Found the whistle - now what?
#1
Found the whistle - now what?
Hello!
Ok so my engine has a whistle for about 5 minutes after starting and I was able to locate where it was coming from - see pics.
So this hose is coming from the fuel injection rail. Should the whistle be scaring me in that I should not drive this until it is fixed? I pull the hose and it seems to be in pretty good shape it is plyable with no cracks or anything; however the nozzle it fits over is completely smooth so I cant imagine it carries any kind of real pressure.
If the hose seems to be ok is there some sort of compound I should use to tighten the seal? Should I just replace the hose and if so can someone tell me what I am looking for (material, diameter, etc)?
Thank you!
-martin
Ok so my engine has a whistle for about 5 minutes after starting and I was able to locate where it was coming from - see pics.
So this hose is coming from the fuel injection rail. Should the whistle be scaring me in that I should not drive this until it is fixed? I pull the hose and it seems to be in pretty good shape it is plyable with no cracks or anything; however the nozzle it fits over is completely smooth so I cant imagine it carries any kind of real pressure.
If the hose seems to be ok is there some sort of compound I should use to tighten the seal? Should I just replace the hose and if so can someone tell me what I am looking for (material, diameter, etc)?
Thank you!
-martin
#2
It's a vacuum hose. There are one of 2 possibilities - split hose that is leaking vacuum, or the sensor is broken and leaking vacuum. The hose with the white stripe looks a bit short, I'd try replacing that.
Also, I notice that heat shield on your cruise control bellows is upside down. It's the piece that is sitting in between the fuel rails, and in the photo immediately toward the top of of the photo from your circled sensor. The shield should be under the rubber bellows to shield them from the heat of the engine, not trapping the heat around the bellows and cooking them.
Also, I notice that heat shield on your cruise control bellows is upside down. It's the piece that is sitting in between the fuel rails, and in the photo immediately toward the top of of the photo from your circled sensor. The shield should be under the rubber bellows to shield them from the heat of the engine, not trapping the heat around the bellows and cooking them.
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bortbox (12-17-2017)
#3
Hi Bortbox
That Plastic 'thingy' is the Thermal Valve that is supposed to assist with hot starting and those pipes are Vacuum pipes
Hence the reason that those spigots are smooth
The reason for the 'Whistling' 'could' be down to a blockage in a narrow hole under its lid
Don't break it, as they are NLA although the one for the XJ6 is the same
Check out this link to see how it all works
EAC 5086 EAC5086 Jaguar Vacuum Thermal Valve
That Plastic 'thingy' is the Thermal Valve that is supposed to assist with hot starting and those pipes are Vacuum pipes
Hence the reason that those spigots are smooth
The reason for the 'Whistling' 'could' be down to a blockage in a narrow hole under its lid
Don't break it, as they are NLA although the one for the XJ6 is the same
Check out this link to see how it all works
EAC 5086 EAC5086 Jaguar Vacuum Thermal Valve
Last edited by orangeblossom; 12-17-2017 at 10:08 AM.
#4
It's a vacuum hose. There are one of 2 possibilities - split hose that is leaking vacuum, or the sensor is broken and leaking vacuum. The hose with the white stripe looks a bit short, I'd try replacing that.
Also, I notice that heat shield on your cruise control bellows is upside down. It's the piece that is sitting in between the fuel rails, and in the photo immediately toward the top of of the photo from your circled sensor. The shield should be under the rubber bellows to shield them from the heat of the engine, not trapping the heat around the bellows and cooking them.
Also, I notice that heat shield on your cruise control bellows is upside down. It's the piece that is sitting in between the fuel rails, and in the photo immediately toward the top of of the photo from your circled sensor. The shield should be under the rubber bellows to shield them from the heat of the engine, not trapping the heat around the bellows and cooking them.
Do you have any idea what the spec is on that hose?
Thank you!
-martin
#5
#6
The one I took off a 92 was a blind hole in the fuel rail, there is no direct contact with the fuel and sensor.
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Grant Francis (12-17-2017),
orangeblossom (12-17-2017)
#7
Most are removed with no ill affects, but others want them as made.
The hose is nothing special at all, just a standard automotive vac hose of the size related to the spigot (as mentioned).
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orangeblossom (12-17-2017)
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#8
Is this Sensor in contact with the Fuel or is it blanked off like the one on the other side?
#9
If that Thermal Sensor (The one with all the Vacuum Pipes) isn't really needed, could you remove it from the Fuel Rail altogether
And then replace it with something a bit more useful, by drilling a hole through its blanking plate in the Fuel Rail
Then screwing in either a Fuel Pressure Gauge or a Schrader Valve into the now empty stub, which may or may not need an adapter
Good idea or Not?
And then replace it with something a bit more useful, by drilling a hole through its blanking plate in the Fuel Rail
Then screwing in either a Fuel Pressure Gauge or a Schrader Valve into the now empty stub, which may or may not need an adapter
Good idea or Not?
#10
If that Thermal Sensor (The one with all the Vacuum Pipes) isn't really needed, could you remove it from the Fuel Rail altogether
And then replace it with something a bit more useful, by drilling a hole through its blanking plate in the Fuel Rail
Then screwing in either a Fuel Pressure Gauge or a Schrader Valve into the now empty stub, which may or may not need an adapter
Good idea or Not?
And then replace it with something a bit more useful, by drilling a hole through its blanking plate in the Fuel Rail
Then screwing in either a Fuel Pressure Gauge or a Schrader Valve into the now empty stub, which may or may not need an adapter
Good idea or Not?
Greg
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orangeblossom (12-17-2017)
#11
#12
Would I just pull all the Vacuum pipes off, or would I have to block them off in some way Block them off. easy to do with a blanking cap
Where would I get an electronic pressure Sensor, with the right thread to fit in the Stub. As for drilling the hole would a small hole be ok or would it need to be full size? You would have to buy and gauge and sensor set, them weld a threaded nut or similar matching the sensor thread onto the rail, then drill the rail and wind in the sensor, only downside is you do have another potential fuel leak point; but provided the weld is good the sensor might fail but should not actually leak.
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orangeblossom (12-17-2017)
#13
#14
This is the sort of thing, OB. Look at the sensor pic, this needs a boss welded to the rail, that's all. Then just wire it up.
https://www.glowshiftdirect.com/tint...ressure-gauge/
Greg
https://www.glowshiftdirect.com/tint...ressure-gauge/
Greg
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orangeblossom (12-18-2017)
#15
This is the sort of thing, OB. Look at the sensor pic, this needs a boss welded to the rail, that's all. Then just wire it up.
https://www.glowshiftdirect.com/tint...ressure-gauge/
Greg
https://www.glowshiftdirect.com/tint...ressure-gauge/
Greg
Cheers! got the idea
But I was thinking more along the lines of fitting a Schrader Valve, which I could put on all my Cars
To use only as a diagnostic check, for the Fuel Pump/Fuel Filter and Leaking Diaphragm on an FPR
Which took a long while to track down, the last time it went bad on 'Cherry Blossom' which I would add I could never have done
Without the Fault Finding Skills of Yourself and 'The Wizard'
So I'm thinking of a Schrader Valve and a Fuel Pressure Gauge which I can get off Amazon for about £20 + The cost of the Valve
#16
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orangeblossom (12-18-2017)
#17
REALLY.
Where is the FAITH guys, fair dinkum.
OK, later cars, and USA cars have a schrader in the fuel rail, we dont. Never looked the S Types, care factor quite low, the car does what a JAG does, why mess with it.
The a/c charge ports are sealed with a schrader valve, and that pressure is WAY higher than any fuel system we will encounter.
Once you have sorted the V12, and verified pressure properly, drive it, worry not, and repeat in 15 - 20 years time, works for me.
I see all this stuff as something else to go wrong, and worry about, too old for that, fact.
Where is the FAITH guys, fair dinkum.
OK, later cars, and USA cars have a schrader in the fuel rail, we dont. Never looked the S Types, care factor quite low, the car does what a JAG does, why mess with it.
The a/c charge ports are sealed with a schrader valve, and that pressure is WAY higher than any fuel system we will encounter.
Once you have sorted the V12, and verified pressure properly, drive it, worry not, and repeat in 15 - 20 years time, works for me.
I see all this stuff as something else to go wrong, and worry about, too old for that, fact.
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Greg in France (12-18-2017)
#18
Hi Bortbox
I took the Thermal Switch off (my parts cars) to see how it works and what it does
When Cold this Valve is open allowing Vacuum to pass through and closes when it reaches a certain Temperature
The Thermal Switch allows Vacuum to pass through it, from the Inlet Manifold to the FPR (Fuel Pressure Regulator)
In Normal Operation: The Thermal Switch/Valve is Open by default and allows Vacuum from the Inlet Manifold to pass to the FPR Fuel Pressure Regulator
The Default Position for the FPR is Closed (within its set parameters) and needs Vacuum to make it open and operate correctly
At Idle the Vacuum is Higher which gives you a maximum return flow to the Petrol Tank and because of this the Fuel Pressure will be lower
Which also gives you Minimum Injector Pulse Length at Idle
If/When, the Thermal Switch Sensor reaches a Certain Temperature, it can either reduce or cut that Vacuum off (not sure which)
If/When this happens, this loss of Vacuum causes the FPR to Close, which then increases Fuel Pressure and also Injector Pulse Length
Enriching the Engine (ie giving more fuel to the Injectors) to make Starting easier if the Fuel in the Rail gets too hot and starts to Vaporize
Then once the Engine Starts and the Fuel starts Flowing normally again, then the Valve/Switch re-opens allowing normal operation
So what this could mean in your case is, if you've got a leak in your Vacuum Hose from the Inlet Manifold, through the Thermal Switch/Valve to the FPR
The FPR will not operate properly and start to close off or 'Maybe' even close completely depending on how bad the Vacuum leak is
Which could then increase Fuel Pressure and make your Car run Rich, as the Flow Back to the Fuel Tank would be more restricted
So to prevent your Car from Running Rich, make sure that the Vacuum Hoses from the Inlet Manifold, through the Thermal Switch/Valve to the FPR are not leaking
That's the basics of how it works, without getting too technical
I took the Thermal Switch off (my parts cars) to see how it works and what it does
When Cold this Valve is open allowing Vacuum to pass through and closes when it reaches a certain Temperature
The Thermal Switch allows Vacuum to pass through it, from the Inlet Manifold to the FPR (Fuel Pressure Regulator)
In Normal Operation: The Thermal Switch/Valve is Open by default and allows Vacuum from the Inlet Manifold to pass to the FPR Fuel Pressure Regulator
The Default Position for the FPR is Closed (within its set parameters) and needs Vacuum to make it open and operate correctly
At Idle the Vacuum is Higher which gives you a maximum return flow to the Petrol Tank and because of this the Fuel Pressure will be lower
Which also gives you Minimum Injector Pulse Length at Idle
If/When, the Thermal Switch Sensor reaches a Certain Temperature, it can either reduce or cut that Vacuum off (not sure which)
If/When this happens, this loss of Vacuum causes the FPR to Close, which then increases Fuel Pressure and also Injector Pulse Length
Enriching the Engine (ie giving more fuel to the Injectors) to make Starting easier if the Fuel in the Rail gets too hot and starts to Vaporize
Then once the Engine Starts and the Fuel starts Flowing normally again, then the Valve/Switch re-opens allowing normal operation
So what this could mean in your case is, if you've got a leak in your Vacuum Hose from the Inlet Manifold, through the Thermal Switch/Valve to the FPR
The FPR will not operate properly and start to close off or 'Maybe' even close completely depending on how bad the Vacuum leak is
Which could then increase Fuel Pressure and make your Car run Rich, as the Flow Back to the Fuel Tank would be more restricted
So to prevent your Car from Running Rich, make sure that the Vacuum Hoses from the Inlet Manifold, through the Thermal Switch/Valve to the FPR are not leaking
That's the basics of how it works, without getting too technical
Last edited by orangeblossom; 12-19-2017 at 12:32 AM.
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Greg in France (12-19-2017)
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