I bought a 1999 SLE with 111,000 miles in very good condition from a local dealer last weekend, and I have a few questions.

1) The previous owner's receipts show that the lower intake gaskets were replaced with GM PN# 89017816. I can't remember whether or not the upper intake gasket was also replaced; I'll have to look through the receipts again. When I looked at the car, the coolant level was about 2" low (not a good sign) but there were no signs of any external leaks. The oil looked like normal oil - ps: how can you tell if there's dexcool in oil? The intake manifold itself has a '99 date stamp, so I assume it's original. Do I need to replace the intake manifold and upper intake gasket to ensure that the intake internal coolant leak problem won't be a problem, and if so, which intake and upper gasket have fixed the coolant leak problems? I haven't driven the car since I drove it home, and I want to look into this and ideally replace the intake and upper gasket if they need to be replaced, before I begin driving it.
2) The receipts also show that the coolant bypass elbow was replaced with GM PN# 24503423. There was no record of a 2nd coolant bypass being replaced, and I only saw 1 bypass on the engine (looks to be black plastic, and I couldn't see how it would be replaced, either). Where is the 2nd coolant bypass, and does it need to be replaced if it's still the original part?
3) I noticed that the normally aspirated Series II shifts and revs differently than my '92 SSE s/c and my '93 SSEi. The '99 SLE seems to shift a little later than both of my supercharged Series 1s, and revs at around 2,000 RPM in overdrive at around 60 MPH. Is the normally aspirated Series II supposed to rev at around 2,000 RPMs at 60 MPH? In contrast, my supercharged Series 1s both rev at around 1,800 RPMs at 60 MPH.
4) The radio appears to be the stock CD player unit with the red display. The radio and the electronic climate control seem to work ok, but when I turn on the headlights, the displays on the radio and on the electronic climate control turn off (but the radio and climate control seem to work ok while their displays are off). I'm guessing the problem is the headlight switch? If so, can I temporarily swap one from my '92 or '93 to see if that fixes the problem before I buy a replacement switch? If I remember right, the twilight sentinel/dimmer off switch is near the top (1:00 position) on the '99 SLE, but it's near the bottom (5:00 position) on my '92 and '93, so the '99 appears to be the converse of the '92 and '93, and maybe the headlight switch isn't interchangeable.
5) I also noticed that it looks like you have to remove the upper engine support in order to replace the serpentine belt on the Series II? If so, how difficult is it to replace the belt?
Thanks!

1.) From looking online, the gaskets you have are the aluminum gaskets. Shouldn't have to worry about them ever. However, the UIM will need replacement. Read up: http://www.pontiacbonnevilleclub.com/fo ... =53&t=1061

2.) IIRC the older cars have a steel elbow on the bottom. That upper elbow would be replaced by removing the tensioner bracket if you needed to do it.

3.) I'm guessing your car has a 3.05 FDR vs. the 2.93 on your SSE/i.

4.) No idea

5.) Yes, you have to remove the bracket. Some say it's a PITA, I've never done it myself.

_________________
Bye Bye:

RIP sandrock

Well, I just ordered the 'Sure Fix' upper intake kit from ineedparts.com
If that's not the best upper intake problem solution available, please let me know!

Nope, that's the best one.

_________________
Bye Bye:

RIP sandrock

No need to remove the whole engine mount. There's a stud that needs to be yanked on the firewall side of the A/C compressor. The belt will feed through the opening that creates. It's not that hard, should be 30 minutes total to put on a new belt.

_________________
2012 Chevrolet Cruze Eco - Current car

1999 Buick LeSabre Custom - Former car

Learn from the mistakes of others, that way when you mess up you can do so in new and interesting ways.

Up through 1995 is a 2.97 ratio, not 2.93. And the Series 2 motor has lighter rotating internals, so it revs quicker and has a higher redline, all shifts are at higher rpm's.

The belt change procedure including the mount removal is in Techinfo. Link at the top of the page.

_________________

Click here for mod list for both cars
93 SSEi, 95 SLE (supercharged) 97 Buick LeSabre Limited
PontiacDad at WCBF '04: Cruise control? That's like surrendering!
Comprehensive guide to troubleshooting, rebuilding, and modifying Eaton Superchargers