I just picked up a used japanese EJ-25 for my 98 Forester. My question is: What would you suggest I replace on it before I put it in. I know the timing belt and water pump. What about the front crank seal and camshaft seals? Anything else? Thanks,

Richard

Rear engine plate, all 4 cam seals. Pull the oil pump off, and tighten up the screws with an impact driver. Replace the O-Ring behind the oil pump. and the front crank seal. Otherwise, I'd do plugs while it's out and cam cover gaskets. Then you should be leak free for a good while. Oh...and of course, head gaskets

Headgaskets. Buying a JDM engine doesn't add any value in terms of head gasket issues.

 

I'd do the valve cover gaskets and spark plugs too while it's out of the car. Due to space they're annoying to do in the car but can be done.

 

Of all the EJ's I've ever done I've only ever done one late 90's (98) that didn't need any pulleys replaced. All the rest had at least one pulley that was noisy or free spinning and needed replaced. I would at least test them all. Also keep in mind these later style tensioners on this motor are less reliable than the old style, so significant wetness at the seal means replace it.

 

Reseal oil pump, tigthen the backing plate screws with thread locker, cam seals. At least inspect them - if they're completely dry you can leave them. Although I don't think I've pulled an EJ oil pump yet that hasn't had a loose backing plate screw - but that also tells me it's not all that dangerous since it's so common.

 

All of this is covered in other threads too, a search would answer all of this.

Send the heads out to check for flatness. Maybe change the valve seals since the heads are off. Check valve clearances before it goes in. Since you do have to remove the engine, may as well do everything while its out.