Leaking V6 oil pan and Valve covers

[craigb]

This has been my biggest problem with my conversion and I feel pretty stupid about it. I have tried over and over to get my 2.8 to not leak at the valve covers and have redone the oil pan once since my original rebuild and still have leaks. Unfortunatly searching the word "OIL" on the forum will not work because it is only 3 letters. I am sure there must be a few threads on this topic! Since it is raining hear for the next 4 months I think I can find the time to tackle this issue and get it ready for nest season... maybe even the Invation! If I am the only one who can't seal an oil pan and valve covers... be sure to really let me have it, but I hope you include your remedy! As always, Thanks!

 

[RootesRacer]

Got PCV?

You need functional PCV (breather, unclogged PCV and correct hose routing) else you wont be able to seal most any unvented engine.

 

[craigb]

oh. Geez, I didn't think of that! The lack of vacume venting may be the problem for sure since I didn't run the line.

As my kid would say OMG that is awesome! an easy fix.

I will let you know if that was the only problem, Thanks so much, Craig

 

[Series6]

Got PCV?

You need functional PCV (breather, unclogged PCV and correct hose routing) else you wont be able to seal most any unvented engine.

Ok.. I'll bite. Can you describe the correct routing? (please)

 

[RootesRacer]

Ok.. I'll bite. Can you describe the correct routing? (please)

It varies and can be altered, but consists of:

1) Fresh air enters one of the valve covers (often from the carbs air cleaner, but sometimes from a simple filter put on the valve cover itself).

2) The opposite valve cover feeds a PCV valve, which then goes to the intake manifold on the vacuum side of the carb.

The stock V6 config has a short rubber hose that connects the bottom of the 2V air cleaner to the rear of one of the valve covers.
The other valve cover (which has the oil filler) has a hose that goes to the PCV, which branches to a large fitting at the rear of the intake,
where lots of other hoses connect.


works like this:

Scenario 1 (idle/cruise) Fresh clean air is allowed to enter the engine, it allows the flow of vapors across the crankcase of the engine, to the PCV, which under manifold depression allows vapors to be consumed in the engine via the intake.

Scenario 2 (high load/wide open throttle) Since there is no manifold depression to allow the PCV to pull the vapors into the intake, excess crankcase gasses dump straight into the main air cleaner which has a slight depression due to the restriction of the filter. If the main air filter is not the source of the fresh air, the separate air filter on the valve cover becomes the vent (into the engine compartment).

 

[V6 JOSE]

Hi Craig,

Most of the time these little engines don´t leak from the oil pan, but if you take it down again, I suggest making sure that the metal around the bolt holes, is flat and not dented because of over tightening. I use the neoprene Felpro gaskets, for both oil pans and rocker covers. They are the best.

On the rocker covers, again, make sure that the sealing edges are flat around the holes. The other thing I suggest, is to buy a set of load spreaders for a 4.0 V6. The Ford dealers carry them. They go under the bolts, and sperad the load over a larger area, so the bolt head doesn´t dent the rim.

Make sure that you don´t over tighten the bolts, or you may make more leaks.

Jose

 

[Barry]

All engines have blow-by; the only question is how much. With nowhere to go (no PCV system or crankcase vent), the blow-by pressurizes the crankcase. Any engine will leak if the crankcase is pressurized; if there is oil at the leak, the engine will leak oil. Working on the leaks does not address the real problem.

 

[Series6]

I have alloy valve covers on my engine and on the passenger side, there's a breather. No PCV. There's a hose running from the breather to the air cleaner. Do I need to have a hole machined into the driver side or can I place a PCV in the existing hose?

I'm still learning the basics....

 

[RootesRacer]

I have alloy valve covers on my engine and on the passenger side, there's a breather. No PCV. There's a hose running from the breather to the air cleaner. Do I need to have a hole machined into the driver side or can I place a PCV in the existing hose?

I'm still learning the basics....

You have a choice, you can run PCV or a breather.
If you want to run PCV, you have to have one cover as the intake the other cover as the PCV. If you dont, you cant sweep the blowby gasses/vapors from the engine.

If you run a breather, be sure the filter you use is not restrictive as this will build up pressure in the crankcase, and the oil will find a way out of any leaks.

I personally prefer PCV as it keeps the oil cleaner and prevents sludge.
The downside is that the vapors it pulls in are consumed and often reduce the effective octane of the fuel since the oil and blowby vapors are lower effective octane than your fuel.

Another less used method, (but becoming popular for racers) is to put a venturi scavenger in the exhaust. This uses exhaust flow to create a depression on the crankcase and the gasses/vapors are put into the exhaust.

Jose should chime in on his opinion in regards to vented vs. closed PCV.

 

[bulldurham]

oil leaks

R/R, I am running the PCV to one side and have filter on the other which has an open line due to the fact that I am using a different style breather. My leak appears to be the rear main oil seal only. Is what I described adequate to properly vent the engine??
Thanks

 

[RootesRacer]

R/R, I am running the PCV to one side and have filter on the other which has an open line due to the fact that I am using a different style breather. My leak appears to be the rear main oil seal only. Is what I described adequate to properly vent the engine??
Thanks

It may be, just be sure the filter used is not restrictive as it will vent out the filter when there is no manifold vacuum.
Its better to use the air filter plate as the filtered air supply as it allows the engine to consume the vented vapors at wide open throttle.

 

[Series6]

Thanks! That makes sense now.

 

[V6 JOSE]

These liittle engines can be oil leakers, and can have more than one reason for leaking. Usually, they don´t leak from the oil pan, even if the blow by gases are not being vented somewhere. If the blow by gases are building up, they will leak from the crank seals first. Rocker cover leaks can happen pretty often, even on an engine that is vented properly.

I just wanted to give him some more answers, in case the leaks continue after the engine is vented properly. He didn´t say definitively that his engine wasn´t vented properly. He said he´d look into it.

Jose

All engines have blow-by; the only question is how much. With nowhere to go (no PCV system or crankcase vent), the blow-by pressurizes the crankcase. Any engine will leak if the crankcase is pressurized; if there is oil at the leak, the engine will leak oil. Working on the leaks does not address the real problem.

 

[bulldurham]

It may be, just be sure the filter used is not restrictive as it will vent out the filter when there is no manifold vacuum.
Its better to use the air filter plate as the filtered air supply as it allows the engine to consume the vented vapors at wide open throttle.

That is probably why I have that wonderful smell of burned oil/gas inside the car..

 

[MikeH]

Guess you could do like my 65 Mustang 289. It uses the vented oil cap on leading end of the rocker cover on one side and a draft tube on the trailing end of the other.

 

[bulldurham]

Do you mean the ' draft tube ' is open to the engine bay rather than being attached to the carb filter system or the vacuum side of the carb?

 

[MikeH]

The draft tube connects to the rocker cover and extends down the side of the motor to put it in the air flow under the car when moving. Before PCV valves this was pretty much the norm.

See the black tube at the red arrow in the picture.
http://www.google.com/imgres?imgurl...4aC8Aw&esq=1&page=1&ndsp=2&ved=1t:429,r:0,s:0

 

[bulldurham]

OK, I'm with you. I may go back to the original filter assembly which I like. Hides a lot of the engine though.
Getting ready to start mechanical work on an early Mustang convt. once I get this oil leak plugged.

 

[Barry]

A road draft tube is an old, reliable, low tech way to vent crankcase pressure, but it may not be legal in some states and it WILL drip oil on your garage floor.

 

[MikeH]

Guess you could do like my 65 Mustang 289. It uses the vented oil cap on leading end of the rocker cover on one side and a draft tube on the trailing end of the other.

That was meant to be kind of a tongue-in-cheek comment.