Went for a drive this evening - car seems like it runs better every time I take it out! On the way home I really hammered a very long sweeping right hand turn -- probably held a steady 65 mph or so around this long curve -- all of a sudden , I smell oil burning !! Temp was fine , saw just a little puff of smoke -- pulled over after another mile or so as soon as I could get off the road. The drivers side engine shelf had oil all over it -- couldn't really tell where it came from. There wasn't any sign of anything leaking. My car has a hose that connects above the valve cover on either side , Ts together and goes in the breather -- like a crankcase breather. It also has a little round filter element by the oil filler. I can't figure where this oil came from -- but looking at it -- it seems the crankcase vent system is not right. Any ideas ??? Anybody had this happen ??

What year & what motor? Carbs or FI?

usually oil on top of the tins is the sign of a blown valve cover gasket.

check that the hose/vent is still connected on that side first..
then replace the valve cover gasket if it is.

b

1975 model GA 2.0 engine with dual Dellortos

Looking at it from underneath it doesn't look like a valve cover gasket has blown -- there isn't much oil visible on the bottom side. Still don't know what happened.

Post a pic of your engine so we can see your setup ...

Take the valve cover off and check the gasket, clean all of the oil off of the engine and check your oil level. Take the car for a short drive and check for leaks. Once the engine is clean it should be easy to tell where the oil leak is.

The O.E. vent tubes in the heads are thin wall aluminum tubes that press into the heads. I have seen many that leaked and even pulled out of the heads. The easy fix is to just tap the opening for a 1/4"npt. No drilling required.

Since you are running carbs you don't need the head vents so you can just screw a pipe plug in the newly tapped openings and run a single vent line from the breather on top of the engine. Eliminating the head vents will greatly reduce oil pooling in the valve covers during spirited driving. If you want to continue with the head vents you can use 1/4" hose barbs.

Len, I'm running 40IDFs on my new 2056. There's a lot of air pressure coming from both head vents and the oil filler vent, so we routed all three hoses to a breather box.

I'm leery of capping off the head vents. How is all that pressure supposed to escape?

the vents dont exist on the later 1.8s. I assume if thefactory got rid of them they might not be needed.

He said he's got the vent tubes on his cyl heads, so that too is my guess for the source of the leak.

The head vents were eliminated in 75 for emissions purposes.

The valve cover gasket can sag on the top, in the middle. A hard right turn will fill up the drivers cover and pressure will blow it out the cover and up on top of the tin. Its happened on my 75.

As was mentioned above, maybe inertia pulled a lot of oil into the driver-side rocker cover during the turn and just overloaded your breather box?


Don't know if my leak is from too much c/c pressure or just a bad 'O' ring on the dizzy. Hoping a new ring will cure the problem.

Click to view attachment
I haven't really had time to diagnose this yet -- not a distributor seal - no oil in that area. I believe it has something to do with drivers side vent or valve cover gasket. Pictures aren't much - but here they are. ONLY oil is on drivers engine shelf.

I think that is your vent hose in the middle picture?

is it still connected to the head vent on the wet side... ?

if so, pull your valve cover.

how many miles since the last time the valve cover on that side was off?
usually these will blow fairly soon after they have been off recently.

also I had a race car (high rpm) once where my vent hose had a "dip" low spot in the routing. I became convinced that it was pooling oil in the low spot and then effectively sealing the vent pathway. I would loose valve cover gaskets frequently

(also had an accusump and a lot of rpm/cornering... so mine could of been a combination of things)

anyways, make sure there are no low spots in your hose routing. And I'm almost positive you will find a blown valve cover gaseket on the wet bank of the motor.

That is the T where the two sides meet -- then run to the breather. I haven't finalized the hoses yet - just connected everything with what I had available. When I got the car they where connected together with some really old ratty hose. I figured it needed a crankcase vent somewhere !
Hate to admit it - but I've never had the valve covers off. I've only had the car a few months now and haven't done a valve adjustment yet

its not too bad really
you can do it easily
you will have to manuever your hands through a lot of tunnels to get there....

-order fresh gaskets
-make sure the car is cold... 24 hours without running is good enough before you do the job.
-popping the bales can be a little bit challenging if you have never done it. A really long screw driver can work well. Another technique I've used at times is to wrap a piece of rag over the bales and then pull down on both ends of the rag to get more "force" if needed.

after 20 years of doing this I just started using captain krusty's valve adjustment procedure. I love it... much quicker and easier. So I would recommend getting a 8$ remote starter switch and doing this technique and get the valves while you are there. You also need a set of feeler guages, a couple of different length screw drivers, and a scraper for the old gaskets.... maybe some ultra grey for one side of the new gaskets... a spray can of brake cleaner for cleaning the valve covers, a pair of safety glasses.. oh and a box open wrench to loosen the lock-nut.. (I think 13mm... but it may be 14mm depending on the year)

thats about it.
its not that bad
I'm guessing you will find the upper side of the gasket on your wet side shows that it has been leaking and is wet on the gasket face (oil seeping by)