Regular gas
boose00
10-11-2006, 05:02 PM
#1 Hey guys i just picked up a 2000 gtp and after selling it to me so told me that he ran regular in it for the last 2 years. Since he was the original owner it had premium in it for the first 4 years. Am I going to be looking at some big repairs in the future? Anyone have any experience with something like this?
:banghead:
:banghead:
BNaylor
10-11-2006, 05:15 PM
Even if there was any possible engine damage there is nothing you can do about unless you are getting driveability problems. So we would just be speculating. Just run some GM Top End engine cleaner or Seafoam through it and start using premium gas.
rubberman
10-12-2006, 01:20 PM
whats that seafoam stuff do
BNaylor
10-12-2006, 01:43 PM
whats that seafoam stuff do
It is a top engine cleaner like the version GM has. There is Seafoam for engines and another for transmissions/power steering. Normally, you feed the stuff into the intake system right at the throttle body. Supposedly it does the following:
* Stabilizes fuel
* Cleans carburetor/throttle body/intake manifolds
* Cleans carbon from pistons/cylinders
* Removes moisture
* Assures fast starts
* Frees sticky rings
* Restores power
* Upper cylinder lube
* Smooths rough idle
* Cleans fuel injectors
More data here (http://www.seafoamsales.com/motorTuneUpConsumer.htm)
Around $6.00 at AZ/Checker/Kragen/NAPA.
It is a top engine cleaner like the version GM has. There is Seafoam for engines and another for transmissions/power steering. Normally, you feed the stuff into the intake system right at the throttle body. Supposedly it does the following:
* Stabilizes fuel
* Cleans carburetor/throttle body/intake manifolds
* Cleans carbon from pistons/cylinders
* Removes moisture
* Assures fast starts
* Frees sticky rings
* Restores power
* Upper cylinder lube
* Smooths rough idle
* Cleans fuel injectors
More data here (http://www.seafoamsales.com/motorTuneUpConsumer.htm)
Around $6.00 at AZ/Checker/Kragen/NAPA.
1typhoon
10-12-2006, 09:28 PM
I have been running the cheapest 87 octane gas with 10% ethanol in S.E. Wisconsin in my 2000 GTP since it was brand new. 120k miles and no problems at all. And I drive it like I stole it!
tblake
10-13-2006, 12:08 AM
higher octane fuel does nothing but ignite slower. Its what you shoud use if your engine pings (running lean, hot spots on the pistons, incorrect ignition timing) Premium has nothing to do with performance, and since it burns slower, may even cause a little worse performance. Check your owners manual, im not familiar with gtp's so it may recommend 91 octane, but if it doesnt say anything, save yourself some money and buy 87.
BNaylor
10-13-2006, 01:17 AM
Tblake for your information a '97 - '03 GTP (L67) requires 91 octane or better per the GM owner's manual. However, 87 may be used in emergency situations for a short period of time. Has anyone weighing-in every run a Autotap scan monitoring knock retard running regular v. premium?
1typhoon
10-13-2006, 06:39 PM
Tblake for your information a '97 - '03 GTP (L67) requires 91 octane or better per the GM owner's manual. However, 87 may be used in emergency situations for a short period of time. Has anyone weighing-in every run a Autotap scan monitoring knock retard running regular v. premium?
I have run several on mine. Difference between 87 and 91 octane is about 2 degrees. Nothing to worry about and a lot cheaper on the wallet.
I have run several on mine. Difference between 87 and 91 octane is about 2 degrees. Nothing to worry about and a lot cheaper on the wallet.
BNaylor
10-14-2006, 10:26 AM
I have run several on mine. Difference between 87 and 91 octane is about 2 degrees. Nothing to worry about and a lot cheaper on the wallet.
Nothing to worry about? :shakehead I find 2 degrees unacceptable but typically knock retard is higher than what has been claimed. The conditions for the knock retard readings were not stated and I am assuming this was with regular unleaded with 10% ethanol which is probably irrelevant for most of us since it is not available in our areas and/or its use in a car not approved for use is questionable. You do not have to be a rocket scientist to know ethanol reduces detonation, therefore knock retard. Also, a lot of GTPs are modded or WIP on mods. I've run tests with Autotap on both L67 and L36s and the results are surprising. I've seen as high as 4 - 6 degrees between regular unleaded (non-ethanol mix) and premium on a stock L67. The highest readings will be at rpms over 4000 and WOT.
Here are some interesting facts:
For every 1 degree on a L67 SII 3800 you will lose approximately 2 - 3 horsepower.
For every degree of knock retard it takes .8 seconds recovery time.
"Once the PCM has retarded timing sufficiently to reduce knock below the currently detected peak level, a changeable parameter in the PCM governs how quickly the overall ignition timing can be restored to normal levels. The engine could see a peak of 15 degrees of KR from which the originating detonation may immediately disappear. However, the PCM will not instantly restore timing to pre-detonation levels. Instead, the PCM cautiously and conservatively restores ignition timing at a rate of 0.8 degrees per second. In the event of a 15 degree KR event, it would take nearly 19 seconds for the ignition timing to be restored to pre-KR levels. By the time your car sees full power again, the race is already over. This 'time' that the PCM takes to restore the ignition timing is called the Recovery Rate. The Recovery Rate will continue in this slow fashion until KR reaches zero, KR increases back above the current recovery value, or the throttle is released."
FAQ: Why is knock retard (KR) bad?
"Due to the retardation of the ignition timing, KR causes the vehicle to lose substantial power. More importantly, though, the flame front collisions are EXTREMELY harmful to the pistons. These highly volatile areas in the cylinder can cause stress cracks in your piston, which will eventually give way causing an entire CHUNK of your piston to lift right off and begin banging around inside the cylinder. This is why when the spark plug is removed after such an event, the plug end is bent all the way over. The broken piston can be VERY expensive to fix if you are not capable of doing the work yourself. DON'T EVER DISABLE YOUR KNOCK SENSORS. It takes less than 3ms to damage your engine due to knock."
BTW - I'd rather be safe than sorry later. The extra 20 cents per gallon is money well spent.
Nothing to worry about? :shakehead I find 2 degrees unacceptable but typically knock retard is higher than what has been claimed. The conditions for the knock retard readings were not stated and I am assuming this was with regular unleaded with 10% ethanol which is probably irrelevant for most of us since it is not available in our areas and/or its use in a car not approved for use is questionable. You do not have to be a rocket scientist to know ethanol reduces detonation, therefore knock retard. Also, a lot of GTPs are modded or WIP on mods. I've run tests with Autotap on both L67 and L36s and the results are surprising. I've seen as high as 4 - 6 degrees between regular unleaded (non-ethanol mix) and premium on a stock L67. The highest readings will be at rpms over 4000 and WOT.
Here are some interesting facts:
For every 1 degree on a L67 SII 3800 you will lose approximately 2 - 3 horsepower.
For every degree of knock retard it takes .8 seconds recovery time.
"Once the PCM has retarded timing sufficiently to reduce knock below the currently detected peak level, a changeable parameter in the PCM governs how quickly the overall ignition timing can be restored to normal levels. The engine could see a peak of 15 degrees of KR from which the originating detonation may immediately disappear. However, the PCM will not instantly restore timing to pre-detonation levels. Instead, the PCM cautiously and conservatively restores ignition timing at a rate of 0.8 degrees per second. In the event of a 15 degree KR event, it would take nearly 19 seconds for the ignition timing to be restored to pre-KR levels. By the time your car sees full power again, the race is already over. This 'time' that the PCM takes to restore the ignition timing is called the Recovery Rate. The Recovery Rate will continue in this slow fashion until KR reaches zero, KR increases back above the current recovery value, or the throttle is released."
FAQ: Why is knock retard (KR) bad?
"Due to the retardation of the ignition timing, KR causes the vehicle to lose substantial power. More importantly, though, the flame front collisions are EXTREMELY harmful to the pistons. These highly volatile areas in the cylinder can cause stress cracks in your piston, which will eventually give way causing an entire CHUNK of your piston to lift right off and begin banging around inside the cylinder. This is why when the spark plug is removed after such an event, the plug end is bent all the way over. The broken piston can be VERY expensive to fix if you are not capable of doing the work yourself. DON'T EVER DISABLE YOUR KNOCK SENSORS. It takes less than 3ms to damage your engine due to knock."
BTW - I'd rather be safe than sorry later. The extra 20 cents per gallon is money well spent.
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