Is it my head gasket?

I have a '95 Lumina with the 3.1L V6 with 59k (yes, 59k) on it.

Recently; a few months, I was noticing that my gas mileage was beginning to drop. I get like 250 miles until the needle is at the 1/4 tank mark and it usually comes out to around 20-22 mpg. I am not sure what I used to get but I know I had over 300 miles before filling up with the needle around the 1/4 mark.

I figured it just needed a tune up, so I changed all the spark plugs and wires, the pcv valve and air filter. Afterwards the car felt better. It seemed quicker but my gas mileage remained poor.

Over the winter I had a valve tick every once and a while. Then the one time it would do it every time I started it up while being cold. I checked and it was down one hole on the dip stick but not in the low mark. I topped it off and it went away. I don't think I have heard it since.

Another day, more recently to the valve ticking I was driving on the interstate and noticed my low coolant light came on. Then it went off, came back on, ect. It eventually went off completely but once I got home I topped the res tank off.

I've talked to some people and told them what all I have done and how the car acts, and they are suggesting it might be my cat that is blocked... I'm not sure. Lately the car basically dies going up steeper/longer hills. It just has no power like it did and the temp gauge will actually start to climb as I am going up some of the hills around here. So I was planning on gutting the cat completely this weekend...

About 2 days ago I took my rad cap off and it was a little brownish. The res tank was a little low but not really brown or anything. So I dumped more antifreeze in and now I checked it today and the res tank fluid is a nice brownish color...

Is the problem with my car the head gasket? What are some other methods to check if this is the problem or not? I just want to get better mileage out of the car and make it last. This is my daily driver so I want to make it last as long as I can.

I'm so tired of problems with this ______ car. I spent about $1000 on it last year fixing things and now it is looking like I have even more of a major problem on my hands.

Any help would be great. I think I am going to put off gutting the cat for now and I might just change the oil and flush the coolant system. Then keep an eye on it but I really think they are mixing some how and it doesn't seem like it will be too easy of a job replacing the head gaskets.

Look for signs of coolant seepage at the ends of the intake manifold, especially at the front passenger side and rear drivers side corners. These cars are notorious for blowing intake gaskets, and will cause the symptoms you describe. If it is the intake gasket leaking, get it fixed ASAP, or you risk blowing a head gasket, or worse, washing the oil with coolant and seizing your engine.

How exactly would I do that? Do I need to remove the upper intake manifold that says 3100 whatever?

Whatever it is, I want it fixed ASAP. I just need to figure out what it actually is.

sell it and get a 240sx

To see if it's leaking, you don't need to remove the upper plenum. The passenger side front corner is the easiest to see. Look for dark brown/orangish sludge around the seam between the intake and cylinder head/engine block.

Pressureize cooling system and then check for leaks around intake manifold if it looses pressure fast and you do not see any leaks check oil dip stick for over full oil. If it is over full after pressureizing cooling system suspect blown headgasket or cracked cylinder head. These 3100 engines are nown for blown head gaskets expecially after they have over heated. Also see if there is a weird smell in radiator when you take cap off.

sell it and get a 240sx
You f%&kin fag, Go over to your queer ass Nissan Forums and leave us alone. No one here is going to sell a lumina for a piece of shit rice burner. On this forum we respect other people and try to help with reasonable responses. Think about this, Every car out there at was at one time someone's pride and joy. Thanks for taking a stab at mine. There is no way in hell i would ever sell my car for a 1995 Nissan 240sx. Your car has to go fast to look good (with is little tiny ass 2.4L 4 Banger). My car looks good standing still. (even though i know i would walk allover you.) So use your had next time before you start posting stupid shit ass remarks.

hell yeah tblake (http://www.automotiveforums.com/vbulletin/member.php?u=116655), tell him how it is!

I dunno about the leaking or bad gaskets but my mechanic friends told me to get rid of the red antifreeze(if you havent already) and go with the green stuff. For some reason thered evaporates away for no explained reason and will corrode the aluminum bits of your motor(something to do with an iron block and the aluminum creates a corrosion happy environment with the red stuff. As far as yuor gas mileage have you changed the o2 sensor lately? If its bad you may have a rich condition that will effect gas mileage and performance.Also dependig on where (if its a bad head gasket) the gasket is bad you may be able to see bubbles coming up to the radiator cap while the car is running from the air under compression in the cylinder.

Hey Tblake, I couldn't agree with you more on Mr 240SX, but try to keep it PG13, as the moderators could have an issue with your language. Keep up the good work on here, you're an asset to the forums.

sorry, just had to let it out, i hate when retards come along and say stupid remarks about that, not to mention my hatred or anything that burns rice. I didnt know taht about dex cool? It exaporates for no apparent reason?? mine is slowly leaking somewhere, it has forever, was going to look into it, but havn't had time.

Yes dexcool does that my mechanic buddies said that the GM classes they attend the instructors told them "unofficially" to go to the green stuff if they had customers complaining about coolant loss. Definately check your intake gaskets they have been a problem since the 2nd generation of 60 degree v-6 redesign.