Pushing coolant, no exhaust gas in thermostat housing.

[Bojangles465]

My 90 laser rs-t fwd has been pushing coolant, and for shits and giggles, I rented a block tester, the fluid doesn't change color, so that means there isn't any exhaust gas in the coolant. I replaced the thermostat and the radiator cap, along with the radiator, so idk wtf is going on with it. Please help... I bought arps and a cosmetic mls hg, because I thought it had to be the gasket, but apparently not...:/

 

[Bojangles465]

They both pull air. The driver's side fan will kick on to operate the a/c. The passenger's side fan is for keeping coolant temps below 210* when at idle. If the temps rise enough, they both kick on.

OP, you need to fix that temperature gauge. Seriously amigo, that's like a $10 fix that could help avoid a $1000 fix.

If possible, stick to the OEM cooling system, this includes the radiator and fan(s). It's actually pretty efficient.

ran to oreilley's and picked up a cheapo coolant temp gauge for 22$, im going to slap that on there tomarrow evening and then take the car for a spin to see how hot the temp is actually getting. i also replaced the thermostat housing, and i am going to try running w/o a thermostat to see if the condition changes.(yes, i know, the car wont get to running temp blah blah blah, its just temporary until i figure out some things with the car.) also, im going to attempt to torque the head bolts back down, any suggestions on what i should retourque them to? im running a composite hg with stock head bolts fyi. also, a local dsmer (1badvan on tuners) told me that if the base idle is messed up, it can affect the temp of the car, if this the case with my symptoms? also, i have a video of me driving, if that would help any.

 

[Junfan]

If you need the space for your setup at least grab a nice high CFM Spal or something like it which are reversible and set it up to push through the radiator. I do not believe pushing through a radiator works as efficiently as a pull system like stock however it will be fine since many large turbo guys do this and a high quality 1/2 size radiator.

 

[Bojangles465]

If you need the space for your setup at least grab a nice high CFM Spal or something like it which are reversible and set it up to push through the radiator. I do not believe pushing through a radiator works as efficiently as a pull system like stock however it will be fine since many large turbo guys do this and a high quality 1/2 size radiator.

I'll swap the positive and negative wires and make it blow the other way, it should work

 

[Jafro]

Here is my bet...

Coolant overflow system failure.

The purpose of the overflow bottle is to catch the excess coolant that escapes once it expands from heat. Once the temperature of the coolant system drops and the coolant contracts, it's supposed to suck the coolant from the overflow reservoir back into the coolant system. If the coolant overflow system is placed too low in the engine bay, the hose isn't tightly sealed inside the coolant bottle or if the bottle is cracked and no longer air-tight (with the exception of the drain hose)... then what frequently happens is your car sucks air back up into the coolant system and that causes what appears to look like a blown head gasket the next time the engine is hot.

The coolant overflow system can fail. Especially as the plastic and rubber parts dry rot from continuous contact with Ethylene Glycol. If your coolant system holds pressure, if you've replaced the thermostat, cap and verified that ALL the air is out of the system dozens of times yet this persists, then focus on the mechanism that's supposed to refill your radiator when the engine cools. Once air gets in there, it will do precisely what you described.

I had this problem. It's what inspired my monster energy can coolant overflow bottle mod.

EDIT: OKAY, NEVERMIND. I just caught the part about the fans blowing backwards. I bet it doesn't overheat until you're driving over 30 mph. Just a FYI... yes, I've done that before, too. It's a weird problem to troubleshoot, but both fans should blow towards the engine.

 

[Bojangles465]

Do the fans really help that much?

 

[SICK SOCIETY DSM90]

Yep the fans do help that much. if they didnt help to cool system most people would just remove them all together if they served no purpose. i know on ebay or some other sites they sell slim fans for like 50 dollar. my frend just turbo charged his n/t and used the slim fans they where supper nice for money and blow real good. Just did not know whlat your budget looked like. im sure the salvage yard will have some fans also that will work. the jeep fans are a little big for a small car like ours

 

[Jafro]

Oh yes, absolutely. If you're driving, they do enough [wired backwards] to prevent air from even flowing through the radiator. It will make your car only overheat when it's moving. It's exactly backwards from what happens when they don't work at all.

Normally when you start overheating, the instinct is to turn the heat on, roll down the windows, and keep the car moving in the highest gear possible. All that does is let air passing through the radiator cool the radiator while dissipating heat from the heater core, and making as little extra heat as possible. These tricks don't work at all if the fans are wired backwards. It makes it worse. It makes the fans fight the air that flows in naturally when the car is moving and prevents the radiator from cooling at all.

Once the turbo's hot, the front facing fan pulls hot air from the exhaust into the radiator when you're stopped. Things don't improve from there.

Most people check just to see if they're running. You can't stick your hand in there and feel which way it's blowing due to turbulence. If you lower a string, leaf, ribbon, dollar bill, etc... in front of it, you'll know real quick. I was positive I got it right, but no, I got it wrong. It wasn't an easy problem to find because everything worked.

 

[Bojangles465]

Oh yes, absolutely. If you're driving, they do enough [wired backwards] to prevent air from even flowing through the radiator. It will make your car only overheat when it's moving. It's exactly backwards from what happens when they don't work at all.

Normally when you start overheating, the instinct is to turn the heat on, roll down the windows, and keep the car moving in the highest gear possible. All that does is let air passing through the radiator cool the radiator while dissipating heat from the heater core, and making as little extra heat as possible. These tricks don't work at all if the fans are wired backwards. It makes it worse. It makes the fans fight the air that flows in naturally when the car is moving and prevents the radiator from cooling at all.

Once the turbo's hot, the front facing fan pulls hot air from the exhaust into the radiator when you're stopped. Things don't improve from there.

Most people check just to see if they're running. You can't stick your hand in there and feel which way it's blowing due to turbulence. If you lower a string, leaf, ribbon, dollar bill, etc... in front of it, you'll know real quick. I was positive I got it right, but no, I got it wrong. It wasn't an easy problem to find because everything worked.

Thank you so much jafro for your input, and for reading my message on YouTube