Octane and oil leak

**94redmaro** · 03-04-2007, 07:32 PM

How important is it to use Premium every time you fill her up? Ive been using mid grade, and i think i mightve f'd up because today when i started her up the idle was awful ,and when i take off to drive feels like the car is about to shut off, horrible accel...etc So i put some injector/gas cleaner in and $20 bucks of premium and take her on the freeway still no difference.....whats the deal you guys?

P.S im also having this weird issue with an oil leak. its not leaking onto the ground, but burning through my exhaust. my antifreeze level is perfect. but i burn almost 2 quarts every two weeks or so, and when i washed her the other day i wiped my finger inside my exhaust tips and noticed that their is oil or a black film inside them.....

please give me feedback on this issue you guys, because ive only had the car for a month and im trying to get the car totally running right

**Danger731** · 03-04-2007, 08:35 PM

check your plugs, they are prolly fouled, clean em up real good, mild wire brush w gasoline, dry em off and reinstall them, give it a week and recheck to see which cylinder is fouling out the most.

**BlackLT1Z28** · 03-05-2007, 08:13 AM

I use 93 octane because the LT1's comp ratio is 10.5. So the higher octane is definately something not to skip out on. Some people have/can run on 87 octane, but I wouldn't recommend it. It won't save you much money anyways, just a couple buck every time you fill up.

**jasonisdn** · 03-06-2007, 04:28 PM

How important is it to use Premium every time you fill her up? Ive been using mid grade, and i think i mightve f'd up because today when i started her up the idle was awful ,and when i take off to drive feels like the car is about to shut off, horrible accel...etc So i put some injector/gas cleaner in and $20 bucks of premium and take her on the freeway still no difference.....whats the deal you guys?
could be some trash in the filter, water in the gas,trash on the pump filter even trash in the injectors.
P.S im also having this weird issue with an oil leak. its not leaking onto the ground, but burning through my exhaust. my antifreeze level is perfect. but i burn almost 2 quarts every two weeks or so, and when i washed her the other day i wiped my finger inside my exhaust tips and noticed that their is oil or a black film inside them.....
the film in the exhaust is normal , its not oil. you are telling us that you are having to put 2 quarts of oil in your car every 2 weeks? yet there is not 1 drop on the ground? how many miles are on your car and have you even done a compression test?
please give me feedback on this issue you guys, because ive only had the car for a month and im trying to get the car totally running right

**94redmaro** · 03-06-2007, 05:23 PM

im going to get it diagnosed, because i just had my trans rebuilt, and got it back now the oil problem. Some people say valve guides, and some say it could be rings. There are 115,000 miles on the motor as i know it, when i bought it i never asked if they had dropped a new engine in it. Whats happening is on the passenger side there is oil seeping from somewhere and its getting into my exhaust, because if you wipe your finger inside my tips you'll get a dark oilly film, and on the back end of my car you see black dirt, because of the oil burning from my pipes.......

**5.0THIS** · 03-07-2007, 12:49 AM

Originally Posted by 94redmaro

im going to get it diagnosed, because i just had my trans rebuilt, and got it back now the oil problem. Some people say valve guides, and some say it could be rings. There are 115,000 miles on the motor as i know it, when i bought it i never asked if they had dropped a new engine in it. Whats happening is on the passenger side there is oil seeping from somewhere and its getting into my exhaust, because if you wipe your finger inside my tips you'll get a dark oilly film, and on the back end of my car you see black dirt, because of the oil burning from my pipes.......

As someone has already told you.. it indeed could be rings or valve guides... or valve seals. Oil isnt getting into the exhaust up front from the outside. Otherwise it would burn off of the outside of the pipe (as the exhaust is extremely hot the closer you get to the motor. It is most likely getting into the chambers, and whatever isnt getting burned goes through the system. This could lead to fouled plugs and poor O2 sensor readings if it goes on long enough.

**94redmaro** · 03-07-2007, 06:59 AM

im not even sure about the 02's i know the car has 3in borla exhaust minus cats from to back, and hooker super competition coated headers....i just got the car maybe like a month ago, and im not too familiar with even all the modifications done, but the transmission shop i got my car done at let me look under the car when they were finished rebuilding and installing the trans, and showed me heavy oil spots that were outside my exhaust closer to the front, but somehow the oil is in my tips in the back.......so if the oil is getting into my chambers what could the leak be? my dad and me are going to try and tackle this since he does most of my repairs via tune up etc....i just spent a lot of money with the trans, im trying to avoid heavy labor prices by having my paps do it

**Chad97z** · 03-09-2007, 11:50 PM

Originally Posted by BlackLT1Z28

I use 93 octane because the LT1's comp ratio is 10.5. So the higher octane is definately something not to skip out on. Some people have/can run on 87 octane, but I wouldn't recommend it. It won't save you much money anyways, just a couple buck every time you fill up.

Not only that, but anything that is less combustible requires more of, to propel your car. In any style of driving habits you are going to use more fuel to get your car rolling the same speed as a higher octane fuel. Mere logic. Higher combustion is what creates torque. So even if you're not racing, the car still has to be pushed up to 40 miles per hour even if you do it lightly. see what I'm saying? So if the fuel is not very combustible, it will just take more of it to get the car going 40 miles per hour.

People don't think of things the way I do.

**Bobby97SS** · 03-10-2007, 04:24 AM

Originally Posted by Chad97z

People don't think of things the way I do.

Maybe thats a good thing because your understanding of octane ratings and combustibility are all wrong. Lower octane is more prone to detonation from heat and pressure. Higher octane (premium) resist detonation. Thats why you use premium in performance cars. Higher combustion chamber pressure. If you feel your car makes more power on premium its because absent of detonation the computer will give the engine more spark advance.

**jasonisdn** · 03-10-2007, 06:01 AM

Originally Posted by Bobby97SS

Maybe thats a good thing because your understanding of octane ratings and combustibility are all wrong. Lower octane is more prone to detonation from heat and pressure. Higher octane (premium) resist detonation. Thats why you use premium in performance cars. Higher combustion chamber pressure. If you feel your car makes more power on premium its because absent of detonation the computer will give the engine more spark advance.

+1 also you should get slightly better mileage out of the higher octane fuel, less wasted energy

**94redmaro** · 03-10-2007, 07:15 AM

nice way to put it. I didnt think of it that way..

So my problem is my valve guides, and I have to get my spark plugs taken out and cleaned up.. I also have to change out my 02 sensor. Now that I know about the fuel theory I will always put premium in my car, because seems to be a very popular suggestion....Thanks

**Bobby97SS** · 03-10-2007, 08:36 AM

Originally Posted by jasonisdn

+1 also you should get slightly better mileage out of the higher octane fuel, less wasted energy

Not according to experts.(ie the people who make the stuff)
http://www.chevron.com/products/prod...h_Rvw_chp1.pdf
Go down to pg. 8

**Chad97z** · 03-10-2007, 09:13 AM

ok so actually, according to wiki, octane refers to its ability to resist pre-detonation. So if a fuel has higher octane and resists more predetonation, then more fuel is reaching the cylinder without being burned prior to. So, it seems you should get more HP and better fuel economy since more of the fuel is reaching the cylinder before it burns.

What jasonisdn said seems to be a reasonable theroy about mileage and wasting fuel. Best way to see, is just check your own mileage with 87 vs. 93

However, one article I just read said that higher octane may cause your engine to run hotter and may cause extra decay or wear. The primary objective should be to run your engine without any Pinging. Some say never run you engine with pinging. So, maybe the best way is to have a high enough octane to keep your engine from pinging but yet not so high it causes decay and hotter temps. Also check your mileage between 91 and 93 and see if there is a difference. And see if there is any more pinging with 91.

If no pinging exists with 91, then maybe 93 is not necessary. But I tell you, my LT1 does seem to ping with lower octane fuels. I'll have to really check ithese things now that we have had this conversation.

**jasonisdn** · 03-10-2007, 11:00 AM

Originally Posted by Bobby97SS

Not according to experts.(ie the people who make the stuff)
http://www.chevron.com/products/prod...h_Rvw_chp1.pdf
Go down to pg. 8

what i get from that write up is every signal batch of fuel is different. hench different mileage results even from the same octane and same company. so no matter if you actually measured each oz of gas your results would never be the same. thats weird, looks like they would have a formula to use (thats seasonal) to keep things in certain specs. i also didn't see anything that stated 87 vs 93 gives better or worse mileage. i'll poke around on the net after the game goes off and when i get done with cleaning the shop up. late gents

**Bobby97SS** · 03-10-2007, 11:18 AM

Ive been looking all afternoon for an old Hot Rod mag. where I read something interesting. They took a pump gas motor and ran it on Rocket 110 and it actually lost horsepower. If I find it I will reference to it later. Later Gents, it a T-top in the trunk day around here. BTW, I run super in mine. Do as I say, not as I do. (Im a parent, I can get away saying that

)

**jasonisdn** · 03-10-2007, 11:30 AM

Originally Posted by Bobby97SS

Ive been looking all afternoon for an old Hot Rod mag. where I read something interesting. They took a pump gas motor and ran it on Rocket 110 and it actually lost horsepower. If I find it I will reference to it later. Later Gents, it a T-top in the trunk day around here. BTW, I run super in mine. Do as I say, not as I do. (Im a parent, I can get away saying that

)

yeah i can belive that about the 110 , i wouldn't doubt the ign was to weak to fire it off very well. do having 3 dogs and a lazy ass wife make me worthy of the parent I.D lmao

**Bobby97SS** · 03-10-2007, 01:34 PM

Originally Posted by jasonisdn

yeah i can belive that about the 110 , i wouldn't doubt the ign was to weak to fire it off very well. do having 3 dogs and a lazy ass wife make me worthy of the parent I.D lmao

Yeah, it works for me.
I wish Sarge would chime in on this thread. He is the resident dead dinosaur expert!

**5.0THIS** · 03-10-2007, 11:56 PM

There's a certain point with any motor where you could theoretically have too much octane. More octane will let you add more timing to a motor, but if you've added all the timing you can, and you're not detonating, then you dont need any more octane.