I have a 1978 280Z with 144+ miles that is a fair weather driver. I've added new carpet, seat covers, dash cover, headlights, tires, hood latch cable and bra. It runs great and when I had the oil changed the machanic I take it to (only does Japanese imports) feels it leaking oil from the rear seal and probably is getting oil on the clutch. Also leaking around the valve cover. His estimate is about $1000. I do have some minor rust behind each front rocker panel otherwise it looks very good. Again, runs strong and is fun to drive. Should I invest in getting the engine work done? Would rather spend the money on rust repair and save for a total repaint. Any advice would be appreciated. Thanks

A good running car is more important then a good looking car.

The lubrication system in a car is a closed-loop system. Any external leak should be addressed. The leak around the valve cover is a very easy fix. Take the opportunity to have the valve lash checked while the cover is off.

The rear seal is a more involved. I've never payed anyone to work on my 240Z, but a rear seal can be replaced in about two-hours by someone that has done it before, 3 to 4 by someone that hasn't. In that regard, $1,000 sounds excessive.

Oil from a rear main seal rarely gets on the clutch. The oil drips down the rear engine plate. The clutch is on the flywheel, which is between the leak and the clutch. I really don't know why the mechanic would tell you that he thinks it is getting on the clutch, unless he wants to make it sound important enough to be certain you have the job done.

Price seems a bit steep to me as well. While I'm with Gary in that I would do that myself, I did pay a local German car specialist shop to replace the rear main seal on the family BMW. Same basic job, but the BMW is more involved. That shop (who specializes in BMW, Mercedes and Porsche repair) charged me $700. Can't see that the far simpler Z should be more than the BMW.

Time to find a new wrench.

I'll throw another vote on the pile, $1,000 to repair a rear main seal is way too much. If that cost included a new clutch it would be more reasonable. The two jobs often go hand in hand as it makes sense to service the clutch while the system is removed anyway. Zero additional labor time save for surfacing the flywheel.

I would fix the valve cover first, it may be leaking enough to run down the engine and look like the rear seal is leaking. Start simple. After the vavle cover is fixed, take it to the car wash with some Gunk engine degreaser and hose it down. Then drive and look for the leak. HTH, Richard.