: 1996 Fleetwood Brougham overheating, Help!!



cookieeater
08-29-10, 09:03 AM
Hello All,
I am back after a semi long vacation from Cadillacs. I have owned a 1978 DeVille, and a1993 Sixty Special a few years ago. I just bought a 1996 FW with 79K miles on it and in excellent condition, however it has been sitting for about 6 or so years. It's a 1 owner car, the owner passed away in 2004, and the Son let it sit till now. I bought it and had it shipped to me here in Orlando.

I changed all the fluids, flushed the radiator, and all was fine, I have put about 150 miles on it locally. I went on the hiway yesterday and after about 15 miles the temp lite came on, I pulled over, and yes steam every where. I let it cool a bit drove to a quick mart, used their hose and refilled the tank after it cooled. I drove back home with no problems. So now, I am wondering what happened. Thermostat? Radiator? Air in system? Both fans are working. Any suggestions? I am thinking of taking it to my shop and have them flush it and replace the thermostat. Thanks in advance, Kim

jayoldschool
08-29-10, 11:23 AM
Did you change the thermostat?

Did you properly bleed the system after flushing the rad?

HUF
08-29-10, 11:24 AM
What were the driving conditions when it overheated? Did you bleed the air well after flushing and refilling the system? The cooling system of LT1 is tricky, you could have air pockets. The serpentine belt, tensioner and water pump should be inspected as well. Coolant tank cap might be faulty.

You can bring the coolant temperature reading on your climate control to monitor it while driving.

cookieeater
08-29-10, 12:05 PM
Thanks for the quick reply!! I did not change the thermostat but that's first on my list this afternoon. When I flushed the Rad/system, I did get a lot of crap out of it. It had the original pink (Dexcool) antifreeze in it. Like I said its been sitting idle for a bit. I had to replace the A/C compressor, drier, and orrifice tube. I replaced the belt tensioner and belt. The water pump looks fine (from the outside). I know about bleeding as my Son had a 96 Cavalier and I had a heck of a time getting the air out of that. That is why I think it is either air pockets or the thermostat. I do have a shop manual, so I will look upm how to monitor the temp, unless you can tell me easier. My old 60 Special was great for OBD, I guess this has OBD2 so I am not so familier with it. Anyway It would be great to monitor. The conditions were as follows: I was doing about 68, then cruised up to around 74 to pass, then I noticed the temp light on, pulled over and it was boiling over. I cooled it off with a hose, topped offed the tank, drove home with absolutely no problems, no leaks, etc.!! I believe the cap is fine also. Just wish they had a gage rather than just an idiot lite. Kim

HUF
08-29-10, 12:37 PM
Watch the video in FAQ. The pointer for coolant temperature is 8.
http://www.cadillacforums.com/forums/rwd-19xx-1984-deville-fleetwood-1985/173800-rwd-faq-tech-info.html

cookieeater
08-29-10, 12:56 PM
Huf,
Thanks, but i must be stupid or something, LOL as I can not find the video!!! I looked under FAQ but can not locate!! Kim

HUF
08-29-10, 01:04 PM
Huf,
Thanks, but i must be stupid or something, LOL as I can not find the video!!! I looked under FAQ but can not locate!! Kim

Click this link: http://www.cadillacforums.com/forums/rwd-19xx-1984-deville-fleetwood-1985/173800-rwd-faq-tech-info.html

Scroll down. See the dash of a Roadmaster? Click that clip. Despite it is a Roadmaster, you will get an idea.

cookieeater
08-29-10, 03:52 PM
Huf,
Thanks, I got it now. Somehow my puter at work did not show the clip. I will change the thermostat then see what happens. Kim

cookieeater
08-29-10, 06:15 PM
OK Guys,
Here's what I have now!! I just replaced the thermostat bleed system and ran the car at idle it creeped up to 190-195 on the A/C panel using the onboard dianostics. I drove it around a bit and the temp stayed at about 185. The left fan does not seem to come on but it did yesterday, maybe it has to be really hot to come on. Anyway the low coolant lite is on and it is not low, so that's another issue. When I parked it and idling the coolant tank cap is seeping, and still seeping when the engine is shut off. So maybe it is losing coolant to the point of overheating?? Next step is to replace the cap. What do you all think? Kim

sven914
08-29-10, 06:48 PM
185 is normal temperature for cruising. The fans should not come on until 225 degrees or unless the A/C is on.

jayoldschool
08-29-10, 07:20 PM
Get the nose of the car up in the air, and bleed the air out of the little valve on the thermostat housing. Keep bleeding until no air comes out, just coolant. Put a new cap on, too. Note, if you are changing the thermostat, they are different than the old Gen 1 small block thermostats. Your car takes a 180, and the gasket is like an o-ring that goes on the edge of the thermostat itself. There is no gasket between the thermostat housing and the block.

If you ever find your car getting hot, just put your AC on MAX. This will turn on both rad fans.

sven914
08-29-10, 08:09 PM
^Wouldn't turning the ECC to max heat and defrost work better? That would turn the cooling fans on plus vent the extra heat off the engine.

HUF
08-29-10, 08:11 PM
Replace the cap and inspect the reservoir. Your problem seems to be cap-related, it does not hold pressure.

cookieeater
08-29-10, 08:38 PM
Thanks Guys,
The cooling system is so simple but this one is kicking my but or I think kicked my butt. I installed the new cap, no leaks now, temp at idle is 195. I will drive it to work tomorrow rather than ride the motorcycle as I normally do. I think it is fine now, just need to put antifreeze in it as its 100% water now till I figure it out. I got the new thermostat at Autozone, no temp marked on it or the box. The old one that came out was a 180. I got all the air out of it with the bleeder. I think I won the war. Its nice to see the coolant temp on the ac panel, Thanks for the info. Thanks again, I'll keep you posted!! Kim

jayoldschool
08-29-10, 08:46 PM
Glad it worked. Happy to help.

cookieeater
08-30-10, 04:15 PM
Hi Guys, Back again. I drove the car to work today and this morning it stayed at 175 when I got to work. I drive about 8 mile, 40 mph tops, OAT 78 degrees. Got back after work and temp was 195, ac on idling both fans on. The top of the tank is a little damp, not leaking like before but just a little damp. Should it be bone dry? Is 195 ok for idling? This is Orlando and it is 95 degrees outside! Kim

csbuckn
08-30-10, 05:20 PM
Sounds pretty good to me, especailly for having just water.

HUF
08-30-10, 08:26 PM
Hi Guys, Back again. I drove the car to work today and this morning it stayed at 175 when I got to work. I drive about 8 mile, 40 mph tops, OAT 78 degrees. Got back after work and temp was 195, ac on idling both fans on. The top of the tank is a little damp, not leaking like before but just a little damp. Should it be bone dry? Is 195 ok for idling? This is Orlando and it is 95 degrees outside! Kim
The top of the tank should be dry. You still have a leak.

cookieeater
09-05-10, 08:41 PM
Huf,
Thanks, I also found the little hose that goes from the top of the tank to the water pump had a small cut next to the clamp. I shortened the hose, re-clamped it and all dry now. refilled with anti-freeze and water. Just wondering, Where is the overflow? Older cars had a overflow hose that ran down the radiator, then they put on a overflow tank. I do not see an overflow on this set-up. Am I missing something? Kim

jayoldschool
09-05-10, 09:31 PM
The tank IS the overflow. It is a sealed system.

HUF
09-06-10, 01:48 AM
Because of the cut you found, the system was not really pressurized. So, it could boil over at some point. You should be fine now (hopefully).