03 cobra boost issue

99LS1 · 06-19-2006, 07:29 PM

99LS1's friend posting under his account.

I have an 03 cobra that has exhaust, lower pulley, intake, handheld tune, misc mods. Boost when I bought it was set at 15lbs and has always been that. I had a minor accident outside Washington D.C. during rush hour traffic. I rearended the car in front of me going 20mph.

The radiator was damaged, some bodywork, nothing on the engine was messed up.

When I got the car back it was only hitting 8lbs. At one point the intercooler reservoir was bubbling over. I thought when they reset the ecu it wiped the tune, causing it to only hit 8lbs. After reloading the tune nothing changed. The belt doesn't appear to show signs of slippage either.

I checked for damage to the ic/piping, none was noted. Any thoughts? Thanks in advance.

Italian LX · 06-19-2006, 09:45 PM

What condition is the air filter in?

TheJeanyus · 06-19-2006, 09:55 PM

The tune should not affect boost pressure.

If you have an air intake that extends into the fender, make sure the tube and air filter weren't damaged (could be restricting flow).

coupe · 06-20-2006, 10:13 AM

Leak in the intercooler somewhere causing it to bubble up the reservoir

...surprised it's not ingesting water too, steaming out the tailpipes?

99LS1 · 06-20-2006, 11:01 AM

99LS1's friend posting under his account.

Intake was undamaged in the accident.

I visually checked the intercooler for leaks but didn't see any. I'd expect a rather large tear to cause a leak that big. Plus it builds boost fine, just not enough.

No steam coming out of tailpipe or milky coolant. So heads are fine.

lukem80 · 06-20-2006, 11:36 AM

the belt ok? what about any loose vacuum hoses/tubes?

Italian LX · 06-20-2006, 12:01 PM

What gauge are you using to measure the boost? Does the car feel a lot slower than before?

I think you can rule out any boost leak issues that everyone is mentioning. If you were losing that much air, it would wreak havoc on your A/F and the car probably wouldn't run worth a damn.

99LS1 · 06-20-2006, 01:48 PM

99LS1's friend posting under his account.

The belt seems fine. This is my first performance car, and it seems to me if the belt was slipping I'd smell it. Or have some build up of dust somewhere, but that's not really the case. Free-revving the car with the hood up (not sure if it's a good way to test) doesn't show anything unusual.

QWKSNKE · 06-20-2006, 02:20 PM

How long have you had the car? What is the time frame that you last saw 15 psi. Reason I ask, is that you will lose boost (not make as much) with our current temperatures being so high. Like someone else also mentioned, you need to check your air filter. How many miles are on the car?

Italian, the stock gauge only goes to 10psi so he must be running a aftermarket gauge to be able to see 15psi.

I also agree with Italian in that it can't be boost leak. The way the system is designed in those applications it can't leak without a bad running engine being one of the systems. Gotta remember the blower is on top of the motor, therefore the only boost pressure there is between the top of the motor and the heads. Its not like he can blow pipe or anything.

TheJeanyus · 06-20-2006, 02:39 PM

Quote:

Originally Posted by QWKSNKE

Italian, the stock gauge only goes to 10psi so he must be running a aftermarket gauge to be able to see 15psi.

Or one of those boost overlays you can buy on Billetflow's site (as well as some other sites). It allows you to read up to 16 psi on the stock gauge, though I'm not sure how accurate it is.

06-19-2006, 07:29 PM	#1
99LS1 WWIP Saving for Evo XXI Join Date: Dec 2004 Location: You like my biodata. B-i-o-d-a-t-a! Posts: 1,693	03 cobra boost issue 99LS1's friend posting under his account. I have an 03 cobra that has exhaust, lower pulley, intake, handheld tune, misc mods. Boost when I bought it was set at 15lbs and has always been that. I had a minor accident outside Washington D.C. during rush hour traffic. I rearended the car in front of me going 20mph. The radiator was damaged, some bodywork, nothing on the engine was messed up. When I got the car back it was only hitting 8lbs. At one point the intercooler reservoir was bubbling over. I thought when they reset the ecu it wiped the tune, causing it to only hit 8lbs. After reloading the tune nothing changed. The belt doesn't appear to show signs of slippage either. I checked for damage to the ic/piping, none was noted. Any thoughts? Thanks in advance.

06-19-2006, 09:45 PM	#2
Italian LX Daddy x4 ...we're done Join Date: Dec 2004 Location: Oxford, AL Posts: 11,551	Re: 03 cobra boost issue What condition is the air filter in? __________________ -Brian '86 Mustang GT Convertible '88 Mustang LX coupe '11 Odyssey TE '21 Insight Touring

06-19-2006, 09:55 PM	#3
TheJeanyus Administrator Join Date: Dec 2004 Location: Huntsville, AL Posts: 14,774	Re: 03 cobra boost issue The tune should not affect boost pressure. If you have an air intake that extends into the fender, make sure the tube and air filter weren't damaged (could be restricting flow). __________________ 1998 Mustang GT Coupe - World's Slowest Racecar 2005 Toyota 4Runner SR5 V8 2013 Volkswagen Jetta Sportwagen TDI

06-20-2006, 10:13 AM	#4
coupe Super Moderator Join Date: Dec 2004 Posts: 6,313	Re: 03 cobra boost issue Leak in the intercooler somewhere causing it to bubble up the reservoir ...surprised it's not ingesting water too, steaming out the tailpipes? __________________ " If you can't explain it simply, you don't understand it well enough. " - Albert Einstein

06-20-2006, 11:01 AM	#5
99LS1 WWIP Saving for Evo XXI Join Date: Dec 2004 Location: You like my biodata. B-i-o-d-a-t-a! Posts: 1,693	Re: 03 cobra boost issue 99LS1's friend posting under his account. Intake was undamaged in the accident. I visually checked the intercooler for leaks but didn't see any. I'd expect a rather large tear to cause a leak that big. Plus it builds boost fine, just not enough. No steam coming out of tailpipe or milky coolant. So heads are fine.

06-20-2006, 11:36 AM	#6
lukem80 日本語 Join Date: Jul 2005 Location: Montgomery Posts: 1,661	Re: 03 cobra boost issue the belt ok? what about any loose vacuum hoses/tubes?

06-20-2006, 12:01 PM	#7
Italian LX Daddy x4 ...we're done Join Date: Dec 2004 Location: Oxford, AL Posts: 11,551	Re: 03 cobra boost issue What gauge are you using to measure the boost? Does the car feel a lot slower than before? I think you can rule out any boost leak issues that everyone is mentioning. If you were losing that much air, it would wreak havoc on your A/F and the car probably wouldn't run worth a damn.

06-20-2006, 01:48 PM	#8
99LS1 WWIP Saving for Evo XXI Join Date: Dec 2004 Location: You like my biodata. B-i-o-d-a-t-a! Posts: 1,693	Re: 03 cobra boost issue 99LS1's friend posting under his account. The belt seems fine. This is my first performance car, and it seems to me if the belt was slipping I'd smell it. Or have some build up of dust somewhere, but that's not really the case. Free-revving the car with the hood up (not sure if it's a good way to test) doesn't show anything unusual. __________________ 08 cbr 1000 73 mach 1

06-20-2006, 02:20 PM	#9
QWKSNKE 3v's are slow Join Date: Dec 2004 Location: Here and There Posts: 17,152	Re: 03 cobra boost issue How long have you had the car? What is the time frame that you last saw 15 psi. Reason I ask, is that you will lose boost (not make as much) with our current temperatures being so high. Like someone else also mentioned, you need to check your air filter. How many miles are on the car? Italian, the stock gauge only goes to 10psi so he must be running a aftermarket gauge to be able to see 15psi. I also agree with Italian in that it can't be boost leak. The way the system is designed in those applications it can't leak without a bad running engine being one of the systems. Gotta remember the blower is on top of the motor, therefore the only boost pressure there is between the top of the motor and the heads. Its not like he can blow pipe or anything. __________________ 2009 Porsche Carrera S 2008 ///AMG C63.. Eurocharge Tune. RIP 2019 AMG GLC43..wife's 03 F250 SD.. Edge Evo, AFE Stage 1 CAI 08 GT. JBA axle back, FRPP springs, FRPP swaybars.. daughter's 01 Cobra vert... wife's I need a new toy