Upon taking apart some of my engine today (4000 miles on it, it is new, injectors were not new though) I found a white residue on the inside of the firewall exhaust manifold. What could cause this? I am not burning any coolant. The other side appeared normal. Are the 2 sides of injectors controlled separately or do all 6 batch fire at once? All six of the plugs look exactly the same. Just wondering what it could be, I was planning on flow testing my injectors anyways so this works out perfectly.
Are the two injector banks controlled separately? I don't see how they could be with only one O2 sensor in which case both sides would be running lean. I really do not think I have an exhaust leak, there is no indication of an exhaust leak (soot or other residue around joints or on the exhaust pipe. I will test my injectors today and hopefully that is the issue.
Also seriously all 6 plugs look identical I can post a picture. None of them look like they have been getting super hot. Could this have been a problem 4000 miles ago when the engine was new and now it is fine and the residue remains, or is there no way and the residue has to be recent? Because when I was first running my engine it was running a little lean on that side ( I could tell by the exhaust manifolds glowing) but then once the injectors cleaned themselves out it stopped after like 30 miles of driving.
