british-cars
[Top] [All Lists]

Oil Pressure/temp. in '73 TR-6.

To: british-cars@encore.com
Subject: Oil Pressure/temp. in '73 TR-6.
From: key@cs.utk.edu
Date: Fri, 02 Aug 91 17:35:54 EDT
Greetings folks!

Many thanks for the replies on the Tranny check plug, the 8-point
socket is on order (my local Sears doesn't stock it...)

Something else has cropped up that has me worried.  First
a little info.  I've put an estimated < 150 Mi on the TR-6
since I bought it.  The car had had (supposedly) a complete
tear down and rebuild.  In the course of the rebuild, the
clutch was replaced, the carbs rebuilt, and the valve seats
re-ground.  The seller said that the runout on the worst
cylinder was .0005in and the head was true so he didn't bore
the block or shave the head.  He's done 6-7 rebuilds of various
Fiat, Mazda, etc. so I _think_ I can trust his judgement (but
this electrical modifications make me wonder...)  He claims to
have ~700-1000 miles since rebuild, including a 200+ mile trip.

Now the problem. Since I had gotten the car, I had noticed
that the oil pressure is ~75psi going to 100 (full gauge) on
revs.  After a few miles, the car gets down into 50psi at idle.
After ~30 miles the idle is at 15-20psi going up to 35-40 at 
3000RPM.  I recently replaced the temp. sender and the gauge
shows cold at the 75psi, 1/2 to 3/4 scale at the 40-50 psi range,
and is going close to the red when oil was reading the 15psi at
idle.  The head gasket leaks a little oil (on the driver's
side of the block), but there wasn't appreciable oil loss.  No
water in the oil (but it is black).  The engine runs incredibly
smooth.  The exhaust is clean.  I let things cool for ~ 6hrs.
Started up first try with oil pressure back at ~75psi, dropping
back to 50 and then continuting to head south as temp. rises.

My question.  Is losing that much oil pressure due to more than
the overheating problem?  The pressure loss seems excessive for
just the loss of viscosity.  I've never had the head off an engine 
before (this will change quite soon).  I'm going to check the 
thermostat and channels when I replace the head gasket, what 
other things should I look for while I have the head off?  I 
plan to pull just the head and see if I can find the 
culprit.  Pulling the engine will mean finding a different
garage to work in.

Words of advice for an engine neophyte (I've got Bentley's,
Haynes, some friends that did brit-car engine work)?

Many thanks,
Ken Key  (key@cs.utk.edu)


<Prev in Thread] Current Thread [Next in Thread>