SL55/63/65/R230 AMG: SL55 is no Sports Car
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MBWorld Fanatic!
Joined: Jul 2002
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From: UK
SL55 AMG
SL55 is no Sports Car
Almost had a major accident yesterday after I under-estimated how long it would take to pass a truck (on an undivided road) and pull in safely in the face of another truck coming the other way.
Turned out the SL55 seemingly took forever to get past the truck even though I had preselected 3rd gear, and the turn in to get back in lane was pretty soggy. Only just made it.
Haven't been using the SL55 much recently and this heart-stopping moment convinced me the 996 TT is MUCH quicker in a straight line, MUCH more nimble to turn in and, on the roads I drive, a MUCH safer car.
Turned out the SL55 seemingly took forever to get past the truck even though I had preselected 3rd gear, and the turn in to get back in lane was pretty soggy. Only just made it.
Haven't been using the SL55 much recently and this heart-stopping moment convinced me the 996 TT is MUCH quicker in a straight line, MUCH more nimble to turn in and, on the roads I drive, a MUCH safer car.
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Joined: Feb 2004
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'14 ML BT
Your IC pump okay? That's a very common problem and drops your performance down to econo-box range.
Or maybe, just maybe mind you, regor is right.
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Joined: Nov 2001
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From: THE Orange County, California
2024 C8 Z06- 2025 BMW CS- 2022 Porsche 992 GTS
Almost had a major accident yesterday after I under-estimated how long it would take to pass a truck (on an undivided road) and pull in safely in the face of another truck coming the other way.
Turned out the SL55 seemingly took forever to get past the truck even though I had preselected 3rd gear, and the turn in to get back in lane was pretty soggy. Only just made it.
Haven't been using the SL55 much recently and this heart-stopping moment convinced me the 996 TT is MUCH quicker in a straight line, MUCH more nimble to turn in and, on the roads I drive, a MUCH safer car.
Turned out the SL55 seemingly took forever to get past the truck even though I had preselected 3rd gear, and the turn in to get back in lane was pretty soggy. Only just made it.
Haven't been using the SL55 much recently and this heart-stopping moment convinced me the 996 TT is MUCH quicker in a straight line, MUCH more nimble to turn in and, on the roads I drive, a MUCH safer car.
I had a stage III 996TT pushing 560hp and my E55, modded as well, pulled better.
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MBWorld Fanatic!
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From: Arizona
SL55AMG, Ferrari 348, Ferrari Testarossa, Ferrari F40, Ferrari Mondial t, Ducati 916, Indycar
The SL55 is no slouch, even compared to the Turbo Porcky. But this sounds like either a poor choice or an IC pump issue that would make the car down on power.
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Thread Starter
MBWorld Fanatic!
Joined: Jul 2002
Posts: 2,447
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From: UK
SL55 AMG
Certainly accept my judgement was off, but it was calibrated based on my experience of the 996 TT.
Stock, the 996 TT is the quicker car, it has a higher power to weight ratio so that providing you are in the correct gear, this will translate to better performance.
My SL55 has just been in the shop, no sign of any problems, it's just not as quick, as sure-footed and as nimble as the 911. How could 493bhp/1955kg be faster than 420bhp/1530kg?
If you think otherwise, you're trying to re-write the laws of physics.
Stock, the 996 TT is the quicker car, it has a higher power to weight ratio so that providing you are in the correct gear, this will translate to better performance.
My SL55 has just been in the shop, no sign of any problems, it's just not as quick, as sure-footed and as nimble as the 911. How could 493bhp/1955kg be faster than 420bhp/1530kg?
If you think otherwise, you're trying to re-write the laws of physics.
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Joined: Sep 2004
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From: Ventura County USA
'06 E55, '05 SLK55, a few others
Without specifically looking for an IC pump problem, it's easily missed. No, the Sl is not a 996 in the corners, but unless your judgement is failing, the car didn't move as fast as it once did, else you would have had enough time to safely pass no? Being an '03, I would definitely do some data logging and/or dyno the car to be sure. If you're still not happy, do a pulley/ECU and cooling upgrade and you will certainly enjoy the car more.
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Joined: Oct 2005
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From: CA
2010 CL65
Had various new 996TTS/997TT and SL55/65 (at times simultaneously)....disagree w/your conclusions....all great cars in their day, but all somewhat dated tech today...but would argue, overall, new SL55 is just as safe as any new 997TT in active safety....suspect 997TT's rigid coupe body/roof struc may offer superior passive safety vs any retractable hardtop (even when closed)....and SL65 does have traction issues on wet/bumpy roads that may compromise its active safety vs 997TT....
997TT has turbo lag/tq issues (have always had greater confidence in 55/65 tq/gearbox speeds than in 997TT's turbo lag in solving daily traffic "jigsaw puzzles" on busy urban freeways); gear selec error risk w/manual; chassis damping issues on bumpy roads; and high-speed stability weaknesses, esp on bumpy, hilly freeways, as well as cross-wind stability issues....not convinced its steering is necessarily more precise/well-damped vs SL at speed on imperfect public roads....agree, PCCB offers markedly better pedal feel than SL's...but found SL braking superior to PCCB in rain/wet conds...
997TT has turbo lag/tq issues (have always had greater confidence in 55/65 tq/gearbox speeds than in 997TT's turbo lag in solving daily traffic "jigsaw puzzles" on busy urban freeways); gear selec error risk w/manual; chassis damping issues on bumpy roads; and high-speed stability weaknesses, esp on bumpy, hilly freeways, as well as cross-wind stability issues....not convinced its steering is necessarily more precise/well-damped vs SL at speed on imperfect public roads....agree, PCCB offers markedly better pedal feel than SL's...but found SL braking superior to PCCB in rain/wet conds...
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From: Irvine, CA
Car Whore
Certainly accept my judgement was off, but it was calibrated based on my experience of the 996 TT.
Stock, the 996 TT is the quicker car, it has a higher power to weight ratio so that providing you are in the correct gear, this will translate to better performance.
My SL55 has just been in the shop, no sign of any problems, it's just not as quick, as sure-footed and as nimble as the 911. How could 493bhp/1955kg be faster than 420bhp/1530kg?
If you think otherwise, you're trying to re-write the laws of physics.
Stock, the 996 TT is the quicker car, it has a higher power to weight ratio so that providing you are in the correct gear, this will translate to better performance.
My SL55 has just been in the shop, no sign of any problems, it's just not as quick, as sure-footed and as nimble as the 911. How could 493bhp/1955kg be faster than 420bhp/1530kg?
If you think otherwise, you're trying to re-write the laws of physics.
Super Member
Joined: Dec 2002
Posts: 911
Likes: 1
From: Wichita
2005 SL600, 2011 Honda Odyssey Touring Elite
I am sure that blueSL would notice a performance decrement in his SL that was due to a malfunction. He has had his SL55 almost since the launch and is as knowledgeable about the vehicle as anyone on this board.
This whole intercooler issue has arisen only in the last year or so and my guess is that it is being perpetuated by people who want to sell new intercoolers.
Don't cut it so close next time blueSL.
This whole intercooler issue has arisen only in the last year or so and my guess is that it is being perpetuated by people who want to sell new intercoolers.
Don't cut it so close next time blueSL.
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Joined: Mar 2006
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From: San Jose area
'19 E63S sedan
I am sure that blueSL would notice a performance decrement in his SL that was due to a malfunction. He has had his SL55 almost since the launch and is as knowledgeable about the vehicle as anyone on this board.
This whole intercooler issue has arisen only in the last year or so and my guess is that it is being perpetuated by people who want to sell new intercoolers.
Don't cut it so close next time blueSL.
This whole intercooler issue has arisen only in the last year or so and my guess is that it is being perpetuated by people who want to sell new intercoolers.
Don't cut it so close next time blueSL.
It's not the intercooler. It's the intercooler coolant pump, and it's a very common failure on MB supercharged engines. If the pump on a 2003 is original, it's due to fail. Lack of coolant recirculation means the intercooler doesn't cool. When intake air temperature rises, the ECU turn off the supercharger. It's not about a better intercooler via modding. It's about the one you have not switching on.
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Joined: Feb 2004
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'14 ML BT
It's the intercooler pump and it's been malfunctioning since MB put them in the 55k cars.
Also, please notice that Blue said, "seemingly took forever to get past the truck" --- that's just not normal with a 55K engine. Hence the easy diagnosis of intercooler pump.
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Joined: May 2007
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From: Irvine, CA
Car Whore
I am sure that blueSL would notice a performance decrement in his SL that was due to a malfunction. He has had his SL55 almost since the launch and is as knowledgeable about the vehicle as anyone on this board.
This whole intercooler issue has arisen only in the last year or so and my guess is that it is being perpetuated by people who want to sell new intercoolers.
Don't cut it so close next time blueSL.
This whole intercooler issue has arisen only in the last year or so and my guess is that it is being perpetuated by people who want to sell new intercoolers.
Don't cut it so close next time blueSL.
Not to mention that the Johnson IC pump is actually a true upgrade with a higher volume capacity for recirculation and is less than $100!
Even if you arn't seeing issues, I would still do this upgrade right away! Can't beat lower IATs and stronger butt-dyno feeling for all under $100... especially with the cost of normal upgrades for MBZ.
Senior Member
Joined: Apr 2005
Posts: 314
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From: Malibu, Ca
SL65, 427 COBRA (CSX-3127)73 911S, 246GTS (DINO SPYDER), CORNICHE,1962 PORSCHE TWIN GRILLE ROADSTER+
Johnson Pump? Who has these?
Whats the story on the Johnson IC pump and where can I get one?
Super Member
Joined: Dec 2002
Posts: 911
Likes: 1
From: Wichita
2005 SL600, 2011 Honda Odyssey Touring Elite
It's not the intercooler. It's the intercooler coolant pump, and it's a very common failure on MB supercharged engines. If the pump on a 2003 is original, it's due to fail. Lack of coolant recirculation means the intercooler doesn't cool. When intake air temperature rises, the ECU turn off the supercharger. It's not about a better intercooler via modding. It's about the one you have not switching on.
That being said, If the change in performance is as great as is being stated here, then I am sure that blueSL would have said "something is wrong with my SL55" rather than "SL55 is no sports car".
Super Member
Joined: Dec 2002
Posts: 911
Likes: 1
From: Wichita
2005 SL600, 2011 Honda Odyssey Touring Elite
The intercooler pump issue is a documented and proven issue, with dealership warranty replacements and only recently has the Johnson pump movement started... and even so they are usually purchased from random ebay sellers, not any particular vendor, so your statement is false and unfounded.
Not to mention that the Johnson IC pump is actually a true upgrade with a higher volume capacity for recirculation and is less than $100!
Even if you arn't seeing issues, I would still do this upgrade right away! Can't beat lower IATs and stronger butt-dyno feeling for all under $100... especially with the cost of normal upgrades for MBZ.
Not to mention that the Johnson IC pump is actually a true upgrade with a higher volume capacity for recirculation and is less than $100!
Even if you arn't seeing issues, I would still do this upgrade right away! Can't beat lower IATs and stronger butt-dyno feeling for all under $100... especially with the cost of normal upgrades for MBZ.
Super Member
Joined: Dec 2002
Posts: 740
Likes: 0
From: Charlotte, NC
No longer car shopping...
Certainly accept my judgement was off, but it was calibrated based on my experience of the 996 TT.
Stock, the 996 TT is the quicker car, it has a higher power to weight ratio so that providing you are in the correct gear, this will translate to better performance.
My SL55 has just been in the shop, no sign of any problems, it's just not as quick, as sure-footed and as nimble as the 911. How could 493bhp/1955kg be faster than 420bhp/1530kg?
If you think otherwise, you're trying to re-write the laws of physics.
Stock, the 996 TT is the quicker car, it has a higher power to weight ratio so that providing you are in the correct gear, this will translate to better performance.
My SL55 has just been in the shop, no sign of any problems, it's just not as quick, as sure-footed and as nimble as the 911. How could 493bhp/1955kg be faster than 420bhp/1530kg?
If you think otherwise, you're trying to re-write the laws of physics.
Member
Joined: Jul 2007
Posts: 110
Likes: 0
From: Los Angeles
06 SL65, 08 S550, 08 Range Rover SuperCharged
Do what I did - sell the SL55 and buy an SL65. Then Renntech the ECU/TCU and you'll have a car that'll pass anything, anytime while giving you a touch of whiplash 
. That's what I did and I'm not in anyone's rear view mirror anymore.
. That's what I did and I'm not in anyone's rear view mirror anymore.
Senior Member
Joined: Sep 2006
Posts: 455
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From: P'cola, FL
'03 E55
I know we are talking about the intercooler pump, sorry if I confused everyone with the shorthand. My view on this issue has been shaped by the discussion on these boards of inadequacy of the intercooler pumps on the V12 which leads to my cynicism.
That being said, If the change in performance is as great as is being stated here, then I am sure that blueSL would have said "something is wrong with my SL55" rather than "SL55 is no sports car".
That being said, If the change in performance is as great as is being stated here, then I am sure that blueSL would have said "something is wrong with my SL55" rather than "SL55 is no sports car".
