Down shift, check engine light, V8 grumble, power loss, and a burning smell. (20 sec)
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From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
So to save money, do the fuel filter first, right?
Yes
This is where I get confused. If I have poor fuel pressure, wouldn't all my injectors be causing misfires?
At your mileage it is unlikely that all injectors are identical anymore due to wear & deposits etc. So one injector might be down on performance more than others & this would show up with out of spec fuel rail pressure
Or is the techron all part of the scheme? We're cleaning out injector four, while giving back maximum fuel pressure, which should cancel out the misfires, correct?
If deposits are the cause of injector 4 not atomising fuel properly then the Techron will clean those deposits & performance will return to normal. If the injector is physically damaged Techron can do nothing. Injectors can also be cleaned by removing them & placing the tip in an ultrasonic bath. The trouble with this method is it is difficult to control & can damage the coils in the injector - an injector is a solenoid at the end of the day. Techron is the safe way.
Lastly, if the injector is just faulty, we'll replace that.
Is that the correct road to take?
Yes
Thanks!
Edit: Also, can someone please explain limp mode to me a bit more? My car is terribly choppy and sounds absolutely horrid when limp mode kicks in. I guess that's regular?
Yes
This is where I get confused. If I have poor fuel pressure, wouldn't all my injectors be causing misfires?
At your mileage it is unlikely that all injectors are identical anymore due to wear & deposits etc. So one injector might be down on performance more than others & this would show up with out of spec fuel rail pressure
Or is the techron all part of the scheme? We're cleaning out injector four, while giving back maximum fuel pressure, which should cancel out the misfires, correct?
If deposits are the cause of injector 4 not atomising fuel properly then the Techron will clean those deposits & performance will return to normal. If the injector is physically damaged Techron can do nothing. Injectors can also be cleaned by removing them & placing the tip in an ultrasonic bath. The trouble with this method is it is difficult to control & can damage the coils in the injector - an injector is a solenoid at the end of the day. Techron is the safe way.
Lastly, if the injector is just faulty, we'll replace that.
Is that the correct road to take?
Yes
Thanks!
Edit: Also, can someone please explain limp mode to me a bit more? My car is terribly choppy and sounds absolutely horrid when limp mode kicks in. I guess that's regular?
EDIT - the reason that stopping & restarting clears limp mode is that you are rebooting the TCU & ECU & the fault condition recorded was relatively minor. If the vehicle encountered a major problem like loss of oil pressure then it would lock in limp mode & rebooting would make no difference. Limp mode reads levels of severity - or at least trys to.
Lane - you are obviously a technically competent guy. I'm keeping these explanations simple so all will understand. Please don't think I'm being patronising & trying to insult your intelligence.
Last edited by Glyn M Ruck; Jul 24, 2010 at 10:38 PM.
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From: Orlando, FL
C240
Simply put - "limp mode" or "limp home mode" can be triggered by the TCU or ECU - This happens when a sensor sends information to either the TCU or ECU that engine or transmission operating conditions are not normal for example overheating or fluid level too low or mixture too lean, bad driving , like selecting reverse while travelling forward or whatever. Limp mode is then triggered by either the TCU or ECU to protect the engine or transmission by reducing power output, cutting some cylinders, locking the transmission in a low gear or combinations of these so that you can drive the vehicle home at reduced speed or whatever without doing damage to the drivetrain. Of course if a sender unit or sensor fails & sends no signal or nonesense to the CU's the it will also trigger limp.
EDIT - the reason that stopping & restarting clears limp mode is that you are rebooting the TCU & ECU & the fault condition recorded was relatively minor. If the vehicle encountered a major problem like loss of oil pressure then it would lock in limp mode & rebooting would make no difference. Limp mode reads levels of severity - or at least trys to.
Lane - you are obviously a technically competent guy. I'm keeping these explanations simple so all will understand. Please don't think I'm being patronising & trying to insult your intelligence.
EDIT - the reason that stopping & restarting clears limp mode is that you are rebooting the TCU & ECU & the fault condition recorded was relatively minor. If the vehicle encountered a major problem like loss of oil pressure then it would lock in limp mode & rebooting would make no difference. Limp mode reads levels of severity - or at least trys to.
Lane - you are obviously a technically competent guy. I'm keeping these explanations simple so all will understand. Please don't think I'm being patronising & trying to insult your intelligence.
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From: Orlando, FL
C240
Just replaced the fuel filter, going for a drive. Roads should be very clear of traffic. 
..those four clamps on the fuel filter lines were a pita. Just saying.
Edit: Glyn! We're victorious! No misfires, flooring through first and second gear. Hopefully it stays that way.
..those four clamps on the fuel filter lines were a pita. Just saying.
Edit: Glyn! We're victorious! No misfires, flooring through first and second gear. Hopefully it stays that way.
Last edited by laneshift; Jul 24, 2010 at 02:07 AM.
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From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Just replaced the fuel filter, going for a drive. Roads should be very clear of traffic.
..those four clamps on the fuel filter lines were a pita. Just saying.
Edit: Glyn! We're victorious! No misfires, flooring through first and second gear. Hopefully it stays that way.
..those four clamps on the fuel filter lines were a pita. Just saying.
Edit: Glyn! We're victorious! No misfires, flooring through first and second gear. Hopefully it stays that way.
This is good news but I'm not rejoicing yet. Let's give it a few days. Directionally though, we are learning - I'm fairly confident that we have a fuel delivery problem on our hands - MAF effects fuel delivery & filter effects fuel delivery. I would like you to be more conscious of fuel pump noise. The pump is mounted in the sender unit under the drivers side rear seat squab. If the car has stood overnight & the rail pressure has dropped - listen carefully for the fuel pump buzz - when you first turn on the ignition before cranking - you should hear the pump start - run briefly & stop - when it gets the rail pressure up to spec & ready for cranking to start. Listen carefully - I want to make sure that the pump stops - this tells us that it is, or should be, achieving full pressure.
Also try & listen to the pump in normal running - it should give off a fairly constant buzz. You might have to train your ear to listen for it. Some people like me are very conscious of the pump whine. Others don't seem to hear it.
Good luck
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From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
The fuel pressure regulator is built into the filter - so you have replaced that as well & it might have been part of the problem - see pdf. The pump is mounted in sensor 120. Access is via round cover plates under the rear seat. We don't need to touch anything. Let's monitor the situation. No unecessary expense!
https://mbworld.org/forums/attachmen...1&d=1279969411
https://mbworld.org/forums/attachmen...1&d=1279969411
Last edited by Glyn M Ruck; Jul 24, 2010 at 07:30 AM.
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From: Orlando, FL
C240
The whine lasts one or two seconds, then goes off. I can hear the whine while the car is on though..
The whine is also a little different sounding from before I changed the filter. Is this normal?
The whine is also a little different sounding from before I changed the filter. Is this normal?
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From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
If the problem returns we will pressure test the rail - if pressure is below spec we will change the pump. If it's on spec we will compression test cylinder 4 to make sure we don't have a valve problem & then replace the injector if the compression test does not reveal a problem. Don't do anything further at this point. I'm hoping we are in the clear.
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From: Orlando, FL
C240
Great Lane! - then all is operating normally !!! If the whine has changed with the engine running your filter was partially blocked & the pump is now having an easier time & not cavitating. This is all positive news! I'm now more confident that we have solved the problem.
If the problem returns we will pressure test the rail - if pressure is below spec we will change the pump. If it's on spec we will compression test cylinder 4 to make sure we don't have a valve problem & then replace the injector if the compression test does not reveal a problem. Don't do anything further at this point. I'm hoping we are in the clear.
If the problem returns we will pressure test the rail - if pressure is below spec we will change the pump. If it's on spec we will compression test cylinder 4 to make sure we don't have a valve problem & then replace the injector if the compression test does not reveal a problem. Don't do anything further at this point. I'm hoping we are in the clear.
Thank you, Glyn, for all you've done. You've saved me much time and money! Hopefully I'm good to go for a good while.
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From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Super Moderator
Joined: Jun 2008
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From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Damn - back to the list of things to check above. Major suspicions - Maf, Fuel pump, injector if you are absolutely sure that wires & coilpack are OK for cylinder 4
BTW - now many miles did the car do without a misfire?
BTW - now many miles did the car do without a misfire?
Last edited by Glyn M Ruck; Aug 1, 2010 at 11:38 AM.
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From: Orlando, FL
C240
This might be a stupid question, but, could a cause of these misfires be abuse? I don't know how the previous owners treated the car, but I floor it very often.. misfires never happen when I baby it. That just puts me at a question mark, though. If that were the case, what if I needed to absolutely give it gas to avoid being rear ended while pulling into traffic?
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From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
This might be a stupid question, but, could a cause of these misfires be abuse? I don't know how the previous owners treated the car, but I floor it very often.. misfires never happen when I baby it. That just puts me at a question mark, though. If that were the case, what if I needed to absolutely give it gas to avoid being rear ended while pulling into traffic?
Overevving, doing burnouts etc is what does damage. Not the sort of trouble this is. Intermittent problems are always the worst e.g. why has the darn thing not misfired for 400 miles??
The transmission is usually the first to show signs of abuse by driving. Endless high torque gear changes will usually damage the first to second one way clutch & jerk badly when cold. Transmission fluid will smell burnt & the filter will be full of clutch plate material. Transmissions also get noisy.
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From: Orlando, FL
C240
I put the car on a winstar system. Ran the smoothness test and cylinder 2 and 5 were acting up, hitting 8's and fluctuating. The rest were chilling out at 0. I take a look at the relative locations and my recirculating covers are, once again, leaking. The oil is coating coil pack 2, and 5, and the respective wires.
I also bought a batch of platinums, I'll be resealing the covers (both driver and passenger) and changing the plugs, along with air filters.
Hopefully this will help!
I also bought a batch of platinums, I'll be resealing the covers (both driver and passenger) and changing the plugs, along with air filters.
Hopefully this will help!
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From: Orlando, FL
C240
Upon detaching the rubber hoses from the driver side recirculating cover, I'm quite sure I've cracked both hoses. Is there a fix, or must I buy new hoses and replace them? They lead far back and are going to be one pain in the %*#.
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2019 G70 6MT & 2022 Ford Maverick XL
Are you stuck with this car? I know a guy who bought a Saab 9-3 earlier this year and then it started having issues two weeks in and he sold it to Carmax. It almost seems as though you should start over with something different.
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From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
New hoses lane, if they are leaking air - or you could put a suitable piece of metal pipe inside them & clamp them. Just don't restrict ID too much. I really don't know - I think you have taken the car so far you may as well finish sorting it, keep it & enjoy it. It's mileage is low.
What year is that car? - C240's are mechanically tough throughout. Very early ones just had all the typical non powertrain problems. The powertrain is from proven earlier models.
What year is that car? - C240's are mechanically tough throughout. Very early ones just had all the typical non powertrain problems. The powertrain is from proven earlier models.
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From: Orlando, FL
C240
Yep, 2002. Hope I don't run into any more electrical issues. Or any issues at all.
I got the hoses in. Spark plugs are a huge pain near the firewall, so limited room! I feel sorry for the c55 guys!
I thought about getting the car to run okay for a few miles and shove it over to carmax, but I've already put in new brakes, headliner, done the service, etc.
So, how much do you guys pay for an oil change including a filter?
I got the hoses in. Spark plugs are a huge pain near the firewall, so limited room! I feel sorry for the c55 guys!
I thought about getting the car to run okay for a few miles and shove it over to carmax, but I've already put in new brakes, headliner, done the service, etc.
So, how much do you guys pay for an oil change including a filter?
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From: Orlando, FL
C240
Update:
Removed all plugs, I'll be putting in new ones tomorrow morning. Resealed both driver side and passenger side recirculating covers.
Driver side's cover has two hoses. Both cracked upon removal, so I bought replacements.
One fit just fine, the other, though, seems to be the wrong part. My parts guy says there are only four hoses that have to deal with recirculating the oil. One on the passenger side, two on the driver side, and one in the back that doesn't touch the covers.
The one I got does not have a junction, but the one that is on my car at the moment does. Just to confirm, I need the first hose picture, correct? The second one is currently sitting on my desk.
Thanks!
Removed all plugs, I'll be putting in new ones tomorrow morning. Resealed both driver side and passenger side recirculating covers.
Driver side's cover has two hoses. Both cracked upon removal, so I bought replacements.
One fit just fine, the other, though, seems to be the wrong part. My parts guy says there are only four hoses that have to deal with recirculating the oil. One on the passenger side, two on the driver side, and one in the back that doesn't touch the covers.
The one I got does not have a junction, but the one that is on my car at the moment does. Just to confirm, I need the first hose picture, correct? The second one is currently sitting on my desk.
Thanks!
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From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Lane - that looks correct. There were some changes made to breather hosing & cam covers over the life of the C240. You are going to have to match up visually/physically
The rear plugs can be a PITA to change. You should try a V12 with 24 plugs - the mechanics all run away at my dealership!
The rear plugs can be a PITA to change. You should try a V12 with 24 plugs - the mechanics all run away at my dealership!
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From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Please compression test cylinder 4 while all the plugs are out! Just need one plug in Cylinder 4 to perform the test. I'm sure Autozone will lend you a compression tester.
