Dade305

dont kill me for this but i am going to spill out a hell of a story about this sc im working on lol...
heres some general history, i bought this stock sc300 about 3-4 months ago planning to drop all the parts i had in storage onto it (pretty much everything i wanted for it that was taken off my previous SC). i took it for a test drive and it was fine BUT It had overheated ONCE from sitting in a parking lot after we again test drove it hard and was left running for about 10-15 mins in miami afternoon heat. when we checked for a source, the coolant was low so i assumed it was the problem. That very same occasion while the car was still hot (not top bar but 3/4 temp) i drove it to see if the rushing air would cool it down and it did just that in a matter of seconds! i continued to drive it for 25 mins and it didnt overheat. i then decided to make a reasonable offer, picked her up for dirt cheap, drove her to my garage and got to work. after fumbling through all the compartments etc i found a receipt from a repair shop that showed the previous buyer repairing/replacing (hopefully not fake) the timing belt, water pump, radiator, head gaskets, and serpentine belt and a few etc etc's. this find put me in a good/bad state of mind considering the receipt was dated march of THIS YEAR. it was either a really good thing, or a really bad one lol. i checked the belt and it really was a new timing belt so i assumed the rest was legit.
i have already spent time getting it boosting an easy 8psi, its already been put on coilovers, ive spent plenty of days on minor upgrades/details and i really am too far into this car to back down now. after the turbo was on and the idle was fine i took her for a couple drives in intervals and amazingly everything was working perfectly, quickly building boost, driving super smooth, etc etc. after some more tweaking and 5 non-stop GOOD test runs the temp slowly started to climb, so i pulled up to the garage. mind you i havent been driving this car at all since purchase, ive just been starting her regularly and letting her run once a week or so (very busy with work). so anyways when i opened the hood, the reservoir was bubbling and overflowing all over and it was a vivid brownish color. almost a mix of chocolate milk and orange dye yet still had the consistency (thickness etc) of water/coolant. i checked the engine oil and it looked perfectly normal. my clutch fan is working and when the car is off it wont spin more than a rotation if you try to spin it your hardest (usually a sign of a good clutch fan). there is NO SMOKE coming from the exhaust even after we installed the turbo. i guess u can say the water looks seriously rusty but its too solid of a color and that doesnt explain why it would overheat. someone plz tell me its not my HG..

iridebmx

iTrader: (6)

did you pull the motor and flush all the fluids to put the turbo on?

Dade305

not all the fluids but the coolant was drained and refilled with basic shelf 50/50 and the rest water to top off radiator. probably done two months ago.
edit-- also power steering since we relocated the reservoir for it but i still don't think that's the answer u were trying to hear lol

soarer93

It is very difficult to change out ALL the coolant in these engines - so its very likely its just a mixture of new and old stuff... unless you did flushed the coolant a few times before adding new stuff.. or change the water pump and such - but it doenst sound like it


my 0.02

Dade305

thanks for the feedback guys. tomorrow im going to try to flush the fluid properly and replace it with only coolant. also going to check the stat. and see if the water pump is working. if all three work fine i guess my last hope is the clutch fan being replaced with an electric (wanted to do anyways but just cant find a decent deal). if the car isnt smoking it shouldnt be a blown head gasket right?

soarer93

your oil can usually be a sure way of telling if the HG is the culprit, it can turn oil into a milky white - not always but commonly seen from coolant mixing with the oil.
the smoke is from the oil and coolant being burnt.

and maybe things have progressed alot in a few years.... but the clutch fan, if its working, will push More CFM's (volume of air) compared to an electric fan.. so if overheating is your problem, and the fan's working its not wise to replace it.
again my 0.02

scviolence

iTrader: (17)

Hey govto autozone rent a block tester if it changes color wa la blown hg. Itll let u know where to go. If u want to make sure pour the fluids in clear shot glasses after u test, to reassure the color. Its easy good luck...

Dade305

thanks guys, im keeping the clutch fan on and trying thie block tester first thing tomorrow. wait.. tomorrows labor day isnt everything closed?

DriftVIP

iTrader: (4)

yup closed on Labor Day good luck with it

93SC300.

iTrader: (7)

i seen brownish orange coolant from rust also... the radiators do get nasty so if it hasnt been flulshed in a long time then that could be it also.

Starfx5

iTrader: (1)

i think you got rust in your radiator i had symptoms like this with the fluid not the overheating tho but check your rad out might be the culprit

Redtallman

iTrader: (1)

hey I had same problem...I put the car on ramps and cut the heat on..had a lot of air trapped in the heater core...the over flow tank bubbled for about 10 minutes and then stop ,,i did rev a couple of time to make sure all trapped air was out..never overheated again knock on wood....try that its free..you have to make the radiator or overflow at a higher elevation than rest of the coolant system...

Nova

iTrader: (21)

i guess ill be the first to ask. any way u can get a sample of the coolant and take a pic of it for us. cant really chelp thru the internet when i dont know what im looking at

Bender25

iTrader: (10)

Flush the system and replace your radiator cap. When a tired radiator cap cant hold the proper pressure in the cooling system the boiling point of the fluid is lowered and boils out through the reservoir.

Dade305

thanks guys, the flush helped tremendously.. it looked as if my car had explosive diarrhea when we flushed it all out lol. it doesnt overheat anymore but im also going to replace the cap anyways cause i can hear it leaking air in. thanks to all who helped out, im now one step closer to posting my complete build thread from start to finish of before and after's and hopefully some video =D