My car has suddenly started getting bad gas mileage, what could be wrong?

Over the years, the various vehicles I’ve had, a drop in gas mileage has been the first indicator of a bigger problem. My first car went from 25 mpg to 8 mpg, when I noticed I had a leak in the gas line. my next car would routinely drop from about 20 city/25 hwy to about 15 for either when it needed the timing belt, or spark plug replaced. So I began taking my car to my mechanic friend any time I noticed a drop in my gas mileage. He has since moved, and I don’t trust regular mechanics (got charged $300 to replace a water pump and timing belt; they replaced it with junkyard parts, skipped town by the time I found out); plus I’m broke.

Boat wouldnt start, cranks but no ignite could it be the fuel ?

I have a mercrusier alpha 1 the starter engages it would start for like one time then suddenly shut off right afterwards fuel is pumping in carb too so I do have old gas in there could it be because there’s water in there and it wouldn’t ignite…?

What could be wrong with the grizzly 660?

It will start up and run fine for a bit then it will spit and sputter and then just die sometimes it fires back up and sometimes you have to leave it alone for a while we thought maybe the water in the gas so we put dry gas in it and im personally thinking maybe its the spark plugs it happened after we played in water and mud and the baffle was out but there is no water in the airbox we checked that and if it is the spark plugs where would they be located on the engine because we looked all over and tore it apart and couldnt find them but we are 15 and still have much to learn so any ideas?

Could a person use a device that splits water like for hydrogen fuel cell car but keep oxygen for scuba diving?

I heard that this canadian invented a device that splits water into hydrogen and oxygen. Companies use this device to store hydrogen in tanks until it can be used for a hydrogen fuel cell car(like they do in iceland). My question is can you store the Oxygen instead to go on the ultimate scuba adventure? My dads a scientist, but we’re not talking right now so I thought I would ask here.

How much hydrogen (gas and/or liquid) could an oil tanker covered in solar panels produce in a day?

if you take one of those big enormous oil tankers that they have today, and convert it and cover it with solar panels and park it on the equator, how much gas hydrogen could it produce in one reguarl sunny day? and how much liquid hydrogen could it produce?
thanks for the info Ecko, i was really thinking of the feasibility of a hydrogen powered commercial airplane that could travel from LA to Miami. not really cost effective, but green energy is not about making a profit, just being sustainable and beneficial

Physics: If I could mix 55 cm^3 of gasoline with 60cm^3 of water, what would the average density be in kg/m^3?

I can’t find my notes for this type of problem, so help would be terrific. Thanks!

My Volvo Penta 4.3 liter engine keeps stalling in my boat. Could it be water?

I took my Larson 26 footer (2001) out of storage last week. I replaced the impeller and put a new battery in, and it started up great. Took it down the river without a problem for 30 minutes. After than, I filled the tank. A couple days later I took it out for a longer run including going through a lock before making my way to Lake Michigan. It ran fine until I got out of the lock. I opened up the engine to about 40 mph to get around a tugboat and the engine just stopped. Cold. Panic set it. I tried to restart it but it sounded like was flooded, not an electrical issue. After a few tries it got going but that was it for my big trip. We made it back to the lock slow without incident. However, once I got out I brought it up a little faster only to have it die once again. It was harder to restart this time. Made it a few more minutes before it died although I was just crawling along. This went on until I made it back to my dock. The next day, I changed the fuel filter (it looked clean), added a fuel stabilizer and started it up. It ran for a while out of gear and died. And then it ran a longer time including at high RPMs but now I am afraid to take it out. What on earth could this be? The carb? Bad fuel? Thanks in advance.
Guys, thanks so much. I am going out today or tomorrow to see if the new filter and additive made any difference. However, since water is never going to burn, if there is water on the carb, how do it get rid of it? Do I have to pay the mechanic to do a complete rebuild? That would be expensive and timely. Thanks again.

What could be causing this high pitch noise?

I’ve got a high pitch noise that occurs with my throttle response in my ’96 Ford Thunderbird V8. When I hit the gas, I hear this whistle; so if I hit the throttle with a tap-tap-tap, I’ll get three whistles that are ever so responsive to me tapping the throttle. It REALLY shrieked similarly, when backed my car up a good 30-40 ft. the other day on a dead street to read a sign that I had to take a second look at. So, that tells me it could be coming from my transmission; at least that noise and the first one I mentioned which happens only in drive, with my throttle; from the fuel line, alt. voltage or a bearing from a pulley/pump pulley from under the hood. I just put in a brand new water pump and serp. pulley kit less than a month ago; could it be the new water pump? It only made this noise mainly on the highway before, but was happening even louder on the expressway the other day. Seems like it’s getting worse unless it’s just the water pump breaking in. Thanks for your help!
If it is the water pump, could the new water pump pulley in that pulley kit be putting too much strain on my new pump, as it’s stock and the pulley’s not; so therefor, it may be making the water pump spin too fast. Could I need a more capable water pump…just to keep up with how the pulleys are spinning?

What are some Bad things that could happen if i put 3 Cans of SeaFoam in my gas tank every Fill-up?

And why?

Fuel Injected

.. it had Run ouut of Gas and had Bad Gas in it before that.. should i “Let it run for an Hour” to “Flush” and “Burn off” all the SeaFoam and B-12 ChemTool, then just refuel with Good gas, like BP?

Thanks!

152,000 Miles, sat for one year.. Sour Gas, new Fuel Pump and Filter, i have put in MANY Cleaners.. i also wonder if i should put in a Water Remover..

Thanks!

what all could cause water in my oil of a 99 4.3 mercruiser?

i took my boat out at begining of year and was out for about an hour..it idled and ran great not under pressure but when it was in gear moving it seemed straining and wouldn’t go over like 25 and it was a lil shakey…well i winterized it last year by running fresh waer through it then i drained the block put the plugs back in then hooked a container with 5 gallons antifreeze to the muffs started it and ran all the anitfreeze in shut it down and left it alone all winter…in spring i changed the oil…..after i ran it for the first hour i checked the oil and it seemed a lil high, at first i thought it was getting gas in the oil but i checked it out by pumping some oil out and come to find out it looked like milk so it’s water in there…is there any other possibilities besides a cracked block i should check b4 replacing? thanks for your time
already checked compression on all cylinders and they are fine all firing at 165psi….would the head gasket go bad just from sitting through the winter? it was fine all last year…i was told by my father when it got in the negatives he seen antifreeze had oozed out the lower unit where u hook the muffs to which makes me think something froze but i don’t understand how anitfreeze would freeze makes no sense to me