Change the antifreeze and stat that would be a start.Make sure fans come on.look for crap blocking air flow.

 

My money goes on fans not working or the thermostat.

 

OK...Update...This leads me to beleive my radiator is clogged. I went to drain the coolant, and much to my suprise, only a couple of cups came out. The water that came out was clear (no sign of antifreeze) and, the best way I can describe it, looked as if it had soot in there.

So I went to flush it with this cleaner I have. It said to fill the radiator with water, run for 10 mins, then drain and add the cleaner w/ water. No problem. Go to fill it, it only takes a few cups before the radiator is filled. So I fill the overflow tank to the "cold" mark. And start the motor. Temps are rising 1 degree every second. It went to 150, and I shut it off. Any ideas?

The fan is working.

The "scoop" on the bottom of the car where the air enters is clear, minus a few bugs in the rad.

 

I'm having a pretty hard time imagining why you'd only get a few cups of liquid out of a filled radiator, even with a significant blockage in the core. Did you remove the radiator cap to allow air to replace the coolant that was draining out?

I'd suggest you open the radiator petcock, and both block drains on the engine (with the radiator cap also removed). See what comes out then, in terms of both the quantity of juice and its appearance.

Be well,

SJW

 

it is possible that it water was used only and no antifreeze, the water could have just evaporated. Be sure to check all the simple things first. Get some antifreeze in there, start it and see if the fans turns on when it gets up to temp. Remove the radiator shroud, and with a flashlight check to see if theres leaves in front of the radiator. There are a lot of simple things to check prior to removing a water pump. Did you notice and type of leak with the overheat?

 

I had the caps off. Where on teh block are the drains? I called the auto store and they said they have a flushing device that you hook up to the garden hose. I would be afraid of getting whatever is stuck in the radiator stuck someplace else in the engine? Logical fear? Or should I get it?

 

check your lower rad hose

 

I haven't noticed yet, but have you checked th t stat to see if its opening and closing?

 

I am posting and wrenching at the same time.

I will check these within the next few minutes.
Thanks for the help guys, much appreciated.

 

There are drain plugs at the bottom of the water jackets, one per side on the engine block. Look for them from underneath of the car. If your car has knock sensors, they will be installed in place of the block drains, which were simply pipe plugs. I don't know if yours has knock sensors (I'm an LT1 guy, and not an expert on L98s).

Be well,

SJW

 

Ok, I ran the flush through. Temp climbed to 195, at which point I shut it off. Fan did not turn on at 180, which they should have. I heard something that sounded like a electrical spark, but that was at about 160 I beleive. At 195, the fan was turning very slowly, almost like it was being held back. Are these electrical fans, or mechanical?

 

Fans are electrical. most l98's run much hotter unless some mods were done. Check your connections, voltage

 

The reason there was no water in the system when you first drained it is because it was blown out through the overflow tank. A radiator will not plug up from one momemt to the next so I don't see how it could be a clogged radiator. It would have run hot from the first day you purchased it if it was clogged. You can't totally fill a cooling system until the thermostat opens to allow the pump to flow the water through the radiator and through the block. A thermostat can quit working all at once. Flushing and filling at this point in time is wasted effort. Pull the thermostat and replace with a new one. When you refill just use water so as not to waste anti-freeze. Let the engine run while you are filling it but watch the temperature while doing so. Get a friend to help because it is hard to watch a guage and fill the cooling system. If it runs cool, drain and refill with anti-freeze and water mix. If it overheats again, pressure test the system to see if it holds pressure. You can flush and fill until you are blue in the face, replace water pump and howl at the moon but if you don't check the item that fails the most often, the thermostat, you aren't getting anywhere.

 

Replaced thermostat. Fired it up, and its leaking. Stupid kid at Advance auto parts gave me the wrong gasket, I was even more stupid for trying to make it work. I gave up and had dinner, and will try it again tommrrow. I fitted a 180 instead of a 195, figure it will only help it.

 

Some days it doesn't pay to get out of bed. When I changed the thermostat on the 90 I had, one of the bolts broke off. Had to pull the intake and have a machine shop drill it out and put in a helicoil. Hang in there, you'll get if figured out yet. Half of most mechanical repairs is persistence and patience.

 

I think once you replace that thermostat its gonna run fine. You didn't go to the advance auto in latham did you? They screwed up on my stuff a dozen times!

 

For times like these it pays to buy that sheet of gasket material....Then you just cut out the shape you need.

 

I disagree.

Put a thermostat in a pot of water on the stove and warm the
water to boiling. The thermostat opens in a linear manner,
gradually reaching the fully open point at approximately the
temperature it is designated for if it is operating properly.

About the water for the fill. While tap water is convenient
for the trouble-shooting and cleaning phases, 'distilled' water
(not the mountain spring drinking water) from the grocer or
pharmacy should be used for the final fill. Minerals in regular
water will contribute to early failure of various cooling system
parts due to corrosion. (A leaking heater core is a sad discovery
in a C4 due to the effort required to R&R it.) Also use antifreeze
for the same reason - it contains additives to help slow
corrosion.

.

 

When you pull codes on the 86 the fans come on. Do the paper clip tango and see if the fans do infact come on.

 

That is cool to know.