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2004 Taurus High Idle issue

3133 Views 114 Replies 9 Participants Last post by  retho78
Hello,

I have 2004 Ford Taurus with high idle issue. I did a live data scan with my OBD2 tool and the RPMs during cold start is approx. 1450 and when driving or at operating temp, it stays around 925. Also, when the AC/heat is on, the RPM drops to around 750 to 800.

There are no check engine light/codes. I sprayed brake cleaner around all the hoses/vacuum lines and it didn't make any difference. I swapped the throttle body & MAF sensors and it didn't resolve the issue. Also, the fuel pressure fluctuates between 39.5 to 41.5, so could it be a bad fuel pressure sensor, faulty fuel injector(s) or the manifold runner control o-ring?

Thanks in advance.
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Well I looked through all your data, and bank 2 LTFT is a little bit high, but anything under 10% shouldn't cause any issues like this. I'm curious, when the car is running can you visually inspect your accessory drive? I'm wondering if you've got a dragging accessory or pulley that the car is trying to compensate for. That idle value is about right for when the A/C compressor is engaged, although looking at the data the car isn't asking it to be. I'm not sure what the engine load should be (I don't have the ability to compare on my car), but 15% seems high for just idling.
The power steering pump does have a whine and could that be a problem?
The power steering pump does have a whine and could that be a problem?
Yeah, but many of them whine so it's not necessarily indicative. I'd take the belt off and run it for a few seconds, see if the idle is what it should be. You won't damage anything by running it with no belt as long as you start it dead cold and don't let it run more than a few minutes.
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If you take the belt off just go ahead and hand-spin all the spinny bits to see if anything else is binding.
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Update:
I did a smoke leak test and found 3 leaks. Please see attached pictures.

The smoke from EGR location is actually coming out from the EGR and not from where I replaced the gasket & O-ring to the intake. Bad EGR or is this normal?

Also, I noticed very little smoke coming out from the throttle body spring location. Is there an o-ring in between?

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Thanks.
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Replaced the o-ring on this piece and no leak found. Still need to sort if the smoke coming out from EGR is normal and if there's an o-ring in the throttle body.
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The smoke from EGR location is actually coming out from the EGR and not from where I replaced the gasket & O-ring to the intake. Bad EGR or is this normal?


View attachment 222198
It's supposed to be a sealed system so I cannot imagine that it is normal. Someone with more experience and with more experience of the Vulcan might be able to confirm if it is common for an EGR on a Vulcan to do that. Also, the video I shared earlier had a Vulcan with an EGR leak.

But perhaps more importantly, in your picture above, the vacuum hose is not connected to the EGR. Was that just for the smoke test?
It's supposed to be a sealed system so I cannot imagine that it is normal. Someone with more experience and with more experience of the Vulcan might be able to confirm if it is common for an EGR on a Vulcan to do that. Also, the video I shared earlier had a Vulcan with an EGR leak.

But perhaps more importantly, in your picture above, the vacuum hose is not connected to the EGR. Was that just for the smoke test?
Yes, I watched the video but it was coming out from the gasket and o-ring location.

I unplugged the line for smoke test purposes only.
Yes, I watched the video but it was coming out from the gasket and o-ring location.

I unplugged the line for smoke test purposes only.
The EGR tube nut is supposed to be torqued to 37ftlb. Might want to give that a check first.
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The smoke is coming out from these holes.
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Also, I noticed very little smoke coming out from the throttle body spring location. Is there an o-ring in between?


View attachment 222200
There is a throttle body gasket where the throttle body mounts to the intake. My Taurus is not at home so I don't know how close that is to your leak area.
There is a throttle body gasket where the throttle body mounts to the intake. My Taurus is not at home so I don't know how close that is to your leak area.
It's not leaking where throttle body mounts to the intake but from the throttle flap spring location.
The smoke is coming out from these holes. View attachment 222206
I would ask others to chime in, but it seems that the diaphragm inside the EGR valve is not closing. This would explain your high idle.

This video is a good explanation of how the system should work and what exactly might be the issue:

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I would ask others to chime in, but it seems that the diaphragm inside the EGR valve is not closing. This would explain your high idle.

This video is a good explanation of how the system should work and what exactly might be the issue:

Sounds good. Thank you!
I believe you may have a crack in the diaphragm that controls the egr valve. I would think that you should be able to pull a vacuum on that diaphragm and it should hold that vacuum. You could temporary plug those holes with putty and see if the rpms drop. Those hole should be there to make sure there is atmospheric pressure on that side of the diaphragm.
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Short trips can lead to excess carbon which might prevent the diaphragm from closing. With a bit of luck, cleaning might be all you need rather than a new EGR valve.

Okay, I'll try cleaning it.
The crack would be in the EGR pintle, &/or the EGR shaft seal. No, it should not leak up from the intake out the EGR diaphragm housing holes. No, there is no O-ring on the throttle shaft - there's a sealed bearing that is not replaceable. With the engine running, you could try adding a thick (gear or silicone) oil through the spring onto the shaft so the engine vacuum pulls the oil into the bearing, creating a viscous seal.
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So, I did a vacuum pressure test on the EGR and it is has very slow leak. Ordered a new one and will update everyone accordingly.

Thanks!
A quick egr test is the "suck" test. With engine idling, remove the egr vacuum hose and replace with a 12" piece of scrap black rubber vacuum hose for testing. Suck on the open end of the test hose opening the egr diaphragm/pintle. Engine should stumble or die due to the fact that there should be no egr flow at idle or wide open throttle (wot).
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