Chevy Malibu Fuel Gauge, Impala Overheated Won't Start - Mechanic Live Chat

Question: i replaced the fuel pump in 1997 malibu 3.1 v6 and now the fuel gauge does not work.
 Mechanic: I assume it worked before? Did the new pump come as an assembly with the fuel level sensor?

I bought the tank and fuel pump as one unit.
 Was it all assembled and you just installed the tank with everything in it?

Yes.
 OK. Then you are going to have to remove the tank, take the pump out and make sure there is a sensor on the pump assembly, it is plugged in, the float is there or something to be wrong. Also look at the color of wires from the car harness to make sure they match on the pump harness. Something inside is not right.

Could it be that a sensor outside the tank maybe bad?
 There are no sensors outside the tank for the gas gauge. The fuel level sensor is part of the fuel pump module assembly. This is assuming you bought a fairly good part and not some super cheap no-name brand. You would have had to look closely at it before you installed it, or you could take the gas tank out again and look at the assembly.
OK, thank you !

 

Question: my car overheated and shut off and it will come back on.
 Mechanic: Does it start and run ok now? You may have damaged the engine depending on how bad it overheated.

I check my battery, starter, alternator, spark plugs, fuel pump. It will crank but it wont start it sounds different.
 OK. The next thing you need to do is check compression.

How would i go by doing that cause that what i wasn't thinking but i don't know how.
 Remove the spark plugs, disable the fuel and ignition, install a compression gauge then crank the engine and compare readings of each cylinder.

I would have to remove all the spark pugs at the same time?
 Yes, then check each cylinder with gauge one at a time.

Ok but we checked that it reading where fine. And we used a code reader and no codes popped. I dont remember the pressure numbers.
 What are the pressures on the cylinders? If engine sound different, something broke inside.

It sounds high pitch like it wants to start but nothing afterwards.
 Ok. The high pitch noise may mean the timing chain jumped or the cam broke.

You would hear if the cam broke right? How i would i check the timing chain?
 That would show up on the compression readings. Remove valve covers, crank engine and watch that ALL rocker arms move. If they do not, then either the timing chain or a gear broke or I have even seen a camshaft break and cause the same condition. This is only on a certain engine- a 3400 3.4L V6 and only certain years have had a few problems of this type. The only real way to be sure is to remove the timing cover.