[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [New Search]

[T3] Low Oil Pressure on a GEX rebuild


<x-charset iso-8859-1>Hi:

This will be long, but please bear with me.  And advice would be GREATLY
appreciated.

I have a '69 Squareback with a GEX rebuilt single relief case motor that has
about 10,000 miles on it.  At about the 5,000 mile mark, I noticed that
after running 55-60mph for a couple of miles, when I came to a red light and
idled, my oil pressure light came on.  I talked to the local VW mechanic and
he said this was most likely overheating and that I should remove the
thermostat since it was probably malfunctioning.  In hindsight, I realize, I
should not have followed this advice.  At the same time I removed the
thermostat and flaps, I installed an oil pressure gauge (electric sender)
with a "T" on the oil cooler (so I could still run the warning light) and an
oil temperature gauge (also electric sender) measuring oil temp in the sump
from the drain pan.  Here are my observations since then (mostly on a 640
mile trip I took over the weekend): oil temp takes about 5 or 6 miles (at 45
mph or so) to reach abou170 degrees - during this time, oil pressure is
about 40-50 psi moving and about 25-30 psi at idle.  For about the next hour
of driving, with outside temp about 50 degrees, it will hover around 180 to
190 degrees. The oil pressure will drop to about 15 to 20 psi during this
time but at idle it is around 10 psi (according to the gauge, which doesn't
have any tick marks under 10 psi) and my oil pressure light comes on.
Basically, the same problem I was having before (like a big dummy) I removed
my thermostat and flaps.  After that first hour of driving, the oil temp
slowly climbs to 210 degrees and will stay around there unless I try doing
over 60 mph and then it will get near the 230 degree mark.  I drove 3 hours
straight at 55-60mph and the oil temp stayed right at 210 degrees and oil
pressure was 15 psi (according to the gauge).

I know that gauges aren't 100% accurate but I think I can trust the relative
data AND the oil pressure light and realize that I definitely have an oil
pressure problem.

I had been running 10W-40 for the winter but before the trip changed to
straight 30W in hopes of a thicker oil holding up better on a long trip.  My
readings were exactly the same as with 10W-40 oil.  Also, right before the
trip I put a new sender unit in for the idiot light just in case the gauge
was wrong AND the old one was malfunctioning - no such luck... same
symptoms.

Also, a side note on maintenance.... I have changed the oil every 2000 miles
or so since I bought the car because I make very short trips usually.  I
also adjust the valves at every oil change.  I've checked/set the points gap
and timing 2 or 3 times over the 8500 miles I've driven the car. I removed
the oil cooler to put new seals in (mine were leaking) and blew some air
through it so I know it does not/did not have any blockage as of 4000 miles
ago.  Also, I am running dual Weber ICT's if this makes any difference.

I checked out my oil pressure relief spring and piston.  My spring was 3"
long and had the solid type piston.  I got a new spring and it was 3 1/8"
and installed it with the type piston that has the ridge/indention running
around it.  This actually resulted in lower oil pressure.  In a Clymer
manual for Type 3 that I have, it says the spring should be right about 2
1/2".  Which length spring and which piston is correct for a single relief
case?

I called GEX about my problem.  They kept insisting that without
thermostats, the "erractic heating of the motor" was causing my problem and
that the pressure relief valve was "working overtime" with no thermostat in
place.  I kept reiterating that I had this same problem BEFORE I removed the
thermostat and flaps.  He told me to screw an engine stud into the hollow
end of the piston and push it into the shaft and wiggle it around and see if
there was excessive slop.  He says if there was, I would need to hone out
the shaft and put in an oversized piston.  I've talked to 2 VW guys with
over 30 years motor building experience and neither have ever heard of an
oversized oil pressure relief piston and I can't find any such animal in any
VW parts catalog that I have.  Is there such a thing?  Or can we assume that
a worn out oil pressure relief shaft is an indication that it is time to
retire the case?  An even better question is, why did GEX rebuild this case?
Their Customer-No-Service rep explained that the person who purchased the
motor should have spent the extra money for a new case.  Apparently he finds
a 10,000 mile life expectancy on one of their rebuilt motors acceptable.
Also, according to GEX, the spring length in the oil pressure relief valve
makes "absolutely no difference".

At this point, I am considering getting a new case, tapping it for a remote
spin-on oil filter, going with new crank, cam, main/rod/cam bearings, oil
pump, lifters, rods, etc. and using my existing pistons, heads, and other
parts (outside of the case) since they only have 10,000 miles on them.  I
need a reliable car and even if there is a relatively cheap/easy fix for
this case, how much damage might have been done over the past 4000 or 5000
miles of low oil pressure? If I do go with a new case, for Type III
applications, where are the lines tapped into for a remote oil filter?

I have a friend with a case that is not new, but it is uncut.  He is talking
about line boring it to .020" over and using new bearings but a refurbished
crank (fresh from the machine shop and still wrapped in plastic).  Are there
any reliability issues I should be concerned about if I go this route?  I
also notice all of the recent talk of old camshafts vs. new..... should I
see what this cam looks like that is in this motor? Or should I go with a
new one?  On cam bearings, I see single and double thrust advertised...
double thrust sounds like they are mainly for high performance applications
but will they extend the life of a stock motor? Same for a counterweighted
crank? Is it worth the money for added reliability or should I leave that
for the high performance crowd?

THank you very much for any help you can give me.  It looks like I will have
to lay out some significant money in the next few weeks and I want to be
sure I do things RIGHT the first time.

Fortunately, this GEX motor with 2000 miles on it was already in the car
when I bought it fairly cheap - so with what I have in the car, I really
didn't "pay" for this motor.  However, it has been a very unpleasant
surprise to find out I may need a motor so soon.

Thanks again!

-Justin Earl
Cartersville, GA
'69 Square
'00 New Beetle (wife's toy)
'79 Corvette (ZZ4 motor, chrome side pipes)
'51 Chevy 1 ton dually (in pieces in the basement)

-------------------------------------------------------------------
Too much? Digest! mailto:type3-d-request@vwtype3.org Subj=subscribe

</x-charset>

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [New Search]