i have an 89 si. i get dectn milage on the highway(150 at halfway) but in the street. im getting **** milage (89 at halfway full). also i smell exhaust in the cabin most of the time? clutch sometimes slips also i dont konw fi this contributes? btw the motor has 300,000 miles on it. can you guys help me out and tell me what i should check for.

 

Check exhaust leaks, and do a compression check on the motor... tired motors don't get the mileage they used to.

 

how do you chek for exhaust leaks?

 

Look under the car, look and see if you can see holes in the exhaust. Listen for loud tapping or exhaust noise from the piping, and see if you can see fumes coming out where your donut gasket is, it may have gone bad, too.

But that wouldn't cause bad gas mileage.

 

cat might be fried but yea check for leaks and dow comp test.

300K is alot but i'm sure you can get more

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Diseased Dreams &raquo;</TD></TR><TR><TD CLASS="quote">Look under the car, look and see if you can see holes in the exhaust. Listen for loud tapping or exhaust noise from the piping, and see if you can see fumes coming out where your donut gasket is, it may have gone bad, too.

But that wouldn't cause bad gas mileage. </TD></TR></TABLE>

Pre-O2 exhaust leaks can decrease mileage.

 

also sometimes the car act like it wants to die. ie rpm dropping down to 400+/- rpm. then goes back to normal?

 

do you have any cels?

 

you mite want to do a tune-up..

 

maybe even a swap...

 

tune up for now. swappin when i find the right deal on a z6!!!!!
pulled the spark plugs. they were all carbon fouled "CHAMPION SPARK PLUGS"
i guess the guy i bought the car from is an idiot!!! my mechanic said that champions are for domestics. gonna do the cap and rotor this weekend. also my cat is f'ed up. anybody ever use the ebay hi flwo cats? im might wanna get one?