High Speed - Danger Lights.
Thread Starter
Racer
Joined: Apr 2007
Posts: 494
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From: Dubai Mirdiff
High Speed - Danger Lights.
First the car:
Stock 2004 Model C5 LS1 Vette Convertable Le Mans Edit.
Only had its 15km Serverice a few weeks ago.
The Scary bit for little n00b me.
Driving back from airport get to my favourite stretch of road and open her up to 155mph. Then i thought well lets see what her top end is as nothing near. But the car seemed to have max'd, the HUD said "SHIFT" on the top right - worrying as i have an automatic. Then a yellow light came on in the shape of an Engine. Instantly i lifted off and let it roll to slow. The light went off and no sign of problems.
I need to know what the Hell those lights were. Is 155 the max, should i have tried go harder? Why is the Auto box telling me to shift and what is what i guess the Engine management light doing coming on.. HELP Mucho worried about this... (Note:
12:30pm and i am here typing to you and not sleeping in bed)
Note: Hood was down, Full of fuel Extreme 98 Octane, Oil life at 97%. One week ago i added some STP Engine cleaner as well..
tell me she will live and that its my own fault for hurting her
Stock 2004 Model C5 LS1 Vette Convertable Le Mans Edit.
Only had its 15km Serverice a few weeks ago.
The Scary bit for little n00b me.
Driving back from airport get to my favourite stretch of road and open her up to 155mph. Then i thought well lets see what her top end is as nothing near. But the car seemed to have max'd, the HUD said "SHIFT" on the top right - worrying as i have an automatic. Then a yellow light came on in the shape of an Engine. Instantly i lifted off and let it roll to slow. The light went off and no sign of problems.
I need to know what the Hell those lights were. Is 155 the max, should i have tried go harder? Why is the Auto box telling me to shift and what is what i guess the Engine management light doing coming on.. HELP Mucho worried about this... (Note:
12:30pm and i am here typing to you and not sleeping in bed) Note: Hood was down, Full of fuel Extreme 98 Octane, Oil life at 97%. One week ago i added some STP Engine cleaner as well..
tell me she will live and that its my own fault for hurting her
Melting Slicks
Joined: Apr 2003
Posts: 2,989
Likes: 10
From: Columbus OH
Thread Starter
Racer
Joined: Apr 2007
Posts: 494
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From: Dubai Mirdiff
lol lost in translation.
Hood in the rest of the world refers to the convertable roof.
Fuel is in the Fuel Tank - Fuel Type High Octane 98
Oil Life shows 97% remaining (Just serviced)
Additional note: STP Injector cleaning soloution was added to full tank of fuel around one week ago.
All of the above was just some additional back ground in case it was relevent I am no Petrol head
Hood in the rest of the world refers to the convertable roof.
Fuel is in the Fuel Tank - Fuel Type High Octane 98
Oil Life shows 97% remaining (Just serviced)
Additional note: STP Injector cleaning soloution was added to full tank of fuel around one week ago.
All of the above was just some additional back ground in case it was relevent I am no Petrol head
I'm "Apache" a psycho dog
Joined: Jan 2001
Posts: 3,085
Likes: 31
From: N.J.
Sorry i cant help you on why the engine light came on, but what interests me strangely enough is that you were doing that speed without a roof
do you have hearing or hair left? 
Last edited by Rob 99; Apr 25, 2007 at 11:09 PM. Reason: content correction
Heel & Toe
Joined: Nov 2006
Posts: 15
Likes: 0
From: Punta Gorda Florida
Going fast without the roof??
I've done 125+ many times in the convertible with no problems.
I do turn the radio off to get the antenna to drop before running up past 90, but other than that, it runs really nice sans top at speed!!
AD (silver 04)
I've done 125+ many times in the convertible with no problems.
I do turn the radio off to get the antenna to drop before running up past 90, but other than that, it runs really nice sans top at speed!!
AD (silver 04)
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Racer
Joined: Nov 2002
Posts: 397
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From: Auburn AL
It's possible that your clutch is slipping. That would explain why your engine rpm would be higher than normal at 155mph. How many miles do you have on the current clutch. You should be able to hit about 174mph before you hit the rev limiter. I would check your clutch fluid before you drive again. My guess is that it's pretty dark. If it's dirty I would use Ranger's clutch fluid changing procedure to fix the problem.
Never mind, I didn't catch that it's an auto. I assumed since the HUD said "shift" that it was a Manual.
Greg
Never mind, I didn't catch that it's an auto. I assumed since the HUD said "shift" that it was a Manual.
Greg
Last edited by electronbluec5; Apr 26, 2007 at 12:36 AM.
Tech Contributor
Joined: Oct 1999
Posts: 41,058
Likes: 9,818
From: Charlotte, NC (formerly Endicott, NY)
CEL is emissions related. You can do some pretty serious damage to the engine and the CEL will not come on as long as the emission readings are in range. A lot of people in this country drive for a year with the CEL on. If their state doesn't require an emissions check they may drive for years with it on.
What gear were you in? From your description it sounds like you were in OverDrive and not in Drive. Did you happen to see the tach reading when you hit 155? In Overdrive you may not have had the horsepower to push the car any faster since the rpms were too low. At 155 mph in OD the engine would have been turning around 3700 rpms and producing about 280 horsepower. At those speeds the aerodynamic load increases quite quickly and the engine couldn't produce increased horsepower as fast as the load increased so the speed balanced out to 155.
Bill
What gear were you in? From your description it sounds like you were in OverDrive and not in Drive. Did you happen to see the tach reading when you hit 155? In Overdrive you may not have had the horsepower to push the car any faster since the rpms were too low. At 155 mph in OD the engine would have been turning around 3700 rpms and producing about 280 horsepower. At those speeds the aerodynamic load increases quite quickly and the engine couldn't produce increased horsepower as fast as the load increased so the speed balanced out to 155.
Bill
Drifting
Joined: Oct 2000
Posts: 1,396
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From: Sacramento CA
I have had my Vert up to 168 with the top down, the wind was a bit loud, but what a rush. But to anwser your question I have seen the shift light before in that mph range also. But in drive not OD as suspected above. That is where I drop to OD when I see the shift light. It will still pull after that but it is slow climb in mph. I do have the sport axle with 3.15 rear end. Not sure why the check engine light but something did go out of spec, for the time needed. If it was gone right away and not returned I would not worry.
Jeffy
Jeffy
Thread Starter
Racer
Joined: Apr 2007
Posts: 494
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From: Dubai Mirdiff
Ok guys first thing – the car is Automatic
I am unaware of any overdrive button or facility on my car, where is it located? (2004 Model)
The light that came on is a yellow one on the analog dial and it looks like an Engine. No text warning was provided only “SPEED WARNING”
Of course there are speed limits, but hell where else do you speed but on the roads. My car will never see a track. When the roads empty and it’s late at night I will risk the fines and I am not putting anyone else other than myself at risk.
This might sound strange but is it a potential that the car is limited to 155mph, I know my mates Mustang GT was limited? I am not sure because as soon as a warning light comes on you take your feet of the pedals to reduce any damage. Are you saying that this light means my emissions where high?
Thinking today maybe the car was on the Verge of going into 6th Gear, but by easing off the gas never made it and like you said the drag was making it more difficult.
I don’t speed with the roof up simply because 125+ the window seal folds in and causes the window to vibrate.. also it scares me lol. Noise with the roof down is brilliant.
Car showed no signs of problems this morning
Cheers folks for your help
Big Kiss.
I am unaware of any overdrive button or facility on my car, where is it located? (2004 Model)
The light that came on is a yellow one on the analog dial and it looks like an Engine. No text warning was provided only “SPEED WARNING”
Of course there are speed limits, but hell where else do you speed but on the roads. My car will never see a track. When the roads empty and it’s late at night I will risk the fines and I am not putting anyone else other than myself at risk.
This might sound strange but is it a potential that the car is limited to 155mph, I know my mates Mustang GT was limited? I am not sure because as soon as a warning light comes on you take your feet of the pedals to reduce any damage. Are you saying that this light means my emissions where high?
Thinking today maybe the car was on the Verge of going into 6th Gear, but by easing off the gas never made it and like you said the drag was making it more difficult.
I don’t speed with the roof up simply because 125+ the window seal folds in and causes the window to vibrate.. also it scares me lol. Noise with the roof down is brilliant.
Car showed no signs of problems this morning
Cheers folks for your help
Big Kiss.
Race Director
Joined: Mar 2007
Posts: 18,308
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From: Marlton. Increasing performance one speeding ticket at a time! NJ
First thing for everyone else. I believe 98 octane is eqivalent to 93 here in the US. Other countries it is common to specify max octane rather than the R+M/2 method here.
If its an auto, its a 4speed. 4th gear is overdrive, with a .70 ratio. (FYI, 3.06,1.62,1,.70 ratios 1st to 4th). Drag increases with the square of speed, and you are pretty close to top speed, especially with the top down, drag is increased further. I'm assuming you have the 2.73 rear axle. A lower gear (higher number) limits top gear speed, but may actually give you a higher top end (drag limited) since you are at higher RPM and more torque.
Where was this car purchased. Import laws can be funny sometimes, and exported cars may have other features required for Euorpe, Asia, etc. Just an example, my friend bought a GTO, and it has some quirks that are Austrailian based, since that's where the car was designed, but also American ones, like they had to move the gas tank into the trunk because it wouldn't pass saftey standards stock.
Don't know why is said shift, maybe the computer was confused. Only as good as its programming.
I doubt you hurt anything.
If its an auto, its a 4speed. 4th gear is overdrive, with a .70 ratio. (FYI, 3.06,1.62,1,.70 ratios 1st to 4th). Drag increases with the square of speed, and you are pretty close to top speed, especially with the top down, drag is increased further. I'm assuming you have the 2.73 rear axle. A lower gear (higher number) limits top gear speed, but may actually give you a higher top end (drag limited) since you are at higher RPM and more torque.
Where was this car purchased. Import laws can be funny sometimes, and exported cars may have other features required for Euorpe, Asia, etc. Just an example, my friend bought a GTO, and it has some quirks that are Austrailian based, since that's where the car was designed, but also American ones, like they had to move the gas tank into the trunk because it wouldn't pass saftey standards stock.
Don't know why is said shift, maybe the computer was confused. Only as good as its programming.
I doubt you hurt anything.
Thread Starter
Racer
Joined: Apr 2007
Posts: 494
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From: Dubai Mirdiff
lol my bad...
Wowza i really didnt know the Auto box really only had four gears. if that is the case and i had maxed the revs and the Engine had no where to go then it would scream "Shift" also as when you hit any limit of a gear the warning light would flash... hmmm so 155 with roof down how depressing.
Car is stock. Baught in Dubai from the GM dealership. Not sure if you are correct on the Octane levels as we are in the Oil capital of the world and a lot of people like proformance products but could well be.
Wowza i really didnt know the Auto box really only had four gears. if that is the case and i had maxed the revs and the Engine had no where to go then it would scream "Shift" also as when you hit any limit of a gear the warning light would flash... hmmm so 155 with roof down how depressing.
Car is stock. Baught in Dubai from the GM dealership. Not sure if you are correct on the Octane levels as we are in the Oil capital of the world and a lot of people like proformance products but could well be.
Racer
Joined: Dec 2005
Posts: 321
Likes: 3
From: bloomington Indiana
I read on some Corvette Forum somewhere that the HUD "shift" light acts that way on the A4, just a carryover from the M6 that 95% of the Vette owners would never see.
As far as the CEL, maybe he prolonged WOT & fuel enrichment might have got the cats close to overtemp.
As far as the CEL, maybe he prolonged WOT & fuel enrichment might have got the cats close to overtemp.
Race Director
Joined: Mar 2007
Posts: 18,308
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From: Marlton. Increasing performance one speeding ticket at a time! NJ
Le Mans Master
Joined: Aug 2005
Posts: 5,375
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From: CA.
St. Jude Donor '13-'14-'15
Hello---a couple things--- The stock shift point from 3-4 in your car if it hasn't been tuned is 5900---So depending on what the RPM's were will tell you if you were in 3rd or 4th---IF you had it at 100% tps (floored)--doing the math on the EFILIVE shift point calculator--puts you at 145 MPH at the 3-4 shift at 5900 RPM's. So I would guess that it missed the shift point and was over revved in 3rd but did not hit the "in gear rev limiter " of 6200 yet ---hence the shift now light.The check engine light may be associated with the tranny & the missed shift----
AND it does happen from time to time--mostly on modded cars though--It has happened to me in lower gears and I hit the "in gear rev limit" and I would back off---
I don't think you were in 4th gear because you would not have gotten the "shift now" message---there are no more gears !!!!
AND it does happen from time to time--mostly on modded cars though--It has happened to me in lower gears and I hit the "in gear rev limit" and I would back off---
I don't think you were in 4th gear because you would not have gotten the "shift now" message---there are no more gears !!!!
Last edited by tblu92; Apr 26, 2007 at 12:53 PM.
Pro
Joined: Apr 2002
Posts: 726
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From: Denver CO
I read on some Corvette Forum somewhere that the HUD "shift" light acts that way on the A4, just a carryover from the M6 that 95% of the Vette owners would never see.
As far as the CEL, maybe he prolonged WOT & fuel enrichment might have got the cats close to overtemp.
As far as the CEL, maybe he prolonged WOT & fuel enrichment might have got the cats close to overtemp.
So, we'll have to see what UAE-Vette says.
BTW, the computers do really wierd things. I had my traction control go haywire 8 months back when I kicked it at 70 going down a hill (A4, I didn't do anything but romp on the throttle). It went into reduced power mode. I limped off the exit into a gas station. Turned the car off, prayed for 10 secs, started it back up, no problems since (other than the @#$#@%#$@ CLB GM installed as a "fix", but that's another story). If you don't have codes in the computer, I'd say don't worry about it.
Now, do you have leaded or unleaded fuel?
Could be speed limited... but I'd expect the engine to start cutting out (sputtering) from fuel and ignition cut-out just like when you pass the redline. That's what my Cavalier would do in KSA when I pushed it up to 115 :-)