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Engine has sweet smell & Runs rough 1992



I have a 1992 that the anti-freeze level has been going down, I do not see any thing mixed with the oil or I see no oil in the anti-freeze. There is also a sweet smell of what I think maybe anti-freeze when the car is first started up in the morning, this seemd to go away but I do not know for sure, there is no smoke coming from the exhaust. I see no leaks. Could this be a start of a bad head casket or something more sesrious?
Also the engine has been running rough, so I pulled all the plugs and they look fine. If I let the car sit for more than a day when I go to start it up I get what I think is a lifter noise.
Desperatly seeking help on this.
Ken N of Kissimmee
While an important piece of information is how rapidly the coolant level is dropping, I'm going to guess this is a possible failed head gasket with coolant leaking into one or more cylinders.

Have the cooling system tested by a shop which has equipment that can detect exhaust byproducts in the coolant. Also, a leakage test while watching the coolant fill tank for bubbles might find the problem.
Oops forgot that tid bit of info. The coolant level drops and I must refill the tank every week to week and half. But if this is head gasket would the spark-plugs show some sign of this? No evidence of this so far. Or is this in the early stages?
Appreciate the help, I have been stumped on this for awhile, I will have checked out asap though.


Do you see any steam/white smoke out the tail pipes?

My only guess here seems to be a bad head gasket, cracked head, or bad intake manifold gasket. I assume you see NO coolant anywhere on the ground or seeping around the engine. If you have a bad head gasket or cracked head, the coolant may force iteself into the cylinder when under pressure causing you to loose coolant but not see it on the ground. However, most of the time when that happens the cylinder pressure backs up into the coolant system and you get air bubbles in the radiator and usually end up overheating. Then again, I also assume you have overheated this engine at least once for an unrelated problem prior to this happening?

Or, if the intake manifold gasket is leaking at the water jacket, there is some small chance it could be squirting coolant across and into an intake port under pressure. This would not back up in the system, and would cause the engine to run rough and coolant to dissapear. However, you would see steam/white smoke out back and that cylinder should have had a strange looking spark plug.

Finally, a hair line crack in the head or block in a water jacket will cause coolant to spray out under pressure. You say you smell it when you first crank up. This could be because it stays under pressure and continues to leak after you shut down. That coolant eventually is just puddled up in the exhaust system. When you first crank it up it smells strong until it can steam it off.

Give us more details. In any event you are in for some kind of overhaul if the rough running is in conjunction with the missing coolant.
You have given some great advice and shall follow your suggestions. The part about running hot previous has struck a cord, since my wife run the car about 20 miles with NO COOLANT about a year ago. I will blame her for this one now. And make her pay for the repairs. {:~)

My wild assed guess!

This is just a thought,
Could the water pump be leaking a small amount of coolant onto and into the opti-spark distributer causing the rough running, but not leaking so much as to cause a puddle under the car?
Seems the heat from the motor could evaporate the leaking anti-freeze causing the sweet smell.

It's worth a look.
No water on opti-spark. Water pump and opti-spark unit repaced about the same time the wife did the nasty deed with the car, running with out coolant. That is the first thing that I checked, thanks for the thought though.
I have an appointment with a vette mechanic Friday to go over the suggestions from here.
Thanks gentlemen.

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