Other than the lack of power, what are the biggest problems with the 307 used from 86-90? I hear they are a very reliable motor, and are pretty easy to work on, and parts are cheap.
Biggest Problems with 307?
1 - 11 of 11 Posts
Very prone to knock. EGR passages get plugged up with carbon.
Thats a simple fix though right?
Yup, I consider it fairly easy. Best way, remove carb, run a drill bit down each of the EGR tube extentions, OR, as I did for a longer term fix, removed them, installed brass plugs, and drilled them with 3/8" holes.
In a bad case, you will need to remove EGR valve and run a piano wire thru each tube and ensure they are cleared.
Mine was able to go back to 87 octane on 12 degrees timing with no pinging.
The 307 isn't a powerhouse, but the Olds V8 design is one of the best in the industry. Simple mods will make it pull more power. The 307 HO was a 180HP engine. Nearly matching the 403 (185hp). Airflow is everything. Drop in some 3.73's or 4.10's, HO 407 cam, revise the ECM programming, headers and duals and you have a great running car. Just pattern what the 302 Mustang boys do...
Oh, I forgot, that Mark IV I found is light blue, not tan, the night lights make it look tan.
In a bad case, you will need to remove EGR valve and run a piano wire thru each tube and ensure they are cleared.
Mine was able to go back to 87 octane on 12 degrees timing with no pinging.
The 307 isn't a powerhouse, but the Olds V8 design is one of the best in the industry. Simple mods will make it pull more power. The 307 HO was a 180HP engine. Nearly matching the 403 (185hp). Airflow is everything. Drop in some 3.73's or 4.10's, HO 407 cam, revise the ECM programming, headers and duals and you have a great running car. Just pattern what the 302 Mustang boys do...
Oh, I forgot, that Mark IV I found is light blue, not tan, the night lights make it look tan.
ah cool! So there ARE some mods for the 307!
From a reliability standpoint, the 307 is sounding superior to my 4.9. My 4.9 has the main bearing thump, it leaks coolant bigtime (it just pisses out a lot of coolant, occasionally) those are my 2 big problems with the 4.9.
Other than that, it's been a good motor. But a main bearing thump and a coolant leak in the block are not things that are easily fixable. To fix the bearing, you would have to pull the oil pan, and pull the crankshaft out, and no one I asked wants to do that. ( I asked the service advisors at my work, if it would be possible, and they said that it would be so much work, and cost so much money that it wouldnt be worth it
I asked my uncle, who was a mechanic at a Chevrolet dealership for 10 years if he wanted to do it, and he won't do it either because it's very easy to botch the job, and the main bearing thump isn't hurting anything anyways, so it's kind of pointless to fix it)
And the tiny little hole in my engine block where the coolant is coming from is impossible to permanently fix, When I bought the car, one of the first things I did was put in those GM "stop leak tablets" into the radiator, and then last time it pissed out coolant back in May, we threw in a bottle of "Alumaseal" into the radiator and that worked for the most part. It would leak out a little bit here and there, but thats expected of any 13 year old car. But now that it's pissing out a 8"x8" puddle again, what can I do? If i put another bottle of alumaseal, I run the risk of plugging up my heater core and doing real damage. I can't weld another piece of aluminum over the hole because you can't weld aluminum.
I dont know what to do! Help please!
The EGR problem on the 307, looks easy enough to fix, and it doesnt seem as though it's a real big deal. But like I said earlier, the 307 stock, is lethargic, and my budget (college) doesnt allow for much in the way of performance parts, and i'm not sure how well it would want to start, due to the quirky computer controlled carb, when it gets to be -20 out in January.
And I know my parents would not let me have a car with no ABS, which wasn't standard on the Broughams until 1990. Was it an option earlier? I'm not sure if my folks would let me have a car without air bags :/
If somehow, I find myself in the position where I need a new car, and if my parents say "yes" to the Brougham, should I stick with the cheap, reliable 307, or go for the more expensive TBI 305/350? I know the 350 is the best of the three, but it commands the highest prices, and I most likely wont have more than $3500 to purchase with. So that throws that out of the idea. I've heard the 305's love to burn oil, but other than that, they seem to be pretty reliable. They're inbetween the 307 and 350 for performance, with 170hp, its 30 more than the 307, and 15 less than the 350, but the torque on the 305 is a measly 255 lb/ft, which by no means is enough to propel 4276 lbs of Cadillac down the road.
I've driven a 305 TBI '89 Firebird once, and it's acceleration was about the same as my devilles. But, IIRC, the 305 had no low end torque, but it had good upper end power. (the 4.9 is opposite) If I remember correctly, a Firebird with the TBI 305 will run about a 16.2 in the 1/4 mile, now throw on another 900lbs and you can imagine, that 305 Brougham would probably run high 17's- low 18's. A '91 350 Brougham runs a 17.1 stock.
Otherwise, if they say no to the Brougham idea, my second choice is a 91-94 Town Car, there are a lot of em around for good money, they're reliable, and for the most part, built like a Brougham, the SOHC 4.6 makes decent power, and is one of the best modern Ford V8's. If they say no to that, then I'll go get a 91-96 Park Ave. Excellent 3800 V6, good performance, good luxury.
From a reliability standpoint, the 307 is sounding superior to my 4.9. My 4.9 has the main bearing thump, it leaks coolant bigtime (it just pisses out a lot of coolant, occasionally) those are my 2 big problems with the 4.9.
Other than that, it's been a good motor. But a main bearing thump and a coolant leak in the block are not things that are easily fixable. To fix the bearing, you would have to pull the oil pan, and pull the crankshaft out, and no one I asked wants to do that. ( I asked the service advisors at my work, if it would be possible, and they said that it would be so much work, and cost so much money that it wouldnt be worth it
I asked my uncle, who was a mechanic at a Chevrolet dealership for 10 years if he wanted to do it, and he won't do it either because it's very easy to botch the job, and the main bearing thump isn't hurting anything anyways, so it's kind of pointless to fix it)
And the tiny little hole in my engine block where the coolant is coming from is impossible to permanently fix, When I bought the car, one of the first things I did was put in those GM "stop leak tablets" into the radiator, and then last time it pissed out coolant back in May, we threw in a bottle of "Alumaseal" into the radiator and that worked for the most part. It would leak out a little bit here and there, but thats expected of any 13 year old car. But now that it's pissing out a 8"x8" puddle again, what can I do? If i put another bottle of alumaseal, I run the risk of plugging up my heater core and doing real damage. I can't weld another piece of aluminum over the hole because you can't weld aluminum.
I dont know what to do! Help please!
The EGR problem on the 307, looks easy enough to fix, and it doesnt seem as though it's a real big deal. But like I said earlier, the 307 stock, is lethargic, and my budget (college) doesnt allow for much in the way of performance parts, and i'm not sure how well it would want to start, due to the quirky computer controlled carb, when it gets to be -20 out in January.
And I know my parents would not let me have a car with no ABS, which wasn't standard on the Broughams until 1990. Was it an option earlier? I'm not sure if my folks would let me have a car without air bags :/
If somehow, I find myself in the position where I need a new car, and if my parents say "yes" to the Brougham, should I stick with the cheap, reliable 307, or go for the more expensive TBI 305/350? I know the 350 is the best of the three, but it commands the highest prices, and I most likely wont have more than $3500 to purchase with. So that throws that out of the idea. I've heard the 305's love to burn oil, but other than that, they seem to be pretty reliable. They're inbetween the 307 and 350 for performance, with 170hp, its 30 more than the 307, and 15 less than the 350, but the torque on the 305 is a measly 255 lb/ft, which by no means is enough to propel 4276 lbs of Cadillac down the road.
I've driven a 305 TBI '89 Firebird once, and it's acceleration was about the same as my devilles. But, IIRC, the 305 had no low end torque, but it had good upper end power. (the 4.9 is opposite) If I remember correctly, a Firebird with the TBI 305 will run about a 16.2 in the 1/4 mile, now throw on another 900lbs and you can imagine, that 305 Brougham would probably run high 17's- low 18's. A '91 350 Brougham runs a 17.1 stock.
Otherwise, if they say no to the Brougham idea, my second choice is a 91-94 Town Car, there are a lot of em around for good money, they're reliable, and for the most part, built like a Brougham, the SOHC 4.6 makes decent power, and is one of the best modern Ford V8's. If they say no to that, then I'll go get a 91-96 Park Ave. Excellent 3800 V6, good performance, good luxury.
yeah, but really, the 307 is still sipping thru a straw... you can do anything to the intake, cam or exhaust, but unless there is head work done, it wont be effective.... on top of that it isn't that easy to do *enough* head work, and by the time it is said an done an Olds 403 can go right in and youve gat far more power now.N0DIH said:
my mothers Brougham knocked real bad, but the carb was realy messed up... bought a new carb and put it on...
no more knocking, it runs on regular... it actually feels kinda peppy, I was shocked for 170k or whatever it has (speedo broke) it wasn't a slow moving dog turd that it once was...
other problems - frigged up computer controlled carb.... stupid bridge system to have an ECM and a check engine light... but still a carb... yeah, its got an O2 sensor... gosh these things suck.
leaky valve covers, yup.
Olds 307 seems to like to go thru radiators and/or water pumps
gosh, one other thing, I don't remember.
oh yeah, the 200R4 miracle WILL fail between 120k-180k. Putting an aux trans cooler on it ASAP will help, but it WILL happen.
Becuase the way the thing is jambed in there, it is NOT easy to work on, atleast compared to my 425.... example.... check out those valve covers... to swap them you have a nice weekend project
cold starting the 307 is like any carb engine, pump the gas a couple times, turn it over a few seconds, stop, pump gas twice more, and it should fire up.... starting it is only a pain if you are an anemic 90 y/o lady that freaks out if she has to turn the key twice, there is no big deal.
the "problem" comes from, when a carbed engine is cold, it'll laugh at you if you try to move... and by laugh I mean stall. Simple fix, its winter out (haha suckers.... no more of that stuff ) go to the car start it, put the defroster on high, then simply take your little ice scraper thing and go clear off all the windows and lights... by the time you are done, the engine is warmed up and it started to warm up the interior of the car.... its really not a big deal, hell I drove the '79 DeVille in the snow, that was more picky to very cold winter mornings, having a carburator that needed a rebuild and had a dead spot off idle when cold didn't help.... it would nearly stall whenever I would accelerate.... but there was ways around that... see fuel injection takes the brains out of driving a car, start it up and hit the gas... the carb, you gotta learn to work with a few things, but when you do its just so much more rewarding.
I personally really like the 80's Broughams.... back when I was younger, everything to me was 1/4 mile times, if the 1/4 mile time sucked I didn't look at the car... well thats a real frigged up way of looking at things for many reasons. The 307 Brougham is slow, deal with it, there are alot of slow cars on the road. As much as I like to poke fun at the 307 today, nearly 20 years ago it did exactly what it was made to do, and did it fairly well.
If you want to go fast, simply do not get ANY big body Cadillac as a daily driver... the 307 Brougham is somewhat decent on gas, 16mpg town and 24mpg highway with a well tuned/running 307. while all this talk about building up 350's, 425's and 500's in these things are fun, it is simply not practical, the Cad are gas hogs and you'll be winding the little Chevy out to do what the BB Cads are doing... and either way you'll be burning thru gas.
*IF* you are really interested in the Brougham, then its a great choice... but the car is slow, weather that is a make it or break it issue is up to you, it is also VERY hard to get more power from, and the only effective way is to do an engine swap. For me personally, I don't have a problem with the 307 one bit, just avoid the passing lane on hills and don't think you can race everyone, its quite, smooth, reliable and economical. I think something like a 1989 Brougham is a well rounded car that I woudln't be ashmaed of owning, or riving. The reason why I got the '93 Coupe instead of an '89 Brougham as a first car (which I was set on) was because my mother had one and her finacee had an '87.... what 16 y/o wants the same car as their parents? I wanted something new to me, new dash, new engine all that good stuff.
I will however say that the '89 Brougham is much more "my type" of car then the '93 DeVille though, and i used to second guess that decsison often... it seemed to stop once i got the '79 DeVille has it kinda filled in that void.
Just think about the 307 Brougham as an economical and easy way to drive the '79 around... all the time, pretty much the same car, except I think the '89 Brougham looks alot better overall then the '79 DeVille.... again, thats where the well rounded part comes in.
It isn't like its a V6 Mustang with Cobra body kit, where people expect it to be fast, its a 20 year old, old mans Cadillac..... and as much as I like driving the Caddy's fast, truth is, to other people, when you are spinning tires, turning sharp or whatever, it gets rid of the classy image... seeing a mint '89 Brougham slowly roll thru the parking is something else to be seen though, and at that time it dosn't matter if you have 140 hp or 350hp.... neither does it matter when the cruise is locked on at 75mph on the highway and you are just crusing along.
no more knocking, it runs on regular... it actually feels kinda peppy, I was shocked for 170k or whatever it has (speedo broke) it wasn't a slow moving dog turd that it once was...
other problems - frigged up computer controlled carb.... stupid bridge system to have an ECM and a check engine light... but still a carb... yeah, its got an O2 sensor... gosh these things suck.
leaky valve covers, yup.
Olds 307 seems to like to go thru radiators and/or water pumps
gosh, one other thing, I don't remember.
oh yeah, the 200R4 miracle WILL fail between 120k-180k. Putting an aux trans cooler on it ASAP will help, but it WILL happen.
Becuase the way the thing is jambed in there, it is NOT easy to work on, atleast compared to my 425.... example.... check out those valve covers... to swap them you have a nice weekend project
cold starting the 307 is like any carb engine, pump the gas a couple times, turn it over a few seconds, stop, pump gas twice more, and it should fire up.... starting it is only a pain if you are an anemic 90 y/o lady that freaks out if she has to turn the key twice, there is no big deal.
the "problem" comes from, when a carbed engine is cold, it'll laugh at you if you try to move... and by laugh I mean stall. Simple fix, its winter out (haha suckers.... no more of that stuff
) go to the car start it, put the defroster on high, then simply take your little ice scraper thing and go clear off all the windows and lights... by the time you are done, the engine is warmed up and it started to warm up the interior of the car.... its really not a big deal, hell I drove the '79 DeVille in the snow, that was more picky to very cold winter mornings, having a carburator that needed a rebuild and had a dead spot off idle when cold didn't help.... it would nearly stall whenever I would accelerate.... but there was ways around that... see fuel injection takes the brains out of driving a car, start it up and hit the gas... the carb, you gotta learn to work with a few things, but when you do its just so much more rewarding. I personally really like the 80's Broughams.... back when I was younger, everything to me was 1/4 mile times, if the 1/4 mile time sucked I didn't look at the car... well thats a real frigged up way of looking at things for many reasons. The 307 Brougham is slow, deal with it, there are alot of slow cars on the road. As much as I like to poke fun at the 307 today, nearly 20 years ago it did exactly what it was made to do, and did it fairly well.
If you want to go fast, simply do not get ANY big body Cadillac as a daily driver... the 307 Brougham is somewhat decent on gas, 16mpg town and 24mpg highway with a well tuned/running 307. while all this talk about building up 350's, 425's and 500's in these things are fun, it is simply not practical, the Cad are gas hogs and you'll be winding the little Chevy out to do what the BB Cads are doing... and either way you'll be burning thru gas.
*IF* you are really interested in the Brougham, then its a great choice... but the car is slow, weather that is a make it or break it issue is up to you, it is also VERY hard to get more power from, and the only effective way is to do an engine swap. For me personally, I don't have a problem with the 307 one bit, just avoid the passing lane on hills and don't think you can race everyone, its quite, smooth, reliable and economical. I think something like a 1989 Brougham is a well rounded car that I woudln't be ashmaed of owning, or riving. The reason why I got the '93 Coupe instead of an '89 Brougham as a first car (which I was set on) was because my mother had one and her finacee had an '87.... what 16 y/o wants the same car as their parents? I wanted something new to me, new dash, new engine all that good stuff.
I will however say that the '89 Brougham is much more "my type" of car then the '93 DeVille though, and i used to second guess that decsison often... it seemed to stop once i got the '79 DeVille has it kinda filled in that void.
Just think about the 307 Brougham as an economical and easy way to drive the '79 around... all the time, pretty much the same car, except I think the '89 Brougham looks alot better overall then the '79 DeVille.... again, thats where the well rounded part comes in.
It isn't like its a V6 Mustang with Cobra body kit, where people expect it to be fast, its a 20 year old, old mans Cadillac..... and as much as I like driving the Caddy's fast, truth is, to other people, when you are spinning tires, turning sharp or whatever, it gets rid of the classy image... seeing a mint '89 Brougham slowly roll thru the parking is something else to be seen though, and at that time it dosn't matter if you have 140 hp or 350hp.... neither does it matter when the cruise is locked on at 75mph on the highway and you are just crusing along.
Well thank you Rick, for that long, detailed explanation of the pros and cons in the 307 Broughams Thats exactly what I wanted to see :thumbsup:
The nice thing about the 307, is that it's so slow, where I would probably never do any "street races" because I would always lose. And with 140hp pushing 4200lbs of Cadillac, it would be much harder to get a speeding ticket, because it takes so much longer to get above the speed limits. But sometimes, when merging onto a freeway, or getting onto a busy main street around rush hour, the lack of power in the 307 can be scary. For example, When I test drove a '90 Brougham D'elegance with the 307 back in October, I got onto highway 55 via a street that crossed the highway, not your typical onramp situation. I waited for the biggest gap I could find then I nailed it, and by the time I was at 60mph (13 seconds later) The semi and van that were about 1/4 mile behind me, on the highway we're about 300 feet behind me, and gaining fast. I felt a little scared when I saw them that close. Apparently, the car had a sticking choke, so that may have hurt performance a little bit, and the car died 4x on that same test drive due to the choke.
I've heard passing power is better on the highway, is that true? I wasn't on the highway long enough to notice. 307 aside, I love the 90-92 Broughams, they are probably the classiest looking cars ever built, the squared off, formal lines give this car a level of distinction that only a Rolls Royce can come near to. These are cars with an excess of dignity and class, and you have to drive them like that to really appreciate it. In my opinion, they're the best looking Cadillacs ever. I like the digital dash too, its a nice change from the horizontal 85 mph speedo I'm used to.
With the 307, do you save gas because flooring it around town is pointless? Or do you go through more gas because you have to floor it to keep up with highway traffic? How Good would this car be in the snow? It's heavy which really helps, but was a Limited Slip Differential an option? If I do buy another car, It's very important that it's good in snow because I live in MN where deep snow is a fact of life, and if I want to go visit my friends up in Duluth, where they get much more snow, and it's extremely hilly, I do not want a car that will get stuck easily. When I got new tires on my Roadmaster right before I sold it, It was actually better than my deVille in the snow. But that car had an LSD, so that helped. I assume having a car with 140hp and RWD would be a lot more manageable in the snow than a car with 260hp and RWD. Because having 330 lb/ft of torque made it very easy to spin its tires.
If my parents let me get a new car, The biggest problem I can forsee with a Brougham is that it has no air bags. I dont think my parents would let me have a car w/o a driver's side airbag. But anything newer than 1989 has ABS standard which helps a lot.
When did they get rid of the 200R4? I think '89 was the last year. The thing about the Broughams, is they are much simpler than basically any other Cadillac made in 1990, no trip computers or any of that stuff. Less stuff to break.
Thats exactly what I wanted to see :thumbsup:The nice thing about the 307, is that it's so slow, where I would probably never do any "street races" because I would always lose. And with 140hp pushing 4200lbs of Cadillac, it would be much harder to get a speeding ticket, because it takes so much longer to get above the speed limits. But sometimes, when merging onto a freeway, or getting onto a busy main street around rush hour, the lack of power in the 307 can be scary. For example, When I test drove a '90 Brougham D'elegance with the 307 back in October, I got onto highway 55 via a street that crossed the highway, not your typical onramp situation. I waited for the biggest gap I could find then I nailed it, and by the time I was at 60mph (13 seconds later) The semi and van that were about 1/4 mile behind me, on the highway we're about 300 feet behind me, and gaining fast. I felt a little scared when I saw them that close. Apparently, the car had a sticking choke, so that may have hurt performance a little bit, and the car died 4x on that same test drive due to the choke.
I've heard passing power is better on the highway, is that true? I wasn't on the highway long enough to notice. 307 aside, I love the 90-92 Broughams, they are probably the classiest looking cars ever built, the squared off, formal lines give this car a level of distinction that only a Rolls Royce can come near to. These are cars with an excess of dignity and class, and you have to drive them like that to really appreciate it. In my opinion, they're the best looking Cadillacs ever. I like the digital dash too, its a nice change from the horizontal 85 mph speedo I'm used to.
With the 307, do you save gas because flooring it around town is pointless? Or do you go through more gas because you have to floor it to keep up with highway traffic? How Good would this car be in the snow? It's heavy which really helps, but was a Limited Slip Differential an option? If I do buy another car, It's very important that it's good in snow because I live in MN where deep snow is a fact of life, and if I want to go visit my friends up in Duluth, where they get much more snow, and it's extremely hilly, I do not want a car that will get stuck easily. When I got new tires on my Roadmaster right before I sold it, It was actually better than my deVille in the snow. But that car had an LSD, so that helped. I assume having a car with 140hp and RWD would be a lot more manageable in the snow than a car with 260hp and RWD. Because having 330 lb/ft of torque made it very easy to spin its tires.
If my parents let me get a new car, The biggest problem I can forsee with a Brougham is that it has no air bags. I dont think my parents would let me have a car w/o a driver's side airbag. But anything newer than 1989 has ABS standard which helps a lot.
When did they get rid of the 200R4? I think '89 was the last year. The thing about the Broughams, is they are much simpler than basically any other Cadillac made in 1990, no trip computers or any of that stuff. Less stuff to break.
The more I read about knock and pep, the more I think I need a new carb. Where are you guys buying these new feedback Q-Jets at and for how much? I've tuned and tuned my carb to no end, but every now and then the knock comes back and I arbitrarily lose power.
tuning a carb wont do a thing if it needs a rebuild.
I don't remember where we got our carb for my mothers car, I think it was $400 or so, all new, and there was a $50 core or something, but we kept it... by the time we would ship it, it us just good to have a spare carb around.
Lots of companies reman them... honestly, my mothers 307 ran so much better after the new carb, big notice in power, easy to start, now runs on regular etc... I'd say it was worth it.
I don't remember where we got our carb for my mothers car, I think it was $400 or so, all new, and there was a $50 core or something, but we kept it... by the time we would ship it, it us just good to have a spare carb around.
Lots of companies reman them... honestly, my mothers 307 ran so much better after the new carb, big notice in power, easy to start, now runs on regular etc... I'd say it was worth it.
I forgot about the 7A heads/intake. Sorry, ditch them and get some 5A heads from a 84 or older 307. They flow enough for 5000 rpm with a 350, so likely 6000 rpm with a 307.
Ideal, find someold 5a heads (I think), the older 1972 and older higher compression 350 Olds heads. They are getting pretty rare now. You have 64 cc heads now, ideal is around 57 cc. That should get you to 9:1. The 307 needs 9:1. With the ESC on the Cad V8's that would help a lot.
Ideal, find someold 5a heads (I think), the older 1972 and older higher compression 350 Olds heads. They are getting pretty rare now. You have 64 cc heads now, ideal is around 57 cc. That should get you to 9:1. The 307 needs 9:1. With the ESC on the Cad V8's that would help a lot.
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