Oil Leak

[cilynx]

The continuing joys of daily driving a 27 year old car....

I was losing a small amount of oil for a very long time and just attributed it to old car. I recently moved from St. Louis to Milwaukee and with no other option drove the stang. About 3/4 of the way through the first tank of gas, she started to warm up more than I was comfortable with. I checked the coolent: fine. Checked the oil: really low. I stopped every half tank for the rest of the trip and topped off about 2 quarts of oil each time. (Yes, I know, driving a major oil leak is a bad thing. I didn't really have options.)

Anyway, when I get in town and under 60mph, she stops smoking and basically acts fine. I know what you're thinking: PCV valve. So, I checked the PCV valve and it appeared to be fine, but I replaced it anyway. Now, I've got either two leaks or one very interesting leak. Oil is gathering in the little dip on I think the timing cover under the distributer. Oil is also getting on the back spark plug and burning off the exhaust on the driver's side.

What do you think? Valve cover gaskets? Intake manifold gasket? (Does oil even flow there?) I've heard/read a bit that the only reasonable valve cover gaskets are steel like the originals. Are there any available anywhere normal?

Thanks as always --

-r

 

[LedZ 5.0]

You could have a leak at the rear of the intake gasket or the valve cover. If there's a leak at the rear or front intake end seals you will leak oil.

I like to use the cork end seals that come with the intake gasket sets over just using a 1/8" bead of rtv sealer. I coat the cork gasket with felcobond and seat it to the front and rear sections of the block and than just use a light bead of rtv sealer for the top of the cork seals where they meet with the intake. It will not move out of place once it sets up. I seal my cork valve covers the same way and don't have any leaks.

 

[zwhitr]

The continuing joys of daily driving a 27 year old car....

I was loosing a small amount of oil for a very long time and just attributed it to old car. I recently moved from St. Louis to Milwaukee and with no other option drove the stang. About 3/4 of the way through the first tank of gas, she started to warm up more than I was comfortable with. I checked the coolent: fine. Checked the oil: really low. I stopped every half tank for the rest of the trip and topped off about 2 quarts of oil each time. (Yes, I know, driving a major oil leak is a bad thing. I didn't really have options.)

Anyway, when I get in town and under 60mph, she stops smoking and basically acts fine. I know what you're thinking: PCV valve. So, I checked the PCV valve and it appeared to be fine, but I replaced it anyway. Now, I've got either two leaks or one very interesting leak. Oil is gathering in the little dip on I think the timing cover under the distributer. Oil is also getting on the back spark plug and burning off the exhaust on the driver's side.

What do you think? Valve cover gaskets? Intake manifold gasket? (Does oil even flow there?) I've heard/read a bit that the only reasonable valve cover gaskets are steel like the originals. Are there any available anywhere normal?

Thanks as always --

-r

Thats quite a bit of oil but the solution is the same

1- intake gasket replace ,---short term clean it real well and get gasket sealer and apply the the front on the intake

2- timing cover gasket replace [try tightening bolts]

3- the dist even has an o-ring that may be pinched or missing

and I would suspect valve cover gasket for the rear leak.

Although oil leaking in the front will blast the entire engine compartment in a matter of minutes at highway speeds.

pressure wash engine bay use dye and black light
remove fan but re-install pulley run for a few minutes look for leaks

Wow maybe I should practice what I preach

stock valve cover gaskets are fine and cheap from parts stores just dont over tighten bolts about 3-5 foot pounds or hand tighten with a nut driver.


ps I did have the kind with steel inserts around bolt holes with prevent you from over tightening but the other still seall equally as well.

 

[T0BASC032]

I'd pull the distributer and check the O-ring before anything else. If that is your only problem, it'll be a simple fix.

...but more often than not, the source of the problem is gonna be the most painful one to fix

 

[jshcobra]

How tired is your motor? Excessive blow-by can cause oil to come out in all sorts of weird places. I had a 302 once that had so much blow-by (i.e., bad rings) that it blew oil out of the dipstick tube when reved. As I recall, that also formed a pool of oil on the timing cover near the distributor base.

Another item to check is if you have aftermarket valve covers, make sure there is a baffle underneath the pvc inlet.

 

[cilynx]

She's getting up there (~80k) but hasn't been abused and I don't think it should be falling apart just yet. Still had good compression and all that last I checked. You can't actually see the oil come out when looking at it at any rpm range. Thus, I don't --think-- excessive blow-by is my problem, but thanks for the ideas.

I've got the stock valve covers and the baffle is intact. I also cleaned up around the pcv and the breather really well while pressure washing and the oil is definately not coming from there as it's still clean (a few days of driving later) and the timing cover pool is back.

I'm going to replace the intake and valve cover gaskets tonight or tomorrow and I'll let you all know how it goes.

Thanks again...

-r

 

[Wart]

My guess is the poole on the cover is from a gad China Wall. IIRC factory was cork which gets old, brittle and falls apart.

Same with the valve cover gaskets.

You didnt state where the smoke was coming from, out of the exhaust? And only when maintaining a 60 mph cruise?

Could be deteriorated valve stem seals partially blocking the oil return ports in the head. The ports get partially blocked slowing the flow of oil thus (at least partially) filling the head and valve cover. If bad enough the stems could run submerged in an oil bath and the oil consumption would increase greatly.

Blockage could also turn a seaping valve cover gasket into a leaking one.


One thing about powerwashing. It's been known to blow gaskets and let powerwash and other crud get blown inside. Use caution.

 

[cilynx]

So I tore it all apart last night. Turned out neither china wall was particularly well seated and I think the front one was totally out of place. That would explain things. Replaced the intake gaskets and the valve cover gaskets while I was at it. As of today, I have no more oil smoke and no new spots in my parking space. Lets hope it stays that way...

 

[LedZ 5.0]

Good. you squared that away quick.

 

[zwhitr]

So I tore it all apart last night. Turned out neither china wall was particularly well seated and I think the front one was totally out of place. That would explain things. Replaced the intake gaskets and the valve cover gaskets while I was at it. As of today, I have no more oil smoke and no new spots in my parking space. Lets hope it stays that way...

Good Job But it won't last

Mustang II boredom 0