Originally Posted By: The Critic
I still do not understand how engine flush machines can cause harm. Yes, they are usually not necessary and can leave residue behind in the new engine oil, but I cannot see how they can cause the catastrophic failures being described.
Here is one possible scenario:
Let's say that the engine really does need cleaning.
We've all seen pictures of sludged engines here.
Let's say that a solvent flush is applied, but not all of the loosened sludge is recovered during the flushing process.
A new oil filter and fill of oil are installed and the customer goes on his merry way.
The remaining sludge is now circulating into the oil pan.
It gets sucked onto the pickup screen, clogging it.
Oil pressure is lost.
If the engine is instantly shut down when this occurs, no harm is done, and the vehicle can be towed home or to a shop for pan removal and manual cleaning.
If the engine is run for very long with no or very low oil pressure, serious damage will obviously occur.
OTOH, some members have reported good results with Kreen, which is certainly a strong solvent.
Also, there are cases where a solvent flush should be used as a last resort, since the engine will be terminal unless it can be cleaned up internally.
It probably isn't a flush that causes problems, but rather improper or uninformed use of either a flush or a solvent additive.
If the user and owner both understand the potential pitfalls going in, the chances of serious damage occurring are probably minimal.
I still do not understand how engine flush machines can cause harm. Yes, they are usually not necessary and can leave residue behind in the new engine oil, but I cannot see how they can cause the catastrophic failures being described.
Here is one possible scenario:
Let's say that the engine really does need cleaning.
We've all seen pictures of sludged engines here.
Let's say that a solvent flush is applied, but not all of the loosened sludge is recovered during the flushing process.
A new oil filter and fill of oil are installed and the customer goes on his merry way.
The remaining sludge is now circulating into the oil pan.
It gets sucked onto the pickup screen, clogging it.
Oil pressure is lost.
If the engine is instantly shut down when this occurs, no harm is done, and the vehicle can be towed home or to a shop for pan removal and manual cleaning.
If the engine is run for very long with no or very low oil pressure, serious damage will obviously occur.
OTOH, some members have reported good results with Kreen, which is certainly a strong solvent.
Also, there are cases where a solvent flush should be used as a last resort, since the engine will be terminal unless it can be cleaned up internally.
It probably isn't a flush that causes problems, but rather improper or uninformed use of either a flush or a solvent additive.
If the user and owner both understand the potential pitfalls going in, the chances of serious damage occurring are probably minimal.