View Full Version : Burning DexCool

01-07-06, 05:58 PM
Hey everyone.

1997 :canttalk: Catera

Just replaced the starter and change the oil (10w30). Car had been sitting for awhile.


I have a loss of coolant when I drive my Catera. When the car is turned off there is no loss of coolant but when the car is running and has been warmed up, it starts to burn coolant. The smoke seems to be rising from the center of the engine.

I've looked in the oil filler valley for white build-up and there is none. There was some on the cap but from what I've read this is normal. I've also looked into the overflow tank and I couldnt see anything that looked to be foriegn material. Any ideas on what this could be? Any help would be greatly appreciated.

01-07-06, 06:57 PM
I was just thinking and realized something that may be of use in solving this problem.

When I was replacing the starter there was a leak of fluid, orange in color. I didnt know what it was at the time but now that I think about it, it was probably the old DexCool leaking out from somewhere towards the back of the engine on the passenger side, near the firewall.

The leak wasnt extreme and it was rather deceiving. While working on the car I didnt notice it but when I would come back the next day I would notice fluid had leaked on my lights. I figured it was transmission fluid leaking out from jacking up the engine a little a bit. Thats why I didnt pay much attention to it. Hope this helps.

01-07-06, 07:04 PM
Have you taken a look at this post?


IT could either be the oil cooler, the heater (water) control valve or the coolant crossover valve. They're all back in that area.

Mine is having a similar problem to yours right now.

01-07-06, 07:24 PM
Yes I have looked at that thread and I thought it might be the oil cooler but wasnt completely sure. Would pressure testing the system tell me what the problem is?

01-07-06, 07:48 PM
Yes I have looked at that thread and I thought it might be the oil cooler but wasnt completely sure. Would pressure testing the system tell me what the problem is?

I believe that whatever is leaking will do the same thing as if the car were running- which is leak. You'll need to gain more access to the area to see phsyically whats actually happening.

01-07-06, 08:16 PM
Any suggestions on where to start?

01-08-06, 01:19 PM
Alright heres a little update:

I ran the car for a solid 30 minutes today and got it warmed up. I didnt seem to be losing much coolant but I could still smell the burning coolant. I looked under the car and saw a leak so I put my hand there and smelled the liquid. I believe it was water. It snowed here in MA this morning. It didnt have a coolant smell to it.

I turned on the heat as high as it would go and it was working fine. If it was the heater control valve would there be a problem with the heat in the cabin?

So stumped I just decided to look in the oil valley one more time. There was the white build up in the valley and on the cap. I didnt think this was a problem the first time around so did a forum search. All the problems I am experiencing seem to point to the oil cooler as being the problem.

http://www.cadillacforums.com/forums/showthread.php?t=59803&highlight=white+oil This thread seems to describe my problem pretty well.

So I am losing coolant and smelling the burning coolant from the engine compartment. The overflow tank and oil drip stick all seem to be fine. However the oil filler valley is getting that white build-up.

On a side note after running the car for 30 or so minutes I started to hear a squeaky sound from the engine. It sounded like it was comming from one of the pulleys but I'm not enitrely sure. Im not sure if the belt was ever replaced on the car. It has 93,800 miles on it so Im going to replace it anyway. Is it hards to replace by yourself?

01-09-06, 02:40 PM
Alright so I brought the car into my school's auto shop today and worked on it. When I jacked the car up coolant started pouring out from the bottom of the car near the transmission. I went under there and spent the better part of 1/2 hour looking for obvious leaks but because those damn germans like everything so tight I couldnt see anything.

So I started going through the list of problems and thought that the heater control valve was easy enough to check. So I removed the cabin air filter and the bay door to gain access to the passenger side of the engine. I pressurized the system with my pressure tester and could see coolant still leaking from the bottom of the car but when I looked in the bay door to see the heater control valve I couldnt see any obvious leaks.

If the valve was broken would I see the coolant leak right away from this access door? If yes, then I think it is safe to say my heater control valve is fine.

Now I have to check the coolant crossover valve. Where is this located and if anyone has some step by step instructions to get to it that would be nice. Thanks in advanced.

01-11-06, 02:33 PM
Alright so I've been ripping apart my engine the past couple of days and I finally got to the oil cooler today. On top of the oil cooler there is an orange and black crusty build-up. I am assuming this is the coolant and oil and that this is the source of the leak. I'll be replacing the oil cooler sometime soon. What else should I replace while I'm "down there?"

01-11-06, 02:43 PM
Do a search on my user name ("tlarwa") and you'll get a good answer. I asked this same question once before and received a good response on what else makes sense to replace.

01-11-06, 04:52 PM

01-11-06, 04:56 PM
Was this the thread you were talking about: http://www.cadillacforums.com/forums/showthread.php?t=60050

01-11-06, 04:56 PM
That's the one!

01-12-06, 07:27 PM
Ordered the new oil cooler and a new coolant crossover bridge today. Cost me roughly $340 shipping included and 1 year warranty on parts. So I'll be replacing the oil cooler and the coolant cross over bridge over the next two weeks. I beleive this should fix my coolant leak/burning problem.

Any recomendations while putting all of this back together? Are there any cleaning procedures I should take? Should I clean out my throttle body? Anything like that?

01-12-06, 10:12 PM
Take a look at this link ... it has about all the info you'll ever need regarding the oil cooler replacement...


01-12-06, 10:36 PM
Thanks a bunch.

02-03-06, 08:45 PM
Ok everyone I replaced the oil cooler, coolant cross-over bridge, and camshaft cover gaskets but once my car heats up the burning DexCool still presists. What else could it be? Any ideas?