If the oil comes out as clean as it looks going in is that a good sign that my engine is pretty clean inside? I'd think so. My truck doesn't get the mileage that it used to do, so when I change the oil it comes out looking really clean. I use full synthectic and change it every 4 months, mileage not an issue. If that's the case, then my engine must look like new inside w/57k on the motor. I tried to go longer between oil changes but I am old school, anything longer than 3 months gets me nervous. I waited 4 months this time, but I couldn't go longer.

 

The oil filters don't last much past 4,000 miles. So it's good you keep changing your oil. If you're concerned with the engine being dirty, run a flush through it. But how many miles do you have? You could have a lot of carbon build up in the intake manifold, throttle body/carb, and exhaust. A good way to to check if it could be one of the following is to stick you finger inside the throttle body and if there is a lot of carbon build up on the back of the butterfly, then you're looking at a full systme cleaner. Clean it out the best you can with carb cleaner or throttle body cleaner, rags and brushes. Get an in tank fuel cleaner and then get a bottle of sea foam. Start the engine and pop off the vacuum line that goes to the brake booster and carefully dip the hose into the bottle of the sea foam. That will circulate into your intake manifold and break down a lot of the carbon. It will clean the manifold, injectors, valves, and catalytic converter on its way out. If you feel nervous about doing it, take it to a quick lube... Shouldn't cost more than $65 and dealerships want $150 so depending on your budget and your comfort level you have a couple options. Check your power steering fluid too, if it's dirty then you should have that sucked out and replaced. The old fluid drags the engine not to mention breaks down the seals. Rear differential fluid is another thing to check if that's dirty, transfercase and front differental. Those are supposed to be changed at 100,000 miles. Transmission fluid is some where else you'll notice a lot of milage lost if you don't change that fluid. It's supposed to be changed every 30,000-40,000 miles. Again you have a few options here. Drop the pan and change the filter, but that takes out about only 30% of the fluid. Take it to the dealership and again pay $150. Or shop around and look for a quick lube that has a machine that pumps the fluid out and pumps it back in at the same rate. It might run you no more than $100. Good luck and hopefully that helps you.

 

thanks for the advice.

much appreciated.

 

Go with the owners manual recomendation. Use a good oil and a good filter and its no problem. Thoroughly warm up the engine when you drive it to limit condensation in the crankcase. When in doubt, use oil analysis. I use Stavely services out of Ren, Nv for most of my oil analysis.