Detonation
Thread Starter
Intermediate
Joined: Jun 2007
Posts: 29
Likes: 0
From: Wesley Chapel Florida
Detonation
I am in Florida, and have a stock 03 C5 convertible with 31K. The car has been running strong, but then it happened, Maybe I way off about this but I changed gas last night from 93 Shell to 91 Chevron. Everything seemed fine for about 75 miles and a quick blast to 130 on causeway, then I noticed the engine knock under load on my way home last night, so I babied it home listing. I read the other threads about detonation under load. This morning I put octane additive and ran it for about 1/2 hour driving around thinking maybe I got bad fuel but the knock is still there. I was going to change the oil, plugs, wires this next weekend and now figure I might replace at the temperature sensor as well. But then I read about the Knock Sensors. Where should I start. Should I seafoam first?
Drifting
Joined: Aug 2006
Posts: 1,407
Likes: 46
From: Tampa FL
People will say to run colder plugs only for forced induction but I tried a step colder NGK TR55 plugs in my 02 which has been pinging for months and they took care of 95% of the pinging immediately.
I am going to go get an IAT sensor too.
I added a catch can and it didn't help at all but I still like having it.
I tried SeaFoam in the tank and that didn't seem to help either.
I am going to go get an IAT sensor too.
I added a catch can and it didn't help at all but I still like having it.
I tried SeaFoam in the tank and that didn't seem to help either.
Racer
Joined: Sep 2006
Posts: 280
Likes: 0
I am in Florida, and have a stock 03 C5 convertible with 31K. The car has been running strong, but then it happened, Maybe I way off about this but I changed gas last night from 93 Shell to 91 Chevron. Everything seemed fine for about 75 miles and a quick blast to 130 on causeway, then I noticed the engine knock under load on my way home last night, so I babied it home listing. I read the other threads about detonation under load. This morning I put octane additive and ran it for about 1/2 hour driving around thinking maybe I got bad fuel but the knock is still there. I was going to change the oil, plugs, wires this next weekend and now figure I might replace at the temperature sensor as well. But then I read about the Knock Sensors. Where should I start. Should I seafoam first?
Everyone raves about Chevron Premium 93 but my car runs horribly on it with the same pinging you describe. Ever since I switched to Hess, running great with NO pinging.
Burning Brakes
Joined: Dec 2003
Posts: 855
Likes: 0
From: Tampa FL
If all else fails take it to the boys at RevExtreme in Tampa. Also may want to watch your speed on the causeway there has been a HUGE crackdown lately.
http://www.tamparacing.com/forums/ge...attention.html
http://www.tamparacing.com/forums/ge...elle-60-a.html
just a FYI
-James
http://www.tamparacing.com/forums/ge...attention.html
http://www.tamparacing.com/forums/ge...elle-60-a.html
just a FYI
-James
Race Director
Joined: Jul 2004
Posts: 16,795
Likes: 62
From: Lake Havasu City, AZ
It sounds like your car needs 93 octane...
What did you use to increase it...?
those small bottles will only raise a tank about 0.1 octane..
buy a gallon of Xylene from Home Deppot... ( paint section).
It has an octane of 114... you can safely use i gallon per 10 gallons of gas in our tank
To calculate your blended octane you need to do some basic math... weighted average...
(gallons x octane 1 + gallons x Octane 2) / total gallons
for example... (10 gallons x 92 + 1 gallon x114)11 = 94
What did you use to increase it...?
those small bottles will only raise a tank about 0.1 octane..
buy a gallon of Xylene from Home Deppot... ( paint section).
It has an octane of 114... you can safely use i gallon per 10 gallons of gas in our tank
To calculate your blended octane you need to do some basic math... weighted average...
(gallons x octane 1 + gallons x Octane 2) / total gallons
for example... (10 gallons x 92 + 1 gallon x114)11 = 94
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Le Mans Master
Joined: Feb 2006
Posts: 5,488
Likes: 4
From: USA
I'd try the Seafoam first. Seems to help the best for pinging under load. I ran it in the gas first but didn't help much. When I put it in the pcv valve and let it sit overnight, it helped tremendously, but probably needs it one more time.
If this doesn't help then I would try knock sensors and temp sensor.
If this doesn't help then I would try knock sensors and temp sensor.
Thread Starter
Intermediate
Joined: Jun 2007
Posts: 29
Likes: 0
From: Wesley Chapel Florida
I am going to try the Lucas Oil upper cylinder lubricant and Injector cleaner cleaner today and then change my oil this weekend. I am kinda leary of the seafoam in my PVC valve. Is everyone running Mobile 1? What about this royal purple? What wieght should I run for Florida heat during the summer 5w30?
Intermediate
Joined: Feb 2007
Posts: 30
Likes: 3
From: San Diego CA
My 2000 convertible loves Lucas Upper Cylinder Lubricant. Now using it in both my cars and pickup truck. LS1 runs quietly and smoothly on UCL. Not sure what its doing, but UCL makes a huge difference in throttle response. Engine revs to 5K effortlessly.
Can anyone offer a technical explanation?
Sorry to hijack the post.
I'm running Royal Purple and Lucas Oil stabilizer.
Can anyone offer a technical explanation?
Sorry to hijack the post.
I'm running Royal Purple and Lucas Oil stabilizer.
Le Mans Master
Joined: Aug 2001
Posts: 8,145
Likes: 1
From: Bradenton FLORIDA
Le Mans Master
Joined: Feb 2006
Posts: 5,488
Likes: 4
From: USA
Pro
Joined: Feb 2005
Posts: 725
Likes: 89
From: East Northport NY
really strange. I asked this question a year ago about adding an additive to the oil to eliminate that noisy cold startup. Everyone said - DON"T ADD ANYTHING TO THE MOBIL1.
Now you guys say how good this stuff is, and I see they make one for synthetic.
So once again.....what do the experts think?
Now you guys say how good this stuff is, and I see they make one for synthetic.
So once again.....what do the experts think?
Le Mans Master
Joined: Dec 2000
Posts: 7,096
Likes: 153
From: "Atlanta" Ga.
really strange. I asked this question a year ago about adding an additive to the oil to eliminate that noisy cold startup. Everyone said - DON"T ADD ANYTHING TO THE MOBIL1.
Now you guys say how good this stuff is, and I see they make one for synthetic.
So once again.....what do the experts think?
Now you guys say how good this stuff is, and I see they make one for synthetic.
So once again.....what do the experts think?
