One of the better cleaning additives out there is Auto-RX, it is well respected over at the bobistheoilguy forums. It gently cleans the engine using a cleaning cycle interval, much better than those quick flushing products that can do more harm than good. This is the product that I would use.

http://www.auto-rx.com/

 

Cool way of saying you changed the oil.

Oil Change Interval

 

I know what it means, lol just wondering what kind of oci the poster with the 230k mile engine was running.

 

I have always done oil changes with 3 to 4 k miles .. Closer to 3 when I first bought the car ..
Started with Quaker state high rpm synthetic in 2005 .. Then castrol blue racing oil for a while then Mobil 1 and I'm now at rotella t6...

 

Provided you change out the oil at a shorter interval. And change the filter. All that gunk as to go somewhere. IME, regular oil (even mineral based) has enough detergents and other agents to clean varnished engines. Just do several changes in a few months. Changing the filter, at the same time.

Old time "trick" was to add automatic tranny fluid (like Dexron) to the engine (say 1 quart Dexron + 4 quarts motor oil). And run it through the engine for a few days. Dexron has high detergent content and low viscosity. The idea is it get into stuck parts --- like lifters --- easier.

Then, drain out the mixture. Change to 100% motor oil + new filter. Do a quick change. Then, go to regular routine changes. This trick did work for some really varnished and gunky engines.

 

I bought 5 bottles of the AutoRX. It's actually very expensive, I think $27 per bottle, and it's only like 8 oz. ea. or something. They had very specific instructions on how to compliment OCIs. If I'm remembering correctly, they want you to put a bottle in at the last 1,000 mi of your oil, change it 1,000 mi later (obviously), do a fresh oil change with no additive, then 3-5k later on you next oil change, put the bottle in with the oil and run it for the 3-5k, then on the next oil change not use any additive. They called them clean (or something) cycles and rinse (or something) cycles. Basically using no additive every other oil change. I don't remember exactly, but they seemed to be very specific on how to use them.

Like someone above said, this is a very reputable product. Sure some people don't necessarily agree with any of these "types" of products, but if you're going to use one I can almost guarantee that AutoRX is the safest. I only used 2 bottles in my car, I kept the other 3 for my truck/wife's car for a later date. Speaking of which, I should probably use it on my wife's car lol

Edit: also, as an FYI, I've put about 20k on the car since stopping the AutoRX additive and have done 2 Blackstone UOAs and they came back with flying colors. Also tested compression a few months ago and I was 240 psi across the board. So I'm not worried.

 

jkelley, thanks, for the personal account. I agree, that I'm a little old school about engine rebuilds and what-not. Good to know there are products that work, as advertised. Keep AutoRx in mind.