hms200 Posted January 13, 2011 Author Report Share Posted January 13, 2011 Thx for the confirmation on my logic with this BBF. Placed an online order for the tank last night. Yep...fingers will be crossed on this. HMS Link to comment Share on other sites More sharing options...
Texas Jim Posted January 13, 2011 Report Share Posted January 13, 2011 Thx for the confirmation on my logic with this BBF. Placed an online order for the tank last night. Yep...fingers will be crossed on this. HMS I have been following this from the beginning. I hope the tank is your problem. I will also keep my fingers crossed for you. Link to comment Share on other sites More sharing options...
BodybyFisher Posted January 13, 2011 Report Share Posted January 13, 2011 Keep looking for the receipt for the engine rebuild, we would love to know what was involved and if any holes were timeserted But let me insert a BUT...... If your cap was not holding say 16 to 18 psi, and the new cap help 16 to 18 psi, you may have blown the tank that was weak from age at that point, 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...
hms200 Posted January 13, 2011 Author Report Share Posted January 13, 2011 Thx for the confirmation on my logic with this BBF. Placed an online order for the tank last night. Yep...fingers will be crossed on this. HMS I have been following this from the beginning. I hope the tank is your problem. I will also keep my fingers crossed for you. Thx for all your ongoing support guys...much appreciated. If I get bored before new tank arrives I may pull it and make an attempt to epoxy the crack. Wouldn't want it that way long term but if I get tired if waiting it might keep me moving forward for the moment. For testing sake the tank will either leak or not leak. JB Weld is pretty darn strong stuff. Yes BBF...I'll keep looking for that shop order receipt for the block rebuild. Will advise if/when it turns up. I never lose things so evidently I just forgot where I had put it away for safe keeping. LOL Link to comment Share on other sites More sharing options...
BodybyFisher Posted January 13, 2011 Report Share Posted January 13, 2011 I found this, just think if your cap only held 8 PSI, times 3 PSI that would be a reduction of 24 PSI, if the cap was intended to hold 16 PSI. Therefore, at 16 PSI, times 3 PSI pressure adds 48 PSI over the boiling point of 212 degrees or a total boiling point of 260 degrees, if the cap only held 8 psi, the boiling point would be reduced to 236 degrees. This is with straight water and assuming the cap holds 8 PSI but you can see the impact of a weak system cap. Here is an interesting article Modern cars, like many of those built after 1955, started using pressurized cooling systems. The benefit was that, for every pound of pressure created in the cooling system, the boiling point of the water was raised by three degrees. By sealing up the cooling system, and adding pressure, the boiling point of the water was raised. Then, the engine could be operated at a higher temperature and operated more efficiently. Today, most modern cars use a 16-lb. cap to raise the boiling point 48 degrees higher than the normal 212 degree boiling point Read more: http://wiki.answers....e#ixzz1Aw8tS5H2 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 January 13, 2011 Report Share Posted January 13, 2011 In real basic terms.... An automobile engine is nothing more than a "HEAT PUMP" Thermal efficiency rises as temps increase. The hotter an engine runs internally...the more efficient it is. I know there all kinds of "BUTS" to that...but simplified...that's the way it is. Link to comment Share on other sites More sharing options...
hms200 Posted January 13, 2011 Author Report Share Posted January 13, 2011 Yep...Ranger raised the leak down test to me earlier and described it. But I don't think he mentioned bubbles...seems he spoke to pressure loss, which suggested to me that I didn't have proper test gear to perform such. If there is a special spark plug adapter and bubbles are what we'd be looking for then that may yet be within my abilities to perform. I'll watch for more info from you on that.... You might have more than bubbles. Read post #38 again. The picture is a home-made shop air to spark plug adapter. The far right fitting is a spark plug with the porcelin punched out. Next is a short fitting in the hole that you tap with the appropriate threads. Next is a coupling to adapt the short fitting to a flexible (grease gun extention) hose. The other end of the flexible hose is adapted to shop air fittings. Pretty cleaver homemade fitting... Ok well...as promised, results from highway road test... Results: Um...would you believe a split/crack in the lower underside of the coolant collection tank? Yep...very fine little squirt coming out down near the clamped bottom hose. No overheating whatsoever because I didn't allow it to go dry. Ok, so that's something...and it makes total sense!! So...obviously next step is to replace the tank and then do further testing from there. I don't believe excessive pressure could have blown the tank, because the pressure relief cap would have or should have prevented that. But...the old cap did allow boil out. So, if I'm to speculate on what was happening before with prior owner I'd guess a combination of weak cap and the crack...both combined not allowing proper pressure to be retained and the associated coolant loss. I replaced the cap and that then moved sole issue to just the crack. Can this cracked tank be associated with excessive pressure from blown HG's? To me it doesn't seem so since old cap allowed boil out and new cap is properly pressure rated and it's NOT boiling. My logic make any sense? Anybody have any personal thoughts or insight on this? HMS FOLLOW-UP: Removed the tank and determined crack was actually in the bottom return hose neck molding coming off the bottle rather than within the bottle surface itself. Guess the spray was bouncing off the tank to give wrong impression of source location. The neck was actually 99% snapped off to be more exact...barely got the hose off without snapping it rest of the way off...was hanging on by a thread. So...JB Weld applied to the neck as an attempted temp fix until new bottle arrives so I can hopefully proceed with further testing right away. If it doesn't hold then hey, didn't hurt to try. It's drying now so we'll see...JB Quik actually used so maybe four hours needed to dry rather than overnight...but not gonna rush it in any case. That tube obviously is a high stress point with little true holding surface...so I'm not overly hopeful for success. But...I'm a really big fan of JB Weld so I may be surprised. If it holds then that will cool and strictly temporary...no way I'd trust it long term. HMS Link to comment Share on other sites More sharing options...
JohnnyG Posted January 13, 2011 Report Share Posted January 13, 2011 JB Weld is pretty strong, but contains lots of filler material so its main strength is in its high build qualities which add bulk to the repair. If you do not have enough room to repair that joint as it is, try adding some reinforcement to the mix. I have often used epoxy saturated cloth or fiberglass matting to make a very strong repair. In fact the left headlight assembly on my old '99 STS was done in just that way. What you really need to pay attention to is the adhesion to the plastic tank, so clean, clean, clean first. By the way, I think we have a winner here, NOT a bad HG. Failure mode not correct. Never underestimate the amount of a persons greed. Link to comment Share on other sites More sharing options...
hms200 Posted January 13, 2011 Author Report Share Posted January 13, 2011 JB Weld is pretty strong, but contains lots of filler material so its main strength is in its high build qualities which add bulk to the repair. If you do not have enough room to repair that joint as it is, try adding some reinforcement to the mix. I have often used epoxy saturated cloth or fiberglass matting to make a very strong repair. In fact the left headlight assembly on my old '99 STS was done in just that way. What you really need to pay attention to is the adhesion to the plastic tank, so clean, clean, clean first. By the way, I think we have a winner here, NOT a bad HG. Failure mode not correct. Yep...thx. I did clean the area multiple times with brake parts cleaner and sanded down the bond area good with very low grit paper...then cleaned again. I also did build up the repair as I went along and made sure hose area remained clean/smooth and inside of tube remained clear. Feels pretty darn strong right now but will let it sit for a bit longer for extra drying since no big rush. HMS Link to comment Share on other sites More sharing options...
Ranger Posted January 14, 2011 Report Share Posted January 14, 2011 JB Weld (if done right) is a temporary repair at best. Been there, done that. I think mine lasted about a year. Link to comment Share on other sites More sharing options...
hms200 Posted January 14, 2011 Author Report Share Posted January 14, 2011 JB Weld (if done right) is a temporary repair at best. Been there, done that. I think mine lasted about a year. Right...would see it no other way. I have new tank ordered so all I'm looking for is a week or two of problem free service to get me thru balance of testing. I sureeee hope this is total extent of problem and not just a residual or secondary problem. I feel confident that this will resolve the issue...but I've seen how that grimlin has already fooled me before. HMS Link to comment Share on other sites More sharing options...
joeb Posted January 14, 2011 Report Share Posted January 14, 2011 5 pages of comments. starting to loose track of thread. will a car with good headgaskets overheat without a radiator cap installed? the thermostat is 180 so all coolant in radiator and pipes is way below that temp. Link to comment Share on other sites More sharing options...
hms200 Posted January 14, 2011 Author Report Share Posted January 14, 2011 5 pages of comments. starting to loose track of thread. will a car overheat without a radiator cap? or boil over without one? a car with good headgaskets that is. Hi Joeb...you joking with your question, yes? Yes to both questions...pressure lowers the boiling point. HMS Link to comment Share on other sites More sharing options...
JimD Posted January 14, 2011 Report Share Posted January 14, 2011 ....pressure lowers the boiling point.HMS Say what?? Jim Drive your car. Use your cell phone. CHOOSE ONE ! Link to comment Share on other sites More sharing options...
BodybyFisher Posted January 14, 2011 Report Share Posted January 14, 2011 5 pages of comments. starting to loose track of thread. will a car with good headgaskets overheat without a radiator cap installed? the thermostat is 180 so all coolant in radiator and pipes is way below that temp. It is fully open at 180, but that does NOT mean that the TOP temp will be 180, we know that, we constantly see highway temps of 192 to 205, and traffic temps of 215 to 230, with the 180 stat, enough to spontaineously boil out the system if you removed the cap at those temps If a CAP is left off, you have no pressure build up at all, water boils at normal atmosphere at 212, but it will boil at 260 with a cap holding 16 PSI What are you getting at? 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...
hms200 Posted January 14, 2011 Author Report Share Posted January 14, 2011 ....pressure lowers the boiling point.HMS Say what?? I didn't see the last point to the questions..."a car with good head gaskets"...so now maybe I don't understand the question? Normal operating temp is typically above 180 degrees (190-210 by spec I believe for the Northstar). HMS Link to comment Share on other sites More sharing options...
BodybyFisher Posted January 14, 2011 Report Share Posted January 14, 2011 5 pages of comments. starting to loose track of thread. will a car overheat without a radiator cap? or boil over without one? a car with good headgaskets that is. Hi Joeb...you joking with your question, yes? Yes to both questions...pressure lowers the boiling point. HMS I hope you made a mistake with this post, PRESSURE RAISES the BOILING POINT And YES an engine WILL overheat with NO cap or NO pressure from a bad cap, as the coolant will boil at a lower pressure, this is basic SCIENCE See the link in my post #55 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 January 14, 2011 Report Share Posted January 14, 2011 ....pressure lowers the boiling point.HMS Say what?? I didn't see the last point to the questions..."a car with good head gaskets"...so now maybe I don't understand the question? Normal operating temp is typically above 180 degrees (190-210 by spec I believe for the Northstar). HMS Read what you said, pressure lowers the boiling point That is what JIM is getting at 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...
hms200 Posted January 14, 2011 Author Report Share Posted January 14, 2011 ....pressure lowers the boiling point.HMS Say what?? I didn't see the last point to the questions..."a car with good head gaskets"...so now maybe I don't understand the question? Normal operating temp is typically above 180 degrees (190-210 by spec I believe for the Northstar). HMS Oh...just spotted what I said!! I meant to say raises the boiling point. Link to comment Share on other sites More sharing options...
BodybyFisher Posted January 14, 2011 Report Share Posted January 14, 2011 5 pages of comments. starting to loose track of thread. will a car overheat without a radiator cap? or boil over without one? a car with good headgaskets that is. Hi Joeb...you joking with your question, yes? Yes to both questions...pressure lowers the boiling point. HMS One more thing. I am guilty of this at times myself also. But to say, "you are joking with this question, yes?", is not polite or sensitive to the person asking the question. It does not foster good feelings The only bad question is the one that is not asked. Again, no offense, I have been insensitive myself at times, and go back and change my rough statement. 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...
hms200 Posted January 14, 2011 Author Report Share Posted January 14, 2011 5 pages of comments. starting to loose track of thread. will a car overheat without a radiator cap? or boil over without one? a car with good headgaskets that is. Hi Joeb...you joking with your question, yes? Yes to both questions...pressure lowers the boiling point. HMS I hope you made a mistake with this post, PRESSURE RAISES the BOILING POINT And YES an engine WILL overheat with NO cap or NO pressure from a bad cap, as the coolant will boil at a lower pressure, this is basic SCIENCE See the link in my post #55 Yes of course it was a mistake... A 50/50 mix of water and antifreeze in the cooling system will boil at ~225 degrees if the cap is open I believe. But as long as the system is sealed and holding pressure with proper antifreeze mix (70/30 mix maximum) then that number increases significantly. HMS Link to comment Share on other sites More sharing options...
hms200 Posted January 14, 2011 Author Report Share Posted January 14, 2011 5 pages of comments. starting to loose track of thread. will a car overheat without a radiator cap? or boil over without one? a car with good headgaskets that is. Hi Joeb...you joking with your question, yes? Yes to both questions...pressure lowers the boiling point. HMS One more thing. I am guilty of this at times myself also. But to say, "you are joking with this question, yes?", is not polite or sensitive to the person asking the question. It does not foster good feelings The only bad question is the one that is not asked. Again, no offense, I have been insensitive myself at times, and go back and change my rough statement. You are 100% correct BBF and thank you for pointing that out. It absolutely wasn't intended to be insensitive or rough, but in reading again I see how that was taken. Blogs, like emails, lose the expression of the talker (the typer)...as was the case here. I'm a nice guy have humor and that's the part that got lost in my reply to have made it look snappy or sarcastic. Very sorry Joeb...my apologies...wasn't intended as it came out. HMS Link to comment Share on other sites More sharing options...
hms200 Posted January 14, 2011 Author Report Share Posted January 14, 2011 Btw the gents...the JB Weld idea failed...as I honestly had suspected might be the result. I still love that stuff...but this was simply the wrong application for it. Didn't even hold long enough to tighten down the hose completely...popped right out. Left a really great mold of the tube end though. Just as well...saved me from draining the radiator again for the new tank later. Will just wait for the new one to arrive and then go from there. HMS Link to comment Share on other sites More sharing options...
BodybyFisher Posted January 14, 2011 Report Share Posted January 14, 2011 Thanks Oh well, you'll have the tank soon By the way, when I bought mine, I got rockauto.com's price and took it to my local dealer and they honored it (surprisingly), this way I got the part immediately 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...
JimD Posted January 14, 2011 Report Share Posted January 14, 2011 While we are waiting for the replacement reservoir to arrive, a couple of points jump out at from the collection of various comments. Maybe some of this will clarify the physics. OR maybe not!! Cooling system pressure: Modern cooling systems are closed and pressurized solely and simply to raise the boiling point (vaporization point) of the coolant. As the coolant temperature increases, the coolant volume expands and since the system is sealed, the pressure likewise increases providing an automatic boiling point increase. That does not mean that every time the engine reaches the normal operating temperature the cooling system is pressurized to the value of the relief valve in the cap. Far from it. The cooling system pressure is related to the amount of "work" the engine is doing, or the "load" on the engine. Urban/suburban driving in an empty car on flat land does not raise the pressure to the limit of the cap if everything else is performing as designed. Under those conditions you can expect no more that 7 to 9 or so PSI buildup in the cooling system. Now take a fully loaded car over some hills (or a high speed run across the desert) in the middle of an August afternoon and that engine is doing some serious "work". The wasted heat has to be removed and the cooling system pressure "might" increase to the pressure limit of the cap. Boiling point (I use boiling point terminolgy but I think in terms of vaporization temperature): At atmospheric pressure (that is to say - unpressurized) pure (distilled) water boils at 212 degrees F at mean sea level. Unless you live at ground level in New Orleans, you will never see plain water reach 212 F before it vaporizes. On my kitchen stove which is 950 feet above mean sea level, pure water vaporizes at 210.5 degrees F (99.1 C). And just a reminder, once the water reaches vaporization temperature, adding more heat energy will not increase the water temperature. The higher above mean sea level you are, the lower the boiling point. In fact, you can determine your altitude based on the boiling point of unpressurized pure water! A 50/50 mix of distilled water and ethylene glycol boils at 223.5 degrees F (106.4 C) on my kitchen stove. The 50/50 mix is adding 13 degrees to the unpressurized boiling point. Thermostat rating: Comparing the temperature at which the thermostat is fully open to the coolant temperature display on the dash is an exercise in futility. The thermostat is responding to coolant temperature at the water pump inlet which is considerable distance in terms of coolant travel from the location of the coolant temperature sensor. Pressure / pressure relationship: In a closed system such as the Northstar (and most other modern engines), boiling temperature increases approximately 3 degrees F for every one psi increase in the system pressure. So for my stove top example above, if my cooling system ever reached the pressure limit of my 15 psi cap, the 50/50 mix boiling temperature of 223.5 "could" increase to 223.5 + (3 times 15) = 268.5 degrees F. Anyone need another reason to NOT remove the pressure cap on an overheating system?? BTW; the 3 degrees per psi is not linear but in the range of temperatures and pressures referred to here, it is close enough. Jim Drive your car. Use your cell phone. CHOOSE ONE ! Link to comment Share on other sites More sharing options...
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