I found an 87 brougham that i'm looking to buy with the 307 in it. I've looked through this forum and i saw alot of different opinions on it, so i though i'd ask. simply, would you recomend me a car that ways 2 tons with an Old's 307 engine?

i would like it to be powerful, well more powerful that my other caddy with the HT4100 :helpless: . but i'd rather have it be more reliable than powerful. it needs a new radiator, and i hope that's the only thing that needs to be wrenched on.

The 307 runs forever, it's just a dog in the power department.

They tend to leak around the intake manifold, too.... not my favorite motor.

I going to hazard a guess and say "Don't buy...".

Others on this forum may correct me, but I've seen at least one thread where a recurring complaint among many owners of 307 and HT4100's 80's units with the 200R4 is that they give you abysmal mileage at freeway speeds (say ~70) because these combinations are "constantly" downshifting from OD to 3rd on "every little hill".

I can't swear if this is the trans fault or the combo - and indeed if this is easily or completely correctable. The shift is internal to the trans and is controlled by a governor with weights. I've heard it can be fixed, but not on this forum.

they give you abysmal mileage at freeway speeds (say ~70) because these combinations are "constantly" downshifting from OD to 3rd on "every little hill".

that wouldn't be a problem for me, i live in wichita, kansas :) .

come on, no one likes it?

Well, like barge master said, it runs forever. Pretty decent on gas too for powering such a giant vehicle. It's got an edge on 4100s for sure.

They do have their little quirks, like Mastertech pointed out. The intakes start to leak oil out of the ends and do develop coolant leaks at the intake over the years, but that stuff happens in all engines with aluminum and cast parts combined. It's not some kind of unfixable headache.

Had one in a '85 Toronado. Bullit proof. Ran 140k without ever being opened up. Just normal maintenance ( and a water pump at 40K, but that's my own personal curse ). The engine ran like a swiss watch when I took it to the crusher because the body rotted out. If it's been maintained go ahead with it.

I'm sneaking into Olds 5.0 territory here :)

My g/f's dad is a VERY gifted mechanic; he has an '80 Toronado with the Olds 350 (same block as the 307) and then an '84 Delta 88 with the 307. Great motors; I think the '84 has 239,000 on it! Gets GREAT mileage, too.

Yeah, they're going to downshift often, but you can rectify that by just dropping it into 3rd. The problem was the "fuel economy" axle ratio; the ratio was like 2.92, which is ridiculously low for a 140 hp/255 lbft car that has overdrive and weighs over 4000! On the other hand, our '87 Caprice, with the Cheeby 305 with 170 hp never really had problems. That 30 hp wasn't noticeable around town, but on the highway, you bet...

But yeah, I think it would be a great car; just don't expect a performer. Again, g/f's dad runs his 307s in 3rd gear all the time. Those 200R4s can break apart, and as we said, the motor doesn't have much to give!

What ^^ they said. I have the 90, and it works. I pound mine, since I live near Boston, and that's all stop and go, and it gives me no real trouble. can't kill them. go for it. after all, you can get a bigger motor anyways - the Olds 403 will bold right up, and that will give you performance :p

If it's been maintained go ahead with it.
the salesman says everything under the hood works except the radiator, it needs a new one. could this be a symptom of bad maintanence? i'm willing to fix the radiator problem, that's no biggy, but not much more else.

eh, I have read this a few times... so I'll chime in....

the 307 is a bullet proof engine.... it'll run forever.... thru overheats, high stress, long oil change intervals etc.... what it will not do for you in return is give you a sports car.... or anything to beat a 4banger Honda Accord either... but in the full size RWD car, it'll get nice millage (when compared to my 425) about 16/25 or so.....and........ run forever....

... my mothers boyfriend had an '84 Olds Delta 88... it went thru a tranny (I think) and he towed a small utility trialer with it... trailer and weight on it was about 2,000lbs.... he sold the car when it had 226k miles on it.... due to it starting to get excessive cancer rust.... he siad the enigne ran as good as ever when he sold it.

my mothers car has about 160k on it ('89 Brougham) has overheated.......about a dozen times in the last 5 years... and has 2 new radiators.... a carb rebuild, tranny rebuild, and some other stuff... but the engine itself refuses to go down....

her b/f current caris an '87 Brougham... also tows the same trialer with it, uses regular Auto Zone brand oil and changes it every 5k miles or so.... the enigne had 192k on it, when the distrubutor gear on the cam broke.... keep in mind the engine ran great before this happened.... the car is now in the shop awaiting a new long block... tranny was rebuilt 60k or so, body is stright and clean.... so with a new 307, it should bring another 150k in... I told him it is time for a built 455.... but he is too practical :)

307= great engine made form 1980-1990.... but no power.. and no aftermarket... if you can deal with that alone.. then leaky valve covers, bad waterpumps/radiators and sometimes alternators will be your only problem....

I wonder what would happen if a 307 and a 3800 battle it out.... which is the more reliable engine?... both wil run forever.....

well i've had 2 caddies both had the 307

the old one we got rid of when the tranny started going.. at 315 000kms
had it from new...

then at the dealership we saw one just like the 88 but mint... with sunroof etc

anyways we sold the 88 for 500 and bought the 87 for 14,500 with 62 000 orig kms...

the 87 now has like 240 000kms on it still runs like a charm the choke is a little ****ed but i can get it fixed...

it eats oil like u wouldnt believe every 100kms it needs a quart of oil :P

anyways to make a long story short the 307 in wont stop!

i fill my oil up and when my check oil light starts coming on i add 2 or 3 liters
LOL!

i know its bad but i got sick of adding oil all the time but she always starts! and i know shes been down to like 1 liter of oil before too...

in the summer i took a trip and it was a 3 hour drive anyways in that 3 hours i burned 2 liters of oil :P

anyways the point of the story is the 307 is solid!

and i change the oil about twice a year lol i figure since i keep adding fresh oil i dont really need to change it as often :P

So, not downshifting on hills is actually a good thing? I ask because I was concerned about my speed loss on hills and though that perhaps the trans should downshift to make up for the loss of speed. I usually drive about 80mph and on hills drop to about 75mph.

What do you think about the 89 with the 240b?

Yeah, they're going to downshift often, but you can rectify that by just dropping it into 3rd.

Forgive my ignorance, I am clueless when it comes to cars. Is it OK to shift into 3rd gear going highway speed?

I just wanted to add that the 307 rocks...and wasn't there another thread like this?! :P

You shouldn't need to manually switch into 3rd from OverDrive the transmission will do it automatically when you floor it. Of course OD is meant to give you more fuel economy at highway speeds. Unless you want to stay in 3rd the whole time...you'll be able to pass everything but a gas station...eh eh eh

Reliability-
I've got an 89 307. Make sure it's the Y code, because that extra 20hp makes all the difference. And while what they say about oil leaks is true, I just got the coolant leak at the manifold at 150,000 and stop leak seems to take care of that. I had a friend with an 87 with the 307, between him and his mom, put 100,000 miles on her, never changed the oil once and the car still runs fine (although it's been retired from active duty at this point and is awaiting a buyer).

Slander-
And shame on anyone who compares a 307 to an HT4100, because the 307 does not utilize a different metal for the headers than it does for the rest of the engine, anyone who says it does does not know what they are talking about. There's a reason why most of the caddy's you find are 307s and there's also a reason why it's hard to find a 4100.

Gas Mileage-
I get 19 mpg highway 15 mpg around town, and I've recently decided that she needs distributor work, so that's not so bad. She also likes premium.

Downshifting-
RWD pre-93 cadillacs are slow. Deal with it. I met a girl that had an RWD, although I'm not sure of the engine, she was driving through the mountains, (she was moving and the car was loaded) and was trying to drive too fast. The check engine light came on but before she could pull over the engine seized up and the car ground to a stop. RIP caddy. Another freind of mine was driving someone else's RWD caddy, on a beer run no less, and apparently dogged it a little bit too much. The car made it home fine but once he turned the engine off, it never started again because the cylinders were fused in place. If the quickie mart was a little bit further away he probably would have had the same experience as the girl. Read some threads about the oiling system on our cars, and it's apparent why this happens. If you keep the rpms too high for too long say goodbye to your caddy. And since RWDs don't have a tachometer, I'd say to be on the safe side you should just slow down and not let drunk idiots drive your car. Why do you need to get somewhere fast anyway, inside a cadillac is my favorite place to be.

correction to the above: you want the "9" code, not the "Y" code. You have the y code. it's 140 hp. the 9 is 180 :-) (why yes, I am an Olds head :D )

Downshifting-
RWD pre-93 cadillacs are slow. Deal with it. I met a girl that had an RWD, although I'm not sure of the engine, she was driving through the mountains, (she was moving and the car was loaded) and was trying to drive too fast. The check engine light came on but before she could pull over the engine seized up and the car ground to a stop. RIP caddy. Another freind of mine was driving someone else's RWD caddy, on a beer run no less, and apparently dogged it a little bit too much. The car made it home fine but once he turned the engine off, it never started again because the cylinders were fused in place. If the quickie mart was a little bit further away he probably would have had the same experience as the girl. Read some threads about the oiling system on our cars, and it's apparent why this happens. If you keep the rpms too high for too long say goodbye to your caddy. And since RWDs don't have a tachometer, I'd say to be on the safe side you should just slow down and not let drunk idiots drive your car. Why do you need to get somewhere fast anyway, inside a cadillac is my favorite place to be.[/QUOTE]



Question:

I have an '87 Brougham with the 307. I'm not normally a fast driver, but is there a speed that, used on a normal highway as opposed to climbing Mt. Washington, would be too fast for the 307. Like, should one avoid going 75?

Forgive my ignorance, I am clueless when it comes to cars. Is it OK to shift into 3rd gear going highway speed?

Absolutely fine, you can drive forever in 3rd if you want.

Consider most old cars had 3.08's or lower (numerically higher) gears and had no OD. You have OD and 2.56's. So no problems.

The best thing to do to a 307 Olds powered ride is to swap in 3.73 gears. It will be much better on power.

There is some things to do to a 307 to make more power, but most require pulling heads and cam.

Get a set of 1981-1984 5A heads, intake and a 1985 442 Cam. Tune the carb to perfect factory specs and you will pickup 40-50 hp easy.

The 307 isn't doomed to poor running, just most won't do much about it. The cam in a 307 Olds (eng code Y) is only around 374 lift. And duration is MILD at best. So it gets some off the line power, but by the time you are on the highway you are above torque peak (note torque peak is measured at WOT, you don't cruise at WOT). In my best theories the part throttle torque peak is around 500-700 rpm lower than WOT torque peak. So at cruise, you are doggy. But in 3rd gear you are adding the torque multiplication of the better gearing hence the better throttle response.

The heads are a restriction for higher rpm operation, the cam is way out of powerband above 3500 rpm. This cam is just as mild as a 76 Pontiac 455 which made 200 hp at 3500 rpm max. Similar cam specs in a smaller engine move the peak power up some, around where the 307 peaks and then starts to wimp out quickly.

The GM timing curves aren't helping much either. I knew a guy who did have some new ROM's he did for his 442 that helped a lot. But he was working 6-7 days a week and never was able to do much else to work on any more.

My thoughts would be (if $$ isn't an issue to you)

1. Do the steps above.
2. Get a 747 ECM (the one that ends in P/N 747 from a Chevy truck, late 80's early 90's) and the full TBI system from it.
3. Get active on the DIY-EFI site and get a custom prom for your ride
4. Get 3.42's or 3.73's for the rear end. Note the HT4100 cars all had 3.42's and optional 3.73's for high alt and towing, just on a 7.5" rear, which you can't break anyway without serious abuse. The towing package gears were around 3.23's I think. The Cutlass was rated to tow 4000#'s with 2.56's and no OD. So don't knock the 307 too hard.

This will get you well on the way to a bulletproof 307 which some decent power. #1 is first choice. The heads and cam will give you a great improvement in power and retain full emissions. Do not knock the Q-Jet. It flows 800 CFM if the secondaries are opened up to open fully. They are very slow openers, so that can be tweaked too. A properly setup Q-Jet will still rival any TBI fuel injection. The reason for #2 is timing tunability, not for EFI improvements. Although there will be some.