The fun begins

[kellcats521]

First, my 930 developed an oil leak - well actually it has a small oil leak when I bought it (what I thought to be a flywheel seal leak), and the leaking has grown tothe point where I needed to tackle it.

So, new clutch and rear seal in hand, the motor and trans have been removed in my garage. There are many 'since it's out' tasks that I'll do over the next few months (like CLEANING), but the 1st one was to run a leakdown on it. The motor was stone cold (which is not the best way to do a leakdown), and here are the numbers:
CYL %
1 6
6 5.5
2 4.5
4 4.5
3 7
5 17

3 has ring leakage, and 5 is laekin thru the exhaust valve. Wayne is good with any readings under 30%, but I've heard many who look at 10-12% as needing a rebuild (actually we would tear our SCCA Mustang down at 12%). My thoughts are to pull the heads and have them reconditioned, and re-ring the motor. Any other advice?

[William930t]

You know the problems with a cold engine evaluation

As an experiment, try squirting some oil in the spark plug holes and do another leakdown test. Post your results.

Can you do a compression test as well?

Any broken head studs?

If motor is out, I say measure everything on top end for in-spec, replace as necessary. Send out heads & valves for service. If cylinders measure ok, then re-ring is fine. Also include, your choice of strong head studs, check flow of injectors, new hoses, seals, gaskets, thermostat, etc.

Where in Atlanta are you, maybe I can offer help.

[kellcats521]

I am in East Cobb. I cannot do a 'real' compression test with the motor out of the car, but I did both verify valve lash and hit the valve with a rubber mallet (while pressurized). I couldn't get anything to dislodge, and the leakdown # didn't change. I'm pretty confident that I have an exhaust issue in #5, and I'll see for sure in the teardown.

Where I am on the fence is whether I spilt the case and go for the total rebuild.

PK
87 930 Slant

[William930t]

How many miles on the car/motor & how regular was the maintenance? Was the car tracked?

930 bottom ends are quite strong, what makes you want to split the case?

[kellcats521]

I would split the case to replace the bearings..... My thought is to set this engine up for another 20 years, since I'll be 'in there'.

I do not have a good handle on the motor's mileage, maintenance, or history. I would assume it has over 100,000 miles, although the odometer only has 43K on it. I bought this car at a fairly low price, with the expectation that, although it is a good running car, it would need some work.