I took the heads off so I could get some broken exhaust manifold studs out and retap (actually I was advised to use a Heli-Coil instead so doing that) one of the other stud holes.

The piston heads and the bottom of the valves had some buildup on them. enter image description here

enter image description here

The image of the piston heads is after five hours of scowering, a lot engine degreaser, carb cleaner, wd-40, and even some scraping. Yes there are some teensy weensy abrasions on the piston heads now but before it was coated with a rough surface of carbon so I'm pretty sure it's better.

To be honest I'm not even sure why I did it other than they were really filthy and I saw a YouTube video where a guy did it so there wouldn't be any hot spots on the pistons (not wifi hotspots obviously but like with temperature). Did I even need to do any cleaning (sorry, no before picture but they were coated in black and it was even a bit lumpy on some of the edges)? Is what I've done good enough or does it have to be perfect?

I haven't touched the bottom of the valves yet. I don't want to disassemble the heads so I'm really hoping just cleaning up their bottoms will be good enough. What do you think?

1 Answer 1


You can do as little or as much as you want, it is your engine.

Since you have already done a load of work disassembling the engine, to me it would make sense doing as much as you can while it is in bits.

I would totally disassemble it, clean and lap the valves in and replace the valve oil seals to make sure that there was the least chance that I would have to take it to bits again in the near future.

Don’t use anything that can scratch the pistons or the head, you could then be adding more hot spots and also somewhere for carbon to grip onto.

As i said however, you may be happy removing the head, fixing the thread then putting it back together. If it ran well before, it should run well again after.

  • Would you change the lifters while doing this? It's about $100 but I'd like to never go this deep into the engine again. I've heard some people say that if you replace the lifters you need to replace the whole camshaft as they wear together. True or disinformation?
    – user875234
    Mar 8, 2022 at 15:46
  • 1
    I would only replace the parts that looked worn. For example, if the valves look ok after cleaning them and there is no play in the valve guides, then I would keep the originals. If the cam shaft and lifters look ok, then reuse them. However, for the small cost of the valve oil seals, I would definitely replace them. Any scoring on the cam is likely to be on the lifters, so it would be a good idea to replace both otherwise the new component could be damaged by the old. With all these things, it depends how much you are willing to spend.
    – HandyHowie
    Mar 8, 2022 at 15:53

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .