Don't be scared. Check the oil for coolant and the other tests that are mentioned above. We have a 98 Montana with all of the extras and it has been a very reliable car and has not broken down on us at all. There is 130,000 miles on it and it still runs smooth. The gaskets went at 99,000 miles.
We just replaced the Evap Control canister today, an expensive repair, and had to replace the seatbelt sensor about a year and a half ago. All in All the van in reliable and fun to drive.

Curious, I just bought a '98 Olds Sihouette GLS from a local dealer that had been traded in because it overheated. It has 130,000 miles on it. I bought it to repair and sell, but I may keep it. It is a very nice van. Mine had the orange Dex-cool in it and after I replaced the cylinder head gaskets and the intake manifold gaskets, I flushed and refilled with Dex-cool. So, you can't always tell whether or not work has been done on that basis alone.

Your plans look pretty good. However, I would not run premium fuel. You should be fine with 87 octane. And, I would not add any flushing or cleaning agents into the fuel tank, cooling system or crankcase. If something gets dissolved, or broken loose and causes a problem, you don't want it to be on your 950 mile drive back home. I would wait 'til i got home to do all the flushing and cleaning.

This is not an easy vehicle to work on. Because of the van'* design, it is difficult to get to the rear bank of plugs and wires, the oxygen sensor, the alternator, and the heater hose connections for the rear heater core. It is not easy to get to the battery, for that matter. Keep this in mind when you work on it or have work done on it. It is a good idea to make sure all the replaceable stuff on that back bank is done at the same time, to save effort in the future. I think these vans are shipped with platinum - iridium plugs, to minimize the service on that back side.

I would not recommend synthetic trans fluid. I would also NOT recommend having the trans flushed. I would drop the pan, drain all the fluid that comes out, (about half), replace the filter, clean the pan, install a new pan gasket and refill with Dexron III. I would repeat that service annually.

Good luck.

Getting off topic abit: seems like all the minivan are pretty cramped under the hood, i.e. it'* hard to work on them. Any suggestion for a mini-van that'* owner friendly? I have considered a Toyota Previa with a tilted Inline four cylinder mounted underneath driver'* seat. Any other minivan choice?

Too bad it'* never like our H-body car where everything is easily accessible with the spacious hood.

Made it safely back to Houston after the one-thousand-mile journey in twenty four hours. Minivan drove nicely without any problem. Paint/body looked amazing! It shines like it'* new, I don't know how the previous owner did it (or maybe dealer painted it, but I can't tell if it'* repaint, it looked flawless everywhere), I am VERY VERY HAPPY with the purchase. Also I was getting 26-27MPG on the minivan (a tank of gas runs me 500miles), and that IS an amazing mileage in my book. I did add a bottle of Gumout Regain Complete Fuel System cleaner at start of the trip, so that might boost it abit. BTW, if anyone is thinking about buying vehicle on eBay, I would definitely recommend seller STINGRAYSINC.

Back to observation of the 3400 engine, it runs fine and smooth, my is mated with a 4t60 transmission, no problem on the trip, even in the stop-n-go rush hour traffic in Baton Rouge and Beaumont. It still has the orangish Dexcool in the coolant reservior. I will perform all the maintence mentioned above this coming weekend.

Now comes the rant: the layout in the engine bay is H-O-R-R-I-B-L-E. Everything is hard to reach. <sigh> I feel terrible for GM engineers (can they even call themselves engineer?!!). Did they just throw in everything in space they can find?! Battery is burried under a fuse box and cross-bar, alternator is all the way back in the engine bay where it'* not easily accessible. Servicebility IS NONE-EXISTENCE. I wonder if they created this mess so the auto-mechanics at dealership can get more business. No wonder my mechanics loves to fix Japanese car, and frown when I mentioned I got a Silhouette. I guess I just have to put up with it and get more grease elbow down the road. Thanks for all of your suggestions.

Glad to hear all went well. I really like our Silhouette, too. And it is a great time of year to get a great deal. That engine layout is really a nightmare, though. That'* why I think it is a good plan to think ahead when doing maintenance, especially on that rear bank.

Good luck with the new van!

Does it have the radiator support dogbones that can be released and pulled forward to rock the motor and make everything accessible?

Yeah, it has the dogbones, and yeah you can rock it forward SOME, but that does little to make anything more accessible. For example, just to remove the alternator, you need to loosen and lower the cradle at the front and remove the wiper linkage! For the alternator! Not the vehicle for an impatient man.

This will really make you appreciate the 3800 H body:

Pictures of my '98 Silhouette 3400:

Im000056.jpg

Here is the overall layout

Im000057.jpg

GM plays " Can you find the alternator?"

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Here'* the conveniently located battery

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How hard can it be to change an air filter, or top radiator hose?

Not designed with service in mind.