looked at last year. I had noticed the resevoir was empty so I filled it, then it got empty again. I re-filled and took the car in. They could find no leaks, but did put in dye into the system. But since then I've not had to add any fluid so it doesn't seem to be leaking.

I cleaned the K&N filter recently (about 20k miles ago). I believe the manual says to do this every 50k.

[RAF7789]

It only took me an average of about 30 minutes per plug when i changed mine!!!

I agree with Fred, if you do the maintainence yourself (by this, i mean everything that you are able to do in your garage/driveway) you will save your money. Instead of paying $50-80/hour for labor that anyone is capable of(unless you have hulk hogan arms that can't fit to change some plugs) you can do it all yourself!!!

[Al 96 Ram Air T/A]

Hey Fred...

I had the same issue with regards to changing schedules for Mobil 1. I only put 1,000 miles or so on my car a year. I had been changing the oil twice a year anyway. I sent an email to Mobil and asked them for their recommendation.

In summary, a Mobil tech. stated that the oil would be fine for 12 months, so long as the vehicle was being frequently started and allowed to come up to normal temperatures. (burns off the moisture) . For longer periods, he recommended using their extended synthetic, which would provided longer change intervals but at an added cost per quart.

Since I start the car once per week, and allow it to run for 15 minutes or so, he felt confident the stabilization package designed into the fully synthetic oil was more than up to the task of lasting for 12 months. Standard oil does not hold up as well, and should be changed every 6 months.

I've started to follow this schedule and so far, can't say I've noticed any issues. The oil looks and smells the same as it did after 6 months of use. Hopefully, the Mobil guy knew what he was talking about.

I don't think he was making this stuff up, as you'd think they'd want you to change it more frequently to generate revenue. Now, if it was a car manufacturer giving me the advice, I'd think twice about following it.

[Injuneer]

I agree.... if you drive it hard enough to get the oil up to full operating temp, its more likely to be acceptable. However, I'd question whether letting it idle for 15 minutes is enough to achieve that. I have an oil temp gauge, and it takes at least 15-20 minutes of active driving to reach full operating temp. It won't do it with idling alone.

Synthetic oil's main advantage it the ability to stand up to higher operating temperatures, without breaking down the viscosity enhancers, or carbonizing the base oil. Synthetic doesn't need viscosity enhancers. It will tolerate higher temperatures. I'm not aware of any additives that would make it more tolerant to acid buildup, from excessive moisture content, and the blowby that collects in the crankcase. Maybe Mobil has that taken car of.

[Al 96 Ram Air T/A]

Good info. I'll make sure to increase the warm-up time just to be safe.

I may split the difference and start changing the oil after 9 months. It's cheap insurance in the long run.