New EGR head gasket conspiracy theory / how to REALLY delete the EGR (if you believe it could/ should be deleted in the first place) (1 Viewer)

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Nov 14, 2016
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Atlanta
I'll start this with, I'm still not sure I want to delete EGR, mostly because after I rebuild my engine from a cylinder 6 head gasket failure, I have to pass emissions ONE MORE time in Georgia before the truck is 25 years old and no longer requires emissions. I just don't want the extra headache to get it back on the road and driving. I'll also state that I'm not convinced EGR has anything at all to do with head gasket failures. But I'm not convinced it doesn't either!

I think there is a lot of misinformation about EGR and what the actual components look like, where they are located on the engine, where the EGR gas comes from and where it goes. At least I didn't have a good idea until I took the motor apart. So, if all my jibber jabber isn't useful, at least hopefully the pictures will help someone a little.

Here's my cylinder 6 head gasket failure. The #6 piston top got steam cleaned from coolant. You can see in the close-up picture where the gasket deformed.
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EGR pictures.
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I'm not going to talk about how or why EGR works or why you should or shouldn't delete it. I hope this doesn't turn into that. That info is out there already. So I'll get to my main point:

If I agree EGR causes a cylinder 6 head gasket failure, I do not think it is because EGR gas is getting pumped into the intake manifold; I think it is because hot exhaust gas passes through the back of the head right behind cylinder 6. Explanation below.

A lot of people say that EGR gas dumps right into cylinder 6 in the intake manifold. I took this at face value until I actually had the manifold off the engine. This is just simply not accurate. Look at the picture of the intake manifold. EGR gas dumps straight into the middle of the intake manifold, not "directly into cylinder 6". Any EGR gas that gets injected here will get distributed evenly to all cylinders. Now, the internal plumbing for the EGR gas gets routed along the cylinder 6 intake manifold runner, I'll give you that. Maybe this heats up the air going to cylinder 6 by a few degrees, MAYBE! But no more actual hot exhaust gas goes into cylinder 6 than any other cylinder. And maybe this is what people have been saying all along and I misunderstood it, but the language people use doesn't seem to make that clear.

So let's say we want to stop exhaust gas from going this far to keep the intake passages clean and keep the cylinder 6 intake runner cooler. We all know about the resistor mod. It prevents hot EGR gas from going into the intake manifold as well as running along the runner for intake 6. Great, that solves part of the EGR issue, but not all of it.

The next issue is that even with the resistor mod, the hot exhaust gas still makes its way through the bottom end of the EGR pipe and makes the wiring harness vulnerable to melting and chafing. I have had issues with that in the past, solved temporarily with extra wraps of heat tape. The only way to fix this completely is by using block off plates to remove the hot EGR pipe. A block off plate on the back of the head, and a block off plate on the intake manifold will allow you to do this. So, if you do that, you've prevented the EGR gas from coming through the pipe and damaging your harness and you have completely removed EGR and you can forget about it, right?!

I don't think so. Hot exhaust gas is still being scavenged from cylinder 6 and just sitting there all hot and toasty, right in the back of the head, wait for it, right next to cylinder 6! I'll repeat for emphasis: even if you delete the EGR hardware with block off plates, millimeters away from the back side of cylinder 6, inside the head, is a pocket of hot exhaust gas just sitting there! Now take a look at where my gasket failed. It deformed on the back side near where the hot exhaust gasses are sitting in the head. Now again, I'm not saying I am 100% convinced, but if I was going to allow myself to believe EGR had anything to do with my head gasket failure, it wouldn't be from exhaust getting "dumped into cylinder 6 intake manifold" it would be that the hot exhaust is going in the head right behind to cylinder 6. And if I wanted to remove EGR for this other reason, not a single popular method of "completely deleting the EGR" addresses this issue.

That brings me to the next part, how can I completely get rid of EGR to fix this other issue of hot exhaust still getting pumped into the back of the head? The little extra runner on the cylinder 6 exhaust manifold needs to be eliminated and sealed off. I tried to find a non-US, non EGR exhaust manifold and gasket but I came up empty. I have seen aftermarket headers that might work, but the easiest cheapest way I could think of is to weld up that runner on the exhaust manifold and have it machined back flat. I know, cast iron has to be welded a certain way, you wouldn't want the weld from your Harbor Freight flux core coming loose in there. Then that leaves the exhaust manifold gasket. The stock gasket accommodates that runner and would not seal off that hole in the back of the head from the exhaust. Well, it turns out you can use the front exhaust manifold turned upside down, just one of the holes doesn't quite line up. You could drill it larger a bit and make it work without issue, I think.

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What do you guys think? Has someone already figured this out or come up with a reason it is a waste of time? I certainly couldn't find anyone talking about this.

Just to be clear, I have not tried this yet! I just want to hear some thoughts. I'm still putting my engine back together, possibly still complete with the EGR equipment, and then I will go about deleting it later. Maybe, probably, if I have time. Haha But I might also try my chances at passing emissions without it. (Resistor mod + relay to fool ECU into achieving readiness, but that's another conversation.)
 
Joined
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so you can doa a little reading here Exhaust manifold question, as it was discussed and pretty much the answer is fill in the egr runner in the manifold by filling it with weld, then flat grind the manifold face. you can use the front manifold gasket by just notching the bolt hole to make it work. I didn't go that route when I had the exhaust repaired and manifolds installed but if I did the jpb again I would have dome it that way
 
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Awesome @bigredmachine ! Glad I'm not the only one to have the thought.

@vegasfj40 I really don't want to get into that here if I can help it. It has been discussed in lots of other threads. There is evidence, non-evidence, name calling, information, misinformation, intelligent and well expressed opinions and research on both sides already. And to be honest, at this point, the only other person I'd be interested in hearing from on the matter is the person who actually programmed and designed the ECU and motor. And we STILL probably all wouldn't agree on wether it's a good idea to delete it or not!
 
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but the easiest cheapest way I could think of is to weld up that runner on the exhaust manifold and have it machined back flat. I know, cast iron has to be welded a certain way,
Just an idea, but instead of going to all the trouble of welding up the exhaust manifold, why not just plug the passageway on the exhaust side of the cylinder head instead. Welding cast iron is always a pain in the ass, plus you'll need to remachine it flat after you weld it.

So it looks like it would be a whole lot easier to press a plug into that hole in the cylinder head. Look for a small press in freeze plug, or you could have a machine shop make you a press in plug out of Aluminum. Another idea, depending on the size of that hole, you might be able to drill, and tap it for a screw in pipe plug.
 
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I always thought our trucks were designed to operate with EGR. The PCM is calibrated for EGR. Doesn't EGR actually cool the combustion chamber? Would deleting it affect the fuel mapping?

yes and no. in every other market the 1fz did not come with egr so no not necessarily, if you get a jdm head there is no egr port in the head. we do run in the us and yes the ecu is programed to accommodate the addition of egr. yes egr cools the combustion chamber by adding exhaust gasses into the intake to control n0x emissions. deleting the egr will not affect fuel mapping, that is hard programed into the ecu. fuel trim as set by the o2 sensors may be affected slightly but not enough to worry about it
 
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Welding cast iron is always a pain in the ass, plus you'll need to remachine it flat after you weld it.

that should be done anyways to straighten the manifold matting surface so there is no warpage and give a better seal with the gasket. I did that to mine and it was just a few quick hits on a belt sander to clean them up and not a lot of extra work
 
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Yes, the front gasket flipped over will work on the rear exhaust bank with the farthest aft hole trimmed out. That’s how Ive got my headers set up(and EGR totally eliminated).
 
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I put a 5/8 freeze plug in the head port at the exhaust manifold and a plate between the EGR pipe and head on the other side port.

I'm liking this freeze plug idea. But I like the ability to remove/ reverse with the manifold.

Any pictures? Do you use a sealant with freeze plugs or just press em in dry?

I have wondered about exactly how I would seal up the head. I think It might be best to leave one side "open" to atmosphere so the air inside the head has a place to go when it gets hot.

I am reminded once of a radiator I put in my Volvo. Since my car is a 5 speed, the radiator had extra cooler ports for the automatic transmission that I didn't need, just like the cooler in the bottom of the radiator on our trucks. Well since I didn't need it for my 5 speed car, I just left the nice little rubber caps on the two ports. After the first drive with the new radiator, I heard a loud "POP" that scared the crap out of me! Turns out, that the air inside the transmission cooler got hotter, expanded, and blew one of the rubber caps of the cooler. I wouldn't want a similar situation to happen in the back of the head, to seal in that channel from both sides and create a pocket of hot air that expands and tries to get out. Maybe I am overthinking that, though.
 
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I will be going with the freeze plug also. But instead of welding I cleaned up that area on the rear manifold and filled it with high temp RTV exhaust sealant, I also removed EGR pipe and capped it with a plate.
Welding IMOP is not necessary.
 
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No pictures, sorry. I measured the port with a Harbor Freight ball end inside diameter tool, measured that with a digital caliper and 5/8 was slightly oversize. I used a steel freeze plug and lightly drove it in with a 1/2 drift. It deformed easily and domed into the port. I went about 5/8 or so deep where it looked like a good seal. I didn't use a gasket or sealant on the plate. I use the resistor.
 

TomH

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Seems to me that with a block off plate about 2 seconds after you start the truck you will have pressurized the runner/port and no addition exhaust gas will flow that direction. It's not going to circulate if it is dead ended. I think the temperature of the gas trapped in the runner/port will eventually equalize with the head temperature in that area.
 

Howard705

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Been quite a few years since I obsessed over reading about HG failure causes but thought the consensus was the length of the aluminum head expanding and the triangular water jacket holes in the end of the HG. didn't new T HG cure this by changing them to small round holes? Do HG on non- EGR engines never fail? do the upgraded T HG still fail?
 
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Just throwing it out there:

Why not fill the EGR passage through the head completely with a Copper based RTV sealant and install block off plates? No hot gas can get in or move the sealant and the copper-based plug will ensure there are not gasket destroying hot spots.
 

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