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Thanks Eric. He's a pretty busy guy, so it's something I'd like to consider down the road if he has time.
I tried the two breather test this afternoon, and it didn't go well. I put two new breathers in, and they fit nice and snug. When I fired up the car it was a little off. It might just be in my head, but it looked like it was idling a touch lower than usual.
Driving the car was fine for about 8 miles (2200 rpms), but then I had to pass someone, and revved it up a bit (3000 rpms or so) to pass. I got past them a ways and then in the rear view mirror I saw one of my new breathers shoot out behind me on it's way to the woods.
At this point I'm looking to get a few parts so I can try the stock valve covers to see how much stock baffling reduces my oil consumption.
I'm hoping this really helps you.. PCV in one cover and breather in the other. Thinking you could be pleasantly surprised. Got my fingers crossed for you.
Just following up with a brief update on my progress. I wasn't able to get all the parts I needed for both valve covers before the weekend, but I did get enough to do the PCV valve side. It then also occurred to me I could just drive the car with two different valve covers for the time being since the breather side probably isn't a problem.
Everything looked fine to me when I pulled the cover off.
It looks like they installed some 1442 Competition Cam roller rockers with the 1.6 ratio. I did search the site and saw that a fair number of folks are using those rockers, or at least are asking about them.
I had purchased a Fel-Pro rubber gasket set, so I tried that. The head had studs in place so I put the gasket on and then put the stock cover on without any RTV (everything clean and dry). My car came with t-handle nuts (see post #21 for reference) and I tightened them by hand to what I thought was 7 ft lbs, but I was way off. I drove the car and didn't get 12 miles before I smelled burning oil. The cover was leaking from the middle to the back along the bottom.
I went back home and decided to create a tool to torque them down correctly. I grabbed a metric 1/4"-drive socket I probably would never use and used my cutting wheel to put a notch into it creating this:
I then torqued the t-handle nuts to 84 in. lbs. I wasn't even close when I torqued them by hand. All the nuts needed between 1-1/2 to 2 full turns to be at the correct torque level.
I drove the car and was feeling pretty good because I wasn't smelling burnt oil, but at about the 20 mile mark I started smelling burnt oil again. This time the cover was just leaking oil at the back corner.
Before I started replacing the valve covers I did refer to the service manual, and it indicates you should just put a 3/32" bead of RTV on the cover and install it. I purchased some of that Ultra Black RTV gasket maker and put that on today. It needs 24 hours to cure, so I won't be able to drive the car until tomorrow afternoon.
I've searched this site quite a bit regarding valve covers and leaks, and it looks like most folks are using gaskets. I hope the RTV alone does the trick for me.
Well, I'm still trying to wrap my head around it, but that tiny 3/32" bead of RTV worked. No leaks. I don't want to jinx myself, but I now have 125 miles on the car since I last added oil and the dipstick is still reading 100% full. Now I just need to put some miles on to see how significant the improvement is with the stock valve cover and proper baffling. So far it looks very promising.
This is a common problem people run into with PCV and no baffles. You only need a baffle on the PCV side as the breather on the other side draws in fresh air.
This is a common problem people run into with PCV and no baffles. You only need a baffle on the PCV side as the breather on the other side draws in fresh air.
I very much appreciate your insight into asking about the baffles. So, other than looking nice, what's the purpose of these heavy cast aluminum aftermarket valve covers? Are they functionally superior in any way? The stock covers weigh 2# 0.7oz each and the cast aluminum ones that I have weigh 6# 14.9oz each, so they add quite a bit of weight.
It seems counterproductive to replace a stock part with something that is going to cause a large increase in oil consumption and weigh a lot more. They aren't cheap either. It looks like these are around $150 new (each).
Last edited by Happy Trails; August 22nd, 2017 at 06:05 AM.
Reason: Didn't realize the cast aluminum covers are $150 each when new
Post #35. Fingers crossed that you have a simple cure and that you didn't have to replace a bunch of parts and gaskets. This site is full of great people with a mountain of experience and solutions.
Post #35. Fingers crossed that you have a simple cure and that you didn't have to replace a bunch of parts and gaskets. This site is full of great people with a mountain of experience and solutions.
George
You were right on point George! I completely agree with you that this site has great people that are very knowledgeable, especially on all things Oldsmobile. We are very fortunate that they share that information so readily. We are also fortunate to have this site as a repository where the information can be read and searched by everyone. My car is older than I am, so I don't have that experience to draw from. I'm learning what I can by reading and searching this site, and reviewing the service manuals. In this case the service manuals must assume you have stock valve covers since the excess oil consumption troubleshooting guide doesn't mention to check the baffles.
I haven't spent too much money at this point, but I did spend a little extra to try some things. At this point I'm planning to just use the stock valve covers.
The baffled breather grommet was $5, but I won't be using that. The two breather test was $12, and I can't use those since they are too big for the stock opening. The gasket I couldn't get to work without leaking was $11.
One of the stock covers didn't have the D grommet, so that was $6. A new PCV valve for the stock cover was $3, and a corresponding breather was $8. The RTV was $6. Just over $50 all in, but the learning experience, priceless.
Last edited by Happy Trails; August 22nd, 2017 at 07:39 AM.
Good stuff. My Edelbrock covers, indentical to the M/T aluminum covers out there also have no baffles. Just using the stock PCV grommet and fresh #6 heads with fresh guides and positive seals made a big difference in oil consumption. The stock PCV grommet has a small angled hole vs wide open. How did your valve seals look?
Someone in the chain of ownership had indicated the engine was rebuilt not too long ago, but there is no paperwork to support it. I just chalked it up to being a bonus if it panned out to be accurate since it couldn't be documented. Using one quart of oil every 400 miles didn't help make the case.
I've driven almost 300 miles now since the last time I added oil and it hasn't used any oil (dipstick is still 100%). The stock cover and baffle have stopped the high oil consumption. I'm about due for another oil change. It's looking more like it was rebuilt recently, so I'm curious to see how much oil the engine uses over 3000 miles.
I'd like to thank everyone that helped me along the way. I've learned a lot, had fun doing it, and appreciate you taking the time to share your knowledge.
August 16th, 2017, 08:02 PM
