In the past couple of tanks I have been getting about 15-16 mpg down from 19-20... Last tank I got 180 miles...

At idle it almost sounds like there is a backfire every once in a while. I pulled a couple plugs and noticed there was a white residue on them after only about a year of having them in since my head gasket was changed. I read that it could be a clogged air filter, and the guy at the parts store said that I should check vacuum lines.

Where are all the vacuum lines? Is there a way to test the plastic ones, or do I just have to listen to them and see if I can hear anything? Do you guys have any other things I should look for?

Thanks in advance.

 

Clean air filter, change oil, check tires.

 

1. Will do.

2. Did 2 days ago.

3. All four are at 33psi.

 

You can take a can of starting fluid and spray a little at a time around the vacuum lines to see if you have a leak. If the engine speeds up when you spray it around a certain one, its leaking and pulling in the starting fluid.

 

This might be a very dumb question, but wouldn't a vacuum leak like that make it run more lean since it would be pulling in more air than expected?

 

Good trick.

 

Jack up the rear end then put your car in n and see how easy the rear wheels turn. Engine off of course. I had a rear caliper hanging up and after I fixed that my MPG's increased. just a thought