Triumph Repair: Oil Leaks, oil filler cap, castrol gtx

Question
QUESTION: Hey Howard,

I hope you're up to the challenge for this one. The issue is oil leaks on a '66 TR4A. It's been driving me crazy all summer!  Motor rebuilt 7K miles ago (10 yrs ago).  It runs absolutely perfect but, about 1500 miles ago it started leaking oil and progressively became worse.  It has all the appearances of pressurized crankcase. Oil has leaked from:
-Timing Chain Cover:  occasionally
-Dip Stick Hole:  occasionally
-Oil Filter Housing:  occasionally
-Fuel Pump:  bad leak
-Oil Pan:  gasket appears very wet with oil
-Rear of Engine (rear main seal?):  major leak (3"-6" puddle)
-Oil Filler Cap:  moderate leak
-Valve Cover, Cylinder Head, Pushrod Tubes:  none

Just as additional background, my mechanic replaced the head gasket 2500 miles ago (about 1000 miles before the leaks started).  I run Castrol GTX 10W-40 oil.

Soooo, here are some of the tests I have run
-Re-torqued cylinder head (it was up to spec, no tightening required)
-Dry Compression Test:  180/180/179/180
-Wet Compression Test:  180/180/180/180
-Intake Manifold Vacuum:  20" @ 800RPM and 20" at 2000RPM (rock steady)
-Spark Plugs:  dry, white powder (looks perfect)
-PCV:  brand new from  Moss Motors
-Oil Cap:  new
-Oil Pressure:  50psi at idle, 65psi at 2000RPM

Before I replaced the PCV with a new one, I ran a straight crankcase breather off the valve cover. That worked great for about 500 miles before the leaks returned. That's when I put on the new PCV and it leaks as bad as ever (worse).

The car starts, idles and cruises perfectly.

Lastly, with the engine running, I get a light puffing of air from the oil filler hole which I think is normal. If I cover the hole with my hand, I feel a very slight vacuum as the PCV kicks in.  When I close the oil cap and attach a pressure gauge to the PCV vent tube on the valve cover, it reads a flat -0- psi.

Based on the above tests, I believe I have ruled out plugged PCV or excess blow by the rings.  Could it be that all of my gaskets are giving up at once?  That would be quite a coincidence.  Plus, while I can believe that for all other gaskets, I have trouble believing it for the oil cap leak (since I replaced that too and it still leaks).

I'm not looking for perfection. I can tolerate a few spots per drive but, I don't think 3-6" puddles after a 1/2 hour drive is acceptable.

Thanks

Bob


ANSWER: Hi Bob,
Any time you get the same reading on a wet and dry compression test on any cylinder you need to buy a new compression gauge. If your mechanic gave you these readings you need to get a new mechanic.
Howard

---------- FOLLOW-UP ----------

QUESTION: Howard,

Good call.  So, I have now re-run the compression test with a new compression gauge (which threads-in rather hand hand held!).  More importantly, since this was my very first time doing a wet compression test I don't think I squirted enough oil in the cylinder on the first test.  This time I got a full teaspoon (6 squirts).  Here are the results:

Dry Compression:  180/ 180/ 180/ 180 psi
Wet Compression:  208/ 200/ 200/ 200 psi

Does this tell you anything?  If not, what's next, a leak down test?

Other info which may or may not be helpful:  Engine was cold.  I use Castrol 10W-40 in the crankcase.  I did run a bottle of Techron fuel system cleaner through the gas tank earlier in the year (I'm wondering if that cleaned out some carbon deposits which were actually helpful(?))

Thanks again,

Bob

ANSWER: Those  readings are more appropriate but still high, unless the compression ratio has been raised at one time or on this last rebuild. Along with high compression readings come excessive blow by even though the  is ok. This is why race engine builders put such large case vents with filters on them. Also look at the lower crankcase vent on the lower left side of the block close to the rear and see if your engine has the vent pipe. This can be a problem on hard right hand turns as oil in the pan splashed up into that pipe and blocks crankcase pressure from venting thus causing problems. Race engine builders redesign that pipe. With your high compression readings you may be forced to do the same. A factory vent may be ok for low amounts of blow by but when you have high compression readings and you just make one hard acceleration it can cause a high crankcase pressure for that period of time especially on a hard right hand turn. Just a few more things to look at.
Howard

---------- FOLLOW-UP ----------

QUESTION: Howard,

Finally, thanks to your great help I feel like progress is being made. Here is my own conclusion (based on your input)....
  -the compression readings are at the very top of the high side
  -June of 2006 (2500 miles ago) when my mechanic replaced the head gasket, it was because he "re-planed" the cylinder head
  -I don't know how much he "planed" off but I suspect it was enough to raise the compression ratio
  -this led to an increased volume in blow-by (even though blow-by is within acceptable range as a percentage)
  -this extra volume of blow-by was too much for the PCV to vent which led the crankcase pressurization
  -slowly but surely this excess pressurization compromised the gaskets leading to the leaks. Note, the first notice of leaks was 1000 miles after the cylinder head re-planing (it may have occurred earlier w/o my noticing it).

So, I think my options are:
1.  short term:  just run a 1/2" breather tube off the valve cover vent and route it down the block towards the road
    a.  replace the shot gaskets (although I can't do the rear main seal as that is an "engine out" job. So, I hope that one is not blown)
2.  long term:  consider looking to see if they make thicker head gaskets to return the compression ratio back to normal. Then reconnect PCV.

Sure enough, I took a one hour drive this morning with the vent tube per option 1 above. I checked every 15 minutes and not a single drop of oil.  It wasn't until I got home, parked the car that 30 minutes later a single dime spot of oil appeared....made my weekend!  Sure beats the 6+" pool of oil I had the other night when using the PCV.

Thanks again Howard,

Bob
PS: this TR4A does not have the vent tube on the block.


Answer
Glad to hear of your progress. You could also just vent it into the inside of one of the aircleaners thus slightly lower the crank case pressure and burn any fumes from gas and oil like BMC did with several British cars before PCV valves.

I worked in British bike shops before I went into cars and ALL British cars and bikes leaked a little oil back then. The owners learned to live with it and even had jokes and bumper stickers about it. British bike owners use to say "I like to see my bike leak a little oil because I then know there is some oil in it" and Jaguar owners would say "That's not an oil leak! That is my kitty marking it's territory"
At a Jaguar dealership I worked at, the factory once told us about oil leak complaints "If a customer has (after parking on a clean piece of concrete over night) more than two spots the size of a silver dollar, we will allow a mechanic to attempt to stop oil leaks".

A dime size oil spot from a British car? You have it made in the shade! I have to keep a drip pan under my Jag.
Howard