Burning antifreeze? How do you know? What do you do?

Question

I have a 97 Cadillac DeVille with a Northstar motor. I have to keep adding coolant (dextrol at $17/gallon!!) I can smell antifreeze once in a while, dont seem to be leaking any. I am really starting to notice it when I back up into my exhaust. I assume this means I am burning it through my motor.... so obviously I know it needs to be brought in. I have an appt for next week - but dont want to get screwed because I am not exactly "car savvy". Can you please tell me what you suspect it is, and what I can expect to have done to fix it??
Thank you so much!

Answer 1

ohh my, you probably are experiecing what many have ,head gasket failure. on this engine it is very common and extremely expensive ive seen repair bills on these around 2500 to 3000 dollars, if you can find someone other than a dealer to work on it which is unlikely you can save some . but be careful cause this engine is a creature all its own, when the head bolts come out the threads will too. needing time serts installed.if you are in a position to get clear of the vehicle i would consider it especialy if it has many miles on it ,make sure to rule out any external leaks first.

Answer 2

OK there is a few possibilities, has the performance decreased at all since this prob? When you are behind the vehicle and its running (in park please!) have a buddy accelerate the gas to about 2,500 RPM, then to 5,000 RPM if you see "WHITE" or "BLACK" smoke there is a head gasket or other potential cylinder head problem. Keep in mind when antifreeze is able to escape into the combustion chamber (burns) is lets off a very sweet smell out the exhaust. This is usually followed by a oil consumption issue. Note: 97 Cadillac's require a special Pellet to be purchased from the dealership that is necessary in the coolant to prevent damage. This may also be you mysterious coolant problem. Keep in mind these types of Cadillac's required special precautions so its best to always consult the dealership.

Answer 3

I am not a professional mechanic. I am just a backyard hobbyist, so I am not a great authority. This is only a guess. It might be a blown gasket such as a head gasket. It would seem that the coolant is finding its way into the combustion chamber. Or maybe it is leaking out onto the exhaust manifold and immediately being cooked away, but if that were the case, you would probably smell it more than you do now. Good luck.

Answer 4

Well first, don't tell the mechanic you smell it in the exhaust. But if that is true then it could be a blown head gasket, cracked head or block (think expensive). Check to see if you can smell it in the car when you turn the heater fan on, this would indicate a possible heater core leak (much cheaper). Usually a radiator shop will pressure test the system for free and tell you where you are loosing fluid from. If it is engine then have a competant auto shop do the repair.

Answer 5

I suspect that you have a blown or leaking head gasket that is allowing the coolant to seep into the combustion chamber. That is why you are smelling it in the exhaust.

They will recommend that your gasket be replaced, and the heads resurfaced and rebuilt.

But $17 a gallon is alot for antifreeze. Your local auto parts store should have had a 50/50 mix for no more than $9.

Answer 6

It sounds like a blown head gasket, letting the coolant into the cylinder, and from there past the exhaust valve and through the exhaust pipe. The work will include diagnosis to ascertain which head is causing the problem (and if it's the one nearest to the windscreen, it is harder and slower to work on, and there will be more stuff in the way), removal everything that's in the way of the offending head, replacing the gasket, possibly machining of the head (if it has become warped), and then re-fitting everything, replacing all other gaskets that were removed on the way. Its a pretty big job, and usually fairly expensive.

There may be other possible reasons for your problem, but I can't think of any off-hand. Keep hoping!

Good luck!

Answer 7

Ok if you were burning it, there would be white smoke coming from the cars exhaust. I mean a lot of white smoke and in most cases the car would over heat.
I think you have a hose leaking on the motor and this is the what you smell. Take it to a garage and have them pressure check it.
Thy remove your rad cap and pump air into the system. If there is a leak it will spray out where the hose is broken.

Answer 8

It's your intake gasket or head gasket: I built a '72 Olds 442 W-30 convertible but wasn't ULTRA careful when I seated the intake manifold gasket so it leaked coolant - into the intake - and got burned in the #7 cylinder and out the exaust it would go. That being said, I realize your car isn't a '72, but ALL internal combustion engines do have SOME things in common. "Gun to my head answer" I'd say it is your head gasket ... shop the repair around 'cause it won't be cheap and, as always, NEVER take your car to a dealer to be serviced becuase they WILL dog you.

Answer 9

If you don't see any obvious leaks, it could still be leaking....ie: hoses etc. Do you have any moisture on the floor of the inside of your vehicle? This could indicate a heater core problem. The worst case scenario is that coolant is leaking inside your engine and could result in having to actually replace the engine. This is really bad. Have it checked out as soon as possible

Answer 10

Your head gasket might be leaking, whitch would put water in the engine oil, check you oil dipstick if there is water in with the oil that might be it.

or there could be a small anount leaking on to the header pipes.