oil burn from drivers side tail pipe

[RazorbackGT]

OK, so put on all new gaskets from manifold egr spacer, heat shield , carburetor and fixed a ton of vacuum leaks, now with the engine at 210 degrees while tuning carb and setting timing I'm getting oil burn out drivers side tail pipe. Now while working on vacuum leaks I did notice some oil on manifold on drivers side. Is it possible an intake manifold gasket leak to allow oil burn like this? Do I just need to pull off manifold and check gasket?

Also let me add, I pulled all plugs, all 4 on drivers side were black, all 4 on passenger side clean, for what it's worth.

Thanks
Brant

P.S. 1985 GT 5.0

P.S.S I did not pull manifold off, just carb, heat shield and EGR spacer

[cb84capri]

It's possible the intake gaskets have failed. There are some gaskets on the market that are absolutely garbage. If they have ever been changed I would highly suspect them to be responsible for this. I made the mistake of using some of the garbage standard issue Fel-Pro 1250 and 1262 gaskets, and had similar things happen. How often are you having to add oil to the engine? I would try to make sure the oil you see on the manifold isn't coming out of the pcv/breather caps or valve cover gasket before jumping to conclusions, but a failed intake manifold gasket sounds like the likely culprit. I mean what else is there that affects only one side of the engine? Piston rings failed on that side of the engine only, bad valve seals on on that side of the engine only? Sound unlikely to me. I think a dual plane intake eliminates oil being sucked through the pcv as a likely culprit. Still never a bad idea to do a compression test, leak down test, take vacuum readings, etc.

Is this car stock? Is it 5 speed of was this a CFI/auto originally that someone swapped to carb?

Cale

[Walking-Tall]

... some oil on manifold on drivers side.

Also let me add, I pulled all plugs, all 4 on drivers side were black, all 4 on passenger side clean, for what it's worth.

On manifold? Can you explain this more?

Driver's side spark plugs just black, or black and wet?

[RazorbackGT]

On manifold? Can you explain this more?

Driver's side spark plugs just black, or black and wet?

When I was checking lines for vacuum leaks, there was a small amount of engine oil on top of manifold. I did talk to an engine builder yesterday and he said he would suspect valve cover gasket on that but did recommend next step to be a compression check.
The spark plugs were just black not wet, I probably wouldn't have thought that much about them til I compared them to passenger side plugs because they looked brand new, I had replaced them all in November.
Cale, the car is stock 85 with 5 speed, I was having hell getting a good low idle and it was stalling a lot on take off, so after 2 mechanics couldn't fix it, I bought an Edelbrock 1406 and that's when I discovered all the vacuum leaks.
While messing around with it yesterday, I sprayed carb cleaner around carb base and manifold, on drivers side rear of manifold the engine surged and car really started smoking, so I'm no mechanic, but to me that has to be manifold gasket, right?

Thanks guys
Brant

[cb84capri]

I think you pretty much have this thing nailed down, Brant. The only other suggestion I could make before taking it apart is to go in there with a borescope camera if you have access to one and look for signs of oil entering into the ports.

Cale

[cb84capri]

Good posts in here to read by JACook:

http://vb.foureyedpride.com/showthre...Intake-Gaskets

Cale

[RazorbackGT]

Thanks for posting the link Cale. Tomorrow I'm gonna do compression check and go from there, after reading through your link I'm wondering if my rear manifold gasket isn't sucked in a little on the corner.

Thanks
Brant

[Walking-Tall]

Spark plugs that are black and dry = rich.

Maybe that back end of the driver's side intake manifold gasket didn't get secured in place with the head gasket. Or, could simply be uneven/inconsistent intake manifold bolt torque. Easy enough to lift the intake, and replace the gaskets if 'effed up. All sorts of monkeys out there do not take care or follow any sort of procedure or torque specifications when installing an intake manifold, lol...

[RazorbackGT]

Did the compression test on left side, #5 145, #6 145, #7 145, #8 130 and #8's plug was oil fouled all to hell, changed them all last week, rest of plugs were normal. I called around trying to find a leak down tester, no luck, I will have to order one I guess. I tried using compression tester line to load cylinder with air but fittings wouldn't match up, of course. I'm still thinking manifold gasket, just not real eager to jump in on that though. Before this car, Iv'e never pulled a carburetor off a car,Lol.

[gt4494]

Thanks for posting the link Cale. Tomorrow I'm gonna do compression check and go from there, after reading through your link I'm wondering if my rear manifold gasket isn't sucked in a little on the corner.

Thanks
Brant

Use 1/4 inch bead of Silicon front and back of manifold and throw the gaskets away.

[erratic50]

130 is pretty weak. A little bit of borax might do the trick. I've yet to see it make problems like this worse but I've heard of guys who were on the losing side of that gamble.

On mine I just fed it a little powder while it was running and it worked perfectly- good as new.

Ive heard of guys trying to pack it down at the edge of the piston via the spark plug hole near the ring landings. I don't recommend this approach.

If you have carbon buildup it could be preventing proper valve seal too. You might try some marvel mystery oil down the intake slowly while is running.

Just some of the tricks that have avoided me needing to rebuild my 86 5.0L over the years. if it wasn't for the totally shelled out valve guides and seals on mine I might leave it go a whole lot longer but I'm tired of the smoke and stink. Lord knows the current situation with mine hasn't slowed it down much if any. It just requires constant attention to the oil level.

[RazorbackGT]

130 is pretty weak. A little bit of borax might do the trick. I've yet to see it make problems like this worse but I've heard of guys who were on the losing side of that gamble.

On mine I just fed it a little powder while it was running and it worked perfectly- good as new.

Ive heard of guys trying to pack it down at the edge of the piston via the spark plug hole near the ring landings. I don't recommend this approach.

If you have carbon buildup it could be preventing proper valve seal too. You might try some marvel mystery oil down the intake slowly while is running.

Just some of the tricks that have avoided me needing to rebuild my 86 5.0L over the years. if it wasn't for the totally shelled out valve guides and seals on mine I might leave it go a whole lot longer but I'm tired of the smoke and stink. Lord knows the current situation with mine hasn't slowed it down much if any. It just requires constant attention to the oil level.

Borax? I've never heard that. I guess it is supposed to work like Restore or other products you put in your oil. But I'm thinking low compression is a compromised manifold gasket or valve issue. I will learn more when I can pressurize cylinder and find escaping air.

[gt4494]

Low compression is a valve or head gasket or ring/cylinder issue intake gaskets don't affect it.

[Flyin'Montdude]

130 is pretty weak. A little bit of borax might do the trick. I've yet to see it make problems like this worse but I've heard of guys who were on the losing side of that gamble.

On mine I just fed it a little powder while it was running and it worked perfectly- good as new.

Ive heard of guys trying to pack it down at the edge of the piston via the spark plug hole near the ring landings. I don't recommend this approach.

Borax? I've never heard that. I guess it is supposed to work like Restore or other products you put in your oil.

I normally don't post a lot, but couldn't stay out of this one....
Erratic50, I know your intention is just to share what has worked for you, but in my opinion this is flat crazy! Borax is like Comet or other abrasive cleaners. Keyword is abrasive... This would be like putting sandpaper grit down the intake, albeit a fine grit of sandpaper. That grit is going to get into all 8 cylinders, then into the oil - just crazy. While the 130 cylinder is weak, it is within 10% of the others which is generally considered acceptable.

If you have carbon buildup it could be preventing proper valve seal too. You might try some marvel mystery oil down the intake slowly while is running.

I agree this could be the issue as well. Carbon could also cause the piston rings to be sticky/stuck on the one cylinder causing the lower reading. You could put some Seafoam in the oil and run some down the intake via a vacuum line like the PVC or brake booster hose while it is running. Adding some to the fuel for a tank or two is also a good idea..

Use 1/4 inch bead of Silicon front and back of manifold and throw the gaskets away.

Just wanted to clarify, he meant to just throw the cork end seals away. lol! (which I agree with) As others have said Fel-Pro intake gasket sets are the only way to go..

Low compression is a valve or head gasket or ring/cylinder issue intake gaskets don't affect it.

I concur.

[RazorbackGT]

Right now my next step is to pull valve cover and take off #8s rockers and make sure valves are in closed position, then pressurize cylinder and follow the leak. I'm expecting air from manifold. I could be wrong, probably am.Lol.

[dynodon64]

What was the compression on the right side? Just doing one side doesn't cut it? What did you do about the vacuum leak? The difference in plug colors from one bank to the other, indicates a bad vacuum leak. FIX IT!!!!

[RazorbackGT]

Working on it.

[RazorbackGT]

What was the compression on the right side? Just doing one side doesn't cut it? What did you do about the vacuum leak? The difference in plug colors from one bank to the other, indicates a bad vacuum leak. FIX IT!!!!

Apparently vacuum leak was EGR, replaced it today, the car drives better than anytime since I've had it, (going on 6 months) seriously, I can just let out the clutch without touching gas and the car pulls and takes off without stumble. The stumble has driven me nuts forever!!! It is gone! Bad news, car still burning oil out left tail pipe. Will try sea foam and hope cleaning out carbon build up will help.

[dynodon64]

Tell tale signs of bad rings would be smoking all the time when running. If you accelerate hard and lift the throttle, which cause the car to push the engine, and you see a large puff of smoke, than that is a sign of valve bad seals.

[RazorbackGT]

Tell tale signs of bad rings would be smoking all the time when running. If you accelerate hard and lift the throttle, which cause the car to push the engine, and you see a large puff of smoke, than that is a sign of valve bad seals.

I only see smoke when car is at 210 degrees, could this be allowing a worn ring to increase blow by? I have a 190 degree thermostat, thinking about going cooler. Also where the header connects to exhaust there is a gap, like PO didn't reconnect for some reason. Now this gap is closest to the #8 cylinder, could this allow that cylinder to get hotter than the rest?
After replacing EGR I sprayed more carb cleaner around manifold and don't hear anymore idle surging so I guess that was the last vacuum leak around manifold. Car still has a hanging idle so there maybe other vacuum leak elsewhere, like possibly in all that emmisions crap. I don't have time to work on it much right now, building a new carport for all my crap,Lol.

[erratic50]

Yes - Borax is an abrasive. It's useful for taking the glaze off the cyl walls and hopefully get the rings to reseat in cases where they aren't. Useful if you have evidence the rings have given up and you are making a last ditch effort to avoid a rebuild.

I agree - diagnose the problem first. Here's hoping it's just a little carbon on a valve and it cleans up.

[RazorbackGT]

Thanks erratic50, I appreciate your input.

Thanks,
Brant

[RazorbackGT]

OK, I finally got around to pulling intake and replacing the gaskets. There were no torn gaskets, but I could see where #8 was sucking oil from the valley. looked as though the sealant used on the ends might have been a little thick and not allowed the intake to seat properly, my theory anyway. I went back with the cork on the front and back on top of a layer of ultra black, let it set up and then put ultra black on the corners and dropped intake back in. Followed the long and slow tightening process and apparently did it right, no more oil sucking into #8.

So now I'm having a high idle (1100 rpm) if I try to adjust A/F down to drop idle, carb starts makimg a sucking noise, like a duck call. Could my mechanical fuel pump be a little on the weak side and need to be replaced? BTW, carb idle speed screw is all the way out and timing is right where it needs to be, just scracting my head on the high idle.