My 84 500sec had a bit of a rough idle when I got it with 80k miles on it. I spent at least $500 chasing it, I imagine, new rotor, plugs, wires, various things relating to the fuel injection, all the while it never really quit with the rough idle. Finally I gave up and just kept driving it. When I sold it it had about 140K on it and it was going strong. The last summer I had it I autocrossed it. I don't think the guides were ever done. Probably should have been. But it never missed a beat and as long as I owned it it kept running better and better.

Just put the gas pedal down about a third of the way on every startup and when it is good and hot don't shut it down unless it will get a chance to cool off or it will be hard to start.

I was going to say that 500K was possible but given the statement about the 420 above, I suspect that figure might be too low.

I would recommend not trying too hard to get a dead smooth idle like a modern fuel injected car. The system is really really simple and durable but its not perfect.

They are rugged durable beasts.....if you can afford the fuel.

Tom W

Thank you for the comments all :) I should have a chance to look at it on Sunday and go over the maintenance records such that there are.

:( I bought it today

This one is defintly a keeper, It's a 2ND gen W126 500SE, Imported in 1989 apparently by the stickers on it. One dead hole on the fuel distributor for cyl 3 causing the rough idle, and a poorly repaired radiator that leaks and will need to be replaced. All in all not a bad car and should see service for many years to come.

The best part about it? Tri-Y's!

Sounds like you have a handle on it.

Enjoy!

Tom W

Yeah I'm definitely very excited about the car, though I think John may have actually been more excited when he saw the exhaust headers...:confused:

Perhaps leaving the car there this week wasn't such a good idea

I think 15 is too low. My 420SEL used to get 19 or so in Denver (more highway travel) and 17-18 in New Orleans. A 560, now, might be closer to 15.

Mine had "only" 198,000 on it when it was totalled while parked.
.

that's good to hear, the biggest risk we're taking with this car is the fuel bill, but with diesel jumping so high because of ultra low sulfur regulations premium in a newer (albeit higher mileage) V8 almost sounds logical.

fifteen is not too low unless you don't drive city at all, imho.

ninteen was the best I ever got with my 500sec on the required regular gas. that was driving 65.

I drove about 35k miles almost all highway between Lafayette and Indy one year when my first grandson was in the hospital there for the first eight months of his little life.

Tom W

I got 14-15mpg out of my 380 this weekend during the NC gtg. I was driving with a lead foot most of the time though.

This thread is just worthless without pics, here's some of the 500SE:
http://i5.photobucket.com/albums/y15...0SE/pic004.jpg
http://i5.photobucket.com/albums/y15...0SE/pic003.jpg
http://i5.photobucket.com/albums/y15...0SE/pic002.jpg
http://i5.photobucket.com/albums/y15...0SE/pic001.jpg

thanks a lot John those pics are beautiful, I was thinking about trading you for the wagon but now that I have seen those pics you've got me back on track ;)

Does yours require premium unleaded? Mine did.

That 19 mpg in Denver was about 50% highway, and the 17-18 was about 75% city down here in The Swamp. Mine had regular oil (15W-40) and tranny fluid changes, had the timing chain changed at 150K, breathed through a K & N air filter, and rode on tires I kept at least a pound or two higher than the stock psi, so some or all of that might have helped.

I love my Buick . . . but looking at the pics of your 500SE's giant steering wheel and dash layout makes me wish I could have another one. . . .

(No! Down, sir! Behave yourself!)
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well it has an ECE which I believe is for changing the timing for different available fuels but I will always be putting 93 octane in it.

So... I've got an 85 500SEL grey mkt car in the back field.

Does it have these elusive headers as well?

Jim

the best way to tell would be to look, if the headers are one piece "logs" then they aren't if the middle two and outer two cylinders on each bank have their own header and down pipe then you have tri ys, look in the second pic John posted