I am replacing the damaged sump pan on my 1998 Daimler Super V8 and have refurbed the second hand sump I recently purchased. I have treated it firstly with Motip Zinc Primer which is heat resistant to 350 degrees Celsius. I then put further coats of Hycote VHT paint on top and this is heat resistant to 560 degrees Celsius.
I have treated both the inside and outside surfaces of the replacement pan.
My question is this : although the heat generated will come nowhere near to causing any problems what about contact with the engine oil ? It states that the Hycote VHT paint is oil resistant but I am worried about paint degradation and possible mixing of the paint with the oil and the problems that it could potentially cause.
Any knowledge or advice would be gratefully received on this matter.
As always sincere thanks to all on the forum
Kindest Regards
Joe

 

Oil resistant is not a strong enough wording for me. It makes me think of water resistant glue, which is not waterproof.

Does the manufacturer have a phone# on the label, or a web page where you can ask a specific question?

 

I cannot recall ever seeing a sump (tin or alloy) with a painted finish internally.


Logically, all the oil in the sump sloshing around should keep corrosion to a minimum.

 

Getting paint to stick long term to the outsides of cast Aluminium engine blocks/sumps is pretty difficult which is one of the reasons the OEM usually leave in an as cast state.


However, If you must paint it for whatever reason , I would completely degrease and bead or sand blast the surface to clean it (making sure no bead or sand get lodged behind any baffles or cast surfaces inside the sump) , followed by a good quality no sand etch primer like PPG DP40LF or Limco LP20.(only on the outer surfaces)


Then use the best quality heat resistant paint you can find like GE Glyptal which is usually used in electric motors.


I have painted the outsides of Aluminium engine blocks, sumps etc in standard urethane automotive paints (after epoxy primering) for a custom look but I wouldn't recommend it long term on a daily driven car.


Powder coating is another option you may want to explore, but that's a process not usually able to be done at home.


I wouldn't apply any coating to inside the oil pan itself though, you are running the risk that any paint that could detach will end up blocking the oil pickup causing low /no oil pressure and loss of engine.

 

No "paint" or other coatings are usually allowed inside an engine due to the possibility of the material coming off and blocking things up.

As has been said, the oil should keep things from corroding very well.

This is an easy risk to benefit analysis to do on this one.

Vector