So, I picked up a 1998 T/A WS6 Auto almost a month ago.

Since the car had 149k miles, the previous owner had over $3k+ of head work done to include the valves, gaskets, spark plugs, etc. done to it and the car runs cherry!

When I bought it, I replaced the tires and performed an oil change as well as replaced the oil filter and air filter (Mobile 1 in all my cars and K&N drop-in filter like always).

I just got the coolant flushed out today and replaced with Dex-cool. Also, over the past 2-3 days I've been cleaning and detailing the engine and there isn't a single leak anywhere at all in the car. I also took apart the air intake and cleaned everything out and cleaned the MAF with CRC MAF cleaner.

- Anyway, I'm wondering what else should I look into doing to the car just in case it wasn't done? I plan on getting the transmission fluid replaced too. What kind of fluid should I use exactly?

- Also, I've read that the tach's in these cars aren't very accurate....but while in park my car idles at 900 on the tach. I think this is kind of high, even if the real RPM should be reading roughly 150rpm lower like everyone says which means I'm at about 750rpm. Could it be my IAC? PCV? While in gear or neutral the tach is at about 650rpm (which means it's at around 500rpm).

I know I could simply do a search regarding the tranny fluid but I just thought I'd throw that question in here. My real reason for the thread is I'm wondering what else anyone else would do to the car and if they have any suggestions regarding my idle.

 

Oh and just to add, the idle has always been at about 900rpm while parked since I bought it in case anyone thinks I screwed anything up during my cleaning/detailing of the engine bay. I love a clean engine bay, plus it makes it much easier to detect leaks.

 

is the engine cold when you read the idle? i have an ls1, so its not quite the same, but when i start it, it idles at around 1k, then once it warms up, it drops to around 500.

 

Yeah my '98 is indeed an LS1.

When it's cold, it's at 1.1krpm or so but when the engine gets warm it drops to 900rpm. I read on several posts/threads (to include LS1tech) that the tach on our cars reads about 150rpm or so higher than what it's actually idling at so I'm taking a stab and saying I'm at about 750rpm. However I think that's still a bit high for an automatic while in park....someone correct me if I'm wrong?

Mine drops to 650rpm (which means it might/should be 500rpm) when in gear (D) or neutral (N).

 

im brilliant, i read 97. my bad. it sounds like you might be a hundred or two high sometimes. could be a slight vacuum leak. i wouldnt worry about it if i were you

 

Change the fuel filter.