Oil leaks causing smoke and leaving a trail behind

Happy Holidays fellow longroofers. My 92 RM 5.7 Automatic with close to 300,000 miles on this great land of ours is leaking oil. It took me by surprise at first when I found the rear main seal had begun to leak and I almost ran the motor out of oil. Got the car home and changed the rear main seal and that part of the engine stopped leaking but I was finding the oil dip stick was being blown open when I would step on the gas overtaking and the crankcase pressure was blowing oil all over the right side of the motor. I noticed some smoke coming out of the PVC valve that goes from the valve cover to the back of the air filter box. I tried some shrink tube on the oil dipstick tube and that holds the dipstick from opening. I changed the valve cover gaskets just cuz. and the leaks don't seem obvious. I do see oil covering some hoses and tubing that goes to the right side exhaust manifolds. Not sure but think that is part of the Smog/Crankcase ventilation. I also noticed some vacuum tubing that runs on the intake manifold and goes from the carb base to the valves at the smog air pump. It seems like mine are brittle and toasty. I notice the oil leak when I am on the highway and the motor is warm and I get that cloud of smoke following me. Does anyone have a diagram showing where those vacuum pipes are supposed to go? And how do I check to see if that air pump is working or how do I decrease the crankcase pressure ? Is time up for this motor? It seems to still run OK. Thank you for any ideas.

your pcv system is plugged,. new hose,. new pcv valve,.

And a can of engine degreaser,maybe two...

I have replaced the pcv valves on the valve covers I pulled the hoses and they are clear. The paper air filter is also full of oil. It seems to be on the right hand side of the motor that gets oiled. Is there a way of checking if that Crankcase ventilation and smog pump are working?

If the pcv system is up to par,.

Then i,d pull the valve covers and see if its' choked with crap ,.if so clean out the oil drainback holes at the ends of the heads,..

oil pooling in the covers with old valve seals,. will give you the blue haze behind the car,.

Worn out rings with too much blow by pressurising the motor internally will cause you your symptoms too,.
and will be exacerbated by a loose timing chain , causing retarded cam timing,.resulting in lower combustion pressures,.

smog pump does nothing for internal pressure,. it just pumps air into the exhaust manifolds,.

Also check the egr port in the throttle body. They tend to plug up with an oily
carbon junk that's hard to totally clean out. Found it easier to remove the TB and do it on the bench.

Bill

convert2diesel wrote:

Also check the egr port in the throttle body.  They tend to plug up with an oily
carbon junk that's hard to totally clean out.  Found it easier to remove the TB and do it on the bench.

Bill

I think your are referring to the PCV port on the TBI.

I have a 110K engine that I believe I have broken a ring or more, and it is suffering the same malady, except for the smoke out of the exhaust. It seems like it is trying to push oil out of every pore of the engine. I am going to replace the engine and trans soon, so I am not too worried about it, but I will freshen up the engine, and use it and the trans in a rat rod in the near future.

My first thought, PCV valves. (but thats already done now)

Fred Kiehl wrote:

convert2diesel wrote:

Also check the egr port in the throttle body.  They tend to plug up with an oily
carbon junk that's hard to totally clean out.  Found it easier to remove the TB and do it on the bench.

Bill

I think your are referring to the PCV port on the TBI.

I stand corrected.

Bill

300k expect some more surprises...

I'm siding with Nick. Plugged up oil returns in the cylinder heads.

How are the OZ's holding up?

Any updates?

Thanks for the responses. I still have not fixed my wagon. But I did mount my Go Pro in the engine compartment and drove around for awhile and found out where it was leaking. It is all coming out of the oil dip stick tube. Some time ago on the freeway I got on the gas to pass someone and soon after I had a bunch of smoke coming out of the engine compartment. I found the dip stick had been forced up off the tube seat letting the oil come out. I fixed that by putting some shrink tube on the dip stick tube and it made for a more snug fit. Now it is still going past all that, first as smoke then drops of oil and when the engine is accelerating it starts streaming out. Someone wrote that a broken ring caused his engine to pressurize and force the oil out, which is what mine seems to be doing. This is all new to me so I appreciate any ideas. I would download the video but have not figured out how thats done yet.

You should be able to rule out issues with the rings if you perform a compression check on all 8 cylinders.

Javier Munoz wrote:

I found the dip stick had been forced up off the tube seat letting the oil come out. I fixed that by putting some shrink tube on the dip stick tube and it made for a more snug fit. Now it is still going past all that, first as smoke then drops of oil and when the engine is accelerating it starts streaming out. Someone wrote that a broken ring caused his engine to pressurize and force the oil out, which is what mine seems to be doing. This is all new to me so I appreciate any ideas. I would download the video but have not figured out how thats done yet.

To my opinion, it´s no doubt that the engine is worn out, refering to all symptoms you`ve told. It has not be be a broken piston ring, with 300k miles the cyl. walls might be worn and are leaking the comb. pressure is  generating a lot of pressure loss. I guess the engine has lost a considerably amount of power. Furthermore, the valve guides could be worn as well due to the side movements of the rockers over this mileage. This supports blowing oil out of the tail especially once you are lifting the gas.

Best way would be a pressure leakage test, supposely you dipstick will be blown out. Just remove the oil filler cap and listen to the sound coming out. I bet on theres a layer of oil carbon inside the valve cover and on the oil cap as well. A quick check can be made by trying to crank the engine without removing the sparks. If this is possible, it´s confirmed what I told. A 5.7 L engine can never  be cranked with sparks in if it´s in good mechanical condition. Be sure to switch off the iginiton before  

Good luck

Udo

I think you are right on the money BuickRM. Sounds like I am going to need a new motor any way you look at it. I considered getting a 94-96 used motor and replace mine with it. Does anyone know what needs to change for the newer motor transplant? (like wiring,ECU,cooling,emissions,etc)
Thanks for helping me understand.

Javier

To put the newer engine in your car and keep it smog legal in CA you will also need to have EVERY part of the newer smog system installed on your car. Visit the CA BAR (Bureau of automotive repair) website for info.

Leaky Wily The Movie

The motor is done,..

Agreed, There appears to be oil mixed with coolant leaking out, so either head gaskets or cracked heads, plus the worn out bearings, cylinder walls, rings, cam, crank, lifters, pistons. it really needs replaced.

Pausing for a moment of silence...Cue taps in the background...

phantom 309 wrote:

The motor is done,..

It´s a pity that I´m located over here in Germany..... Just let your motor  float over the pond for me to rebuild, would be a perfect 400 bhp lump

@Javier:

Apart from topic, what kind of wheels are on your  car? Really nice !
And what tire sizes?

Thanks

Udo

Thanks Udo, The wheels are OZ Racing. The model/style are NOVA. They are 20"x 10" wide, steel wheels made in Italy. I found them by chance on Ebay and find they fit the wagon very well adding a stylish custom racy look to it.[You must be registered and logged in to see this link.] OZ RACING make wheels for F1 & INDY Cars and these wheels are designed like those racing wheels.

10" wide and they  are accepted by the wheelhouse? What tire size?

Cheers

Udo

Udo I have the tire sizes for you. I tried different tire sizes in the front and found that 255 x 35 x 20 just fit. They rub a little on the inner fender well in full lock but never has been a problem. I also noticed that the same size tire from different makers also fit a little different. The rear I used 275 x 40 x 20 I have used GoodYear Eagles and they just fit in the fender. These wheels are a perfect tight fit. Highly recommend.[You must be registered and logged in to see this image.]" />" />