post hydrolock poor gas milage

just as the title suggests, i hydrolocked a few weeks ago. the jeep started back up after the water was cranked out of the engine but there was a misfire. when i got home i changed the plugs and oil, no more misfire. however lately i've noticed absolutely TERRIBLE gas milage. like damn it's obscene. i can visibly see the needle drop after like 20 minutes of around town driving, and i'm only on 31"s.

i tried using sea foam and it definetly made my idle smoother but didn't do too much else for the milage. i also am gonna get my whole transmission flushed within the upcoming week, because the little bit of tranny fluid i saw when i pulled the dipstick out was brown. i'm probably gonna drain out the pan today at any rate and check it out for sure but i wanna get rid of ALL the bad fluid...

anything else i could be trying? one of my friends reccomended this oil additive "Restore" which he used on his old lincoln, which apparently did a pretty good job... i dunno help me out i tried searching but couldn't find anything too relevant. information about why this is happening or how i could fix it would be helpful!

**edit also it's important to note that the engine sounds fine, it doesnt struggle. it runs strong.

just a thought, would hydrolocking be detrimental to the o2 sensor?

Not saying that it's gonna happen, but this is a definite possiblity.....your motor is probably on the way out now. One of my firends and I were wheeling one night and hydrolocked his motor, we cranked all the water out, got it cranked and went home. The next day we flushed and changed everything..... The engine lasted him another 3k miles, it ran strong and smooth....then one morning on the way to work a rod snapped in half. Did you actually compress the water in the cylinder or did you know imediately that was your problem? We didn't know imediately, and compressed water in #6 when it was almost completely full of water.....that was the rod that snapped. Just giving you a warning...anyways we built him a 4.7L stroker It definitely runs strong now....best part is it cost little to no more than a regular engine build.

Hey there,

I pretty much did the same thing a few years back in a near-stock cherokee.

First, methodically disconnect all your sensor harnesses (as to not forget wich plug goes where) and clean the connections on all the locations under the hood and along the downpipe. Sensors such as IAC, Mass AirFlow, Throttle positioning sensor, coolant temperature sensor (my problenm), other temp sensors. Cleaner is a few bucks at any common hardware store.

Secondly, check to make sure you aren't running too rich or too lean. This will cause your catalytic converter to plug after a while. Does your rig spew out black smoke upon high-rev shifts? Also, make sure your cat isn't clogged. Check by getting the temperature above and below the cat. If it's way hotter above the cat, it's gonna need replacement.

Good luck

Kyle

thanks for the help. and news, both good and bad. i think hydrolock is definetly a case by case basis for sure... but anyways

i didn't have that much water in the engine. when we cranked it only very little came out.

and i guess i'll try this cleaner stuff also.


and as a new development... i've noticed that i swear i have more gas reading when i turn the car off, and wheni turn it back on it reads visibly less... if this is gonna help.

i've got emissions due in a few so if i'm runnin rich i'll know damn quick haha. thanks again.

Oizarod115 said:

just a thought, would hydrolocking be detrimental to the o2 sensor?

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x2
Also check the injectors to see if they got damaged, And what about your air filter? Just a thought. I got mine wet once no hydolock but good n wet and my milage went to the crapper!