Is this header primary weld leaking?
Attached is the pic. 7 primaries look completely blackened and normal, but one primary still looks almost new, but has a very distinct black area near the weld. Does this look like a leak to you?
. I would be very interested to see what the plug in that hole looks like compared to the others, I bet you see something that doesn't make sense and you have a dead cyl... whether it's the coil, etc. I have no idea but there's no way that you should have heat in all the primaries except one like that.
It's not a header problem... you have something else going on there.
I would be very interested to see what the plug in that hole looks like compared to the others, I bet you see something that doesn't make sense and you have a dead cyl... whether it's the coil, etc. I have no idea but there's no way that you should have heat in all the primaries except one like that.
It's not a header problem... you have something else going on there.
But the car runs smooth and has good power. I put all new ZR1 plugs in and firecore wires too.
Maybe the previous owner had an issue with a plug/wire and the header primary hasn't had a chance to catch up yet? I'll pull the plugs and take a pic on those two cylinders. I can also log misfires, I will plug my scanner in tomorrow.
Last edited by mchicia1; Nov 4, 2015 at 08:36 PM.
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What I did see in my scanner was on cold start the Bank 1 trims were maxed out to +25% while bank 2 was the normal -5% to 0%. This is definitely indicative of a leak prior to the 02 sensors. The trims came back to normal after about 2 minutes of driving because the heat from the exhaust must be sealing the leak enough to not drive the 02s crazy.
Since the 02 sensors are before the slip fit, I would imagine this means the header flange itself is leaking either at the flange or a weld. Time to hook the compressed air up into the exhaust and poke around I guess. Pain in the *** but has to be done at this point.
Here is an idle vid I took a couple weeks ago, pretty smooth and quiet.
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Here are the plugs side by side. The weird pipe's plug is on the left since pic is upside down.
It made the same exact sound when while still on the factory DOD setup, so it's not just valve train noise through the header.
It is warped, it would not seal at all with stock MLS gasket.
I put thick remflex gaskets on there and that seemed to seal it, at least at idle. With the MLS gaskets on there, you could clearly hear the exhaust leak and see the black carbon on the head.
Sigh, maybe I just need to ship these to ARH and be done with it.
It is warped, it would not seal at all with stock MLS gasket.
I put thick remflex gaskets on there and that seemed to seal it, at least at idle. With the MLS gaskets on there, you could clearly hear the exhaust leak and see the black carbon on the head.
Sigh, maybe I just need to ship these to ARH and be done with it.
. These were on the car when I bought them.They did offer to fix, but I doubt that would be getting a new header but you never know.
Fwiw if you were to dychem the flange on pretty much any header and hit it on a flat table with sandpaper on it you would see none of them are flat, that's one of the things an experienced guy will do with new headers before installing them. Hell I'm going to do it to the set I'm building now.






