Originally Posted By: nitehawk55
Why is it some feel their engine is dirty or in need of cleaning . An engine will always have some accumulation of crud , varnish or whatever but rarely if ever will it cause an issue during the life of that engine . As long as one does resonable length OCI's using the recommended oil viscosity and and of course a known brand of oil filter what can happen unless there is a mechanical failure in the oiling system (pump , pickup tube falls off)or excess oil contamination by antifreeze or fuel?
In the case the engine has rarely or never had oil changes , well that would be the exception.......otherwise.....
NOTHING ! , your engine will be perfectly fine
I'm sorry, but any accumulation of crud is not ok in modern engines. Especially variable valve timing and its tiny oil passages. You plug your VVT with crud, your screwed. Years ago before VVT I agree, it didn't matter.
Why is it some feel their engine is dirty or in need of cleaning . An engine will always have some accumulation of crud , varnish or whatever but rarely if ever will it cause an issue during the life of that engine . As long as one does resonable length OCI's using the recommended oil viscosity and and of course a known brand of oil filter what can happen unless there is a mechanical failure in the oiling system (pump , pickup tube falls off)or excess oil contamination by antifreeze or fuel?
In the case the engine has rarely or never had oil changes , well that would be the exception.......otherwise.....
NOTHING ! , your engine will be perfectly fine

I'm sorry, but any accumulation of crud is not ok in modern engines. Especially variable valve timing and its tiny oil passages. You plug your VVT with crud, your screwed. Years ago before VVT I agree, it didn't matter.