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Help! coolant problems!


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Well, I got myself into a mess trying to help out my folks. I was the one who asked some coolant questions the other day. Anyhow,

it's a 2005 caddy deville, 4.6 L. I drove it up on my drive-on ramps. I got the pain in the *smurf* panel off the bottom. I let engine cool and took cap off of surge tank, then I drained the radiator. A little more than a gallon of coolant came out.

I put in almost a gallon of new dex-cool into the surge tank.

The surge tank is right almost at the top (full of fresh dex-cool).

With the engine warmed up, about 15 minutes running time, 4 bars on the graph bar coolant gauge.

It won't suck the darn coolant into the radiator.

Talked to several mechanics including a caddy master tech in a private garage.

The caddy dealer said to rev the engine after it got up to operating temp and see if that dislodged a probable air pocket.

Another guy said to get it off the ramps and let it set, and see if coolant is sucked in.

master tech at private garage said to let it set and see if coolant is drawn in. When i asked cap on or cap off, he said it didn't make a difference. If it sucked it in, he said to adjust coolant level and go for short drive. Let cool down. Adjust coolant level. Repeat cycles.

Guy down the street agreed with above but said to adjust level in surge tank to 3/4 full. Don't have an old baster. He also recommended breaking a coolant hose loose, but not the surge tank hoses. i told him that's all I can see, no other hoses to burp.

Please help with any recommendations as I have to get this darn caddy moving again. What a nightmare. I have done lots of regular coolant systems, but this is first one with surge tank. Any advice will be greatly appreciated. Thanks, michael

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To the best of my knowledge all you have to do is put coolant into the surge tank. It should make its way into the radiator with no further assistance. Mine ran nearly empty a while back, and I filled the surge tank (with the car off and cold), waited a few minutes until the level went down to about half full, then filled it the rest of the way up. The coolant should be about 2 1/2 inches below the filler neck of the surge tank. Also, when you put the cap back on be sure you put it on all the way!! It's hard to put on. I made that mistake and ended up losing all my coolant onto the ground. If the coolant hasn't made it into the radiator, then I am pretty sure your car would be overheating. Has it?

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It won't suck the darn coolant into the radiator.

Since the reservoir is at the highest point in the cooling system, it is not necessary for fluid to be "sucked" anywhere. The bottom fitting on the reservoir is plumbed directly to the water pump inlet; gravity does the rest.

It sounds as if you replaced approximately the same amount of coolant that was drained. If the water pump belt is turning and the engine does not overheat, I don't see any problem.

Except maybe there is too much coolant in the reservoir.

Jim

Drive your car.

Use your cell phone.

CHOOSE ONE !

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It is now approx. 7:15 P.M. E.S.T. here in Florida.

The surge tank is no longer completely full. It has gone down to approximately the correct level. The owner's manual for the '05 deville says this is about 4.5 inches below the top of the filler neck. It also is just a little below the FULL COLD mark located on the side of the surge tank that faces the engine. So, that is the good news. Bear with me as I am fighting cancer and am on morphine which dulls my thinking sometimes.

1)I drained out of the radiator (with surge tank cap off) approx. only 1 gallon of coolant. I filled up a 1 gallon water jug with a few ounces over (maybe 3) which I put into a 2nd jug for recycling.

2)I wasn't thinking, and poured in a full jug of pure dex-cool. I should have gotten a clean container someplace and mixed it 50-50 with some distilled water first. I don't know what I was thinking as I knew just a gallon of old stuff came out.

3)In the morning should I just drain it all over again (because I didn't mix the dex-cool 50-50)?

4)I just read someplace that a simple drain and fill is not the best method because up to 1/2 of the old coolant remains trapped inside the engine block. When new coolant is added to the system, it will be DILUTED with the old coolant that is still inside the engine, reducing it's ability to resist corrosion as well as reducing it's service life. So, that's an argument against draining the radiator again.

But, I am afraid it is too strong a mixture now.

5)When I filled up the surge tank, it took just about the whole gallon. It went down approx. half-way. That means only 1/2 gallon or 2 quarts went into the radiator, while 2 qts or 1/2 gal. remained in the surge tank. That can't be right, can it- to just have 2 qts. go into the radiator to fill it up completely?

Please give me any advice you have on what I mentioned above. Would you just start from scratch with pre-mixed dex-cool?

The full surge tank really freaked me out as I knew there was none in the radiator as I had just drained it completely.

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....2)I wasn't thinking, and poured in a full jug of pure dex-cool. I should have gotten a clean container someplace and mixed it 50-50 with some distilled water first. I don't know what I was thinking as I knew just a gallon of old stuff came out.

3)In the morning should I just drain it all over again (because I didn't mix the dex-cool 50-50)?

No need for panic or drastic measures. All you have done is lose control of the desired 50/50 mixture of coolant. Your coolant is probably in the range of 70% Dexcool and 30% water. No harm done!

If it was my car, I would purchase one of those inexpensive hydrometer (floating colored balls) anti-freeze testers and calibrate the thing with my own mixture of 50% Dexcool and 50% water. That will give you a base point for measuring the mixture of the coolant in the engine. You can decide what action (if any) is indicated once you know what the mixture percentage actually is.

4)I just read someplace that a simple drain and fill is not the best method because up to 1/2 of the old coolant remains trapped inside the engine block. When new coolant is added to the system, it will be DILUTED with the old coolant that is still inside the engine, reducing it's ability to resist corrosion as well as reducing it's service life. So, that's an argument against draining the radiator again.

That is why long-time Northstar DIY folks drain and refill more frequently than the recommended schedule. My argument against "flushing" is the risk of missing the desired 50/50 ratio on the side of too much water which would be potentially more damaging than your situation.

The full surge tank really freaked me out as I knew there was none in the radiator as I had just drained it completely.

Consider this possiblity. The liquid you were pouring into the reservoir (and it's called a reservoir for a reason) was being gravity fed into the cooling system. Some part of what you poured into the reservoir was flowing into the partially drained cooling system plumbing.

The Northstar cooling system is what it is. And what it is is nothing like a 20 year old small block Chevrolet. You can listen to someone with 30 years experience with ALL brands of engines, or you can listen to the DIY'ers with a history of millions of miles maintaining the Northstar cooling system.

Jim

Drive your car.

Use your cell phone.

CHOOSE ONE !

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You won't be able to remove all the coolant from the block - drain and refill is the way to go. Yes half the old coolant will remain in the block but you can always drain and refill it at a later date. By that time the new coolant will be mixed in with the old and a second drain and refill will get that much more out of the system.

You should always mix the DexCool 50/50 with distilled water. The pre-mixed stuff is a ripoff as you're paying the Dexcool price for water... I doubt if it's even distilled water.

Since you drained only 1 gallon of coolant out, I'd estimate the concentration of coolant to water is 65/35 which is a little high. You could drive it for a few days and then drain off 1 gallon of coolant. Add about 21 ozs of Dexcool to an empty 1 gallon container and top off the rest of the container with distilled water, mix and add that to the surge tank. That should get the concentration back to 50/50 in the car. Double check with an anti freeze tester to make sure the freeze point is -34 degrees F.

You might want to then drive the car for a year and drain the coolant and add 50/50 Dexcool/distilled water just to get more of the spent coolant out of there.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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Thanks for the advice, guys- appreciate it. I drained the radiator again this motor with surge tank cap off. I then mixed up another batch of coolant with distilled water and put it in. Let it set until coolant flowed into radiator. I purposely did not fill surge tank all the way up to correct level- I left myself some room so I can monitor strength of coolant over next few days. Got new Prestone coolant hydrometer. will tweak the mix until I get roughly 50-50 or -34 degrees on the hydrometer.

1)Anybody know how much that radiator holds on the 4.6L engine?

The reason I ask is because when I initially drained radiator and surge tank, only 1 gallon of old coolant came out.

The first time I screwed up (see my old post) and put in 1 gallon of full-strength coolant (not mixed with distilled water).

When I put in the gallon of coolant, it filled up the surge tank completely since it holds about a gallon empty.

When it finally drained into radiator, I still had 1/2 full surge tank. That means only 2 qts. (1/2 gal.) went into the radiator while 1/2 gal. or 2 qts. remained in the surge tank.

How can that radiator only hold 1/2 gallon of coolant?

2)What have your experiences been on a 4.6L with a fill and drain? Anything that confused you? When you filled the surge tank, did it run right into the radiator? Or did you have to wait several hours for gravity to drain coolant into radiator?

Thanks, Michael

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....I drained the radiator again this motor with surge tank cap off. I then mixed up another batch of coolant with distilled water and put it in. Let it set until coolant flowed into radiator. I purposely did not fill surge tank all the way up to correct level- I left myself some room so I can monitor strength of coolant over next few days. Got new Prestone coolant hydrometer. will tweak the mix until I get roughly 50-50 or -34 degrees on the hydrometer.

I'm happy to see the feedback and thank you for that. Since you did not report any cooling system temperature anomolies, can future readers "assume" there never was an actual problem related to mixture percentage?

The 1st, 2nd, and 3rd reasons to change or "refresh" the ethylene glycol (Dexcool) in a Northstar cooling system is to install a fresh charge of corrosion inhibitors. Period.

1)Anybody know how much that radiator holds on the 4.6L engine?

I have no idea how much fluid the radiator contains. What I do know is the complete engine cooling system has a total capacity of 12.5 quarts.

And for future readers -- if your year/model Northstar has a pressure cap on the "overflow tank" or "surge tank"; please think of that tank as a reservoir.

Jim

Drive your car.

Use your cell phone.

CHOOSE ONE !

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And for future readers -- if your year/model Northstar has a pressure cap on the "overflow tank" or "surge tank"; please think of that tank as a reservoir.

Wasn't aware of this. I thought "reservoir" referred to the plastic tanks with the plastic caps on them (not pressure caps) and that the tanks WITH pressure caps were referred to as surge tanks. Guess I was wrong. Is there a different term for the other type of tank without the pressure cap? Or are they all called reservoirs?

I am also not sure exactly how much coolant the radiator will hold. I do know that my coolant system completely de-pressurized...tank, hoses and all when my coolant purged out (due to the pressure cap not being on all the way) and it took about a gallon and a half to fill the reservoir back to where it was supposed to be afterward, a lot of which I assume went into the radiator. Odds are if yours took at least a gallon or so and hasn't had any overheating problems, then it is probably fine. Just check the level in the reservoir after you have driven it to see if it goes down at all, and add to it if necessary.

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....I drained the radiator again this motor with surge tank cap off. I then mixed up another batch of coolant with distilled water and put it in. Let it set until coolant flowed into radiator. I purposely did not fill surge tank all the way up to correct level- I left myself some room so I can monitor strength of coolant over next few days. Got new Prestone coolant hydrometer. will tweak the mix until I get roughly 50-50 or -34 degrees on the hydrometer.

I'm happy to see the feedback and thank you for that. Since you did not report any cooling system temperature anomolies, can future readers "assume" there never was an actual problem related to mixture percentage?

The 1st, 2nd, and 3rd reasons to change or "refresh" the ethylene glycol (Dexcool) in a Northstar cooling system is to install a fresh charge of corrosion inhibitors. Period.

1)Anybody know how much that radiator holds on the 4.6L engine?

I have no idea how much fluid the radiator contains. What I do know is the complete engine cooling system has a total capacity of 12.5 quarts.

And for future readers -- if your year/model Northstar has a pressure cap on the "overflow tank" or "surge tank"; please think of that tank as a reservoir.

Jim: I could have left that 100% pure gallon of dex-cool in there for a week or so and had my folks run the car. But, I was concerned it was too strong a mixture overall. I read someplace that although you can go up to a 70% dex-cool, 30% distilled water ratio (like in upper Midwest, Canada, Alaska), it said that cooling efficiency goes down, with the higher ratio of coolant. That's why I started over.

I have driven car in heavy city traffic for 40 minutes or so twice, and only goes up to 4 bars on the digital graph coolant gauge (just below a horizontal line that bisects the vertical line on gauge). quote:"Since you did not report any cooling system anomalies, can future readers "assume" there never was an actual problem related to mixture percentage?"

Jim: Not really sure on what are you asking (remember I'm on morphine meds, so not too sharp. let me try to add a little more info.

The coolant in the 2005 caddy deville was the original I believe and had never been changed.

When I put in the full gallon of dex-cool (undiluted) I never drove the car. The most i did was back it off my drive-on ramps onto the level garage floor, as a couple of mechanics thought it would drain into the radiator quicker. Remember, that was my first concern, was that when I put in the full-strength coolant, it would not drain into the radiator. It finally did after 3 hours, maybe a little less. I did start car and drive back up on ramps where I drained for 2nd time and remembered this time to mix with distilled water. Am monitoring the coolant closely now (even have a new prestone hydrometer that says compatible with dex-cool, although the coolant in there is actually a mixture of prestone dex-cool and whatever the factory dex-cool is).

1)Am curious on how a couple of folks who commented on the strength of the '05 deville coolant ratio (capacity 13 qts. or 3.25 gal.) after I added a whole gallon of pure dex-cool? How did you do the math? One poster figured with the gallon of pure coolant I added, i was about 70%coolant/30% water, another thought 65%/35%. I went to the local community college a decade ago and seem to remember an algebra problem that was similar, but I have forgotten all my math. I know i drained out 1 gallon. so 4 qts divided by 13 qts=.30 or 30% was all the old coolant I got out. That means 70% is still trapped in there. Guess that's why someone suggested after a

year or so, to drain and fill again. If some one could post the math on how they figured the strength/ratio of coolant after I inadvertently added 1 gal. pure, it might help a lot of people. Thanks, michael

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.... If some one could post the math on how they figured the strength/ratio of coolant after I inadvertently added 1 gal. pure, it might help a lot of people. Thanks, michael

For discussion purposes, say the total capacity is 12 qts.

You drained 4 gts leaving 8 qts in the system.

If that remaining 8 qts was a proper 50/50 mix, that means there is 4 qts of water in the cooling system.

Add in your 4 quarts of 100 % Dexcool to fill the system (12 quarts capacity).

Now you have 12 qts of fluid that includes 4 qts of water.

Ratio of Dexcool = 8/12 or 66%.

Jim

Drive your car.

Use your cell phone.

CHOOSE ONE !

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And for future readers -- if your year/model Northstar has a pressure cap on the "overflow tank" or "surge tank"; please think of that tank as a reservoir.

Wasn't aware of this. I thought "reservoir" referred to the plastic tanks with the plastic caps on them (not pressure caps) and that the tanks WITH pressure caps were referred to as surge tanks. Guess I was wrong. Is there a different term for the other type of tank without the pressure cap? Or are they all called reservoirs?

I am also not sure exactly how much coolant the radiator will hold. I do know that my coolant system completely de-pressurized...tank, hoses and all when my coolant purged out (due to the pressure cap not being on all the way) and it took about a gallon and a half to fill the reservoir back to where it was supposed to be afterward, a lot of which I assume went into the radiator. Odds are if yours took at least a gallon or so and hasn't had any overheating problems, then it is probably fine. Just check the level in the reservoir after you have driven it to see if it goes down at all, and add to it if necessary.

Technically you are correct Carla. At least that's how I have always referred to them.

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Thanks guys for all your help. Especially the math lesson. I should also admit that I took off the plastic retainers that hold on the undercar huge plastic shield wrong too. On the '05 deville, there is a huge plastic shield that runs all the way across the width of the undercarraige. There are about 20 plastic retainers. couldn't figure how to get them out, figured they would pop out. I used a door panel tool to "pop out" all the retainers. These retainers have a horizontal slot on both sides of the retainer. Proper way the caddy parts guy showed me (as had to buy some new ones that were damaged) is to take a little screwdriver and insert it in the little slot of retainer. Then pry upwards. The head of the retainer will slide upwards out of the body of the retainer along with the solid shaft of the inside part of the retainer. Kinda hard to describe. I'm sure you guys have already discussed it anyhow.

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Thanks guys for all your help. Especially the math lesson. I should also admit that I took off the plastic retainers that hold on the undercar huge plastic shield wrong too. On the '05 deville, there is a huge plastic shield that runs all the way across the width of the undercarraige. There are about 20 plastic retainers. couldn't figure how to get them out, figured they would pop out. I used a door panel tool to "pop out" all the retainers. These retainers have a horizontal slot on both sides of the retainer. Proper way the caddy parts guy showed me (as had to buy some new ones that were damaged) is to take a little screwdriver and insert it in the little slot of retainer. Then pry upwards. The head of the retainer will slide upwards out of the body of the retainer along with the solid shaft of the inside part of the retainer. Kinda hard to describe. I'm sure you guys have already discussed it anyhow.

Good to know. I probably would have made the same mistake, assuming mine uses the same kind of retainers. At least now I know to look.

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