When I changed the EGR cooler last week I also installed a new set of spark plugs. The old plugs do not look old at all! I have been using any cheap regular fuel but have been adding about 1/4 of a 10 oz bottle of Techron concentrate plus (Walmart) to every fill -up. Most of my fill -ups are 10 gal. The (short) head intake runners & the valve stems were spotless.
In the past I have used one bottle to treat one tank of fuel. On a continuing basis I thought it would be overkill so I started using the same bottle to treat 4-5 tanks. I suspected my intake was being gummed up from the ICE ingesting a fair amount of PCV supplied oil. The condition of intake manifold confirmed this. The intake manifold air ports had some deposits on them & the small PCV openings were "open" but very gummy. Immediately downstream of the injectors everything was spotless so I'm assuming I was doing something correct. Also: I generally use the cheapest fuel I can find - Racetrak/7-11/Wawa/Walmart. Much of my reasoning came from post #4 on this thread: Chevron Techron Concentrate Plus questions https://bobistheoilguy.com/forums/ubbthreads.php%3Fubb%3Dshowflat%26Number%3D306256+&cd=2&hl=en&ct=clnk&gl=us Here I am quoting from post #4: "Chevron's explanation of Techron Some excepts... "Techron and Techron Concentrate are polyether amines of slightly different structure, each optimized for its specific application. The principal difference between Techron and Techron Concentrate is additive concentration and rate of deposit clean up... A bottle of Techron Concentrate, whose additive concentration is roughly 10 times stronger than the dose in Chevron gasolines, provides a quicker clean up of deposits left by lower quality gasolines." "For consumers who buy exclusively Chevron gasolines with Techron, their cars very likely are delivering their best possible performance and operating at their lowest possible emissions. A bottle of Techron Concentrate, therefore, is not likely to provide any benefits to these consumers.""
That's interesting. That statement from Chevron makes me want to try the same as you. I always used to use Techron in my Chevy vans to keep the fuel gauge free by getting deposits on the sending unit since I heard what GM markets was the same as Techron.
