EGR and idle

2003 FORD EXPEDITION
150,000 MILES • 5.4L • V8 • 2WD • AUTOMATIC
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SUMMERS209
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Hello I own the vehicle listed above XLT model with a Triton V8 5.4. it will not stay running at idle or when I put it in gear it shuts off. when I put it in gear or let my foot off the gas also it's keep telling me to check the EGR valve. which I replace the EGR valve and I happened to lose one of the bolts that go to the air intake manifold. will that cause it to have a vacuum leak?because it sounds like there's a leak somewhere. but all hoses are connected. we're going to be need help. I tried everything the fuel pump. I just replaced it. I also smell gas in the cabin when I try to start it. What hoses should I look for it because it's not holding water in the reservoir.
Apr 19, 2019 at 6:28 PM
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SCGRANTURISMO
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Hello,

Yes, missing a bolt on the intake manifold will absolutely cause an intake leak which will cause poor, rough idle conditions. Also the coolant loss could be leaking from the coolant crossover tube which is an aluminum tube that goes from cylinder head to cylinder head on the front of the intake manifold. If coolant is leaking from here there is a distinct possibility that it is leaking into multiple spark plug tubes. I have a 4.6L engine in my mustang, which is basically the same engine, just different cylinder heads, and these engines are famous for this. If there is any coolant in the spark plug tubes it will cause a misfire and rough unstable idle. The EGR connections at the throttle body must be tight with a gasket in place as this is also a potential intake leak. So let's pick a corner and start. Replace the intake manifold bolt. The best way to do this is to remove a good intake manifold bolt and go to the hardware store. Match it up to a similar bolt in the fastener section and install both bolts. I have included the torque specs in the diagrams down below for you..

Thanks,
Alex
2CarPros
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Apr 19, 2019 at 6:56 PM
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SUMMERS209
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Well what is causing my car to die when i let off the gas or out it in gear? And I'm no mechanic but it said it was running lean in bank 2.
Apr 20, 2019 at 2:23 PM
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SCGRANTURISMO
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Hello,

It has an intake leak on bank 2 probably where the bolt was left out and that is causing that bank to run lean. Your vehicle will run lean when too much air is the system. This happens from vacuum leaks and intake leaks(which are pretty much the same thing). When a leak is present it will let "unmetered" air into the system and your vehicle's Powertrain Control Module(PCM) will not account for this extra air and it will throw off the air:fuel ratio causing misfire at idle and poor drivability.
Bank 2 is going to be the bank on the drivers side. Get a spray bottle full of water. Start your vehicle and let it idle. While it is running spray around the intake on the drivers side with the spray bottle. When the leak is sprayed the vehicle should bog down as the water is ingested into the combustion chamber through where the leak is. Please get back to us with what you are able to find out, please..

Thanks,
Alex
2CarPros
Apr 20, 2019 at 2:39 PM