Cylinder Head "Hot Spots," affect on Oil?

[45ACP]

What effect can one or more cylinder head "hot spots" have on the action of motor oil as a whole? Where would they be? How hot can they get? Is it most likely to be around the "rings?" Is thinner oil like 5w30 perfectly capable of dealing with these hot spots?

I never did get how hot spots would develop, or where they would be. Carbon deposits? Perhaps even hot enough to cause run-on, via igniting fuel/air even after car has shut? Can they be removed with any particular oil or method, or are they there to stay?

 

[synthetic_crazy]

Wow, lots of questions. First, where they are and how hot they can get depend on the engine's design. If you use a synthetic 5w30 that meets both the GM 4718 and Honda HTO-06 specs, then I think the oil is very capable of dealing with the hot spots. Second, I don't think you can remove hot spots in an engine without redesigning it. Certain engines run warmer than others and have more hotspots. Our Toyota Avalon with the 1mzfe v-6 is a very hot running engine with numerous hot spots on the top of the engine where oil lays and "cooks". However, numerous members on here have had these engines run just fine and no sludge build up by using a good synthetic (and in some cases a regular conventional oil). The most important thing you can do in regard to hot spots is to change the oil. Infrequently changed oils loose their ability to handle the heat of hot spots.

I see you are a new member...

to BITOG!

 

[tmorris1]

There are no rings in a head?

 

[Bruce T]

Hot spots exist for many reasons, and I don't pretend to know them all. Obviously, it's very hot near the combustion chamber in the head, especially if there is limited oil or coolant flow in the area.

How much the oil is damaged depends on the temperature of hot spots, their size, their number, their spacing, oil proximity and flow, cooling system, etc. Hot spots don't always cause problems. It's like fire walking across hot coals. If you walk lightly and quickly, you will be OK. If you don't, your feet are too close to the fire for too long.

 

[mechtech2]

'Hot spots' can locally get the coolant overheated.
You can get tiny micro boiling there.
But this is a very small isolated spot that is quickly dissipated by the surrounding coolant.
Rarely a problem.

And with oil, I never heard of a problem from head hot spots.

 

[PontiacFan]

Originally Posted By: mechtech2

And with oil, I never heard of a problem from head hot spots.


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