To start out I did a search and couldnt find the ansewr.

The car I am looking at buying has no overflow tank. And when you start the car the coolant buzzer goes off.

The seller said that once you get up to about 45 mph or so the buzzer stops going off.

The small hose that goes from the radiator to the overflow tank is looped back into the engine.

Do you think that when I get an overflow tank and run the hose correctly it will fix the buzzer problem?

Tim

 

It may be that the guy selling the car doesn't know what's going on or does and is trying to snow you.

That buzzer is reacting to a coolant level that's too low. Right on top of the radiator is a sensor that detects a low coolant level and when it does, the buzzer goes off. I can't think of a reason why someone would eliminate the overflow tank. Where on the engine does the overflow tube run into? Why would the car's speed have anything to do with the coolant level sensor? It all seems pretty screwed-up.

 

It sounds like the car was pushing coolant out into the overflow bottle, thus overflowing it. The owner then rerouted the hose back into the engine to "solve" the problem.

There are two main causes for this:

1. Bad rad cap. Try replacing the cap
2. Dead engine. The engine is pushing combustion gasses into the cooling system. This is the most likely cause as we can assume that the rad cap has already been replaced.

I would avoid the car if I were you, then slap the previous owner for:

1. Being a dumbass
2. hacking up the car
3. Trying to sell you a car with a blown engine

 

the engine is brand new so I don't think that is the problem, the overflow tank was removed because a fmic was put on and the piping got in the way. He is in the process of looking for a new overflow tank.

He said once you get up to about 40 the buzzer goes away because something about airflow and the rad being cooled down.

Tim

 

Maybe it is low and the buzzer is doing what it is supposed to do? I would bet it is not the speed that turns it off - but rather the coolant expanding when the engine gets hot (What the overflow tank is for) and the sensor then sees normal level.
Can you see coolant if you pull the rad cap off?

-billy

 

That sounds like it might be it.

I'll check next time I go see the car.

Tim

 

That's a good way to pop the cooling system. The pressure relief radiator cap and the overflow bottle are there to prevent the cooling system over-pressurising.

As the coolant heats up it expands and that increases the system's pressure. Once the system reaches 13psi the car bleeds coolant into the overflow tank to maintain that pressure. When the system cools and the coolant contracts it's sucked back into the engine.

The way he's set that up there is no way of controlling system pressure. I'd think eventually something will fail from too much pressure (probably a hose) and that could cause an engine failure from overheating.

It sounds like this guy isn't too clued up on cars, or he's just plain lazy. Perhaps you should avoid the car in case he's screwed up something you can't see...

 

I swear I saw this same post a couple of weeks ago. I'd stay away from the car, it's probably full of baling wire and chewing gum holding stuff together.

 

lol..nice, no the car isnt full of baling wire and chewing gum. i bought the car that way after the swap was done and to move the car to my gf's house (about 10 miles away) i did that cause i didnt want it to leak out and blow my new motor. thanks for the confidence