If the engine only had water in it before you got it then I'll bet the cooling system was not properly maintained. And you wiped rust off the radiator cap. Who knows what is floating around in there? Do yourself a favor now and do a complete cooling system service. The more information you post the more a "no brainer" the conclusion becomes. In the end, however, it's your car to do what you want.

 

I think youre right. I put a new Murray ultrastat 180 degree thermostat in. Looked inside the top of the radiator the best I could and theres brown mud in there.

Drained out as much as I could, fought with the drain plug to get it to tighten up, put some blue devil flush in and Im going to drive it a couple times and flush it good.

Tonight its been running cooler even with the fan off, fan on it drops right down to 180.

It had a 195 thermostat, but they were out and I thought ok why not.

The radiator will probably need replacing heater core too I guess.

If those cooling lines from the AT break (I heard they do often) can new pieces be spliced in with compression fittings or rubber pieces even?

Anyone ever heard of a Spectra radiator?

 

Well it was ok for a day or two, new thermostat ran some flush for a while.

Now right back to overheating again.

First thing I guess to do is fix that heater control valve.

Can someone explain or show me exactly what to connect to what to bypass it on an 84? What fittings to buy? A tee and an inline coupler? Inside diameter of the hose ?

Next will be the radiator I might try getting it backflushed then replaced. Some of those cooler lines dont look real good. What do I do if they break?

 

time to flush the entire system. It does sound like u could have rusty sludge plugs in the engine or in the rad. But im guessing the rad.

this may not be met with approval on this forum but I have used vinegar alot to get ridof rust on components however it also releases bits and flakes which may flow through the rad and get caught up elsewhere.

if i was looking at a worst case of replacing the rad, id be removing the thermostat, then filling my system with vinegar, letting it sit fovernight then id flush the crap out of it. literally.

if u have had just water in there, you will be rusted up in there. i may even drain the vinegar once and see how bad it is. if its clear that it dissolved a heap of rust, i may do a second vinegar douchebn

again, there may be other magic potions to dissolve rust in a car system so check that, but id use vinegar, its cheap.


Im sure ill get flamed for suggesting basic old vinegar, but hey. i do know vinegar works wonders on rust. youtube it.

also, if u r getting frustrated, just grab a beerand enjoy that have a beautiful car and is 30 yrs old and just needs some maintainence. cheers.

 

Rather than bypass it, you can either replace it or rebuild it with a Four Seasons heater control valve part no. 74800 obtainable from a variety of places including ebay -
http://www.ebay.com/itm/like/280910374862?lpid=82
Here's a thread on how to use it to rebuild your valve -
https://www.corvetteforum.com/forums...-corvette.html

Since you have a 1984 you can probably just replace it with the Four Seasons part-
https://www.corvetteforum.com/forums...rol-valve.html

 

Im just not that smart I cant figure out how it would hook up, that 74800 part has 4 openings and the 84 part has 3?

 

From post #12 by Randy Ferraro in the second thread I posted -

"I read this thread about 2 years ago and it did not help me then. My 84 had a leaky heater control valve. Running heat all the time meant having lukewarm air conditioning, too much hot air in the cabin. So, with heat in an 84 it is all heat or nothing. Replacing the factory $130 valve was not in the budget, and no amount of bypassing solved the problem. I live in the desert where spring days can be 85 degrees and nights can be in the high 30s. I finally solved the problem with Four Seasons part #74800 Heater Control Valve. It costs about $30. It cleaned up the plumbing in the engine compartment quite a bit. The original design was a clusterf@#k. The Four Seasons part mounted right up by the heater core nicely and works exactly as the factory did. If ever I have to find this part number again for future repairs, then here it is.
Four Seasons part # 74800 Heater Control Valve ".

Apparently he just plumbed into the two lines - one going into the heater core and the one coming out. If you can't figure it out, then maybe you put in a tee like this (you'll have to measure outside diameters to see if it will fit - I don't have the dimensions) -
http://www.ebay.ca/itm/HVAC-Heater-C...-/400527704111

You can contact the seller to see if they can get you the diameter.

Or you can measure your tube diameter and go to NAPA or other parts store and compare it against the Dorman tees they have in stock.

Otherwise you may be able to use the aftermarket valve to rebuild your valve as was done in the first thread I posted.
https://www.corvetteforum.com/forums...-corvette.html
Other than those, I am out of ideas for you. Good luck.

 

I once found a Mercedes procedure to flush and de-corrode. It used a 10% acetic(I think) acid solution. I ran mine up to op temp, then flushed the system. Seems that's the acid in vinegar, which smells worse!

My opinion on the current flush products is very low, FWIW.

 

Drained everything and cleaned out the of tank. Put in a new radiator and cap. So far so good.

Theres little plastic threaded plug that goes in just below the at cooler line. I guess there is some sort of coolant level sensor that goes in there for certain years or cars.


Wonder if I can get a temp sensor of some kind to go in there?

 

The brown mud issue. Hope its just from rust. If its from mixing coolants/antifreeze that mustn't be mixed, this is what you will find. Brown mud, brown clots floating in the system, brown coolant, ect. You WILL know the difference from rusty coolant and what I am writing about. Don't ask how I know the difference.

 

Its not nice its brown mud brown clots in the radiator brown coating in the of tank got most of that cleaned.

 

Back to square one or maybe square two.

Overheating again today. Around 220 230 fan on. Get moving it drops well though. The fan is running sounds strong as the day it was new, a month or two ago.

Water pump I think I can rule out, looking in the radiator last night it was moving lots of water. Dont see how it could be intermittent plus it drops pretty well if Im moving even 20 mph.

So thermostat rdiator water seem to be doing wha they should do.

Heres what Im thinking. Both times now, it semed fine idling after working on it. Idled for half an hour or so stayed at 180 fan on.

The next day both times overheating again.

%That valve may be leaking under pressure after I shhut it off, the coolant lvl gets low enough to cause this issue?

After it gets cooled off from sitting ill go out in the rain and check the level.

Could be if the coolant level is just a little low, more air across the radiator is needed? Or is it more likely the fans runnning new radiator all cleaned up behind it still not getting air through the radiator from the running fan?


I feel like its so obvious but Im stupid.

 

Im going to try to just bypass that valve. Can I connect either hose from the pump to the manifold hose and just block off the other hose from it?

Coolant level isnt low, cools when moving not when sitting still. Still back to the fan unless its a loss of pressure but then would it drop so fast when moving again? I cant get away from the fan even thought its spinning frantically.

 

I connected the hose from the water pump to the hose that goes to or comes from t he intake manifold.

Now it gets hot in 2 or 3 minutes and makes aton of white smoke.

Was this a bad idea?

Do I hAVE A CRACKED HEAD OR HEAD GASKET? iNTAKE MANIFOLD GSKAT?

 

IS that smoke or steam? Neither is good, but...

Watch under the radiator cap as the engine idles. If you see any bubbles, even occasional ones, suspect a head gasket, cracked head or any other place the compressed fuel-air or exhaust is pressing into the water jacket.

I look at the spark plugs for rust, in this case, to find out which cylinder.

There's leakdown and compression tests, too, but I've not had great luck learning much over the other indications.

 

Water bubbling over and out of the radiator before it even gets hot. Guess the motors a goner.

 

I just got through a problem with my car overheating. It's a 1996 Coupe auto. I changed the thermostat because my temperature would go to 240 and drop down to 224 and back up. Got a stock temp. thermostat that already had a hole in it by the manufacturer in case it fails and can still let water through. But, I think the other thing that was just as important was to correctly drain the coolant and correctly add it back. I took off both knock sensors on my block and the coolant and sludge was nasty. Also, it's very important that you refill and burp the coolant correctly because any air in the closed, pressurized system can cause a boil over. How are you adding the coolant and releasing the air in the system?

 

Proper fill and surely, at this point, a proper and complete flush is in order. Air trapped can cause exactly the blowouts described.
All is NOT lost, yet!

 

Just filling the radiator and running with the cap off for a bit, squeezing the top hose.

Where do I find the correct procedure or should I get it done somewhere Im not great with cars Im afraid

Did I scrw up connecting those two hoses directly together?

 

sry for spelling. on iphone.


Toni, exactly as the 2 previous posts.

I didnt follow exactly what you did with the hoses a few posts up but return them to the factory positions and do a very rigorus flush.

You have to flish the rusty globs of crap out!!!

I mean search for Cliff Harris's image of how to setup a garden hose to the block and then gently flush the engine.

Use vinegar, or buy some special solution. Go over the top with your flush. Just kill the potential for a blockage. Irradivate that problem entirely.

You have said there is fluid moving in the rad, this is an awesome sign. If you have any serious blockage it is within the pssageways of the head/block. But i dont think u do.

----

As for the boiling.

As previous poster said, if you have a spot where pressure is leaking off, a bad hose clamp, a bad valve, a bad gasket, or your rad cap is loose/missing/not sealing, you create a condition for boiling. Its freaken hot in there, and then if the system depressurizes, it kind of flash boils.

This is why when u remove the rad cap u get sprayed with burning scalding melt your face off fluid.

So:

reconnect all hoses per normal cooling system configuration
flush like a banshee, use a rust dissolving additive (i use vinegar but to each your own)
flush and get rid of all dissolved rust after the binegar douche
replace any valves that are leaking (allowing pressure to escape)
check all hose clamps that they are tight.

refill rad with 50/50 mix leave radcap off
fill overflow to the cold setting.
start car and walk back to the open rad cap where you should see coolant.
it will get sucked into engine when tstat opens
fill till u cant fill anymore
place cap on all the way so the arrows on cap are in line with overflow hose
now turn car off and let cool a bit.

now get a pressure testing unit for your radiator (its a sqeeze bulb attached to a hose attached to a rad cap), you can usually rent or buy cheaply.

remove the rad cap, put the pressure testing rad cap on and squuuuuuze pressure into your system.

what you want to see is no pressure leakdown.

if you see pressure bleed off, start looking for a leak. it will mean fluid is escaping somewhere. sqeeze the bulb up and keep the pressure high. use your ears around the rad cap, is it leaking there from a poor seal? from a hose? the thermostat hasket? waterpump gasket? if you keep it pumped up and it keeps bleeding off, it should be pooling on the ground somewhere.
if you absolutely cannot find any place where pressure/fluid is escaping then it is probably escaping into your engine.

now pull spark plugs as suggested by previous poster. you should find fluid if you have a comprimised head gasket. if you do find fluid, id suck the fluid out if you can see it. THEN i would go to the parts store and TRY this stuff called irontite. It has a chance of filling the gasket leak. MAYBE. But worth the 20 bucks. follow directions to the T. I have seen it work personally on my 85. I may get flamed as I am condoning a "shortcut" but if it works, even for a year, thats good.

now if you dont find coolant looking into the spark plug holes, then the next step is to drain the oil into one of those black oil catch basins. make sure the catch pil is clean and not filled with scum of previous coolant/oil changes.

Empty oil. See coolant? If yes, you have a cracked block or a blown oil cooler if you have an oil cooler. TRY THE IRONTITE here again.


In summary, your system sounds like its overheating because of a pressure loss(aka, leak) which causes boiling. track it down, plug the leak, and because you are seeing water flow quickly in your rad, i beleive u will solve the issue.

I wish you best of luck and success, and if u have a comprimised head gasket or cracked block, i do hope the irontie works for you (even temporarily) as it is currently doing for me.