Okay, a little back story...
so i purchased this 1993 940 with 180k miles on it for a very low price. it was thought to have blown a head gasket. i was told by the previous owner who is a trustworthy friend that it had never overheated and he was parked one day when a huge amount of smoke came from under the hood. upon inspection i noticed that the plug/senser on the top right side of the radiator had popped out spraying fluid everywhere and would explain for the amount of smoke. it sat parked since that day. i took it to a mechanic friend who replaced the plug and flushed the system a few times. after having it a week or so he said it showed no signs of a blown head gasket and was not overheating. so i had the brakes done all around . at this point im in the car around $500. i drove it for a day or so and everything seemed fine except for a rough idle that kind of bounced at low rpms. no smoke from the exhaust, and once warmed up the temp gauge sat right in the middle. it was later that night that i was parked for about 10 minutes and the plug blew.. just as described a huge amount of smoke.... the car did not overheat. nothing from the exhaust, just the coolant spraying under the hood. i let it cool down, added a bit of water(about a fourth gallon) and drove it home.

when the plug blew, the fluid that sprayed out was green and normal .
upon inspection the next morning when i started the car strange foam/slime oozed out of the hole where the plug was.

there is no sign of this substance in the engine. none on the dipstick.

also to note
previously to this problem the original owner just had the radiator replaced and the timing done.

now my question.

is there anything that would cause this other then a head gasket on a 93 non turbo 940. is there a chance its a cheap faulty radiator?
could something else have failed and caused this?

 

that slime in the overflow bottle looks a lot like emulsified oil+water. whats under the oil cap, and on the dip stick ?

I'm pretty sure you'll need a new radiator to fix that blown plug/sensor, anyways. once that plastic starts to fail, no amount of epoxy or whatever will hold it together.



the transmission cooler is inside the radiator, so yes, if that has failed, that could easily be ATF mixed with the coolant. and you'd find the same slime on the transmission dipstick. I'd do a really thorough ATF flush using 8 quarts or so of cheap Dex-Merc-III after replacing the radiator, then drive it for a few days to thoroughly circuiate the ATF, and do another flush with good ATF (unless you're of the cheap ATF school anyways). I like to use Castrol Multi, which is rated for 80s/90s toyotas, your automatic tranmsission is a Aisin-Warner AW70/71, which is a toyota tranny, Toyota used these in RWD Supra turbos and such, as well as 2x4 pickups all through the 90s.

 

The dipsticks look normal . Both of them as does the oil cap. It appears The only place the substance can be found is in the coolant system. Someone told me that the non turbos don't have anywhere for fluids to mix except a blown head gasket. But no other signs are there. Are you saying there's a good chance it's just the radiator??

 

um, non-turbos have a transmission cooler, but not an oil cooler. that metal pipe just below the blown sensor port is the transmission return line, thats where you disconnect it and hook a vinyl hose into a waste jug to flush the transmission fluid

 

Thank you very much! Any recommendations on the replacement radiator? There seems to be a lot of variables out there.

 

Nissen made the original.

 

You are getting oil into the cooling system, somehow, either the radiator or the HG.
Radiator plug should not blow out unless there's too much pressure (I put a zip tie around all of these to prevent that.)
Did your mechanic take a compression, or a leak down test?
You probably have a bad HG, if I was to bet...

 

You could have the transmission oil cooler leaking inside the radiator or a headgasket that only leaks the oil pressure into the cooling system but isn't bad enough yet to let the coolant get into the oil.

Compression and or a leak down test might tell you something but the headgasket can get bad and not be leaking to a cylinder so wouldn't show up in either test and still be bad.

Have you been loosing engine oil or trans fluid lately ??

 

You can get the original radiator from Tasca parts, that is what I did since I didn't want a cheap chinese radiator that would let me down and cost me the engine. Surprisingly, the additional cost for the original was not that much.

 

I tried to take it out today and it started sputtering at low roms and eventually stalling and bogging down not taking fuel at all or maybe not getting fuel. I was quoted at 1300 for new rad , head gaskets , and timing. At that point I'll be in the car 1800. Does that seems worth it or should I sell as is and cut lossess...

 

$1,300 is quite high! I'd get the radiator pressure tested by a radiator shop for leaks, go from there...

As far as keeping the car, is it a nice car? I worry more about the cosmetics on these cars, as they are either very expensive or hard to get, than the mechanicals. How's the interior? What kind of life has it had?

 

well, he did say head gasket, thats close to a $1000 job at most shops around here (but they likely do a new timing belt, new water pump, replace any failing engine seals, etc, at the same time). the radiator replacement is pretty easy, most anyone with some hand tools can do it themselves.