85LS

I bought a super nice '85 88 a few months ago. Lately, when I've taken it for a run, then return it to the garage, I'll notice a very small puddle of anti-freeze on the floor the next day. This has happened 5 or 6 times now. It's a 307 w/ 42K original miles. I've looked at the water pump (I'm NOT a mechanic), and I'm pretty certain its not the culprit. The location of the puddle is closest to being underneath the overflow reservoir. Could it be that the oil change guy overfilled it?? Are these cars known overheaters? This is the first 307 I've owned. If it needed a thermostat, what would be a potential sign? Unfortunately, I don't have the rally gauge package, so I can't monitor the engine temp while driving.

85LS

This is it
88side2-1.jpg

88seat.jpg
88engine.jpg

Lady72nRob71

Man, that sure is a sharp looking Delta - you could eat off that motor!
That should also make it easy to find the leak. If the reservoir is overflowing, it would be obvious. It is supposed to hold some coolant - make sure the hoses going to it and the radiator have no splits and clamps are secure. Getting under it with a good flashlight, you should be able to find the source. The reservoir ~could~ have a crack in it, too.

The 307 is not a known overheater, but it can happen I suppose. An infrared thermometer would be your best friend here - mcmelectronics.com sells them. I got one to verify all my cars' gauges - very accurate.
I have a 307 in my 86 and it leaks coolant from the intake manifold gasket, a more known 307 issue.

Hope you find the source of the leak.

Again, SHARP car!!

85LS

Thanks, Rob! I'm gonna spend some time on it after work today. Little things like that eat at me big time. That reservoir plastic is pretty flimsy, so maybe you're right in that it could have a crack in it. I'll let you know what I can find out. Thanks for the general 307 info as well!

85LS

Hmm, looks like the radiator itself has a leak on the right (passenger) side. There was a drop "hanging" from it (over a small puddle) just a second ago when I climbed under it. I wonder if it can be welded (cheap), or if someone's going to want to replace the entire radiator? I guess its nothing that needs to be fixed ASAP....as long as I watch it.

Lady72nRob71

Hmmm.. That drip from the radiator at 42K sounds familiar... My 86 did the same thing then - the joint where the lower rad hose meets the side tank was cracked. A skilled radiator shop should be able to resolder it if you pull the rad out. Don't worry - it is a straightforward job.

This would be a good time to first drain some coolant and look inside the rad for corrosion. If it is very bad, and the cleaners do not help, a replacement may be in order.

This may be the original radiator... Is the drain **** at the bottom of the tank or on the side? The original was at the bottom that is visible through a hole in the sheetmetal radiator support frame.

Another good source of general info on the ol' 307 and its tranny may be had at oldsgmail.com and also 442.com. Some of the drivetrain info is interchangable for the 85 year, as the G body Cutlass shares the same engine and tranny. Your engine, like the Cutlass, has the Y code engine; the 442 is the VIN 9 - a 307 on steroids... If you have the OD tranny, you have the 200R4; otherwise it is the 200.

Keep us posted...
BTW, a closeup of the engine needs to be posted - it may motivate me to clean my 86's!

Lady72nRob71

Forgot to mention the easiest and first thing to do - tighten the lower hose clamp if it is loose...

A small leak in that radiator should be repairable by a good rad shop.

85LS

Yep, its the original radiator alright. Thumbing through the service history, I do see where they had it "flushed" a few times over the years....so I guess that's good. I'll work on that engine tight shot.

Lady72nRob71

An original radiator would be worth keeping, especially with only 42K miles.

It may be just time for a SERIOUS cleaning - I just did that to my 72. It did nice work to the radiator. I used two bottles of the Prestone cleaner, NOT the "flush". Just follow the instructions on the bottle. It is much stronger and requires 6 hours of driving. After that, you drain the rad and block (two plugs on the side) and flush it with water. Then would be the time to pull the rad and have it repaired and pressure tested, then backflushed with water.
After that, install it and fill with just water, drive a bit to check for leaks. If it is sealed up tight, drain the rad and block and refill with a 50-50 mix of coolant and distilled water.

Hopefully the last owners at least changed the coolant often enough to prevent excess corrosion.

joe_padavano

There are a few things to check. First, as mentioned above, be sure the hose clamps are tight. Second, while the car has low miles, it IS 25 years old. The gaskets in the radiator cap might be bad. This is an inexpensive part to replace. Finally (and this happened to me), Olds had an option for a low coolant sensor on these cars. The sensor screws into the passenger side end tank on the radiator, near the trans cooler fittings. If your car has this sensor, it may be loose or leaking. If you don't have the sensor, your radiator may have a plug in the fitting that's come loose (that's what happened to me).

85LS

Thanks guys. I talked to a mechanic this morning to let him know that I'm bringing it in tomorrow JUST for a diagnosis of exactly where the coolant is seeping out. I guess they'll do a pressure test. If it's something simple (i.e., a clamp), then surely they can go ahead and fix it right away. I'm going to mention the low coolant sensor to him as well when I drop it off. Here's a larger picture of the engine (as requested):

engine.jpg

Lady72nRob71

WOW! That clean engine is almost beyond belief... I have never seen a 307 so clean for being so old, unrestored...
The only thing that shows any age is some light surface rust on the frame rail and hood supports and springs. Was this thing stored for a long time, or just used very little? They sure kept good care of it!

This is a fine example of an untouched original motor - I bet all those hoses are original, too. The heater hoses still have the black GM ties securing them. Even the air intake duct is clean! That cloth stuff is impossible to clean when it gets bad and it often falls apart, too.

My 86 looked like that when I bought her - I think it is time to clean it up... Lots of dust and dirt and oil leakage even after just 69K miles.

Hope you keep her as is for a collectible - those were some NICE riding old cars! I wish they still made 'em.

BTW, your washer hose is disconnected at the bottle...

85LS

Thanks! Yes, I know, I reconnected it....that photo is one the seller took when we were in negotiations back in March.

Yes, it is very clean....I'm going to try to keep it that way. I bought this car on a whim, and am not sure what the future holds for it. I know I could get my money back at the drop of a hat b/c of the car's overall condition, but I'd hate to see it fall in to the hands of someone who's going to trash it. For that reason alone, I will probably try to hold on to it (space permitting) .

Oh, to answer your question, it was stored for a short period time while the original owner's estate was being settled, but aside from that has always seen regular (but light) use. I am actually the 4th owner...the 3rd owner only kept it about 6 months.

Redog

HA HA HA My 307 never looked that good

My rad broke in mine too, but it had over 123,000 miles on it when it did. I replaced it with a Be Cool Raditor because I was planing to swap out the 307 for a 350. That's done now, but the overflow bottle does overflow quickly when overheated. Also the heater control valve can leak too. It can look like a intake manifold gasket leak, but the 307 was such a low compression motor (8.2:1) it's not very common

joe_padavano

Wow! That engine compartment is so clean and unmolested that it would be really nice to get a few additional photos from different angles to properly document hose and wire routing for prosperity.

J-(Chicago)

Sigh... I remember when my motor looked like that. 10 years ago.
Now it is caked with at least 1/4'' of grime everywhere. I'll be willing to bet there's 5 quarts worth of oil and good ol' terra firma on the outside of the motor.
The oil fill tube is about 1/2'' bigger than it used to be lol.

85LS

Thanks everyone!!

I swung in to a radiator-only shop this morning. They were super nice, but didn't want to listen to what I had to say about where it was actually leaking. All I got was a quick "it'll need to come out and be replaced!". If that's the case, that's fine I guess.....but I went ahead and took it to my usual do-everything mechanic a little further down the street for a second opinion. He's taking a look at it right now....I walked to work.

Lady72nRob71

>>All I got was a quick "it'll need to come out and be replaced!"

Yea, a response like that would have had me walkin' as well!
Good new radiators are not cheap.
If you do have it replaced, make sure it has the correct number of rows...

The shops used by the previous owners of my 72 fitted it with lots of cheapo parts and charged top dollar. I got a 2 core radiator and a 1 year reman water pump. The water pump seals leaked after 1 year, 2 months and the the 350 was too much for a two core. I just upped it to the required 3 core and she keeps her cool, now.

Hope your other shop gives you a better answer. Heck, if you lived around Dallas, I would solder that thing up for you!

85LS

New 3-core radiator.

$285 installed. It'll be ready by the end of the workday.

The fitting that was in place of the low coolant sensor was in fact what was leaking. However, there was an additional crack at the other end of the radiator. I went over at lunchtime and looked at it.

Oh well, at least its done and taken care of.

joe_padavano

I replaced the two row copper radiator in my 86 wagon with a $95 single tube aluminum radiator (with plastic end tanks) from Advance Auto Parts. It was even in stock. The single row aluminum tubes are much wider than the copper tubes, so overall thickness of the core is comparable. Temps dropped about ten degrees with this radiator.

Joeypete

I know this post is old, but man that's a beautiful car...those seats! Dang....

Since I was in high school I wanted an 88 LS...I thought they were pretty swanky

The Stickman

Damn did that just roll off the assembly line? It's SO clean.

Lady72nRob71

Those do look nicer than my couch! That was true luxury back then... My mom had an 86 CSB with plush seats like that - SOOO comfy! Now days it is leather (mostly immitation) or nothing...

J-(Chicago)

I believe he sold this car on ebay a long tiime ago.
It probably has hydraulics, and a Chevy motor in it by now.

Joeypete

I love those seats. Back when I first learned to drive these cars were just a few years old and I remember how much I wanted one, but they were too expensive...LOL My friend had an 84 Monte Carlo CL and the seats were the same material...she used to make fun of me because I'd rub them all the time, they were so soft...haha. I'm a weirdo...

Ack! I hope not and sweet Jesus, not a Chevy motor!!

Viz G

bro can u take a overhead shot of the engine im trynna find a hose diagram for a 307 but cant...

Lady72nRob71

Unfortunately, the owner sold this car long ago...
https://classicoldsmobile.com/forums...lta-88-ls.html
There are some nice pictures in that thread, but no more engine shots...

Joeypete

Damn, I missed that one on Ebay...I was looking for a car back then too...*sigh*

Are you looking for a vacuum hose diagram Viz? I have a couple of service manuals, I'm sure there are some in it. I could probably scan the page and send it to you.

Viz G

^Yes, I am but I just came across a 350 that I am going 2 put in there. So now if any thing I need 1 for that motor...lol
but its not as many vaccum lines on the 350 right??

Viz G

also is there any helpful suggestions 4 da swap???

Lady72nRob71

If you plan to keep the emission crap all intact and working you will have just as many hoses. If not, you might have only a few depending on the year of the 350.

I get more visibility with your inquiries, start a new thread about replacing your 307 with a 350. I think there are some existing good threads on this also - just do a search. The 350 IS the way to go!

Joeypete

I do have some diagrams for 350's in my Chilton manual. It has several different years and even 350's built by Buick and Pontiac. So if you need them just let me know what year you would be getting and I can scan the page for you.

Viz G

alright i will 4 sure do that i should b gettin ready for the swap in bout 2 weeks
WISH ME LUCK!!
this will be my 1st swap