Oil leaks

[Aron Gleason]

So ever since I replaced the cam and lifters and timing chain last year I've been battling a oil leak at the bottom of the timing chain cover on the passenger side. I used the repair gasket piece that comes with the felpro gasket set, with red high temp sealer on both sides paying attention to the corners. I let it sit for a week before starting it. It doesn’t leak just idling, but after driving it leaks at the same spot. I read after replacing the cam that can cause more crankcase pressure and oil will find its way out. For more than 30 years ive either had breathers on both valve covers with the holes, then breathers with hoses running out to the atmosphere. Is running breathers with a hose on both valve covers good enough? Ive seen many people run that way with no issues.

 

[R413]

PCV valve?

 

[Aron Gleason]

PCV valve?

I said ive always ran breathers on both valve covers. Never ran a pcv valve.

 

[Billccm]

I wish you luck and watching this thread. I've battled that leak for 10 years.

My motor is at the machine shop now and I've let them know I want that leaking area addressed.

 

[69Bee]

Then you have always been incorrect. You NEED and PCV valve to the carb to create a negative pressure (Vacuum) to suck out the crankcase gasses and a breather to allow air to enter the engine from the other side.

 

[Aron Gleason]

Then you have always been incorrect. You NEED and PCV valve to the carb to create a negative pressure (Vacuum) to suck out the crankcase gasses and a breather to allow air to enter the engine from the other side.

So everyone whose ran just breathers and hoses ran to the atmosphere is also wrong even if they dont have oil leaks? By doing that I was told oil doesn't build up inside the intake and make a mess.

 

[Aron Gleason]

I wish you luck and watching this thread. I've battled that leak for 10 years.

My motor is at the machine shop now and I've let them know I want that leaking area addressed.

Thank you. Ill need it, a friend said he tore his motor apart 6 times before he got that leak fixed. Im at number 5.

 

[gkent]

Some day I'm going to install a fitting and gauge and measure crankcase pressure. I've often wondered if there is sufficient flow through that itty-bitty pcv hole to create vaccum in the crankcase. And conversely are breathers sufficient to neutralize crankcase pressure.

 

[Aron Gleason]

Thank you. Ill need it, a friend said he tore his motor apart 6 times before he got that leak fixed. Im at number 5.

That would be a interesting test. I had to replace both of my breathers last year cause they were plugged up. I couldn't imagine my intake being plugged up from running a pcv valve.

 

[gkent]

So everyone whose ran just breathers and hoses ran to the atmosphere is also wrong even if they dont have oil leaks?

You're basically stating the pcv is to eliminate oil leaks. Of course not. Oil leaks are due to pourly or insufficiently sealed areas - where crankcase pressure just exacerbates the problem. As for oil buildup in the intake ... maybe after 50,000 miles !!! Ideally a pcv will be evacuating unburned fumes and moisture, there shouldn't be much oil - particularly if you have a baffle below the pcv.

 

[R413]

I had a stock 383 that did that leak and it took several times to fix it.

I said ive always ran breathers on both valve covers. Never ran a pcv valve.

I'm aware of what you said.


A PCV is good thing unless you are a full time drag car that is wide open all the time.
Street cars could benefit from one. But probably not why it's leaking there.

 

[Aron Gleason]

All I did was use the repair gasket that goes between the timing chain cover and oil pan, the oil pan itself is the blue rubber gasket thats been in there for 30+ years.

 

[R413]

When I do this job I like to reuse the oil pan gasket that is there under the timing chain cover as long as it's not falling apart. Ir already crushed and the cover goes on easier. I use sealant on it.

Tell us about this blue rubber gasket, this may be your problem. Does sealer stick to it, sometimes rubber repels sealer.

Do you have a windage tray, maybe the multiple layers is causing a problem?

And what sealer did you use on this repair?

 

[Aron Gleason]

I cut the blue rubber gasket out from the front that goes between the timing chain cover and oil pan cause I was told thats what I needed to do. And I used red high temp sealer.

 

[DanielSlocum]

I would clean the surfaces well with laquor thinner then use The Right Stuff 90 minute sealer a bit liberally there. IMO a pcv helps a lot especially at high rpm. Iv seen adding a pcv make the dip-stick stop popping out the tube on a 6000 rpm 340.

 

[Aron Gleason]

I would clean the surfaces well with laquor thinner then use The Right Stuff 90 minute sealer a bit liberally there. IMO a pcv helps a lot especially at high rpm. Iv seen adding a pcv make the dip-stick stop popping out the tube on a 6000 rpm 340.

I've never had that problem where the dipstick pops out, and ive been 6000 rpms many times

 

[69Bee]

So everyone whose ran just breathers and hoses ran to the atmosphere is also wrong even if they dont have oil leaks? By doing that I was told oil doesn't build up inside the intake and make a mess.

Yes, they were wrong and I have told a number of customers such. If you are just running breathers, it is doing NOTHING. It needs to have a negative pressure to evacuate the crankcase of gasses. If you are trying to equate race engines having two breathers only, again, you are wrong. They are using a "Pan-A-Vac) system where the 45-degree adapters are installed in the exhaust which will create this negative pressure to remove the gasses. Even back before PCV valves and systems, they used a "Draft Tube" with a 45-degree cut to also create the negative pressure to evacuate gasses as the vehicle was moving. The operative word there is "Moving" because it cannot create the negative pressure required to evacuate the gasses. This is why police cars, taxis, etc... that idled a lot were completely filled with crap sludge!!

 

[Aron Gleason]

Yes, they were wrong and I have told a number of customers such. If you are just running breathers, it is doing NOTHING. It needs to have a negative pressure to evacuate the crankcase of gasses. If you are trying to equate race engines having two breathers only, again, you are wrong. They are using a "Pan-A-Vac) system where the 45-degree adapters are installed in the exhaust which will create this negative pressure to remove the gasses. Even back before PCV valves and systems, they used a "Draft Tube" with a 45-degree cut to also create the negative pressure to evacuate gasses as the vehicle was moving. The operative word there is "Moving" because it cannot create the negative pressure required to evacuate the gasses. This is why police cars, taxis, etc... that idled a lot were completely filled with crap sludge!!

Hmmm interesting. I definitely dont want crap plugging up the intake

 

[RemCharger]

The intake won't plug up.. the sludge will form within the crankcase.

 

[69Bee]

It won't because the gasses are directed to the base of the carb, entering the intake and directed to the cylinders to be burned during combustion. None of my cars with PCV valves and customers engines have had any "Clogged Intakes". A few import engines with PCV valves that screw in are clogged rendering the system inoperative because they were unaware that they needed to be maintained/replaced. And yes, those engines had bad smoke and oil leak issues due to an inoperative PCV system.