Is oil supposed to make it to the gauge or is it simply the air in the line that gets compressed by the oil and makes the gauge read a psi. Obviously oil will make it in the line but should that oil ever make it to the gauge?

 

Oil actually makes it through the line and to the mechanical style gauges. But no fear as the ID of the line is tiny. Had one in my VW GTi years back.

 

I had one in my '81 Prelude years ago as well. Never had a problem except for when I forgot to connect the hard line to the gauge when I was first installing it. As gRay rAvEn said, the inside diameter of the line is so small that even with leaving the engine running for five minutes, I only pumped about six ounces of oil onto my carpet (grrrr).

 

Good to know. What I'm worried about now is how tight the 90 degree elbow is on the back of the gauge because I can't crank it another full turn but it doesn't seem tight enough the way it is now! It snug but not TIGHT. Is another wrap or two or three of Teflon tape a good option? I Have to use the 90 or it doesn't fit WITHOUT linking the tubing!

 

It wouldn't hurt to use a little more/less tape to get the fitting to be tight at the angle it needs to be so that you can route the line without kinking it.

 

I asked this same question for another reason a while back

On my 79 I have a clear plastic line from the engine to the ga' and can easily see air bubbles in the line - is is not solid oil. I wndered if the ga' line should be bled. Popular opinion was that the pressure reflected on the ga in psi would be the same, with no disruption due to the air and no one could find a recommendation to bleed the line to ensure a solid oil transmission. Therefore for your question I'd say that in the beginning you may only have air at the meter but eventually there could be oil as I find in my line now there is an alternationg pattern of oil and air segments that can change as the oil and air migrate . . .

I also rec'd several cautions about replacing my plastic line with metal or at least metal braid wrapped. Seems several folks have had that plastic line break and if running at speed you can loose a significant amount of oil out of that little line. My classic will top out the oil pressure at about 45 psi . . . according to the Haynes for a GEN1 MINI the minimum oil pres at normal operating temp and 3000 rpm is up to 5.5 bar - that's just shy of 80 psi .... you can quickly squirt a lot of oil out of a little hose at 80 psi. Can be as little as 1.7 bar too . . . and what is it at 6000 rpm? They don't say a maximum that I've found yet anyway . . .

 

+1 to metal line. When I put in a gauge cluster in an '89 S-10 way back in the day, we used an aftermarket copper one. No worries about it breaking after that.

 

This is why I buy electric gauges ... It's worth the hassle of plumbing a gauge sender.