Radiator side tank cracks

[adallak]

The OEM radiator side tanks are plastic. They are known to develop cracks. In the picture attached you can see ribs on the inlet tank. There are similar ribs on the outer side of the tanks. Usually the upper three-four ribs on the outer side of the inlet tank start to crack. Watch that area carefully with a flashlight. I have replaced the side tanks of my 1991 Seville at around 110,000 miles. The age counts as well.

I just went out and checked out the radiator side tanks of my 1995 Fleetwood. Sure enough the ribs #2,3,4 from above have noticeable cracks. I am going to replace that tank ASAP with OEM part from rockauto.

[JimD]

Age is a factor as well as the accumulated mileage (number of warm-up and cool-down cycles).

Fast forward to my 1998 model. I finally had my radiator replaced at 193,xxx miles after adding two to three quarts of coolant four or fives times per year for longer than I care to admit. I was just not able to nail down the exact source of the external leak. The radiator side tank crack became large enough and obvious enough that even I could see it. When I was 500 Interstate miles from home!

Depending on year/model, owners might have to remove plastic trim/cover panels to get a good look at the radiator end tanks.

[BodybyFisher]

its better to replace them than to have them spontaineously blow. My friend was sitting in my driveway with his Infinity idling and his side tank just blew, leaving coolant in the driveway. That said, I have never heard of any Cadillac side tank blowing like that, whereas we have seen heater cores blow

[adallak]

its better to replace them than to have them spontaineously blow. My friend was sitting in my driveway with his Infinity idling and his side tank just blew, leaving coolant in the driveway. That said, I have never heard of any Cadillac side tank blowing like that, whereas we have seen heater cores blow

Right, I only remember tanks degrading gradually. If one watches the level of coolant (not easy on Northstars because of black recovery tanks)from time to time, one has time to replace a tank before it is too late.

[firefoot0315]

I've had an interesting time with the coolant in my 94 STS. One time at about 118K miles I got a low coolant warning and ended up adding the far better part of a gallon of coolant. I hadn't had that happen before, and it hasn't happened since, just seemed like a bit of an anomaly. From what little I can tell it's holding coolant just fine, but sometimes when I'm taking off while the engine is still warming up I can smell coolant in my car. Thoughts?

[BodybyFisher]

Yes, its possible that a hose clamp or seal sprung a leak and the required cooling supplement tablets did their job and sealed the leak. As you know, while the cooling supplement is no longer used, it is good medicine for our Northstars to prevent nuisence leaks

As far as the smell, the crossover seals caused that on my 96, they were bad and leaked under pressure. That is a possibility, but I would also snug up my hose clamps if I were you. When I replaced my crossover seals, I stopped smelling coolant when she was hot

[BodybyFisher]

By the way Adallak, I dont think that checking the coolant level is so difficult with the NS. I realize that, its easier with the 4.9 with its easy to see level, but its not harder, other than turning a cap. That said, leave my NS alone, , I know you dislike the NS, but to me, its a thing of beauty. If you don't watch out, I am gonna wish the dreaded 4T60e SPRAG problem on ya,

[firefoot0315]

Yes, its possible that a hose clamp or seal sprung a leak and the required cooling supplement tablets did their job and sealed the leak. As you know, while the cooling supplement is no longer used, it is good medicine for our Northstars to prevent nuisence leaks

As far as the smell, the crossover seals caused that on my 96, they were bad and leaked under pressure. That is a possibility, but I would also snug up my hose clamps if I were you. When I replaced my crossover seals, I stopped smelling coolant when she was hot

Thanks. I didn't know it had a leak-stop in place. This is my first Caddy, I've had it about 8 months, and I'm still surprised by so many of its features That said, I'll be asking a lot of questions about how to keep it as much like new as possible, as well as how to eke out more performance.

But for now I'll look at the crossover seals. The car is 16 years old anyhow, plus it was parked for 4+ years. I have replaced the hoses, but any other seals that go aren't a real shock.

[adallak]

By the way Adallak, I dont think that checking the coolant level is so difficult with the NS. I realize that, its easier with the 4.9 with its easy to see level, but its not harder, other than turning a cap. That said, leave my NS alone, , I know you dislike the NS, but to me, its a thing of beauty. If you don't watch out, I am gonna wish the dreaded 4T60e SPRAG problem on ya,

Hey Mike, you made me laugh! People are lazy enough to OPEN THE HOOD, leave alone removing recovery tank cap and looking inside the tank! Hey, my engine is not 4.9 so it is not 4T60E it is 4L60E transmission.

[adallak]

Yes, its possible that a hose clamp or seal sprung a leak and the required cooling supplement tablets did their job and sealed the leak. As you know, while the cooling supplement is no longer used, it is good medicine for our Northstars to prevent nuisence leaks

As far as the smell, the crossover seals caused that on my 96, they were bad and leaked under pressure. That is a possibility, but I would also snug up my hose clamps if I were you. When I replaced my crossover seals, I stopped smelling coolant when she was hot

Thanks. I didn't know it had a leak-stop in place. This is my first Caddy, I've had it about 8 months, and I'm still surprised by so many of its features That said, I'll be asking a lot of questions about how to keep it as much like new as possible, as well as how to eke out more performance.

But for now I'll look at the crossover seals. The car is 16 years old anyhow, plus it was parked for 4+ years. I have replaced the hoses, but any other seals that go aren't a real shock.

Parked for 4+ years? Replace the coolant ASAP. Just disconnect the lower radiator hose, drain (do not flush) and refill.

[firefoot0315]

Yes, its possible that a hose clamp or seal sprung a leak and the required cooling supplement tablets did their job and sealed the leak. As you know, while the cooling supplement is no longer used, it is good medicine for our Northstars to prevent nuisence leaks

As far as the smell, the crossover seals caused that on my 96, they were bad and leaked under pressure. That is a possibility, but I would also snug up my hose clamps if I were you. When I replaced my crossover seals, I stopped smelling coolant when she was hot

Thanks. I didn't know it had a leak-stop in place. This is my first Caddy, I've had it about 8 months, and I'm still surprised by so many of its features That said, I'll be asking a lot of questions about how to keep it as much like new as possible, as well as how to eke out more performance.

But for now I'll look at the crossover seals. The car is 16 years old anyhow, plus it was parked for 4+ years. I have replaced the hoses, but any other seals that go aren't a real shock.

Parked for 4+ years? Replace the coolant ASAP. Just disconnect the lower radiator hose, drain (do not flush) and refill.

I figured that's basically what I did after adding almost a gallon of new coolant when my low coolant warning came on. Or should I still dump it all and start over?

Also, anything else I should go ahead and replace since it sat so long? It's got new belts and hoses, been through a couple oil and filter changes, has new enough plugs although the wires just might be original (unless they make aftermarket wires embossed with the cylinder numbers), and I think that about covers the basic essentials. For the past 5 months I've commuted 100+ miles a day and haven't had any cause for real concern, but I'd like to keep it that way and replace any of the little things that make big problems when they age out.

[adallak]

Yes, its possible that a hose clamp or seal sprung a leak and the required cooling supplement tablets did their job and sealed the leak. As you know, while the cooling supplement is no longer used, it is good medicine for our Northstars to prevent nuisence leaks

As far as the smell, the crossover seals caused that on my 96, they were bad and leaked under pressure. That is a possibility, but I would also snug up my hose clamps if I were you. When I replaced my crossover seals, I stopped smelling coolant when she was hot

Thanks. I didn't know it had a leak-stop in place. This is my first Caddy, I've had it about 8 months, and I'm still surprised by so many of its features That said, I'll be asking a lot of questions about how to keep it as much like new as possible, as well as how to eke out more performance.

But for now I'll look at the crossover seals. The car is 16 years old anyhow, plus it was parked for 4+ years. I have replaced the hoses, but any other seals that go aren't a real shock.

Parked for 4+ years? Replace the coolant ASAP. Just disconnect the lower radiator hose, drain (do not flush) and refill.

I figured that's basically what I did after adding almost a gallon of new coolant when my low coolant warning came on. Or should I still dump it all and start over?

Also, anything else I should go ahead and replace since it sat so long? It's got new belts and hoses, been through a couple oil and filter changes, has new enough plugs although the wires just might be original (unless they make aftermarket wires embossed with the cylinder numbers), and I think that about covers the basic essentials. For the past 5 months I've commuted 100+ miles a day and haven't had any cause for real concern, but I'd like to keep it that way and replace any of the little things that make big problems when they age out.

You covered it pretty well. I like people who care about their Cadillacs, and you seem to be one of them!

As for the coolant, Northstar takes more than a gallon, so in a few months I would drain and refill it again. Never did it on Northstar, but you will probably get less than two gallons drained.

By the way, if you know where your car was serviced before (likely a dealership), give them a call and ask nicely for service records. Have the VIN handy, make sure they use your name when mailing the records to you. First time they sent the records to me, they used the previous owner's name. Sure, the postman did not deliver.

[firefoot0315]

You covered it pretty well. I like people who care about their Cadillacs, and you seem to be one of them!

As for the coolant, Northstar takes more than a gallon, so in a few months I would drain and refill it again. Never did it on Northstar, but you will probably get less than two gallons drained.

By the way, if you know where your car was serviced before (likely a dealership), give them a call and ask nicely for service records. Have the VIN handy, make sure they use your name when mailing the records to you. First time they sent the records to me, they used the previous owner's name. Sure, the postman did not deliver.

Both good ideas. And yes I do care about my Caddy! Thanks! It's the first car that's been legally "mine," so it's my baby.

[BodybyFisher]

By the way Adallak, I dont think that checking the coolant level is so difficult with the NS. I realize that, its easier with the 4.9 with its easy to see level, but its not harder, other than turning a cap. That said, leave my NS alone, , I know you dislike the NS, but to me, its a thing of beauty. If you don't watch out, I am gonna wish the dreaded 4T60e SPRAG problem on ya,

Hey Mike, you made me laugh! People are lazy enough to OPEN THE HOOD, leave alone removing recovery tank cap and looking inside the tank! Hey, my engine is not 4.9 so it is not 4T60E it is 4L60E transmission.

[Bob Mack]

radiator shop changed the cap to 7 lb

[BodybyFisher]

radiator shop changed the cap to 7 lb

Could you explain yourself here? The stock cap is 16 psi.

[winterset]

By the way Adallak, I dont think that checking the coolant level is so difficult with the NS. I realize that, its easier with the 4.9 with its easy to see level, but its not harder, other than turning a cap. That said, leave my NS alone, , I know you dislike the NS, but to me, its a thing of beauty. If you don't watch out, I am gonna wish the dreaded 4T60e SPRAG problem on ya,

Not sure if we discussed this here, but I believe the supplement is no longer used because owners believed the rusty murcky color of the coolant once the supplement is added, and the gunk that's built up on the cap was a concern. Dealerships that did the right thing, and added the supplement got complaints from customers - So it was decided to just stop adding the supplement just to soothe the uninformed. I will continue to add supplement to any aluminum block engine even if it's not required. I don't believe we ever heard anyone say it clogged their radiator/waterpump/cap/thermostat. Additionally we have seen pictures here of disassembled gaskets with supplement doing just what it was supposed to do. Again, it was stopped for coolant cosmetics.

[JimD]

Not sure if we discussed this here, but I believe the supplement is no longer used because owners believed the rusty murcky color of the coolant once the supplement is added, and the gunk that's built up on the cap was a concern. Dealerships that did the right thing, and added the supplement got complaints from customers - So it was decided to just stop adding the supplement just to soothe the uninformed.

I agree - I agree - I agree. And I have mentioned the point here several (many) times during the years. The rusty murcky color was a red flag for folks raised on ferrous metal engines and cooling systems that could actually produce "rust" when oxygen was introduced into the cooling system.

What these folks where not told, or otherwise did not understand, was modern engine cooling systems do not contain any ferrous materials except for the stainless steel water pump cartridge in the case of the Northstar.

I will continue to add supplement to any aluminum block engine even if it's not required.

Myself.

I don't believe we ever heard anyone say it clogged their radiator/waterpump/cap/thermostat.

I would add heater core to that list.

Again, it was stopped for coolant cosmetics.

110% accurate.

PS: Ranger and I agreed to diagree about this several years ago!

[firefoot0315]

Hm...good to know. I noticed my coolant looked like crap after I added BARS tabs and was concerned that something was leaking in there.

[Bob Mack]

radiator shop changed the cap to 7 lb

Could you explain yourself here? The stock cap is 16 psi.

radiator shop changed the cap to 7 lb it stopped cracking the radiator years ago.

It worked for me.

Bob

[KHE]

You won't get as much boil over protection with a 7 psi cap vs the OEM 15-16 psi cap. The inlet tanks are the ones that crack with age and miles. The best thing to do is replace the inlet tank and keep the factory cap.

[BodybyFisher]

radiator shop changed the cap to 7 lb

Could you explain yourself here? The stock cap is 16 psi.

radiator shop changed the cap to 7 lb it stopped cracking the radiator years ago.

It worked for me.

Bob

That is what I thought you meant. That is a RUBE GOLDBERG/HALF AZZ fix, that shop should be SHUT DOWN, I am STUNNED that such mechanics actually exist.

FIX THE PROBLEM, DON'T MASK IT and CERTAINLY DO NOT RECOMMEND SUCH CRAPPY SO CALLED FIXES HERE on your 3rd POSTING!!!

THIS IS SUMMER HEAT, 16 PSI will stop boiling to a higher TEMP, 7 DOES NOT.... I am shocked that a so called mechanic would suggest such a BS 'solution'

Proper cooling system maintenance does not mean taking shortcuts, using patches, taking out thermostats, turning off the AC, loosening the CAP, lower pressure cap, etc. It means:

Proper coolant change intervals

Changing the thermostat

Checking for leaks via pressure testing and REPLACING leaking components, radiators, hoses, clamps, crossover seals, water pump seals, tanks, radiators, radiator end tanks, etc.

Checking cooling fan operation

Minimum 50/50 to a max of 67/33 coolant concentration

Check water pump belt and tensioner

Using cooling system supplement tablets

Cleaning condenser/raditor fins of debris

No short cuts, short cuts are taken by the fools sitting on the side of the road with STEAM coming out from under their HOODS....... You are driving a Cadillac here, perform proper maintenance

[BodybyFisher]

See the following chart

At 50% and 16 PSI, the boiling point of Dexcool is 267 degrees, by lowering the cap pressure to 7 PSI you have dropped the boiling point to below 248 degrees according to this chart. I estimate that to be 245 degrees, WAY TOO LOW for SUMMER DRIVING. When you park your car after a long drive, temps SPIKE, you could pull off into a rest area to take a leak and BOIL OVER, because of this decision to use a 7 psi cap..

Two years ago I was in bumper to bumper traffic going to Virginia Beach in July, it was 100 out. My temp gage went to 245 multiple times..... END OF DISCUSSION