Spark plugs: 7 tan, 1 black

[RICK LAKE]

ceslaw Before you start pulling the motor apart, a couple of ideas on this problem. First off which cylinder is it? Where all the motor parts new? Heads, Block and Intake? if yes go to next idea if not, the milling of the motor block,heads or intake may not all be sitting flat causing the oil to either be pressurize or sucked into a poor sealing area. When you start the motor, does blue smoke come out of the side pipe? If the motor has a lumpy idle the vacuum gauge is not going to help. Are you running a PVC valve on the motor? it may be the wrong one and causing pressure in the motor and pushing oil through a seal. They sell a dye kit for about $70.00 that the dye goes into the oil. You run this for 20-50 miles and then check it with the light and glasses in the kit. It leaves a nice yellow stain and shows you where the leak is coming from. If #4 or #8 are the problem your oil returns may be partially blocked by the gasket, and over filling the valve covers. The Felpro gaskets need to be checked for this. I had to trim both sides to the returns for this problem. The rings are not broken in yet, so 1 quart of oil per 1K of miles is normal. If the engine builder set the ring gaps up wrong this could be a problem. A leak down test and compression test would tell for this. Before I go into more checks start here. If you want to talk call me at 732-254-3536 in the evenings. Good luck Rick L.

[ceslaw]

Thanks for the tips. By way of response:

1. All components are new. Genesis crate motor. Edelbrock head, etc.
2. No PVC valves. Breather caps on both sides
3. Cyllinder #2 is the culprit
4. Yes, the idle is a bit lumpy. Usually idle it around 1000 rpm.
5. When starting, there is a bit of black smoke, not blue, from both sides which quickly stops as soon as the engine starts to warm. I attributed this to running rich at start up. Last only for a few seconds. Then no more smoke at all.

Hope to find time to do a compression test in the next few days and will post the results. Thanks.

Chuck

[vettestr]

Hey all, Still keeping fingers crossed it is an easy fix for you, I think we are all pulling for ya. Mac and Rick brought up a couple points I wanted to table for discussion. We are in agreement not that that means much cause it is the input of others in agreement or not that show different ways to explain or look at the problem. Not to mention the fact I am making this up as I go so a sanity check is definitely a good thing...LOL .
1st Mac=
The oiled cylinder will or can give different and misleading #'s if it is a ring issue on the compression test or until the oil is pushed by the rings as it dries out a bit. A bad V. guide will not care and will show up on the compression test so just another puzzle piece. The leak down will allow you to hear where or by what component the air is going past. This probably tells you more than the just numbers can.
Rick L = More good stuff that made me think from other directions. My point on the vac gauge is not the just # he will get on idle other than if near zero but as numbers to compare. I asked Chuck to get an idle reading and another at a stable 2500 RPM. At idle and around 2.5K the needle movement is the key info. If it is vibrating/unstable at idle it shows V. guide condition, vac leak and to some degree cyl. condition. At 2500 stable RPM it will show a major vac leak but can compare to movement of needle at idle and if it is low reading here it is not a cam function but a system check.

[mr0077]

Say, Rick L and Vettster reminded me of another symptom that could be useful...
Vettster, I thought a bad valve guide would NOT show in a compression or leakdown test since it is on the carb/atmospheric side of the valve seat. How would the compression check show a bad guide?

And speaking of bad guides, if that is the problem, often a bad intake guide will show with a cloud (light or heavy, depending on how bad it is) of blue smoke on trailing throttle...get the sun behind you, get up to speed, let off gas in gear and let engine slow down the car, look in mirror (or have passenger look) for smoke cloud. BUT, this condition will cause oily residue in the pipes, which ceslaw said he doesn't have.

[vettestr]

"I thought a bad valve guide would NOT show in a compression or leak down test since it is on the carb/atmospheric side of the valve seat. How would the compression check show a bad guide?" by Mr0077
The guide would have to be bad enough to hammer out the valve seat to be seen. A guide would have to be worse than (just a loose guide) for sure but my thoughts were if it was bad enough to consume the amount of oil we are talking about it should of hammered out the seat by now. This is also why it would show up on a leak down test if leaking by the valve.

[ceslaw]

All of the good advice has not been ignored. I finally got around to doing the compression check today. Recall that plug #2 has been the culprit. The engine was thoroughly warmed after a good forty mile drive when we checked the compression. The results:

Cylinder Pressure
1 . . . . . . 165
2 . . . . . . 175
3 . . . . . . 170
4 . . . . . . 165
5 . . . . . . 170
6 . . . . . . 170
7 . . . . . . 165
8 . . . . . . 170

The engine still uses oil at the same rate, but there is not a hint of blue smoke when driving nor is there any oily film in the right side pipe. Other than adding oil and plug number 2 being carbon covered, one would not have the slightest clue there was a problem. There is a bit of black smoke when starting but after a couple of minutes of warm up that ends. The engine starts every time, pulls without effort, does not miss, just runs great.

Now have about 2550 miles on the engine.

My inclination is to drive it another 500 miles and see if it has a bit more ‘breaking in’ to do. Sound reasonable???

Chuck

[RICK LAKE]

Ceslaw Chuck If you are using a good compression gauge the numbers are in spec of 10% or less, high to lowest for pressure. The fact that #2 cylinder reinforms me that oil is getting into the cylinder and raising the compression. Another 500 miles is not going to hurt the motor. Try and keep track of oil useage in this time. I think you will find that cylinder go to 180 in another 500 miles. The others will stay the same. I run a PVC valve in the RS valve cover. It may help and stop the oil being sucked through the seal and into the guide. If the rings where not stacked right you would have low compression in that hole. this is not the case. You can drive the car like this for a long time and just keep cleaning that plug. The best thing to do is pull the head and have it checked by a good machinist and new seal installed. You could try and install a new seal yourself. Basic tools, if you have air compressor to pump the cylinder up to keep the valves closed or nylon rope to push as mush as you can in the hole, than rotate the crank to get the piston to hold the valves up and replaced, reverse crank direction and pull rope out. Pul seals on BOTH valves. Good luck RickL. If you have a question or problem call 732-254-3536 est in the evening.

[vettestr]

The advise to install new seals can't hurt by any means. You could remove 1 spring and then release air pressure (with a firm grip one that valve) and check the side to side clearance between guide and valve stem. Then replace the seal with the umbrella type if you are not already running them. Do install new locks even with the minimal miles on old locks.
Repeat the above steps on second valve. This way you can verify the clearances of the valve to guide and new umbrella seals installed for a piece of mind.
Just my 2 cents here and some would question if even worth 2 cents but here goes. I do not think a seal even if it is missing with proper V to Guide clearance will give you these problems. A bad guide would and a seal will not repair or compensate enough to matter. If the guides are good then she is sucking oil through a gasket or porosity or even too aggressive porting but a hole of some type. Hooking an air hose with 150 psi up to that cyl. and the rockers backed off might allow you to see or hear were the air is leaking. A slim chance or 50/50 at best you would see where leaking as you can only see so much but you are there with air to do seal change anyway. Plus the air left on for a bit will blow the rings dry allowing a second test on that hole for a dry compression test.
Might think about just keeping extra plugs in the car and driving it until problem gets bad enough to force deeper dis-assembly and repair costs .

[Excaliber]

Just a thought...

Call me old fashioned but I don't like synthetic oil, it tends to leak and burns easier than dinosaur oil. 10-40 or even 20-50 for me, as I live in a warm climate zone. Shell Rotella and to get more 'zinc' I like to add a can of STP as well.

[ByronRACE]

Have you stopped to consider that the fouling of the plug might be fuel, not oil? I see a lot of talk about oil...not much (if any) talk about fuel.

A high resolution picture would be real helpful.

My first guess would be carbon fouling due to misfire. A bad plug wire can do this. Once the plug becomes carbon fouled, it no longer fires reliably which leads to more carbon fouling...it cascades until you have a soot covered plug.

It could be as simple as wires, cap, boots, the plug itself, etc.

[CobraEd]

Does it smell like oil or gas? Did you check the plug wire and Dist cap?

See if these pictures help.

http://www.4secondsflat.com/plug_chart.html

.

[ceslaw]

Good thoughts and ideas.

I previously switched plug wires and noted no change, so it is not the plug wire. Checked the distirbutor cap and all appeared in order. Don't think it is an electrical problem. The quart every 300 miles or so leads me down the oil path rather than the fuel path.

The point about the oil seal not accounting for this amount of oil consumption is well taken. Perhaps a intake manifold gasket is a more likely culprit.

I am still mystified about the lack of blue smoke in the exhaust or the lack of oily residue in the right side pipe.

I use 20W50 Valvoline racing oil. No synthatics.

Chuck

[ByronRACE]

Get in there with a dental pick and scrape the gunk out of the plug, spread it out on a piece of paper, and let it dry. If it's dry and crumbly, it's carbon residue. If it's gummy or putty like, it's oil residue.

A leaky carburetor can also favor a single hole...a dribble line.

But, yes...it does sound like oil given the symptoms. You'll probably have to dig into the guides and seals before it's over. I'm still hoping for something easier.

Fiber optic borescopes have gotten pretty cheap these days...that might also be worthwhile before you get too deep. Try Ebay using "endoscope" as a search term.

[ceslaw]

Talked with Tim at Genesis today. Probably should have called him sooner, but given I picked up the engine a year and a half ago and it has 2500 miles I was not real optomistic. He proved most helpful and is going to explore options to get to the bottom of the problem with me.

He, too, has suggested starting with a boroscope to determine the status of the intake manifold and then work from there. Good idea!

I will check the residue on the plug and see if we can get a better idea if it is carbon or oil residue. If it were a fuel problem, we still would have to account for the oil consumption, which I would be at a loss to explain.

Chuck

[ceslaw]

I have posted a couple of pictures of the plugs at WWW.GT40s.com, the Engine forum, same name as this thread (Spark plugs: 7 tan, one black). They are not high resolution, may provide some insight.

Chuck

[CHANMADD]

Sounds like an oil ring to me. I hope not for your sake!

[Danr55]

Chuck, I looked at the photos and I agree with the post on the GT40 site. The oil is being forced up around the plug threads. Is there another explanation for the oil around the plug port?

[RICK LAKE]

ceslaw Chuck I don't know where you are at, but if you go to www.percisionmeasure.com they sell a valve seat vacuum tester. It checks vacuum on valve seats and other tests. It also tells about what to look for. I still go with a bad valve guide or seal. They sell a oil dye for the motor to check for externial oil leaks, you could use this to check and see if the oil is being pulled through valves or stem seals or if the gasket for the intake is sucking. You need to pull the head for this tester. Rick L.

[ceslaw]

Rick:

Thanks for the info. $250 for that little gadget! May be easier to just replace the valve seal / guide and intake manifold gasket. I appreciate the thought. Have not yet had a chance to pursue the issue - work committments.

Dan:

Since changing plugs have not noticed the oil puddling around the outside of the plug. Can't explain why, since the plugs we pulled out were all tight. But reinspection of the new plug still demonstrates a problem. Not sure what to make of that part of the puzzle.

The lack of oil smoke still puzzles me. This weekend I plan to let my son drive the car while I follow, just to make sure we aren't overlooking smoke from the view from the driver or passenger seats.

I still cannot understand how an engine can be free of leaks, use a quart every 300 miles and not put out some blue smoke.

Chuck

[RICK LAKE]

ceslaw Chuck go to autozone or pep boys and buy the engine leak down kit. Comes with glasses, special light and a couple of bottles of dye for the engine oil. Put the dye in the oil and drive the car for 5 miles. Use the light and glasses and see where the leak is. It leaves a nice bright trail for external leaks. Will not hurt motor. After repair is done clean area with brakekleen and road test again. Recheck. Are the parts new on the motor? Block, Heads, and intake manifold? Possible machine problem of different angle on mounting surfaces. Rick L.