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Rear exhaust manifold heat shield

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Old 06-18-2018 | 08:31 PM
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Rear exhaust manifold heat shield

I'm almost done cleaning.

Is it possible to remove the rear manifold heat shield without removing the main EGR tube?

I eventually got the secondary shield off (that's bolted to the firewall) but I don't see a way to twist the manifold shield out of there.
Old 06-18-2018 | 08:41 PM
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Originally Posted by reallywildstuff
I'm almost done cleaning.

Is it possible to remove the rear manifold heat shield without removing the main EGR tube?

I eventually got the secondary shield off (that's bolted to the firewall) but I don't see a way to twist the manifold shield out of there.
I remember this being a mfkn PITA but I cant remember exactly what I did
Old 06-18-2018 | 08:44 PM
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I don't know, but you might as well remove the EGR tube anyway to clean it
Old 06-18-2018 | 08:50 PM
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Originally Posted by maximaxi
I don't know, but you might as well remove the EGR tube anyway to clean it
Alright that's fair enough. I sprayed some PB Blaster on both ends and have quit for the night.

I want this to be "the last thing" I take off - the huge spread of parts spread across creation is a little unnerving.

Is there some technique to getting that rusty bolt out of the rusty manifold?
Old 06-19-2018 | 04:15 AM
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Originally Posted by reallywildstuff
I'm almost done cleaning.
Originally Posted by reallywildstuff
I want this to be "the last thing" I take off - the huge spread of parts spread across creation is a little unnerving.

Is there some technique to getting that rusty bolt out of the rusty manifold?
Remind us again why you're doing this?
Old 06-19-2018 | 07:57 AM
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Originally Posted by Turbobink
Remind us again why you're doing this?
Because Im sick in the head.

Because neither valve cover had ever been serviced and there was an extremely thick layer of oil and grime coating every surface below each. How 'ya gonna know the new VC gaskets dont leak if it keeps burning off old leakage?

Because an injector failed and I had to take it all mostly apart anyways.
Old 06-19-2018 | 10:18 AM
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Definitely clean the egr tube. It' much easier to do now than it will be later on.

A clogged tube will set a code. In turn, the code will prevent you from passing emmissions inspection.

You will need the proper gaskets . Two on the tube, and a third for the egr it' self.

You are dealing with all the major pita issues at this point. You will not need to revisit this stuff again for long time, or ever again.

Don't forget to replace the knock sensor if it has a crack. It's very easy to replace now, and quite difficult later on.

I dealt wit the egr tube while the manifold was attached. Not fun at all.

Hang in there......
Old 06-19-2018 | 10:40 AM
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I had previously serviced the EGR guide tube. I have replacement gaskets for both high and low positions. Knock sensor is brand new too.

I didn't know there was a gasket on the primary EGR tube...or are you talking about the EGR _valve_ ?

Last edited by reallywildstuff; 06-19-2018 at 11:19 AM.
Old 06-19-2018 | 10:46 AM
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Originally Posted by reallywildstuff
Because Im sick in the head.
I, personally, don't considered keeping things clean and orderly a sickness ...

Old 06-19-2018 | 11:25 AM
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My initial plan was just to remove the pipe 14120 from the EGR valve 14710.

Should I instead remove the valve from the block? This would require the gasket 14719.

Do I need to look at REPLACING the EGR Valve just on general principle ? EGR was one of the codes that was actually setting correctly and previously reporting "Ready"...

Old 06-19-2018 | 11:57 AM
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If you have cleaned that tube out in the past, never mind.

crud builds up under the egr. I removed the egr to gain access to the passage under it. So only the gasket under the egr was needed.

Since your system says ready, never mind.
Old 06-19-2018 | 11:59 AM
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No, there is no need to replace the egr unless it malfunctions. It' not cheap.
Old 06-19-2018 | 12:12 PM
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So what was the verdict then...?

remove the EGR valve, clean it all, and replace the gasket?

or just remove the pipe from the valve, and leave the EGR/block interface alone?

i did previously completely remove the guide tube and did clean out the galley at the bottom with the guide tube removed...
Old 06-19-2018 | 06:18 PM
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Removing the rear manifold heat shield requires removing:

1. EGR Primary tube
2. Small rectangular heat shield on firewall (the drivers side nut was torqued to the moon, on a flexible bracket - totally awesome)
3. That same flexible bracket on the drivers side of the small retangular heat shield (one nut, one bolt)

once its all unbolted and loose, pull the manifold shield straight back and then up, twisting it clockwise to clear

Last edited by reallywildstuff; 06-19-2018 at 09:24 PM.
Old 06-19-2018 | 07:43 PM
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I found that my egr tube was named shut with carbon. The carbon also blocked the channels in the housing which the egr is attached to. I also bound more in the portion of the uim which the egr tube bolts to. I did remove the egr housing to clean it.
You might be able to clean it while it is still attached.

I did this a few years ago, so my memory is not exactly crisp.
Old 06-19-2018 | 09:49 PM
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Originally Posted by JvG
I found that my egr tube was named shut with carbon. The carbon also blocked the channels in the housing which the egr is attached to. I also bound more in the portion of the uim which the egr tube bolts to. I did remove the egr housing to clean it.
I'm not seeing any of that today. I had previously cleaned out the exhaust gas space that's immediately inside of both the EGR guide tube's lower end and the EGR valve proper.

As the EGR gasket is not leaking and there is no indication that the EGR valve is malfunctioning, I will NOT remove the EGR valve for service. I will however check the space again when I replace the lower guide tube gasket upon final assembly.

I got the main EGR tube off with different English-sized crows feet on each end, as I did not have the proper Metric sized tools. The manifold side took a 15/16" and is about the correct size - is this 20mm? The valve side took a 1-1/4" that was TOO BIG...1-3/16" may have been better, but I didn't have that tool either, and 1-1/8" was too small. The tools I do have were purchased for Oldsmobile A/C line service...a proper large Metric crowsfoot kit is in my future. OLDSMOBILE in the Nissan forum FTMFW!

So I am "drawing the line" on mightaswells re LIM cleaning/service at the EGR valve.

I am done taking things off and have cleaned it once pretty good (to be re-pleated) and will start putting it back together soon. Throttle body cleaner works better on the deeper piles of crud, while brake cleaner is better when it's cleaner to begin with. The brake cleaner took the paint off my rebuilt steering rack. I killed one steel toothbrush just cleaning up all the parts I took off, and need at least one more to finish detail cleaning the engine. The sludge comes off in huge gooey chunks and fouls the brushes quickly.
Old 06-19-2018 | 09:59 PM
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I was referring to crud in the upper manifold , where the gasses from the egr tube enter the uim..

just to confirm, the egr tube which resembles a door handle has een cleaned out at some point?
Old 06-19-2018 | 11:18 PM
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[QUOTE=JvG;9177668just to confirm, the egr tube which resembles a door handle has een cleaned out at some point?[/QUOTE]

YES. I have been calling this the "EGR guide tube". I did that a while back along with R&R IACV and TB and MAF.

What I should have done instead at that time was tested/replaced the fuel pump FIRST. I eventually replaced the fuel pump and things were MUCH better after that. The car was really running well until the injector dropped the pintle cap - aside from the oil leaks.

We shall see what transpires.
Old 06-19-2018 | 11:34 PM
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I have done all that you have.

It was all worth it.

My car has over 200k on it, but drives like a late model car. My engine runs perfectly. Good power and mileage.

Since all my coolant hoses, radiator and water pump have been replaced, I can and do confidently drive my car 400 miles or more a day, just for pure joy and sight seeing.

This includes mountain driving in cool airconditioned comfort while its 100 degrees outside.

I watched the eclipse in Salem, Oregon last year.
On he way back, traffic was so bad that it took five hours to drive 40 ish miles back to Portland. The temperature was in the high 90s. At least I could run the ac all the way home.

Let us know how this turns out for you.

I think you will be very happy.
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