STR fuel rail o-ring
#1
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Cabin has been smelling of gas at startup and whenever car stationary with engine idling. My (reliable) indy confirmed what I had read on this forum, namely it was probably an o-ring on the fuel rail.
Worse news - he says Jaguar don't sell those o-rings as individual parts, so I would have to buy the entire rail, cost $1800, and there is 3-month backorder!
Is this for real? Can anyone confirm the bad news? My indy has managed to use a (slightly different size) o-ring off a fuel-injector that seems to work OK at 55 psi, but this problem sounds like something that needs a permanent fix.
Worse news - he says Jaguar don't sell those o-rings as individual parts, so I would have to buy the entire rail, cost $1800, and there is 3-month backorder!
Is this for real? Can anyone confirm the bad news? My indy has managed to use a (slightly different size) o-ring off a fuel-injector that seems to work OK at 55 psi, but this problem sounds like something that needs a permanent fix.
#2
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If you going to do one I would bite the bullet and change all of them.
In fact I would just send all 8 injectors out to be flow balanced. It's very cheap ($18 each) and you can for sure get the correct O-Rings!!
I have never done this but I hope to if I keep the STR long enough!!
Injector RX - Fuel Injector Cleaning, Flow Testing & Reconditioning
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In fact I would just send all 8 injectors out to be flow balanced. It's very cheap ($18 each) and you can for sure get the correct O-Rings!!
I have never done this but I hope to if I keep the STR long enough!!
Injector RX - Fuel Injector Cleaning, Flow Testing & Reconditioning
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#3
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No, no, it's not the o-rings on the injectors. (My indy has recommended changing those in any event).
What's gone is an o-ring on the fuel rail itself, around a vibration dampener. I seem to remember reading somewhere that these dampeners exist on newer fuel rails ('05 onwards?), as some of the older rails developed problems due to vibration over the years. Unfortunately, the cure seems to have brought on a new disease!
Problem is that these fuel rails are no longer available off the shelf.
Here's the post I found:
https://www.jaguarforums.com/forum/x...ngerous-65343/
What's gone is an o-ring on the fuel rail itself, around a vibration dampener. I seem to remember reading somewhere that these dampeners exist on newer fuel rails ('05 onwards?), as some of the older rails developed problems due to vibration over the years. Unfortunately, the cure seems to have brought on a new disease!
Problem is that these fuel rails are no longer available off the shelf.
Here's the post I found:
https://www.jaguarforums.com/forum/x...ngerous-65343/
Last edited by Robinb; 04-09-2013 at 05:38 PM.
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JagV8 (04-10-2013)
#4
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I am sorry! Just never heard of this until now? Hope it's not another problem that will be common.
I have seen dampers on other manufacturers fuel rails. But we have two! I had to look it up in the JTIS so thanks for that!
With the cost of this repair and if they ever get the rails back in stock. I sure hope someone can come up with the proper O-ring. Seems like it should not be too hard to match up if you take one apart? I can't tell if it's the garter spring type connection or not?
Here is a 2003 STR fuel rail.
![](https://www.jaguarforums.com/forum/attachments/s-type-s-type-r-supercharged-v8-x200-15/39174d1365556846-str-fuel-rail-o-ring-fuel-rail.jpg)
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I have seen dampers on other manufacturers fuel rails. But we have two! I had to look it up in the JTIS so thanks for that!
With the cost of this repair and if they ever get the rails back in stock. I sure hope someone can come up with the proper O-ring. Seems like it should not be too hard to match up if you take one apart? I can't tell if it's the garter spring type connection or not?
Here is a 2003 STR fuel rail.
![](https://www.jaguarforums.com/forum/attachments/s-type-s-type-r-supercharged-v8-x200-15/39174d1365556846-str-fuel-rail-o-ring-fuel-rail.jpg)
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JagV8 (04-10-2013)
#5
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JagV8 (04-10-2013)
#6
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I did that, and now feel really depressed. Here is an extract from a forum member who had the same problem with his '03 XK...
The O-rings originally installed by Jaguar, and the replacement rings
that the Houston fuel injector service company installed, were both
made of DuPont “Viton flouroelastomer GLT” rings - blue in color. After
days research on the “how and why” of fuel dampers, O-rings, and the
material the rings were made of, I discovered that the high performance
GLT grade rings are not recommended by DuPont for use with automotive
fuels oxygenated or blended with MEOH and ETOH alcohols or MTBE
antiknock agents. Unfortunately, this is exactly the kind of fuel (in
the higher octane blends recommended for our Jaguars) available today
at most Midwest USA gas stations!
For the record, research led me to a newer “rubber” called GFLT.
O-rings made of this material are more resistant to the degradation
caused by the corrosive qualities of alcohol in today’s fuel, according
to DuPont.
The faulty o-ring on my car is blue, and I have used only ethanol-free premium since I bought the car 1 year ago. I guess I'll begin a search for o-rings made of GFLT rubber, because the current "fix" may not last too long.
The O-rings originally installed by Jaguar, and the replacement rings
that the Houston fuel injector service company installed, were both
made of DuPont “Viton flouroelastomer GLT” rings - blue in color. After
days research on the “how and why” of fuel dampers, O-rings, and the
material the rings were made of, I discovered that the high performance
GLT grade rings are not recommended by DuPont for use with automotive
fuels oxygenated or blended with MEOH and ETOH alcohols or MTBE
antiknock agents. Unfortunately, this is exactly the kind of fuel (in
the higher octane blends recommended for our Jaguars) available today
at most Midwest USA gas stations!
For the record, research led me to a newer “rubber” called GFLT.
O-rings made of this material are more resistant to the degradation
caused by the corrosive qualities of alcohol in today’s fuel, according
to DuPont.
The faulty o-ring on my car is blue, and I have used only ethanol-free premium since I bought the car 1 year ago. I guess I'll begin a search for o-rings made of GFLT rubber, because the current "fix" may not last too long.
#7
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#8
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Well, my indy has ordered a complete set of injector o-rings from Jaguar. They ARE blue, and we shall see whether or not they can also be used on the fuel rail pulsation dampener. Definitely going to replace that suspect coolant hose under the S/C while we're down there. Also will advise my indy to bleed carefully after re-assembly to avoid a bubble in the I/C coolant circuit that could cause problems once the car is up and running.
A local o-ring distributor has advised that GFLT products are newish, designed for extreme environments and still hard-to-find, and that a waiting period of 3-4 months is not unusual.
Scary, because the problem of fuel leakage from the rail is being reported more than I had realized, and I see claims that the original dampener o-rings do not fully resist attacks from gasolines containing MTBE (octane booster) or ethanol. That's just about every brand of gasoline in North America!
Let's hope the new Jag o-rings are up-to-date.
A local o-ring distributor has advised that GFLT products are newish, designed for extreme environments and still hard-to-find, and that a waiting period of 3-4 months is not unusual.
Scary, because the problem of fuel leakage from the rail is being reported more than I had realized, and I see claims that the original dampener o-rings do not fully resist attacks from gasolines containing MTBE (octane booster) or ethanol. That's just about every brand of gasoline in North America!
Let's hope the new Jag o-rings are up-to-date.
#10
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Chris at fuel injection rx just made a double oringed set of plugs for the dampners whith locks to see how these works for a sc jaguar to eliminate the dampners and single oring. Im gonna go talk to him about this later today as he's also making the air inlet tune to the throttle body for me out of aluminum from the custom are box i made on my truck
#11
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When you have an hour or two to spare
https://www.jaguarforums.com/forum/x...omg-noo-76526/
https://www.jaguarforums.com/forum/x...rt-deux-85186/
https://www.jaguarforums.com/forum/x...omg-noo-76526/
https://www.jaguarforums.com/forum/x...rt-deux-85186/
#12
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When you have an hour or two to spare
https://www.jaguarforums.com/forum/x...omg-noo-76526/
https://www.jaguarforums.com/forum/x...rt-deux-85186/
https://www.jaguarforums.com/forum/x...omg-noo-76526/
https://www.jaguarforums.com/forum/x...rt-deux-85186/
Even if you could get the right o-rings, it really does not seem feasible to try and repair the dampers unless you plan to sell the car "as is" within a day or two after the repair, and then leave the country.
Can't even be sure which lubricant is best, vaseline, petroleum or silicone. Can't even trust pressure-testing at 120 psi on the bench or under soapy water, as is does not simulate the actual pulsating conditions of damper operation.
So, either you replace the entire fuel rail, or seal off the dampers completely and to hell with the clicking noise that Jaguar was trying to suppress by fitting the dampers.
What a mess. Because he is a hands-on Jag enthusiast, I will probably let my indy have a go with the o-ring he thinks may work, and chalk the probable subsequent failure up to experience. In any event, I look forward to hearing about Chris' efforts at RX Injectors, because next time (and there will be a next time) I want a permanent fix for this f***ing fuel rail.
Also saw this quote from Plums:
BTW, Dupont notes that a 25 percent concentration of ethanol in their standard testing fuel which is named "Fuel-C" is more corrosive than either 100 percent gasoline or 100 percent ethanol. There must be some interaction there.
Last edited by Robinb; 04-10-2013 at 09:43 PM.
#13
#14
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OK, going to try and summarize all the pertinent facts on this subject, because it looks like many Jaguars with supercharged 4.2 engines (i.e. higher fuel pressure) will experience this problem some time in the future. Much of the stuff below was taken from posts by member maxwdg, who suffered greatly and really did the legwork. Also, great comments and advice from plums and steveinfrance.
Symptom: Smell of raw fuel in the cabin, especially from a cold start. Goes away when warmed up and in motion, but slowly gets worse over time. Very dangerous if left unattended, can lead to explosions in engine compartment.
Diagnosis: O-ring failure on vibration dampers attached to the fuel rail. The primary function of these (2) dampers is to smooth out fuel pressure variations in the rail, and so reduce a "clicking" noise from the injectors at higher rpm's. The dampers are not critical to the Jag's operation, and the need for damping is less for V8 than for V6 engines because of the design.
Cause: The original o-rings installed were made of a material that, over time, is attacked by gasoline containing ethanol, methanol and MTBE (the octane booster). Today, other materials have been developed with more resistance to these chemicals, but o-rings made of this new material are not available. We are sitting on a ticking time-bomb.
Repair: The manufacturer's instructions state the dampers are not serviceable on a DIY basis, that only brand new o-rings as specified must be used, that special non-silicone lubrication is required, and that special tooling is needed to ensure that the re-installed o-ring is completely concentric within the damper cup. If not, prepare for more leaks and more hours of work to re-install and then again remove the fuel rail. New fuel rails cost up to $1800, but are not readily available. The only reliable quick fix seems to be to plug the damper cup with a stainless steel cap machined to ensure a tight press-fit into the damper cup.
Future action: Try to minimize the amount of ethanol in the gasoline you use. If you do smell fuel in the cabin at startup, don't ignore the problem. If you can't get (or don't want) a new fuel rail, repair both dampers, not just the leaking one. And, finally, if you still want a pulsation damper operation, consider installing a single high-performance damper as described here: http://injectorfi.readyhosting.com/p...duct-sheet.pdf
For the record, my indy first tried fitting a new o-ring. Tested fine under 55 psi, turned thru 90 degrees and rechecked, turned again, always looked good. Re-assembled everything, and…IT FAILED. Back out came the fuel rail, machined 2 stainless steel plugs as described above, cooled down the plugs, warmed up the fuel rail, press-fitted the plugs and, just to be safe, did some brazing to seal and make safe. ABSOLUTELY PERFECT, no fuel smell, no trace of any clicking noise, car drives like a dream and that "suspect" coolant hose under the S/C has been replaced. Total indy hours 9.8, total parts and labor $1490. This is the never-ending Jag tug-o-war – high bills, but you feel like a king again when you're behind the wheel.
Symptom: Smell of raw fuel in the cabin, especially from a cold start. Goes away when warmed up and in motion, but slowly gets worse over time. Very dangerous if left unattended, can lead to explosions in engine compartment.
Diagnosis: O-ring failure on vibration dampers attached to the fuel rail. The primary function of these (2) dampers is to smooth out fuel pressure variations in the rail, and so reduce a "clicking" noise from the injectors at higher rpm's. The dampers are not critical to the Jag's operation, and the need for damping is less for V8 than for V6 engines because of the design.
Cause: The original o-rings installed were made of a material that, over time, is attacked by gasoline containing ethanol, methanol and MTBE (the octane booster). Today, other materials have been developed with more resistance to these chemicals, but o-rings made of this new material are not available. We are sitting on a ticking time-bomb.
Repair: The manufacturer's instructions state the dampers are not serviceable on a DIY basis, that only brand new o-rings as specified must be used, that special non-silicone lubrication is required, and that special tooling is needed to ensure that the re-installed o-ring is completely concentric within the damper cup. If not, prepare for more leaks and more hours of work to re-install and then again remove the fuel rail. New fuel rails cost up to $1800, but are not readily available. The only reliable quick fix seems to be to plug the damper cup with a stainless steel cap machined to ensure a tight press-fit into the damper cup.
Future action: Try to minimize the amount of ethanol in the gasoline you use. If you do smell fuel in the cabin at startup, don't ignore the problem. If you can't get (or don't want) a new fuel rail, repair both dampers, not just the leaking one. And, finally, if you still want a pulsation damper operation, consider installing a single high-performance damper as described here: http://injectorfi.readyhosting.com/p...duct-sheet.pdf
For the record, my indy first tried fitting a new o-ring. Tested fine under 55 psi, turned thru 90 degrees and rechecked, turned again, always looked good. Re-assembled everything, and…IT FAILED. Back out came the fuel rail, machined 2 stainless steel plugs as described above, cooled down the plugs, warmed up the fuel rail, press-fitted the plugs and, just to be safe, did some brazing to seal and make safe. ABSOLUTELY PERFECT, no fuel smell, no trace of any clicking noise, car drives like a dream and that "suspect" coolant hose under the S/C has been replaced. Total indy hours 9.8, total parts and labor $1490. This is the never-ending Jag tug-o-war – high bills, but you feel like a king again when you're behind the wheel.
#15
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Although I do agree that removing the damping function is possible, I still would prefer to have both of them working, as it ensures a more even fuel delivery in each cylinder.
#16
#17
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That was a good write up Robinb!! But the rest of us don't have access to those nice machined plugs?? We may be stuck with replacing the O-rings instead?
Brutal;
Any word on the upgraded seals? With the SC I would only want to do this repair once!!
It's only been reported so far on just a few cars. So like the SC hose it does not seem consistent? I have always used ethanol gas and am at 90K miles with no problems from either area yet!!
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Brutal;
Any word on the upgraded seals? With the SC I would only want to do this repair once!!
It's only been reported so far on just a few cars. So like the SC hose it does not seem consistent? I have always used ethanol gas and am at 90K miles with no problems from either area yet!!
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#18
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Thanks for your comments, everyone...
@avos
I knew that, and told my indy that 55 psi was not high enough. Then I saw a post from maxwdg where the testing pressure was 120 psi and it still failed. As a matter of fact, you yourself suggested that the o-ring might have been damaged because of that high (120 psi) pressure.
If a new fuel rail had been available I would probably have got one, but not prepared to wait 3 or more months. Do you know who manufactures those Jag fuel rails?
@plums
My indy had a machinist friend make up the plugs after the predicted o-ring failure. I never actually saw them until they had been installed and the brazing was complete, but he said there was a small lip on each plug.
@clubairth
If you can find them! Jag does not sell them as separate parts, gotta buy the whole rail (if you can find one) or get a used rail. Maybe as Brutal says, Chris of Injectors RX will have success with his newly-designed double-o-ring plug.
@avos
The actual fuel rail pressure is 65 psi, then as you have a supercharger, add another 15 psi when under boost, so you get to 80 psi. Then to have some safe margin, best to test it at least at 90 - 100 psi.
Although I do agree that removing the damping function is possible, I still would prefer to have both of them working, as it ensures a more even fuel delivery in each cylinder.
@plums
My indy had a machinist friend make up the plugs after the predicted o-ring failure. I never actually saw them until they had been installed and the brazing was complete, but he said there was a small lip on each plug.
@clubairth
But the rest of us don't have access to those nice machined plugs?? We may be stuck with replacing the O-rings instead?
#19
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I knew that, and told my indy that 55 psi was not high enough. Then I saw a post from maxwdg where the testing pressure was 120 psi and it still failed. As a matter of fact, you yourself suggested that the o-ring might have been damaged because of that high (120 psi) pressure.
That’s why I am saying 90 to 100.
But have you determined where it leaks? If is it the unit itself, or was it via the o ring where it fits in the fuel rail cup?
No, but I do know that the exact same fuel pulsation dampers are used on a Aston Martin 4.7, here is the partno: 2W93-9F775-AA
Don't know if they sell them individually, and it depends of course where the fault lies with the unit you have (i.e. unit itself or leaking seal in the fuel rail cup). If you still want a full fuel rail, I have one.
#20
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So if I get your drift, avos, the pressure testing range should be at least 90 psi and at most 120 psi. However, static pressure-testing does not seem to be a reliable test method. The fuel smell was noticeable when engine was idling, when fuel pressure is around 50 psi (or so I have been led to believe).
My indy said the leak was from the o-ring, and I'm glad to report that all seems OK with the damper cups plugged. Would have been very interested in your fuel rail if I had known, but too late now. Would not consider the hassle of incorporating 2 Aston Martin dampers into the STR fuel rail unless there was no other choice.
My indy said the leak was from the o-ring, and I'm glad to report that all seems OK with the damper cups plugged. Would have been very interested in your fuel rail if I had known, but too late now. Would not consider the hassle of incorporating 2 Aston Martin dampers into the STR fuel rail unless there was no other choice.