Just got myself into a 85 Delta 88 and dont know much about the orig 307 engine

please talk about your exp and any issues with a 307

my current engine has only 56k orig

 

other than the timing chain it should be a good engine. you may have more problems with what is hooked to the engine than the engine itself. my dad runs the 88s and 98s from the 1980s. i hasn't had any trouble other than vacuum line and emissions trouble. when he starts having trouble he just bolts on a carburetor and distributor from his old 77 cutlass and the troubles goes away. most of the time he gets better gas mileage with the older carb and distributor.

 

Try a 180 thermostat, and let us know the difference!
Changes all kinds of things!

 

I believe 85's were the roller cam and lifter engine. 307 aint a bad engine, its just small. Trouble is the trans they are hooked to. The lockup converter solenoid usually gives trouble. Stays engaged and when accelerating from a stop its like trying to start out in 4th gear. Really a problem as far as driveability goes but an easy fix.

 

Welcome!
The 307 is an underpowered ultra-choked motor, but it is reliable - mechanically.
Torque is good and makes a great highway cruising motor.
Emission crap is the stuff that goes bad routinely - EGR clogging, TPS sensor in the carb failing...
Valve cover and intake manifold gaskets usually fail after 10 years.
Expect about 16-20 city - HW mpg with it with OD.

Here are some common 307 info...
http://tlentz.oldsgmail.com/more_power.html
And a little more spread herein...
http://tlentz.oldsgmail.com/howto.html

 

Thanks for the help and information guys!!!

I already knew the 307 was a slugbucket of a engine power-wise but this is going to be my daily driver so I just wanted to get some information on the reliability factor and how long these engines can really last.

16-20 MPG city is better then what I thought, I was sure I was going to avg 15 city MPG

K&N filter has been installed and next coolant flush I will try the 180 thermo it just makes sense.

 

16 city, 20 HWay is what I tried to say above.
Not too bad if you do not go far.
As for ride comfort, you willl not get much better than that Delta!
It will make a new Caddy ride seem like that of a stagecoach...

 

Mine was retired from service at about 189K. 150,000 of those miles were mine.

I will list all problems that I recall.

-Exhaust heat tube on the passenger side (the one with the huge fitting) The rubber hose separated from the steel hose. I spliced it with some heater hose that I would change every so often.
The extension tube down into the side of the catalytic converter also rotted off.

-The oil pan always leaked a little bit from the front pan seal. Even when I got it with 36k on it. Was'nt worth the effort to fix it on the 307 until something else went bad, and it didn't make a huge mess.

-Water pump went at 90k. (replaced the timing chain , fuel pump, and front pan seal then as well.)

-120k-150k Is when things started to get hairy.....
The intake manifold front rubber seal started looking like waffle batter coming down the side of the iron. So I replaced the intake gaskets, and replaced every single piece of emission hose on it with new. Took all day.

-Oil pressure sending unit started puking oil out of it.

-ignition module burnt out.

- Switch for the brights in the column broke.

- Mixture control solenoid in the carburetor just stopped clicking one day. The solenoid was like 80 bucks, so Instead I just grabbed 2 carbs from the junkyard for the same price, and used the one that ran better.

-Needed a radiator
-Broke a motor mount and the trans mount.
-Broke a tie rod end

-Power steering pump sheared the stud bolt off in the front of the block, and I had to reshim everything.

-Rear bumper rotted off from electrolysis.

-To top it all off, The rear end pinion gear started clunking about 10 miles from my house, and by the time I drove it home clunking like that and took a look in the differential, about 6 pinion teeth were sitting the bottom of the oil.

Of course, I'm nuts. I went to the junkyard, pulled another carrier and gearset, and put humpty back together again. It was my daily driver, I had to.

All was well until 180k and the 200C metric trans lost its reverse gear. It would only reverse if you revved the engine to about 5000rpms. Not enough pressure anymore I guessed.
I drove it around like that with no reverse gear for around 10k miles before I got sick of it.

I gutted the whole drivetrain from it and scrapped that junk.
It all still (kind of) worked. Motor was blowing oil out the tailpipes, trans had no reverse, and the rear axle end bearing had started chewing into the axle.

I pulled the plug.

 

WHAT HAVE I DONE!!!!!

 

I had two 307's back to back. One was in an 85 LeSabre and the other was in an 88 Cutlass. Both had the intake gasket go out and leaked coolant.

I was going to write about some more stuff that went wrong (what went right would be a shorter story) with the Gutlass, but it put me in such a rage, remembering it, I have chosen to walk away from my computer....

 

250k easy miles on my 307. Replaced the ORIGINAL timing gearset at 190k for piece of mind. Other than that, never been opened up. I use about 1/2 quart of oil every 3,000 miles, and change it regularly. Don't see any reason I can't go another 250k. That is if gas isn't $10 a gallon.

 

The 307 is a runner, but not a power house.

Keep it oiled, and it will stay happy for a long time. The only bad thing about them is they are the 2nd most common failuers when it comes to emission testing. One of the SBC's is the first (305?)

 

Great Bend KS??? ehh nice im orig born and raised in Wichita KS, btw I looked at your photo page of your 85 toronado AMAZING looking car you should be proud of the restoration and what it looks like today.......When you get a change stop in the newbie forum and check my delta out.

Overall from the forum and other people ive heard the 307 is a good reliable engine but or course there are always those "expierences" you get when you want to rip your hair out due to auto problems.

 

Luckily your Delta is past the emission requirements here in TX. As long as the emission parts are there and the check engine light is off, and the safety stuff is working, you should pass with flying colors!
With as few miles as you have, that engine of yours should be just about broke in...

 

I got a problem with my power Windows when I let it down it moves fine for an inch or so then it stop and its a grinding noise what can it be I the belt looks fine no damage I can see. Does any one know what this problem is. Idea apreciate the input... The cars a 85 delta 88 royale brougham

 

Probably the window motor. Not expensive, just got to find one.

Start a new thread for questions, thy'll be easier to spot and you'll get your question answered quicker

 

Ok thanks that's what I figured now should I get the whole assembly or what cause the stock One is riveted together

 

I have had 3 5A early 307's, all good motors, decent power and reliable. I have only drove the later ones a bit. Everone who owns the later swirl port 307's complains of no power. I got 450,000 km out of one, timing chain skipped. Still didn't use oil, one quart every 8k and had decent power.

 

Wanted to revive this thread any other insight from 307 owners out there?

Mine now has 77k and running well, have went through alot of maintence stuff with this engine to make sure its running tip top which imo has been worth it.

 

I can chime in here too on my experiences. I am on my 2nd 307 right now. My 1st was an 85 that I got with 25k on it. I sold it with 204k miles on it, still running like a top. I had to do the intake @80k, the timing chain @170k(for maintenance reasons). Maybe burning about 1/2 quart every 3k miles.

I bought another car with a 307 last year. It had @158k on it. The intake is leaking and the timing chain is loose, actually planning on doing both tomorrow. Otherwise, it is running very well.

These engines are underpowered, but they are very reliable and get good gas mileage.

 

I've had three 307s, an 84 flat tappet motor and two roller cam motors. The butt dyno says the flat tappet motor has more power, but that may be a rear axle difference (or wishful thinking on my part). Never had an intake gasket problem. One threw a timing chain at 112K miles (I thought it was 212K and assumed that the chain had been replaced once). Other than that, no problems with the motor. The CCC system, on the other hand, MUST be adjusted exactly as described in the CSM. If you do, it runs great.

 

I've got the vin "9" 307 in my 83 Hurst/Olds and that motor has never given me a single issue. Aside from thermostats, plugs, caps, rotors, belts, fluids, etc no issues. I got the car when I was 16 and beat the hell out of it being a dumb kid. Put it in storage for 8 years and when I pulled it out I put a new battery on it and it started right up. Everything attached to it wants to break on you but the motor itself is solid.

 

The 307 in a Cutlass I used to own is still producing not much power and ample torque after 200+k miles on its original timing gear, water pump and distributor and carburettor.
The radiator has been recored, it uses no water or oil and still runs like a champ.

Roger.

 

Another thing that's important on the 307 cars is to replace the O2 sensor periodically with an AC-Delco unit. I think the part # is AS-21. Avoid other brands. I just replaced mine, along with the plugs (went to NGK), and the rotor. It ran great before, now it's perfect!

 

Very good information I changed the original 02 sensor at 75k in my car 2 weeks ago along with installing new brake pads. Man big difference the car seems to drive smoother and idle better ever sense, I also used a AC Delco AFS- 21.

Hey what NGK plugs are you running Henry? I did new AC delco plugs but heard of guys feeling a performance difference with NGK plugs.

 

Hey Devil. Sorry, I just saw this!

I cross refd the ac delco part number to NGK. I think these are it:

NGK Part # 4536 {#5981, XR40, XR45}

No definite performance increase, but certainly a smoother idle. The motor "feels" stronger. Don't bother with platinum/irdium/unobtainium plugs; they are a waste of money and are simply not designed for older, carbureted engines. Copper is all you need and they are comparably-priced to standard delco plugs. The NGK plugs seemed to eliminate annoying idle misfires on both cars in my signature. I guess the delco spark plug quality has really declined. I know a lot of people won't use anything except for delco plugs, but I won't use them anymore.

Glad to hear you got the AFS-21 O2 sensor. They are the only ones that work well for me.