need expert help on overheating

Well. I acquired a 94 sl auto that was overheating. it was owned by a mechanic that said the headgaskets were toast. no problem. so after changing the head gaskets and water pump. put it back together still over heats.changed the radiator, took the tstat out, and changed the cap. still overheats. changed the little temp sending unit and the center gauges. still overheats. figured the heads were warped. took them off. went and got them resurfaced (they were warped. one was 8 off an the other was 12 off) dipped an pressurized. all back together an the damn thing is still overheating. wtf am i missing here??? It only drives about 8 minutes before it decides to overheat. turning the heat on wont bring it down.i dont have the ac on while driving it. BOTH fans are on while its overheating. I just dont know whatelse it could be and im getting aggervated with it. PLease tell me theres something else that could cause overheating. one thing i have noticed. I have a 92 sl that i toook the tstat out of because it was overheating too. and now when i drive it it takes a good 20 min of stop and go traffic for that thing to get up to normal driving temp. this 94 i got. gets up to normal driving temp in 3 minutes, kinda strange.

I need help. please

The thermostat is essential to the coolant system.

with it not being in there would not cause it to overheat

Coolant is forced to the radiator by the thermostat.

http://www.stealth316.com/images/stim/tim_07-02.gif

still overheating. anyone got any suggestions??

Get an infrared laser from a parts store and while the car is running, point the laser at different parts of the cooling system. Doing that should give you an indication of where your problem may lie.

Have you pressure tested the cooling system on the car?

You may possibly have a blockage in the cooling system or inadequate flow. If the fans are working and youve got a solid sealed system with no thermostat, and a proper mix of antifreeze and water, I don't see why the car would overheat other than improper circulation.

There HAS to be some blockage somewhere. Try reverse flushing the motor.

Buy.com - PRESTONE Flush & Fill Kit

SUPER RADIATOR FLUSH -- 22 OZ. | The Auto Alley

Go to auto Zone, etc

Good luck !!!!! :D

Quote:

---

Originally Posted by mb3000

Coolant is forced to the radiator by the thermostat.

http://www.stealth316.com/images/stim/tim_07-02.gif

---

Not exactly. Coolant flows into the radiator when the tstat opens. The tstat doesn't force the coolant in.

Removing the Tstat can also overheat the car. If the coolant is constantly flowing through the radiator and has no time to cool down, then the radiator can't do its job properly.

I'll take a stab here and say that the engine has had stop leak in it, due to the head gasket issue. Were all the water jackets properly cleaned when the heads were off the block? Is the system properly pressurized at ~15psi? Is the water pump new?

im buying a laser thermo and a pressure test tmw. Im gonna switch the radiator (again) and the coolant temp switch to see if that will help. doubt it tho. radiator was fine in my 92.

I have never seen a car overheat without a thermostat. but ill put one in a see how it goes. It boggles my mind that this car gets up to normal driving temp within 3 min of runing. Without a tsat it should take it a good 20min of stop an go traffic for it to reach temp.



97 vr4. Im not sure if the guy before me put stop leak in. But yes. The heads were dipped resurfaced pressurized. all the good machine shop shit was done

water pump is new.
and how would i tell what the system is pressurized too???

Thanks guys for starting to chime in. I need the help

Quote:

---

Originally Posted by triggerman454

There HAS to be some blockage somewhere. Try reverse flushing the motor.

Buy.com - PRESTONE Flush & Fill Kit

SUPER RADIATOR FLUSH -- 22 OZ. | The Auto Alley

Go to auto Zone, etc

Good luck !!!!! :D

---

I'm thinking this, don't listen to people telling you your car is overheating because it doesn't have a thermostat please. It can cause hot spots and you should have one but it isn't your problem. Drive it a little, then pull over and turn the car off and pull the key out. If you can feel the radiator see if it has cool spots in it. If the top is hot but the bottom isn't then you know it's blocked. If you can't get to the radiator (I know it's tight) then you can check temps with one of these.

http://www.google.com/url?source=img...FW-vRzRtsBSYmA



Also pull the rad cap off when it's cold and rev it a little bit. If water rushes out you might have a head gasket leak or a cracked head. I wouldn't be shocked if the head was cracked.