SupraFever

Hi all,
I have a 94 90CS and all of a sudden it started to overheat today. It was fine and I drove it a lot the past few months but this caught me by surprise. This is what it does: It starts fine and drives fine unless you step on the gas more, then it starts to shake, but let off the gas and it is fine. The temp climbs to the max and the coolant looks like is being forced back into the reservuor and it overfills and gets forced out of the container. Also, the heater does not work, that is, it does not warm up. It just blows cold air, mind you it is about 15-20F outside here in Chicago. BTW the car has 99000 miles.
Does anyone have any idea what could the problem be?? Can it be the thermostat??
Thanks in advance.
Donatas

4kq

Cold heater is the thermostat. The rough running is probably over-enriched injector on all the time because of the cold thermo. The boilover is a harder one. I once had a plugged rad that gave the same symptoms, the coolant froze...Didn't warp the head, but the AF was not rated for -40c

SteveAngry

Yep sounds like a blockage problem...either in the radiator or somewhere in the "plumbing." Keep in mind that the coolant system is pressurized and once the radiator cap blows(as in boils over at the expansion tank cap) it is suggested to replace the pressurized cap...failure to due so will result in a less than ideal cooling system...also the suggestion that the coolant is frozen is very valid...do you still have the factory "lifetime" pink fluid(pentosin) or has it been changed over to the green stuff(prestone,etc)It might need to be changed if it's old...get it tested. Anyways it's probably not a good idea to drive the car untill it's properly diagnosed...

Steve Ankney
88 5000
Holland, MI

MikTip

Sounds like a stuck or frozen thermostat!

SupraFever

It has the green coolant in it. A few questions: Where is the thermostat? Where is this pressuriaed cap that you guys are talking about?
Thanks, guys, for your help.
Donatas
94 Audi 90CS (disabled)
94 Toyota Supra TT

absolutcq20v

Overflow resevoir gushing coolant when the engine is running...past experiences of mine at my buddies shop say blown headgasket (the compression is pushing into the water jacket). Is that also possible??

MikTip

<center><img src="http://www.pixhost.com/pixm/miktip/thermo.gif"></center><p>Thermo is located under all that cowling on the left (passenger side) front of the engine just above the alternator. It can be changed without
R&R'ing the timing belt!

Pressure cap is on the plastic bottle where you add anti freeze to.