Ive replaced the thermostat, water pump works, dont think its the heads, radiator flows, no clogged hoses, and I flushed but still the damn things shoots up to 260 degrees within 5-10 minutes of driving, all I know is my fan doesnt turn on and I have a metal plug half-way down my radiator with no sensor attatched, any idea what that is, and why Im still overheating, everyone tells me its not the fan but noone has any idea whats going on. I can always count on you guys to help me out, thanks alot for this one

-Ryan-

 

Well, if you're fan doesn't work then that's your problem. If it happens at high speeds, check to make sure you still have your air dam.
Also if it shoot up that fast only after 5 mins, make sure your gauge is accurate and the sending unit too. It takes my car a good 10 mins at least to get up to 180*.

 

Im pretty sure the guage is right because the coolant in my resovior (sp?) bubbles and smoke starts coming out of it after I drive it for 5 minutes or let it sit for about 10-15, this just started happening this week but a couple days before I noticed my gauge would creep up to 240 and then take a nose dive back down to 180 within seconds. Not sure if that helps with the diagnosis. Thanks again

 

Leaky intake manifold gasket will do what you describe......I would take the thermostat out and see what happens without it...Ive got a few bad ones brand new.....sticky

 

Or you could just fix your fan

 

Exactly, I'd like to see the person who said you're fan not working isn't the cause.

 

I tried w/o the thermostat and still overheated, Im going to fix the fan first thing tomorrow and then go from there, thanks alot for the help guys

 

I see you're from MD. Have you heard about the car show in Carlisle, PA on June 14-16th, not sure if it's all Camaro's or some TAs too, but I hear there were like 400 cars there last year, I plan on going, just wanted to let you know.

 

You probably shouldnt keep running it without the fan. The fan is there to COOL the engine.

 

Guess I missed the fan part.....Hey , you,,,,,fix the Fan!!!!

 

Dude, come on now. Fix the fan.

There is something called "Least Evassive Action". It means, fix the simpliest easiest thing first. It's a tried and true principle in all troubleshooting, from medical practice (the practice part is funny) to mechanical, to electrical to plumbing....you name it.

You've got these components (basically) to an average cooling system. Radiator, thermostat, coolant, hoses and fan. Other things can affect cooling, but they're usually not as drastic as shooting the temp up to 260*.

You KNOW that one of those 5 items isn't working. Fix it. Why search for a more complicated and expensive problem when you've already got a known problem?

 

Ok I realize I risk being flamed for this... BUT I'll go ahead with it anyway.

First of all, I don't at all disagree that the fan needs fixed. I ran my 87 LG4 most of the winter without one, but the car got pretty toasty in traffic. I fixed the fan, major city-traffic improvement.

Anyway, if your car is heating up that fast I'd say there's more than just a problem with the fan. The stock set-up wont even turn the fan on until 220-230 (correct me if I'm wrong) so I'd say you're over heating irregardless. Fix the fan, obviously it will help you in that above 220-range, but I'd be willing to be that you wont cool down past the 210 range when you're just sitting at the drive-thru.

You said that you saw your temp gauge hit about 240 before taking a 60-degree dive, and I'd say that when you're stat started letting coolant through... The '87 was always deathly slow for me in catching up with coolant temperature, but sure enough, after it did, the temp dropped rapidly. Partial solution for me there was a lower t-stat. If you've done a flush and checked your hoses, already tried it w/o the stat, I'm interested to know what temp you run at consistently once you get your fan fixed...

Does anyone think his radiator itself is taking a dump?

Mark mentioned that if your car overheats at high-speeds (or like 40 mph on open road), then your air dam is probably missing... Did you ever investigate that?

James

 

I was just gonna say that. My fans dont work either (They just stopped working , getting it fixed this week for sure) and as long as im driving it, it stays cool. But when Its stop and go it starts getting warm. I'll be at 180 and stopped and I'll see it slowly creeping up, as soon as I start driving it goes back down. But ive been only driving my car close to home just to drive it for short periods, I don't want it to overheat. As soon as it starts gettin around 210ish, I come home and pull it in the garage

 

Past 40 mph the fans won't help anyways, if it overheats then, then there's also something else wrong.

 

James it isn't winter anymore... ...You guys think you are driving Volkswagons or what...these are not air cooled engines..they have Radiators, fans water pumps thermostats, and gaskets, They ALL have to function, or you are risking meltdown..unless you are only going 1/4 mile at a time..

 

Riley,

I know it's not winter anymore, that's why I ran my own toggle switch for the lG4..

The point I was trying to make is that if he's driving down the road at a decent speed and his car is still overheating, then his problem is more than just his fan!

James

 

Check to see if the lower radiator hose is collapsing. It should have a big "spring" inside to prevent it from collapsing when the water pump is sucking water thru it. Those "springs" can rust and fall apart. They also get left out occasionally.

 

The plug with the empty metal spade connector is used for later model cars that have a low coolant indicator on the instrument panel. This means the radiator has been replaced. The original radiator did not have this plug, however GMSPO issues the replacements with the plug. Instructions with the new one tell you to ignore this connector.

 

Ok so I fixed the fan and It stopped overheating, I even took 2 50 mile trips afterwards and no problem, the guage did go up to around 240 for a minute but then it dropped back down to below 220, not sure if theres anything else to worry about. Thanks alot for the help.

 

How'd you fix your fans?

 

The fan motor was bad, I connected the fan directly to my battery and nothing happened so I tried replacing the motor first, ($40), and it worked. I only have one fan though, if both of yours stopped working I doubt both motors went up at the same time.

 

Glad to hear you solved your problem. Want to come fix my exhaust leak, damn store didn't have the size gasket I needed.

 

Glad to hear it is fixed. See, the most obvious solution is usually the right solution. And if not, you'd have to fix it anyhow to find out if it was something more complicated.