Now, in summer, the Coolant Temp light comes on after 5 minutes of highway driving. I can get it to go off by turning my heat up to 90 degrees and running in Econ or Defrost mode (taking the windows down of course!) This only seems to help on the freeway, in traffic there’s no relief. Yesterday, when I didn’t do that, the coolant boiled out under the cap.

I always use 50/50 mix
The overflow tank is never used by the system, no draw or overflow
Both radiator fans do work
I’ve never had cool A/C (back to the 83k mile mark)
The dip stick is oil only, no coolant.

About five years ago I had the radiator, water pamp, and heater core all replaced.

Ideas to things to check/replace first? Could the radiator be shot?

 

Hi,
Check that the thermostat is working correctly. Even if it has been replaced before. They are sometimes defective out of the box. Sounds like its not opening enough or is stuck closed and the coolant is bleeding by the by-pass.
Good Luck
Rcad

 

Thanks rcad. I "think" that helped. After I put the thermostat in, I let the car warm up there were no leaks and no Temp light. I buttoned it up, backed out, put it in Drive and had barely any power, like the transmittion was slipping. After adding some fluid to get it back level, it did the same thing.

After letting the car cool down it responded normally BUT, after driving about six miles I again had virtually no power, no torque, getting started from a stop.

This is odd.

 

Hi,
Glad the thermostat worked out for you. I don't think the trans problem is related to the change.
Some questions for you.
Was the trans good before this? How low was the fluid? What color was it and did it smell burnt? How many miles on the car. Has the trans fluid ever been changed? Moves when cold and slips when warmed up sounds like burnt/worn clutches/bands etc. Or maybe a bad torque converter. I have had a few do the same thing over the years. Shifted great when stone cold but when it warmed up a bit it stopped moving. Either way it needs a trans guy to drop the pan and look at the internals.
If they are worn out or cooked its tranny time. If not too bad, fresh fluid and a trans additive might keep you on the road for a while.
Good Luck.
Rcad

 

I drove the car around quite a bit yesterday, and to work today. The thermostat definitely fixed the issue. Awesome. I had my 12 year old son read the Haynes guide and 'do the work' with me. Great, easy project for him to be involved with. He's helped with oil changes, fuel filter change and a few others too.

Tranny is not slipping, hot or cold it acts the same. I didn't check the fluid's smell. It was low, and looked sort of red so I filled it. Car has 230K miles, I bought it at 83K. I've never had the tranny touched in any way. If I manually shift through 1,2,3 it'll move. Only from dead stop it has very little torque in D, it'll eventually get some inertia and start moving. Once I’ve got some speed it seems to respond fine.

I'll post this tranny(?) problem under a more appropriate subject.
Thanks!
-------------
93' Deville

 

Hi Again,
Glad to know its running cool again. As to the trans, sounds like the torque converter is not locking up. I can't remember if your car has the electronic lock up converter or not. If so, there is a sensor or switch that is supposed to lock the converter at a certain RPM/Load. Check your book to see. If it has that type of converter that's where I would look. Also check for any disconnected wires/plugs on the tranny. Great you are having your son help you. We need more gearheads. BTW let us know how it works out. Thanks
Rcad

 

Thanks for the tips on the trans. I've created a new thread about it called " 93 Deville no torque from stop " and it is here
--------
'93 Sedan Deville

 

in working on the stat, you probably moved the distributor and messed up the timing.


.

 

This thread sounds exactly like what is going on with my 93 Deville.
93 Deville no torque from stop .. ERLS fuse blown ?

No 1st gear, E40 error, and I had an A/C error code that I cleared the other day too.

 

As a wrap up to this, replacing the 15 amp fuse (under the glove box) fixed the issue. Turning on the AC must've blown the fuse. The AC doesn't work anyway so now it's officially hands off!

Thanks to this forum and my owners manual for the clues on this one.