Number97 Posted February 6, 2009 Report Share Posted February 6, 2009 My 1997 Deville has a coolant leak that is coming from somewhere on the driver's side toward the firewall. There is so much blocking my view that I can't determine exactly where it is coming from. I suspect the crossover seal may be to blame, but it might be a hose connection, or something else out of my view. I don't think this is a serious mechanical problem, or a failed head gasket, because none of the symptoms are present. I would rather not go digging, because it has been my experience that other mechanical or electrical damages may occur in the process. I have attempted to use the GM sealant pellets, which seem to have slowed the leak somewhat, but it still drips a little bit as the engine cools. Can anyone recommend a more effective sealer that works with the expansion tank system and will not damage or clog the components of the cooling system. Link to comment Share on other sites More sharing options...
Ranger Posted February 6, 2009 Report Share Posted February 6, 2009 It is probably the two coolant pipes that run along the rear head to the heater core. They tend to rust out. They will only get worse. Don't use any other sealer. Replace the pipes. Not an easy job. Link to comment Share on other sites More sharing options...
Number97 Posted February 6, 2009 Author Report Share Posted February 6, 2009 It is probably the two coolant pipes that run along the rear head to the heater core. They tend to rust out. They will only get worse. Don't use any other sealer. Replace the pipes. Not an easy job. Thanks for your reply Ranger. Despite the age of the vehicle; I have found most of the components to be in very good condition. Apparently, the previous owner maintained the vehicle properly, (as I have), and there is very little corrosion present in the cooling system components. I doubt that this is the problem, but I will not rule it out. I will get the car up in the air and take a good look before attempt to do any unnecessary dismantling. Should this be the actually cause of the leak, I won't be purchasing the parts from GM; I foresee a trip to the junkyard for these items if I find it necessary to replace them. I am a firm believer in recycling when it comes to costly parts. If I find that it is the crossover seal; do you have a suggestion for a sealant additive other than the GM Pellets that I have already tried? Link to comment Share on other sites More sharing options...
Ranger Posted February 7, 2009 Report Share Posted February 7, 2009 The heater pipes I referred to are a PITA to get at and tend to rust out for some unknown reason. They are no subjected to road salt, so I don't understand it, but I'd be very leary of putting a used on in. I would not use any other type of sealant. Link to comment Share on other sites More sharing options...
Number97 Posted February 7, 2009 Author Report Share Posted February 7, 2009 The heater pipes I referred to are a PITA to get at and tend to rust out for some unknown reason. They are no subjected to road salt, so I don't understand it, but I'd be very leary of putting a used on in. I would not use any other type of sealant. Thanks again for your response; it sounds like you know what you are talking about. Are you a automotive technician by trade? I have no idea how much these tubing parts would cost from GM. Do you? I don't think that this is the kind of thing that I could find at a local parts store; that's why I am inclined to at least try to find a good salvage part if it is necessary. I'm also pretty darn good at fixing things up. JB weld is one of my favorite products to use for repairing all kinds of things. When properly mixed, that stuff will seal up just about anything. Cold welding is a very effective tool and I have patched up a lot of things that have lasted the test of time. Should I find that it is a cracked or corroded part, I might decide to lay a cold weld on it for about $5.00. This doesn't work for everyone; mixing and application can be a tricky process, but if I do say so myself, I'm very good at it, so no worries, (as long as I can get to it). Link to comment Share on other sites More sharing options...
Ranger Posted February 7, 2009 Report Share Posted February 7, 2009 Nah, I'm not a tech. Just an old shade tree wrench bender, but I've owned Cadillacs for the last 35 years and always get a FSM. Also learned a lot here. I'm sure those pipes are a dealer only item, but you'll see what a PITA they are and won't want to do them again. You may have to tilt the engine forward a little to get at them. Pretty easy to do. Just disconnect the torque strut on the passengers side and replace the other one with a turnbuckle. You should be able to get an inch or two more clearance that way. That's why I suggested new ones. I have repaired many things with JB Weld. Great stuff, but I'll give you a tip. It won't work (permanently) on the surge tank. If that leaks, replace it. Link to comment Share on other sites More sharing options...
BodybyFisher Posted February 7, 2009 Report Share Posted February 7, 2009 There two green hoses also in that area check to see that the clamps are tight we have seen them leak, the hoses are on the two heater pipes and are directly in front of the driver under the crossover. They are silicone hoses and they resist heat so dont replace them with black hose, if they are leaking. The hoses last a long time but we have seen the clamps leak. That said, I replaced my heater hoses last year and they were rusted on the passenger side on the turn. Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
Number97 Posted February 8, 2009 Author Report Share Posted February 8, 2009 Nah, I'm not a tech. Just an old shade tree wrench bender, but I've owned Cadillacs for the last 35 years and always get a FSM. Also learned a lot here. I'm sure those pipes are a dealer only item, but you'll see what a PITA they are and won't want to do them again. You may have to tilt the engine forward a little to get at them. Pretty easy to do. Just disconnect the torque strut on the passengers side and replace the other one with a turnbuckle. You should be able to get an inch or two more clearance that way. That's why I suggested new ones. I have repaired many things with JB Weld. Great stuff, but I'll give you a tip. It won't work (permanently) on the surge tank. If that leaks, replace it. Some good info here; thanks. Link to comment Share on other sites More sharing options...
Number97 Posted February 8, 2009 Author Report Share Posted February 8, 2009 There two green hoses also in that area check to see that the clamps are tight we have seen them leak, the hoses are on the two heater pipes and are directly in front of the driver under the crossover. They are silicone hoses and they resist heat so dont replace them with black hose, if they are leaking. The hoses last a long time but we have seen the clamps leak. That said, I replaced my heater hoses last year and they were rusted on the passenger side on the turn. I can see the two hoses; they're okay, no moisture around the clamps or along the pipe. The leak seems to be coming from below and toward the block, but it could be running down from somewhere else. This requires a better look before I can tell for sure. I saw a cooling system additive at the parts store the other day. It claims to seal radiator leaks, lubricate parts, and rejuvinate the coolant. The label says it's okay to add to expansion tank systems. Can recall the name right now... Link to comment Share on other sites More sharing options...
BodybyFisher Posted February 8, 2009 Report Share Posted February 8, 2009 OK look at the water pump, it is installed in a CROSSOVER. The CROSSOVER is connected at 4 points via seals that crack and leak. I replaced mine last year here is the thread with photos. You will notice photos of the cracked seals also http://caddyinfo.ipbhost.com/index.php?showtopic=13525 Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
Number97 Posted February 13, 2009 Author Report Share Posted February 13, 2009 I have a '97 Deville and I am continuing to have overheating problems. I have come to the conclusion that the radiator is the problem. After warming the engine for about 10 min., coolant dumps out through the expansion tank overflow tube while driving. If it is driven too far, or too hard, it will overheat and messages start popping up on the information center. Originally, I though I was having a thermostat problem, because the top hose wasn't getting hot while the engine was very hot. I changed the thermostat and put it back together, but it was doing the same thing and coolant started leaking from around the water pump housing. I replaced the water pump next and put the GM Sealant tabs in with some more fresh Dexi. It is still spitting out the coolant and overheating, but it seems a little better. There was a leak coming from the driver's side, somewhere near the rear corner of the head. I'm pretty sure it was the crossover seal, but that seems to have stopped leaking. The fans seem to be working okay, but I'm not too sure, because the relay testing methods given in my Haynes manual don't seem to apply to my particular vehicle. The fans are coming on but I can't tell if they are coming on at the right time. This whole problem is complicated by the fact that I have a Service Airbag message on the info center, and it won't let me see the coolant temperture readout. I read someone else's thread and they were talking about looking for cool spots on the radiator as a way of determining if the radiator was clogged. I got the engine up to operating temperature and held my hand close to the front of the radiator; I was surprised to find that the radiator was totally cool over the entire front surface, but the top was hot and so were the hoses. I was really hoping that I wouldn't have to R&R the radiator, but it looks like that's what I will have to do. I am experiencing a bit of a financial crisis right now, so I was thinking about having the old radiator serviced at a shop rather that purchasing a new one. I am thinking that the vehicle has some miles on it and that a flushed radiator might serve my needs just a well as a new one. Can I get some feedback on this? Do you think that my diagnosis of a clogged radiator is correct? Is there something else that I should be checking? Does anyone know how to get rid of the Service Airbag message so I can see the coolant temperature? I have tried changing the fuse and of course removed it to disable the airbag while working around the module, but I don't know how to get this message out of the way so I can properly diagnose the overheating problem. Link to comment Share on other sites More sharing options...
Number97 Posted February 13, 2009 Author Report Share Posted February 13, 2009 OK look at the water pump, it is installed in a CROSSOVER. The CROSSOVER is connected at 4 points via seals that crack and leak. I replaced mine last year here is the thread with photos. You will notice photos of the cracked seals also I have already replaced the water pump and think that I may have caused the leak in the process. It took some very hefty wrenching to remove the old pump with a water pump socket. Since the water pump is housed in the crossover, I may have put stress on the seals and caused the leak to start. However, new information; the leak seems to have disappeared, but go here to read my latest post: http://caddyinfo.ipbhost.com/index.php?showtopic=20944 http://caddyinfo.ipbhost.com/index.php?showtopic=13525 Link to comment Share on other sites More sharing options...
Ranger Posted February 13, 2009 Report Share Posted February 13, 2009 OK, first do an easy and free test. Check the purge line for coolant flow. It's the 3/8" line that runs from the pump to the top side of the surge tank. Pull the line idling cold and be sure that there is flow. If not, locate and clear the obstruction. If that is OK, get a test kit from Napa and test the coolant for exhaust gases before throwing anymore money or parts at it. Either condemn or clear the head gaskets before going any farther. Link to comment Share on other sites More sharing options...
BodybyFisher Posted February 13, 2009 Report Share Posted February 13, 2009 I was not suggesting that you look at the water pump, I was directing you to the crossover and its seals Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
Texas Jim Posted February 13, 2009 Report Share Posted February 13, 2009 What Ranger said. Link to comment Share on other sites More sharing options...
Number97 Posted February 14, 2009 Author Report Share Posted February 14, 2009 OK, first do an easy and free test. Check the purge line for coolant flow. It's the 3/8" line that runs from the pump to the top side of the surge tank. Pull the line idling cold and be sure that there is flow. If not, locate and clear the obstruction. If that is OK, get a test kit from Napa and test the coolant for exhaust gases before throwing anymore money or parts at it. Either condemn or clear the head gaskets before going any farther. HEAD GASKET?!! HA! HA! HA! Why do so many people automatically assume the head gasket is the problem when a Northstar is overheating? I appreciate your response Ranger, but I have to disagree with the head gasket theory. There's no excessive steam or coolant odor coming from the exhaust and no abnormal deposits on the plugs, so I have no reason to suspect a head gasket. The engine is performance is awesome, (just as it has always been), and it sound great purring through the flowmaster exhaust system. However, your suggestion to check the purge line is something that I will do in the process of the radiator job. I don't know if it will do any good, but it couldn't hurt. By the way, I was just wondering, do you own stock in NAPA? Link to comment Share on other sites More sharing options...
Number97 Posted February 14, 2009 Author Report Share Posted February 14, 2009 What Ranger said. Hmmm, interesting response; but don't you think it's a bit wordy? Link to comment Share on other sites More sharing options...
Texas Jim Posted February 14, 2009 Report Share Posted February 14, 2009 What Ranger said. Hmmm, interesting response; but don't you think it's a bit wordy? Nope. Link to comment Share on other sites More sharing options...
ted tcb Posted February 14, 2009 Report Share Posted February 14, 2009 If that is OK, get a test kit from Napa and test the coolant for exhaust gases before throwing anymore money or parts at it. Either condemn or clear the head gaskets before going any farther. Ranger's advice is solid, based on years of discussing this same topic with different people. Once the HG is ruled out, you can start replacing cooling system components. Many have replaced rads, hoses, surge tanks, t-stats, crossover seal, w-pump ... without first checking for exhaust gasses in the coolant. Of course, with your fresh Dexcool, there's no point in checking the new coolant for contaminants until you've put more miles on the car. When the HG's start to go on these engines, you're only clue is sporadic overheating, quick spikes in temp's, sometimes followed by weeks of normal driving. Other than that, no typical HG signs appear with the Northstar motor. Hopefully, its something very minor like a bad rad ... have you checked the plastic side tanks to see if they're cracked? Good luck. 1989 FWD Fleetwood, Silver 1995 STS Crimson Pearl on Black leather 1997 STS Diamond White 1999 STS Crimson Pearl 2001 STS Silver 2003 STS, Crimson Pearl Link to comment Share on other sites More sharing options...
Ranger Posted February 14, 2009 Report Share Posted February 14, 2009 Have it your way. Link to comment Share on other sites More sharing options...
Number97 Posted February 14, 2009 Author Report Share Posted February 14, 2009 Have it your way. I'll let you know how it comes out... Link to comment Share on other sites More sharing options...
Number97 Posted February 14, 2009 Author Report Share Posted February 14, 2009 If that is OK, get a test kit from Napa and test the coolant for exhaust gases before throwing anymore money or parts at it. Either condemn or clear the head gaskets before going any farther. Ranger's advice is solid, based on years of discussing this same topic with different people. Once the HG is ruled out, you can start replacing cooling system components. Many have replaced rads, hoses, surge tanks, t-stats, crossover seal, w-pump ... without first checking for exhaust gasses in the coolant. Of course, with your fresh Dexcool, there's no point in checking the new coolant for contaminants until you've put more miles on the car. When the HG's start to go on these engines, you're only clue is sporadic overheating, quick spikes in temp's, sometimes followed by weeks of normal driving. Other than that, no typical HG signs appear with the Northstar motor. Hopefully, its something very minor like a bad rad ... have you checked the plastic side tanks to see if they're cracked? Good luck. Not a good idea to keep running the car with a bad radiator. The car has an overheating problem and I think the fact that the radiator is cool while the engine is hot is a good indicator that the coolant is not getting through the radiator core. Haven't noticed any cracks in the side tanks; is it possible for there to be cracks in the side tank and not be leaking coolant? I'm taking the radiator out in the morning, so I will be able to take a good look at it, but there hasn't been any leaks from the radiator. I haven't seen any suggestions regarding the SIR messages that are blocking me from seeing the temp gauge. Anybody got any info on this subject? Link to comment Share on other sites More sharing options...
BodybyFisher Posted February 14, 2009 Report Share Posted February 14, 2009 I merged your overheating threads together, keep related threads together so we can see ALL history. As far as your attitude with 14 posts LOSE it. You came here for help, we did not go to you. WE including RANGER have been doing this a LONG LONG time, we DO NOT automatically assume that head gaskets are the problem. Quite the contrary we eliminate all issues before going there. You have not checked for a purge line issue yet. Its possible your system has air in it that is causing your water pump to cavitate causing overheating. Especially since the overheating occurred after you changed the stat, and the refilling of the cooling system. However it is also possible that SUPERHEATED gases and boiling ruined the stat!! It is possible that your radiator is clogged given the age of your car but I doubt it, apparently this started AFTER you replaced the thermostat? Checking the coolant for by products is a quick and easy way to eliminate the head gaskets, then you can focus on other issues. The 93 through 99 NSs DO have problems with head gaskets if the coolant is NOT maintained propertly. Make sure the coolant concentration is 50/50 and that the system holds pressure. You already said your system leaks coolant, has that been fixed or is it still leaking coolant? You were looking to seal it which was the title of this thread, didnt you narrow it down to the crossover seals? As you know a system that does not hold pressure will boil at a lower temp. Fix all the problems first, check the purge line, check the coolant concentrations and pressure test the system then do the NAPA combustion gas test. But pulling the radiator is unnecessary before you check to see if you have air in the system and that its purging. Also make sure the water pump belt is not slipping and the water pump tensioner is not binding and that it is putting adequate pressure on the belt and its not slipping. I assume that its good as you just changed the water pump. What caused the problems with the water pump?, I know that some have problems getting theirs out, mine fall right out with a breaker bar I have never understood the difficulty. You are looking for evidence of head gaskets at the exhaust and on the plugs WRONG! Compression is 120 PSI!, what is the cooling system pressure 15 PSI? What do you think will breach first? Exhaust gases are forced into the cooling system superheating the coolant causing spontaneous boiling. I will be the first to admit that your overheating problem is unusual, to overheat at IDLE. CHECK THE PURGE LINE FIRST. Please LOSE the attitude and criticism of our members, they have LOTS of experience with this. TAKE ALL ADVICE and DO ALL DIAGNOSTICS without being argumentative or move on. It might be best to summarize exactly what you have done at this point and what problems you currently have (leaking, overheating etc) Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
BodybyFisher Posted February 14, 2009 Report Share Posted February 14, 2009 How are the SIR messages blocking the coolant temp? Hit reset/information and see if the SIR message goes away. The side tanks can leak under pressure you dont see the coolant leak it comes out under pressure and immediately vaporizes, you will see white deposits on the side tanks. The radiator will be COOL if you have AIR in your system and the water pump is cavitating also because you are not circulating coolant TED is correct that if you have new coolant a combustion gas test may not be accurate at this point, let it overheat and then test it. IF you have an active leak from the crossover seals because you damaged them doing the water pump and the system is not holding pressure you need to fix the seals. Get a cooling system pressure gage and test to see if the system will hold 16 PSI, and let it leak down and see what it holds or doesnt hold Also check the cap, made sure it holds the rated pressure and that it is the correct one. Also are the cooling fans working. Start with the purge line, remove the bolt with a hole in it and inspect it for a clog Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
Number97 Posted February 16, 2009 Author Report Share Posted February 16, 2009 I was not suggesting that you look at the water pump, I was directing you to the crossover and its seals I understood your post; but I have already replaced the pump, (before I made my post), and I think that I may have caused minor damage to the crossover seal while I was doing the replacement of the pump. I had to crank pretty hard on the old pump to get it out and even more pressure was required to seat the new one. Since the pump is located in the crossover, I suspect the force applied during the removal and installation process of the pump caused the crossover seal to start leaking. To update my info, I took out the radiator and put it in the shop on Saturday. The guy at the shop did a reem job and thorough flushing. After re-installing the radiator the engine seems to be running cooler now and it didn't spit out the coolant, but I still can't see the temp gauge because of the Service Air Bag message. I really need to get that cleared so I can stop flying blind. Any info on clearing the Service Air Bag Message. Link to comment Share on other sites More sharing options...
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