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Can Our Cars Handle Mt Washington?

Chadgervais

Chadgervais

Former GP Owner
I'm wondering specifically about the cooling system and the brakes. I know that Grand Prix's love to run a tad on the warm side. For example, when I climb Mt Cadillac in Maine with an 80-85 degree outside temperature, my engine gets up to about 220*, and even when the fan kicks in it stays between 205 and 210. The Cadillac auto road is about half the length of the Washington road and not quite as steep. This is something I want to do this summer, but with 230k already on the odometer, I dont want to overheat her and drive another nail in the coffin. Not that mileage really matters to our engines, but I want to avoid unnecessary abuse.

I also wonder about the brakes. I just had a brake job done in February, new pads and rotors on the front, pads on the back. I was told the brake lines were sound, no leaks, but I did not ask about brake fluid. Is it standard for a shop to change the brake fluid when a brake job is done? I know that heavy braking is bad, especially with old brake fluid which has a lower boiling point than new.

Thanks in advance for your advice, my goal is to put 300k on this car before I even consider trading in.
 


for the going up the hills drop it into 3 rd gear, forget even trying to keep in O/D.

for going down steep inclines, what truckers do is get to the speed limit, then hit the brakes till you've slowed 10 mph, then back off the brakes, let it coast back at its own speed back to the speed limit, repeat as needed. dont ride the brakes all the way down the hill, your brakes will melt. the using and then not using the brakes lets then cool off, if they never cool they glaze up, and dont work. then you need new brakes.

leave the trans in 3 rd gear too so theres some drag off the engine. dropping to 2 nd is not a good idea, the trans wasn't built to slow you down.
 
Scottydoggs said:
for the going up the hills drop it into 3 rd gear, forget even trying to keep in O/D.

dropping to 2 nd is not a good idea, the trans wasn't built to slow you down.
Click to expand...

Pardon my ignorance, how exactly does O/D work? Does it lock the trans in a certain gear? I've done Cadillac a bunch of times in D with no problem.

Also, I thought conventional wisdom was to put it in 1st on steep downhills, is it really bad for the transmission?
 
Overdrive is just 4th gear. And no, brake fluid is never changed on a brake job unless you ask to have it done
 
like i said, not built for that. its not a 4 speed manual trans. think of it this way, thetrans its build is to drive the wheels forward, not the reverse. 1 st gear would have to red lined at 35 mph too. you dont want that.

going up hill od is what some call 4 th gear, once your going up hill if its steep enough it will drop out of 4 th and into 3 rd on its own, its better for the trans to not be hunting back and fourth for 4 th gear.

and the engine should run cooler in 3 rd going up hill with the added rpm's. under load holding 4 th i could run warmer.

crazy as it sounds, my instant mpg goes up when im going up a step hill and do it locked in 3 rd gear. the engine is simply stronger at that rmp and uses less gas. it also seems like it take less throttle in 3 rd vs od and then being light enough on the gas to keep it from dropping into 3 rd.
 
Thanks Scotty, I think Ill apply that to my every day driving. Every Sunday I pass through a hilly rural area where the speed limit is between 35 and 55. On the hills, it does seem like it doesn't know which gear to use, tomorrow Ill leave it in 3 and see what happens. The manual says that using 3 lowers fuel economy, ill have to test that out.

3 is OK as long as I stay under 60 isnt it?

As for running cooler in 3rd with higher RPM, last summer in 90+ heat, i inadvertently put it in 3rd then got on the highway and set the cruise at 70. I noticed it was revving to about 2800 instead of 2000, and was running at 210-215F. Once I realized and put it back into D, the revs fell back to 2000 and the temp dropped to 205.
 


you can go 100 in 3 rd gear lol and if your flooring it to 100 its in 3 rd, and you'll never see 4 th kick in when its floored.

over drive is what it is, its just a helper gear for mpg. its not a real gear like 1,2, or 3.

and at the slightly higher rpm the engine runs more freely as it not under as much load. most engines dont hit the start of the rpm power range till 2500 rpm, thats where it will start to pull its best and use the least amount of fuel/throttle. going up hill that is lol

on flat ground or hills that OD holds ok, leave it in OD. you'll get the best mpg that way for sure.
 
My GP's RPM's are at 1,500 at 45 mph because that's where the TQ converter locks. That's very low to have the rpm's in city traffic imo.
 
Yeah and it's kind annoying too. I'll be going at 43 mph or so and I'll slowly make it to 45, then it locks, causing the car to start gaining quite a bit more speed, and I have to let off of the throttle quite a bit. Basically I'm hardly even touching the pedal at 45 mph.
 


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