Questions on my 79

[sac001]

I'll see if I can find a picture of the tool I made. It's pretty simple though, two pieces of Angle iron, about 1 1/2" by 1 1/2" by 6" long with holes drilled in it for 1/2" threaded rod. Put one of the angles in the gap between the differential carrier and underside of the car, and the other end below the spring. Put the "C" clamp behind the angle (towards the center of the spring to keep the angle from sliding) then tighten the nuts on the threaded rod to compress the spring.

The reason I used this was the car was up on stands, and when I tried to jack either end of the spring, I wound up lifting the car before I could get tension off the bolts.

To fab these I spent about $20 at Home Depot for supplies and it took about an hour to cut & drill. Actually you're welcome to borrow them if you need to, just let me know.

The entire job is considerably easier than it sounds, but stick with what you're comfort level tells you.

Good luck either way.

Steve

 

[resto75]

I didn't know a person could drive a car without a middle finger to wave to the other drivers who cut you off !!!!!! Just kidding I don't do that.

I might cuss a little.


I just remembered I have my own middle finger story....Many years ago while trying to time my 69 vette outside in the bright sunlight, I could't see the timing light flashing on the damper. So I get the bright idea of suspending a blantket from the top of the open hood to the windshield to shade the engine. Well now I'm trying to time the motor and hold the blantket from blowing around due to the wind from the fan. Well there was too many things going on at once and my hand ended up in the fan blade. This whacked off my middle finger most of the way. The bone was splintered and it was hanging on by a piece of meat.
Off I went to the hospital and they sewed it back on. I still have it now.
I guess it just doesn't pay to do dumbass things working around moving parts.

 

[79blueshark]

Everyone has good ideas, but here is one I ran into on the two 79's I've owned. The temp gauges always read hot. I did what everyone here has sugeested. New 4 core radiator(up'd from 3, new water pump(even tried High flow), engine was new so the passageways were clear, straight water, flex fan. Still ran at 200-210 all summer and 200 in the winter. It wasn't until I bought one of those $30 temp gauges replaced the sender with the one supplied in the kit and found it never was over 190. Seems the sender was the problem in one and gauge in the other.

 

[78SilvAnniv]

Doh!

(lots of hi-$ fixes, then turns out to be sender and guage)
Sounded like a Homer Simpson moment! :L
Sil

 

[sscam69]

I am considering putting an extra temp gauge on the car because I still don't completely trust the one I have right now.

I did change the sender and for example today during the night it ran right at 180 but earlier during the day she was running at about 200 or so. I don't know whats up with that but it wouldn't hurt to get a second gauge. They sell them at autozone for $14 dollars so it won't hurt my wallet either.

sscam69

 

[rpounds]

Concerning the radiator . . . old radiators suffer from a phenomenon known as 'silicate dropout'. There are solid particles that are suspended in coolant/antifreeze, which help to raise the boiling point and lower the point of freeze. Over time, especially when the coolant is not kept fresh, these particles or 'fines' drop out of the liquid in which they are suspended. Where do they go? They coat the inner surfaces of the cooling system, including the radiator.

I'm not sure there really is a sure fire way to loosen and remove this build up other than having the radiator professionally cleaned . . . boiled out as it were. Or, even better, have the radiator re-cored. The stuff that they sell at the local auto parts store certainly don't work . . . Best solution? Autozone will sell you a new radiator for less than $300.00. Order it today and you can have it in hand and ready to install the next day. And as an added bonus, you can take the old radiator down to the scrap metal yard and get some money back!!

I know that 300 smackers doesn't grow on trees, however the money was well worth the peace of mind in my opinion. In my case, I am working on building horsepower far surpassing the stock L-48 numbers. More HSP=more heat. You need all the capacity that you can get.

I'm really sorry to be the bearer of bad news . . . really I am. But, I spent so much money and time (not to mention pulling my hair out, which I can scarcely afford) trying to fix my cooling problem . . . I finally decided there is no such thing as a quick, cheap fix.

 

[vigman]

You got it covered.. now my .02

Flex fan NO WAY, part of the problem is when the blades flatten out they flex (ergo flex fan)

Now the bad news after so many flex's they start to crack ( I had a piece come ALMOST thru my hood), lucky for people around me the hood caught it made of an interesting ride home and unique hood ornament!

Springs.. get the composite 360 lbs A little more expensive, a better ride and a 45 pound dump of metal.

AC new compressor/ new VIR assy ( or rebuild it IF you have the know how) new hoses would be in order at this point and since you will be removing the raidiator, just change em out at that point.

Freon I use F-12 and it works great ( about 3-5deg difference in discharge)


Raidiator... change it or have a new core put in... the old one is slimed and NO amount of flushing will get it back to new condition. YOU LIVE IN THE DESERT!!!!!! Do the thermal math.....

As far as the gauges go... get an auto thermometer stick it in the open filler neck, cap off..let the car come up to temp watch the thermometer compare it to the gauge if they don't match it's ( typically) the sender next is funky wiring.

Mike

 

[vigman]

Oh the second fan

Some C-3's have em sandwiched between the stock fan & the radiator ( so it's a puller )

I however have NO idea how it's implemented on those cars ( Sorry )

Mike

 

[Dave L.]

auxiliary electric cooling fan

-This fan was used on 78-80 L82 and all 81-82 corvetes.The fan is powered through the circuit breaker in the fuse panel when the ignition switch is in the run posistion.The fan motor is controlled by an engine temperature switch which screws into the engine on the RH side.When the engine temperature reaches approximately 238 degrees,the switch closes,completing the fan motor circuit.When engine temperature decreases to approximately 201 degrees the switch opens the fan circuit.Mid-America supplies a replacement temperature switch,
part# 601-972 which will activate the fan at about 205 degrees cooling it to about 180.I just thought I would shed a little light on this fan subject.

 

[sac001]

If I'm not mistaken, on the Right Fender well, around the same area as the A/C Compressor there is a connector with Black and Blue wires that are specificly for that fan. I noticed this the other day on my 1980 L48, and was thinking about adding such a fan as an auxilliary, just in case. I wonder if the L48 also already has the temp switch installed?

Steve

 

[page62]

This thread got me wondering...and as I was poking around under the hood, I noticed a wire going towards the radiator. And there was ... a fan!

Apparently, this fan saved me the other day when my fan clutch was still bad. Engine temp got up a little over 200, then suddenly sunk back. So I'm guessing the electric unit kicked in around that temp.

After this experience, I'd definitely recommend an electric aux fan for ANY engine -- L48 or L82!

 

[Dave L.]

added note to aux fan

I was in error when I stated that 78-L82 engines had that aux fan option.After checking,79 was the first year this was available,sorry.

 

[Dave L.]

Steve, I don't think your L48 has that switch.But you will probably find a pipe plug in the cylinder head where you would normally find it.Its on the right head,towards the back above the spark plugs.I checked my GM shop manual,and that switch is used only to activate the fan.

 

[desertsled]

the fan switch???

Ive got the fan but cant find the switch . Burgler, When you say the R>H> side of the engine do you mean passenger side? Is it better to get at it from under the car? Does it feel engine ambient temp, or water temp?

 

[Dave L.]

It is easiest to access the sender from the top.It is in the cylinder head above the the 2 back spark plugs.The switch senses the water temp in the cylinder head water jacket.I have a picture in my shop manual here.If you want,I'll try to scan it and post here.

 

[Dave L.]

I tried to scan the picture inth shop manual.It is on the rh passenger side of the engine.

 

[Jack]

OXALIC ACID

Parts stores used to sell a DuPont product that contained Oxalic Acid. It was sold as an on-car radiator cleaner/flush. It came in a silver-foil canister much like a Pringles can. It was a powder; I seem to recall it was in two parts ... the second being a neutralizer. I don't remember the name ... nor do I know if it's still available ... but I do remember it worked VERY well. My limited chemistry background tells me one should not use OA with aluminum radiators ... Al intakes, wp's, heads may be ok since they're much thicker.
JACK:gap

 

[page62]

Saw that stuff at my local O'Reilly's the other day. So I guess it's still available. Use with caution!

 

[desertsled]

found it!

yesterday I took a ride on the freeway 65-70 mph 30 mins, temp got up to 230 or so I dont think the fan kicked in or maybe it did cause it didnt get any hotter. Probably not cause it didnt get lower all of a sudden. Ill put 12 volts on the fan and see if it even works.

 

[desertsled]

Getting hot down here

Today was 85 degrees. I drove the Vette on ramps and slid under . There I noticed the flapper valve (waste gate) As im looking at its operation, I figure it should normaly be closed. This would force the only cooling air through the radiator. Does any one know at what instance this flap should open? Why? I noticed that its basic operation was sloppy and it would never really seal closed. So i tried a little experment. I locked it shut. (I figured now the only air would have to pass through the radiator) Went on a long highway ride (40 mi;les round trip) Heres the results:

60 MPH for 5 mins. = 215-220
65 MPH for 5 mins.= 220-225
70 MPH for 5 mins.= 225-230 (electric fan turns on) 3000-3200 rpm
75 MPH for 5 mins. = just below red area on temp gauge 3500 rpm
How does this compare with anyones readings.
I have a 3 speed auto
I will say this .. that electric fan probally saved my a#&.