I had a used engine put in less than 500 miles ago. All fluids were replaced and it ran good. No leaks, No Smoke , oil was 5w30. A compression check was done before I bought the used engine and it was fine. I don't want to have some one go through the engine before I gather all facts on what can cause this problem.I bought a Chilton's repair book and it helps but if someone else out there has had the same problem and it was not something to do with the internal motor parts. I really need to Know. I also know that gunk can block oil ports in some engine parts. Is there a product that I can purchase to flush the motor out and does it work? Some Problems that cause oil consumption are: dirty cooling System,faulty mass air flow sensor, clogged pcv valve , restricted air intake. I checked the air filter and its clean what else could restict air flow? Thanks for any information that you can give me. One more question. The shop that installed the engine informed me that the old engine was equiped with an oil cooling unit but they did not install it on the one they put in because the engine was out of a 1990 Astro van and it did not come with one. By any chance could this be the problem?

You don't say how much oil it being used? If its a lot (<500 miles to a qt), then I suspect there are major engine problems, e.g. rings! Many feel a qt/1000 miles is acceptable oil consumption.

Its possible the engine is just, no good. I had the same experience once. The seller claimed the engine only had 60,000 miles and used to no oil when removed from vehicle. But as I found out later, it sat for over 2 yrs. It seemed to run ok for about a 1000 miles without using oil but then it started using and not smoking out the pipes. Every 500 miles or so, it was down a qt. Finally got tired of that and found another engine. This time I found a rusted out truck with a good GM 350 V8 engine and got that.

I tore open the oil burner and found that several rings on 2 pistions were broken.

AutoRX is a good flush but takes 1500 miles to work. Amsoil makes a flush that works in about 30 minutes.

AUTO-RX
Amsoil

This message has been edited. Last edited by: MikeR,