kentuckyKITT

iTrader: (4)

I've developed a problem that I can't seem to figure out and usually I'm pretty good at figuring things out, but I feel like I'm missing something and after messing with it all day and getting a headache, I need to regroup.

Car 82 Trans Am
Engine: 327 bored .60, 461x heads, Edelbrock Torker open plenum intake and 600 CFM manual choke carb, HEI ignition.
Transmission: vacuum modulated short tail Turbo 350

Engine was built 7 years ago and has approximately 8,000 miles on it.

I noticed some light gray smoke on startup at a gas station two weeks ago and the next day developed a misfire. Timing light narrowed that to cylinder #2. After quick diagnosing discovered plug was not firing and was coated in what appeared to be oil. Replaced plug and ran fine for awhile. Got it out this past Saturday and misfire again, and once again #2 oil fouled with more smoke from exhaust. Today, with a new plug again and testing, plug fouls out in a few minutes as timing light shows irregular fire at idle after idling for about 3 minutes. Holding the engine at 2000 rpm gives consistent fire, but a garage full of thick gray smoke just pouring out. At this point, I'm now cleaning the 5 extra plugs for testing since they keep fouling out.

Okay, so a friend suggested vacuum modulator blown sucking transmission fluid into the intake, huh, hadn't thought of that!, so I disconnected it from the carb, plugged the carb and ran it for an hour (hoping to clear out any remaining transmission fluid, if any), holding it to 2000 rpm for a few minutes at a time, still billowing gray smoke and fouling #2. Pulled all other 7 plugs and they are dry and normal.

Finally convinced I have a broken ring on #2, did a compression test, compression test results: all 8 cylinders around 130-135; #2 being 133 consistently after several go arounds, engine fairly warm. So that didn't help, but maybe it's good news?

Tried a different plug wire on #2, tried a different known good cap and coil, still the same (Bob Seger was in my head). Oil fouling #2, gray smoke while idling and billowing when revving it. Consistent gray color, not black, blue or white.

The last thing I did was check all of the intake manifold bolts thinking maybe I'm sucking oil from the valley and the two bolts over the #2 cylinder were a little loose, but not much, so torqued them, but still same problem. Still think there's something to that maybe. That's as far as I got today. Surprisingly, the engine runs normal at idle and high rpm when #2 isn't misfiring, but it just smokes. What am I missing?

Thanks for any help!

RBob

iTrader: (1)

Check if the valve seal hasn't pulled off the boss and is riding the stem.

RBob.

kentuckyKITT

iTrader: (4)

Good idea! Haven't encountered that before, I'll pull the valve cover tomorrow and inspect. Would this be more obvious to see while the engine is running? Thanks.

3.4 grape

iTrader: (1)

While you have the valve covers off check both valve springs for breakage. I had one break on my car and drove me crazy looking for the problem.

NoEmissions84TA

iTrader: (1)

That's a great idea. If a spring broke and the spring is dancing around, it probably tore up the valve seal, maybe the guide also.

RBob

iTrader: (1)

I check them not running. If that particular spring is compressed just tap the starter. A flashlight and a small mirror are helpful.

RBob.

kentuckyKITT

iTrader: (4)

Updates this morning. No problems with valves or springs that I can tell from the top. Operating smooth as can be after intensely monitoring with a mirror and flashlight and comparing to the rest of the bank.

I tested the PCV system, that checks out okay.

Placed a small shiny white piece of card stock against the #2 spark plug hole and cranked the engine over several times with the hot wire off. I'm getting a small amount of oil appearing on it. Did this a few times.

Ran the engine with hole open very briefly and only got a tiny bit oil dribble from the hole. I half expected it to shoot out they way it fouls plugs, but no.

Still fouling plug, sometimes immediately after starting it.

Done for the day!

mmadden55

Intake manifold gasket leak into that cylinder. Pulling oil into cylinder under intake stroke.

kentuckyKITT

iTrader: (4)

Thanks, we replied almost the same time. Checked both running and not running, no obvious issues when comparing to the rest of the valves.

kentuckyKITT

iTrader: (4)

This was my first impression after discovering that the bolts in the intake above cylinder 2 were a little loose. I turned them maybe an 1/8 to click the wrench, so maybe.

mmadden55

It is holding compression so that has to be it or the valve guide seal , but unless the guide is really bad worn it should not pass that much oil. However if you lost a sizeable piece of the intake gasket....

RBob

iTrader: (1)

If the intake gaskets are FelPro with the blue rings around the ports, they are suspect. What happens is that they move around, happened to me and another fellow here posted pictures of when it happened to him.

RBob.

tealman92

Check the valve guide seals not the valves and springs

kentuckyKITT

iTrader: (4)

Yes, they're FelPro. Had to pull the intake a year and half ago to change lifters and went back with FelPro. I've always trusted FelPro and have never had a problem before... What brand/type would you suggest these days? I'm pulling the intake one night this week to see if I can spot any problems, so I need to order new gaskets!

RBob

iTrader: (1)

I use Victor Reinz, which is embossed around the ports (just like stock GM gaskets). Used to get them from the local CarQuest.

RBob.

kentuckyKITT

iTrader: (4)

I found those. They do look like stock ones. Do they require sealant on both sides or install dry? I've always smeared a very thin RTV on both sides of FelPro intake gaskets for many years and usually don't have a problem, but I found out a few years ago that FelPro says not to do this! I don't use the china wall gaskets either, just a bead of RTV front and back. Thanks for the suggestion.

NoEmissions84TA

iTrader: (1)

I spray hi-tack on the back side of the intake gaskets to keep them in place.

PaulyC

I know you did a compression test but you can see good compression and still have ring sealing issues. I suggest a leakdown test just to make sure you have a good sealed cylinder(s) and you can forget about mechanicals after that. You then narrow it to valve giude seals (I didnt see if you checked them or not). They are easy to replace and cheap and as a bonus you can change them on the engine when you are doing the leakdown test along with the springs if they are damaged. Also with the spring removed you can inspect the sealing portion of the valve stem. The valve guide can be worn still (which is super common on these cars at this age) so they can puff smoke soon after the seals are replaced due to the guide to stem play.

Last thoughts: If your intake is leaking, even in the galley your idle may get a little higher depending how bad it is and if you can get a scanner you can check your O2, STFT and LTFT to see if the computer is trying to compensate for vacuum leak on that bank.

Good luck!

88IROC-USA

My first thought was "gotta be a valve guide going for a ride" .
Actually, that was my SECOND thought. My FIRST thought was "Damn! I reckon that motor is a wicked little dude!"
what kind of RPM do you turn out if it? Pulls hella strong I bet!

Great combo - with the right single pattern camshaft....

kentuckyKITT

iTrader: (4)

I studied the valve guide seals (previous post) didn't notice any issues, but I have not removed the springs either.

Right now, the plan is to run the car long enough to get the plug to foul and a good smoking going, then after it cools a bit, remove the intake. I had planned to remove the intake anyway as I discovered a slight oil leak at the back driver's side corner 4 months ago that is getting slightly worse. Was hoping to put that off until after show season, but it's coming off this week now.

If no obvious gasket damage/leakage, I'll be looking for oil in the port and on top of the valve. If it's only on top of the valve and not in the port, that should tell me valve seal or something with the valve at least. If it's in the port and on the valve, then most likely coming from valley. If there is no trace of oil in the port or on top of the valve, then it has to be a #2 oil ring.

Really hoping it's the intake gasket or a valve issue.

Unfortunately, if it's an oil ring, the engine is most likely not going back in the car. I've had it in there for 7 years, so it's time for something else. I'll fix it if it can be fixed without boring and sell it to some Corvette enthusiast. This engine can not be bored again, it would have to be sleeved and it's not worth it nor practical.

As for checking the intake leak using a scanner, not possible. There is no trace of computer or computer harness on this car anymore. It was all removed years ago.

PaulyC

kentuckyKITT

iTrader: (4)

Most RPM I've gone with it is 7,000 after it was good and broke in just for kicks and that was over 5 years ago. Had to temporarily hook up a 10,000 rpm tach since the stock Trans Am gauge doesn't go that high. It spends most of it's time under 4,000.

It's a good running engine (usually). Casting #3782870. It used to be a race engine with 12:1 domed pistons in the 70s. It now has 10:1 flat tops, original small journal forged steel crank with aluminum rods and new 350HP cam. It's either .447 or .450, don't recall, was actually looking for the paperwork awhile back, but could not find it. After you sleep for 7 years, you tend to forget things. 461x heads that had a lot of custom work done back then, but I had to have them completely redone including hardened seats. The engine sat outside under tarps from 1979 to 2010 and was in the kind of shape most people would not even attempt to rebuild.

Realistically, I could have bought a crate 350 roller motor and every accessory with brackets brand-new for far less money than I have in this 327 build, but it was a fun learning project and the first engine I built myself.

kentuckyKITT

iTrader: (4)

Update. Pulled the intake this morning and yep it was the gasket. It wasn't damaged, but flopping loose at the end with oil all over one side and all inside the port at #2. So, even though it still sucks to have to pull all of that, I'll take that over a ring any day! Now to clean it all back up and re-install! Thanks for the tips everyone! Looks like I found the problem!

NoEmissions84TA

iTrader: (1)

Glad you found it and that it was the easiest of the problems to solve.

88IROC-USA

I still think it's the valve seal...

kentuckyKITT

iTrader: (4)

All fixed or so I thought. The oil fouling problem is gone and it runs like it did, but now I'm left with some white smoke on startup until the engine is warm and then it goes away completely. When holding my hand under the tail pipe while smoking white, I get a nice sticky substance on my hand with the sweet smell of anti-freeze. Looks like I may have had two problems at the same time or this one just started. Best guess is I have a head gasket seeping that seals when it warms up. So far, no coolant in the oil. I think this engine is telling me it's time for replacement or new heads and intake at the very least. Next step is to disconnect the headers from the y-pipe, aggravate the neighbors with race car sound and see which side is giving me the white smoke on start up.

Can't tell which head with a single pipe unless someone knows of a way?

RBob

iTrader: (1)

That is no fun. Maybe the intake is warped or not cut true.

Check the spark plugs. If one is very clean that is the cylinder getting the coolant. It steams cleans it.

RBob.

PaulyC

kentuckyKITT

iTrader: (4)

And...we're back. So, over the summer, the problem was getting somewhat worse, so I quit driving it and was just trailering it to a few car shows the rest of the year, planning to tear into it in the fall. Against my better judgement, I drove it to a local show and back two weeks ago and it was a steam cloud behind me the entire trip. I knew that was the last ride! Yesterday, we did some testing on it. First test was a simple coolant pressurize. I immediately got some hissing at the upper radiator hose neck. After some quick work, figured out the hose wasn't sealing, so cut an inch off of it and re-attached. Problem solved. Pressurized again, still getting some leakage, but not much and can't hear it escaping. Then, my buddy suggested we pull the #2 plug (the one that's been giving me problems) and turn the engine over and see if any thing comes out while it's pressurized. Low and behold #2 pukes the coolant out bad, sprayed all over the engine bay. Ding Ding! Checked the rest of the plugs and the other head, nothing. #2 is puking coolant and bad and only #2. Leak-down test was inconclusive. Could be head gasket, could be cylinder crack, we couldn't figure it out. The gauge showed some leakdown, but very little after multiple tests.

So, after my buddy left, I pulled the intake and valve covers and passenger header. I pulled the header first. First bad sign, oil all in the #2 exhaust port and all in the header tube, just the one. The next bad signs, pulled the valve covers and antifreeze everywhere including on top of the valve cover gaskets and have tan milky residue all over the inside of the valve covers...fearing the worst already. Pulled the intake and antifreeze droplets all over the valley. The oil covering the heads and valley looks normal though, unlike the inside of the valve covers. The interesting thing is, no signs of antifreeze on the dipstick or distributor gear. Drained the oil and it actually looks normal! What the? So I called my buddy to report, and he said it sounded like steam was getting into the crank case.

So, today when the sun comes up, I'm pulling the passenger head since everything is centered around #2 including oil in exhaust port and antifreeze in the cylinder. All other cylinders and exhaust ports are completely normal both sides. I'm thinking cracked head or a combination of something going on.

It lasted 7 years since the rebuild.

naf

iTrader: (7)

check the intake gasket at number two again. it can leak coolant into the cylinder from the adjacent passage. if water didn't come out of number 2 spark plug hole until the engine was turned some (and intake valve opened), this would support same. early vortec intake gaskets were notorious for this issue when over torqued.

a small water leak into the motor can look especially bad when the motor is not run enough to rid itself of the condensation.

kentuckyKITT

iTrader: (4)

Well the verdict is in. Just got a call from the machine shop. The head is cracked under the seat. Time to retire the 461 heads permanently.