I'm looking for advice on what to look at next in terms of maintenance.
Over the last year or two, I have restored the power and fuel economy of my 2003 Sable Duratec that had a few years of exclusive short trips and non top tier fuel.
Although oil was changed regularly, and through the fill hole everything looked great, the car would struggle to accelerate above 70 and stop accelerating at 80 where it was noisy and shaking.
It is now smooth as anything. I recently got it to hit its limit of 110mph and it was quiet all the way there.
Firstly I spent a lot of time cleaning the throttle body butterfly. It was seriously baked. The idle improved significantly.
Then I used Techron and Gumout about 3 times until I couldn't feel any further improvement.
Although the improvement was dramatic, I felt there was still a problem and I could hear a scraping noise when accelerating between 2k-3k revs. So I took it to Walmart for the fuel system cleaning and the noise went and the acceleration improved even more.
I then did another bottle of Gumout which is my annual maintenance and there was a further small improvement.
I am wondering what else was affected by the carbon build up from those short trips and needs replacement or cleaning.
Also I am wondering about the mechanism of the carbon build up. It seems that due to short trips, my oil probably never coked up in the combustion chamber because it was not hot enough. But there would have been significant coking in the combustion chamber from incomplete combustion. Is it possible that this formed around the rings and was responsible for the scraping type noise? I have a theory that enough of it has been removed (as evidenced by the performance improvement), that anything remaining can now be taken care of by synthetic oil and better fuel / PEA annual dosing.
I'm also doing 2 x 1 hour freeway trips every week or two now.
The other strange thing is that I also saw some oil consumption over the last 5000 miles and I think it was in the last 1000 miles after the Walmart fuel cleaning service that cleaned the carbon responsible for the scraping noise. This is strange because I hadn't previously noticed any oil consumption although the oci's were shorter. But I am wondering whether the carbon in the combustion chamber had built up so much that it had gotten into the area above the rings and actually prevented oil from entering the combustion chamber. Now that the carbon is removed, there would be a path for the oil to escape past the rings when the engine is not at operating temperature.
Over the last year or two, I have restored the power and fuel economy of my 2003 Sable Duratec that had a few years of exclusive short trips and non top tier fuel.
Although oil was changed regularly, and through the fill hole everything looked great, the car would struggle to accelerate above 70 and stop accelerating at 80 where it was noisy and shaking.
It is now smooth as anything. I recently got it to hit its limit of 110mph and it was quiet all the way there.
Firstly I spent a lot of time cleaning the throttle body butterfly. It was seriously baked. The idle improved significantly.
Then I used Techron and Gumout about 3 times until I couldn't feel any further improvement.
Although the improvement was dramatic, I felt there was still a problem and I could hear a scraping noise when accelerating between 2k-3k revs. So I took it to Walmart for the fuel system cleaning and the noise went and the acceleration improved even more.
I then did another bottle of Gumout which is my annual maintenance and there was a further small improvement.
I am wondering what else was affected by the carbon build up from those short trips and needs replacement or cleaning.
Also I am wondering about the mechanism of the carbon build up. It seems that due to short trips, my oil probably never coked up in the combustion chamber because it was not hot enough. But there would have been significant coking in the combustion chamber from incomplete combustion. Is it possible that this formed around the rings and was responsible for the scraping type noise? I have a theory that enough of it has been removed (as evidenced by the performance improvement), that anything remaining can now be taken care of by synthetic oil and better fuel / PEA annual dosing.
I'm also doing 2 x 1 hour freeway trips every week or two now.
The other strange thing is that I also saw some oil consumption over the last 5000 miles and I think it was in the last 1000 miles after the Walmart fuel cleaning service that cleaned the carbon responsible for the scraping noise. This is strange because I hadn't previously noticed any oil consumption although the oci's were shorter. But I am wondering whether the carbon in the combustion chamber had built up so much that it had gotten into the area above the rings and actually prevented oil from entering the combustion chamber. Now that the carbon is removed, there would be a path for the oil to escape past the rings when the engine is not at operating temperature.
