pesky untracable oil leak...

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DQ81

'73 Dart
Joined
Nov 12, 2008
Messages
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Location
The Netherlands (Holland)
So I've finally got a good 904 in my Dart, replaced the distributor, adjusted the kickdown linkage and have an engine that runs pretty well and can be dressed up with the cam, intake and 4bbl that currently decorate my living room hahah

The 904 shifts wel etc.

Now my car has decided to pee all over the street.:angry7:

I have a trans leak and an engine oil leak. The trans leak seems pan related, as I have gasket and filter lying around anyway that will probably get solved pretty soon.

the worse of the leaks is the oil leak, can't figure out where the hek it's coming from.

Passenger side front of the engine, idling a half hour long no leakage, rev it up, no leaking. Take it for a drive, just up and down my street 2 mile round trip tops, get up to speed, hit about 5k rpm once or twice, come home and:

The front of the valve cover (psngr side at crank) is covered in oil, so is the breather, the fuel pump etc. basically that whole side of the engine at the front and it's already leaking down onto K-member and header getting all smokey.

I can't tell if it's coming from above and dripping down or from below and blowing up.

Either way I'm 99% sure it's not my pan gasket, it's only slightly damp from trickle down oil. Once I park the car oil drips down onto the K-frame and on the street at a rate of about a dime size dollop per 10 seconds, leaking probably a pint in total. That's quite a bit at quite a rate...

I have a breather on the side that leaks, right above the leak, the other side which stays bone dry (drivers) is plugged and has no ventilation. If anything you'd expect that side to leak if it were crankcase ventilation related.

No PCV installed.

I have chrome valve covers, just replaced the gaskets but I'd never been able to wind the motor up under load before so I can't say for sure if the two are related. but I get the idea it's blowing out of the dipstick tube...maybe the cover is bent and isn't sealing properly.

Any Ideas?
 
My valve covers leak some oil too, I had to seal them up with silicone, mine would seep some and would also spray out some too when reved up under a load. What kind of valve covers do you have? Some aftermarket ones tend to leak bad, especially if they are the cheap China made ones. Maybe having a PVC valve might work? Good luck!
 
Are you sure it's not coming out of the dip stick? With out a PVC connected the lower part of the motor might be building enough pressure to blow oil out of the dip stick.
 
I must admit the sticker on my chrome valve covers does say "Taiwan" so I think I'll start by fitting some stock ones, then I can also run PVC.

Does a PVC HAVE to run via the carb? I have a 2bbl on now which doesn't have a large port...

Can I use any intake port?

I don't want to install anything untill I solve this leak...
 
I have to agree with 66340Sedan about putting a pcv in it.
My dad had one plug up in 20 below weather and it puke oil all over out the dip stick tube.
One of my nephews had a collapsed pcv hose ( previous owner) put the wrong type of hose on it. It did the same thing.
I told him to get it replaced was fine after he did.
Hope this helps.
Good luck on finding the problem.

Tom
 
DQ81 said:
I must admit the sticker on my chrome valve covers does say "Taiwan" so I think I'll start by fitting some stock ones, then I can also run PVC.

Does a PVC HAVE to run via the carb? I have a 2bbl on now which doesn't have a large port...

Can I use any intake port?

I don't want to install anything untill I solve this leak...
Click to expand...

From my understanding most 2bbls had the PVC hose hooked to the air filter pan.

The size of the port needs to 3/8" or larger. Do a search on the internet and find out more about how a PVC system actually works and then you can go from there.

Installing a PVC might just solve your leak problem.
 
I've never seen it go into the intake.Only into the carb.
The service manual shows it going into the carb.
It says there are two type of pcv systems fully closed system .

Which has two hose one goes from the pcv valve to the carb and the other hose goes from the breather on the driver side to the air cleaner.
And the closed system which only has a hose from the pcv to the carb.

That goes for v8s or 6s.
This came from my 68 Plymouth service manual.

Tom
 
dq81,positive crankcase ventilation (pcv) is the usual culprit in most oil leaks. typically, in my experience, if the oil leak is above the crank, pcv is at fault. now, i have seen cases where the oil drains are plugged with sludge,either head or lifter gallery, where it litterally is running out of a gasket. if you don't have it hooked up because of the covers not having provisions for pcv, and you have the ones that do, i'd say change them over so you can fix the oil leaks.
 
Thanks to all you guys, as many suspected it SEEMS to be a lack of PCV which was the culprit. I rigged a quick 'mock up' pcv system and all seems to be well. Tomorrow I'll pick up a PCV valve and get it installed properly. My carb has a rather large port that had been plugged with a short hose and a bolt that somehow I overlooked which was sweet actually as it gave me a place to route it to :)

Do you HAVE to run a PCV valve too? I did notice the increase in idle spead with the hose connected (no leaks, when I pinch the hose it drops idle speed)

Gonna run one, just curious as to it's exact function, I suppose at WOT when vacuum is the lowest a PCV valve will close allowing for more oil pressure to maintain lower down?

Cheers guys
 
You should use a pcv valve.
Here's a little explanation of the pcv valve and how it works for you.

PCV valve
The PCV valve connects the crankcase to the intake manifold from a location more-or-less opposite the breather connection. Typical locations include the opposite valve cover that the breather tube connects to on a V engine. A typical location is the valve cover(s), although some engines place the valve in locations far from the valve cover. The valve is simple, but actually performs a complicated control function. An internal restrictor (generally a cone or ball) is held in "normal" (engine off, zero vacuum) position with a light spring, exposing the full size of the PCV opening to the intake manifold. With the engine running, the tapered end of the cone is drawn towards the opening in the PCV valve, restricting the opening proportionate to the level of engine vacuum vs. spring tension. At idle, the intake manifold vacuum is near maximum. It is at this time the least amount of blow by is actually occurring, so the PCV valve provides the largest amount of (but not complete) restriction. As engine load increases, vacuum on the valve decreases proportionally and blow by increases proportionally. Sensing a lower level of vacuum, the spring returns the cone to the "open" position to allow more air flow. At full throttle, there is nearly zero vacuum. At this point the PCV valve is nearly useless, and most combustion gases escape via the "breather tube" where they are then drawn in to the engine's intake manifold anyway.


Glad you found the problem!:thumbup:
 
right on man. i love it when a plan comes together. post up some pics. we love pics.
 
For the trans pan leak, have you ever used the rigid trans pan gasket available from your Chrysler dealer? (I don't know if you have dodge dealers in the Netherlands). However, if you do, discard the floppy cork or rubber pan gasket that comes with the filter kits and instead, get the really nice double-seal, reusable rigid pan gasket P/N 4295 875AC.

Also, if your pan rails are not true, nice new pans with unwarped rails can be had from the dealer under p/n 52118 779AB, and they even include a magnet to catch metallic shavings. Good stuff for the 904 trans.
 
RDJ said:
For the trans pan leak, have you ever used the rigid trans pan gasket available from your Chrysler dealer? (I don't know if you have dodge dealers in the Netherlands). However, if you do, discard the floppy cork or rubber pan gasket that comes with the filter kits and instead, get the really nice double-seal, reusable rigid pan gasket P/N 4295 875AC.

Also, if your pan rails are not true, nice new pans with unwarped rails can be had from the dealer under p/n 52118 779AB, and they even include a magnet to catch metallic shavings. Good stuff for the 904 trans.
Click to expand...

Those gaskets are super! I have reused mine on my truck at least three times now.
 
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