A couple of early 240z questions

(Yes, I've just asked the question over at GRM but I figured that we have some experts on these over here, too)

I looked at an early 240z today and really, really like it. Sophisticated it wasn't but boy was it fun to drive.

I noticed a couple of things while driving it though and given that I haven't got the foggiest about 240zs, I figured someone will have an idea what's going on...

1) How reliable is the stock oil pressure gauge? The one on the car was hovering around 0 when idling and was about as motivated as I am at 6am before I had my morning tea. I don't think it made it up past 1/4 when revving the engine.

2) Same goes for the water temp gauge, that was sitting a little past the middle but didn't seem to move higher in about 75-80 weather

3) I noticed that the bottom of the oil filter housing was damp/wettish with oil. I assume that's coming through the breather, do they normally blow some oil into air filter housing?

4) The car sports a K&N in the airbox and has a bunch of holes in said airbox above and below the carbs inlets. I assume that's supposed to ease breathing even though it's pulling in hot air from the engine bay?

It has been repainted, looks like a decent job even though some items that shouldn't be painted body color have been (like the rear light surround). It's got a couple of rust bubbles in the passenger rear wheelarch, bottom of the front fender and a few bubbles on one of the rockers. They don't feel 'crunchy' though so I don't think they need immediate attention. Probably in the next couple of years, but not right know.

Underneath it looks pretty clean and unmolested, no fresh undercoat hiding multiple sins. The old undercoat is peeling off but as far as I could tell (no access to a lift) it's only surface rust underneath. Interior is generally clean but the seats need recovering.

The current owner is hopefully going to have the oil pressure and compression tested so we get an idea of what the engine's condition is like. How hard would it be to find a replacement engine in decent condition in case the worst expectation is met and it wants a rebuild I can't afford right now?

How many miles are on the car?? I support your decision to have a compression test and oil pressure check done...

Oil gauge should sit around 1/2 at idle, and maybe go to 3/4 under power.. same with the temperature gauge - but the best way to test is a thermometer in the rad to confirm.

I've never noticed oil on the filter - and the air breather is on the opposite side of the block..so unless they have an aftermarket blow-by valve from the valve cover, or the filter isn't fully on.... (the PVC valve is below/between the carbs on the left side).

Air breather assembly should only have small holes on the backing plate for carb blow-off etc. No holes should be in the actual cover itself (except the front...of course).

Replacement engines - availability totally depends on your location... any 240Z (1970) to 280ZX (1983) L6 will drop in - no modifications to mounts or bellhousing etc required...(F54 blocks are the "turbo" blocks)

A good source of Z info can be found at www.classiczcars.com

Good luck

GWG

ggarrard wrote: How many miles are on the car?? I support your decision to have a compression test and oil pressure check done...

Odometer is showing 50k-something, I doubt it's more than a 150k, the car is too nice for that, judging by the interior.

ggarrard wrote: Oil gauge should sit around 1/2 at idle, and maybe go to 3/4 under power.. same with the temperature gauge - but the best way to test is a thermometer in the rad to confirm.

Looks like the temp gauge is working OK then, but the oil pressure gauge either isn't or the oil pressure has taken a vacation.

ggarrard wrote: I've never noticed oil on the filter - and the air breather is on the opposite side of the block..so unless they have an aftermarket blow-by valve from the valve cover, or the filter isn't fully on.... (the PVC valve is below/between the carbs on the left side).

Definitely looked like PCV valve oil blowby. If I get sensible numbers for the leakdown test I'm probably not too worried about that and otherwise they'd only confirm what I suspected.

ggarrard wrote: Air breather assembly should only have small holes on the backing plate for carb blow-off etc. No holes should be in the actual cover itself (except the front...of course).

It does look like some slightly misguided attempt at making the car noisier, err, improve performance. Thanks for confirming it.

Boxhead Tim...Another possibility with the low oil reading is the viscosity of the oil. L6's like the "heavier" oils like 20w50 as opposed to 10w30 or other. They also have a reputation to last if not abused... I have a 76 with over 300k kilometers, including 2 previous owners that slalomed the car... it's just starting to puff on start-up...

GWG