1991 Cavalier Radiator Cap
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1991 Cavalier Radiator Cap
RE: 1991 Chevy Cavalier, 2.2 wagon.
For a year or so the coolant in my 91 Cavalier radiator drops a couple inches every month or so. I noticed, at the same time, the reservoir is filling more and more. It is now a couple inches above the "fill" line, and getting near the top.
The car doesn't overheat. The temp gauge has the cold mark, then two marks above that, then the half way mark. The needle stays pretty much at the 2nd mark, the one just below the half-way mark. There's no coolant smell and I have put newspapers under the engine for several hours and nothing dripped on them.
Recently I began asking around about this. A couple garages said it could be the head gaskett, another said because the temp gauge isn't at the half-way mark, it's definately is the thermostat, while two other garages said the temp gauge doesn't have to go to the half-way mark.
Two garages said it could be a worn radiator cap. The cap must be at least 10 years old. The problem with this is, it is printed on the cap that it should be replaced with a 13 lb. pressure cap, but at the auto parts stores, the cap pressure for the 91 Cavalier is either 15 or 16 pounds.
I have been all over the internet trying to find which cap is right, but have had no luck.
What is the cap pressure called for, for the 91 Cavalier? 13, 15, 16? If it is 13 and I put on a 15 lb. cap, one mechanic said it may be fine, but it's poossible it could be to much pressure and cause leaks that aren't there now.
Who is right?
For a year or so the coolant in my 91 Cavalier radiator drops a couple inches every month or so. I noticed, at the same time, the reservoir is filling more and more. It is now a couple inches above the "fill" line, and getting near the top.
The car doesn't overheat. The temp gauge has the cold mark, then two marks above that, then the half way mark. The needle stays pretty much at the 2nd mark, the one just below the half-way mark. There's no coolant smell and I have put newspapers under the engine for several hours and nothing dripped on them.
Recently I began asking around about this. A couple garages said it could be the head gaskett, another said because the temp gauge isn't at the half-way mark, it's definately is the thermostat, while two other garages said the temp gauge doesn't have to go to the half-way mark.
Two garages said it could be a worn radiator cap. The cap must be at least 10 years old. The problem with this is, it is printed on the cap that it should be replaced with a 13 lb. pressure cap, but at the auto parts stores, the cap pressure for the 91 Cavalier is either 15 or 16 pounds.
I have been all over the internet trying to find which cap is right, but have had no luck.
What is the cap pressure called for, for the 91 Cavalier? 13, 15, 16? If it is 13 and I put on a 15 lb. cap, one mechanic said it may be fine, but it's poossible it could be to much pressure and cause leaks that aren't there now.
Who is right?
CF Active Member
Joined: Mar 2010
Posts: 173
Likes: 1
From: Saint Amant, Acadiana
It may be the radiator cap that causes this. When engine cools down it is supposed to suck the coolant from the reservoir. If the cap is not tight it will suck the air instead. The cap does not adjust the pressure in the system, it merely serves as a safety valve in case something goes wrong. You can use 15 or 16, it does not affect your everyday driving.
As a side note, if your thermostat is bad and your engine runs cooler than it should then the worst thing (with current fuel prices) is the drop in MPG. It can also cause moisture buildup in oil.
As a side note, if your thermostat is bad and your engine runs cooler than it should then the worst thing (with current fuel prices) is the drop in MPG. It can also cause moisture buildup in oil.
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