Removing a "mushroomed" oil pump piston.

[elgyqc]

I am doing engine out maintenance on my spare 2,7 engine. It is from a 2000... I bought it on ebay and did about 10,000 KM on it before putting it on the engine stand.
One of the upgrades is to replace the oil pump piston. Normally the piston just drops out but that is not the case if it is "mushroomed". This is explained here.
https://986forum.com/forums/performance-technical-chat/83367-oil-pump-piston-some-questions.html
Obviously this engine has the "mushroomed" version of the piston and I have not been able to pull it out. The obvious next step is to remove the oil pump and beat the piston out, unless some one has a better idea like something that can be jammed inside the piston hard enough to allow it to be tugged out. Any suggestions?

[JFP in PA]

Originally Posted by elgyqc

I am doing engine out maintenance on my spare 2,7 engine. It is from a 2000... I bought it on ebay and did about 10,000 KM on it before putting it on the engine stand.
One of the upgrades is to replace the oil pump piston. Normally the piston just drops out but that is not the case if it is "mushroomed". This is explained here.
https://986forum.com/forums/performance-technical-chat/83367-oil-pump-piston-some-questions.html
Obviously this engine has the "mushroomed" version of the piston and I have not been able to pull it out. The obvious next step is to remove the oil pump and beat the piston out, unless some one has a better idea like something that can be jammed inside the piston hard enough to allow it to be tugged out. Any suggestions?

If the piston is sufficiently mushroomed, it has probably also buggered the piston bore; my "rule of thumb" is simple: if the piston is mushroomed enough that it is stuck, can the pump and get a new one as the damage to the bore will lead to pressure leaks and potential piston "rocking", even with the replacement chamfered newer design piston. And while you are changing out the pump for a new one, also can the factory pump drive shaft, which is investment cast crap, and replace it with the cheap LN chrome moly unit.

I like to sleep at night, and not worry about a possible oiling issue caused by trying to save a few bucks.....

[elgyqc]

Finally the piston was not mushroomed, I removed the oil pump cover and was able to easily remove it. It was just held in place in the cylinder by the oil's surface tension.