Before I start, the motor is completely stock, besides 18deg timing.

So, the last few months I've been told there has been a little bit of blueish/black smoke that exits the exhaust whenever I step on the gas...which I rarely beat on the car besides HPDE's/Lapping days, so I would 'assume' that it is normal if you don't step on it regularly.

But when I was participating in my lapping day on the 19th, I was catching up to a slower car when I let off the throttle at about 7500rpms, and used compression to slow down. As soon as I let off the gas there was a LOT of whiteish smoke pouring out of the exhaust...I mean A LOT. It easily took up the whole rearview mirror, and poured out for a good 2-3 seconds before it stopped. It also had a sweet smell...which is not good.

Now, I immediately assumed the worst. I pulled into the pits and let the car cool a bit. Oil level was still the same, so after about 45 minutes of lapping there wasn't any huge amount of burnt oil. And once the car cooled enough, I checked the coolant and there were no signs of milkyness or oil which would be attributed to a leaky/blown headgasket. However, I did swap my head for my JDM one in May, used a new OEM gasket, and re-used my headstuds (I know that is a boo boo). I did torque everything to spec, and never noticed any smoking like this until now either.

I stopped driving that day, and went home early

The next day after work, I did a compression test. Normal operating temps (was on highway for approximately 20 minutes before I did the test). My results were 215, 215, 210, 215. When I picked the car up in March, I did a test then too, with similar conditions, but using a different gauge, those results were 220, 215, 215, 215. I don't think there is a problem there, numbers are very close.

So at that point I pretty muched ruled out my rings and headgasket. So I started asking around. I was told by a few fellow road racers, that blowby could be my problem. I checked the intake tube and sure enough there was a bit of oil resting on the bottom of the rubber tube. Not a puddle or anything, but there was enough to cover my whole finger when I rubbed the base of it.

Could my problem simply be blowby? Or can my rings still be shooting oil past even though my compression is good? Should I still consider my headgasket being a problem? Or are there other factors I should consider? The only other way I can think of is that my valveseats/valvestems are failing...which is very rare from what I hear and is almost never heard of on a motor with under 50k miles.

I do have another lapping day schedualed for the middle of September, and I don't want to risk harming my baby if there is a serious problem...I am really hoping an Oil catch can will solve the problem, but I am open to any suggestion.

Start the comments coming!

Thanks,
Marshall

 

It could be a couple different things. 1st thing I would replace is the PCV valve and drain the black breather chamber on the back of the block. If the valve goes bad, it can actually cause a vacuum and suck oil up into the manifold. While you are changing it, you should go ahead and see if there is any oil in the breather chamber from this as well.

2nd thing (that I can think of) is that it is your oil rings. Your oil ring can be bad and still show a good compression test. The only way of knowing is a complete disassemble. Kinda sux.

Concerning the valve seals leaking... that is usually indicated when you start the car up rather than during hard driving.

I hope it's none of these.

Good luck,
Brad

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 92TypeR &raquo;</TD></TR><TR><TD CLASS="quote">I checked the intake tube and sure enough there was a bit of oil resting on the bottom of the rubber tube. Not a puddle or anything, but there was enough to cover my whole finger when I rubbed the base of it.</TD></TR></TABLE> oil in the intake tube/arm before the throttlebody is oil vapor being supplied from air inside the valvecover, so you want to look at the valveseals as the culprit.

oil in the intake manifold after the throttlebody, where the PCV tube goes is where you need to look for blowby from rings, because the PCv system is "positive CRANKCASE ventialtion".

 

Wouldn't a lot of positive pressure in the head cause oil to go into the intake arm, resulting in it being ingested into the motor and me seeing it blow out the exhaust?

And regarding the PCV valve/tube, this is located on the back of the block underneath the IM correct?

 

Anyone else have anything to add?

 

The PCV valve is located on the top of the black box behind the block and the hose runs up through the cast in the intake manifold, then onto the front of the intake plenum.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b18c1eg &raquo;</TD></TR><TR><TD CLASS="quote">The PCV valve is located on the top of the black box behind the block and the hose runs up through the cast in the intake manifold, then onto the front of the intake plenum.</TD></TR></TABLE>

Thanks.

Has anyone ever had a smoking problem and found it NOT to be rings/headgasket?

 

You said a sweet smell?

Then it could be the antifreeze

Take a look at your oil and see if it looks like a chocolate milk shake, If it does YOUR IN BIG TROUBLE.

 

Oil and coolant look good. I do not think it is my headgasket.

BUT, I can never be 100% positive...I've had some tricky cars before.

 

Up again please.

Still looking for as many opinions as possible.

 

Marshall,
My ITR had the same problem. It would let out a LOT of blue smoke when I would auto-x it. It would occur at hard decceleration in 2nd gear. It would let out a plume for about 100 ft. I checked my compression and although it went down a bit since my last check about a year ago (several auto-x's and 2 lapping events) it was still respectable. I later sourced the problem to a hole in my upper PCV hose. This is the one that goes from the valve cover to the metal hose and into the intake hose right before the throttle body. You might want to check for any leaks there. The following auto-x did not show any signs of blue smoke.

 

Thanks for the reply man.

There aren't any "leaks" per se, but there is a fair amount of oil on the intake arm where the hose enters. My thoughts were that an oil catch can might solve my problem.

I'll check again for leaks, but I've been over the whole system a few times already.

 

We have some Cusco oil catch can's in stock if you decide you want one.

brad.himes@napsusa.com

Brad

 

Thanks I'll consider it.

Anyone have anymore insight?

 

Are you using an after market Intake System? If So did you bypass the stock tube that runs from the breather hole in the valve cover to the hole in the intake are? Some after market Tubes come with a silicone tube that some will use it instead of the Stock tubing. Well the Stock Tubing runs right along with the coolant line and this is supposed to keep the oil vapors from condensing too quickly. Oil as vapor mixed with the Intake air will not be as bad as pooled Oil in the intake arm and then being sucked in in a larger quantity. I am not sure I am explaining this correctly as this is second hand info someone told me a while back. I used to get puffs of white smoke but after I reconnected the Stock tubing the problem went away.

 

I am using the stock intake tube and plumbing...

I think I will get the oil catch can and pray that it works. I have another lapping day the 17th, so we will see. First sign of smoke and I'm going home.

 

I had same problem lately. I took my PCV box off the back of my block and there was no o-ring on it. I added an o-ring, put the box back on, and it has stopped smoking. It sure smokes ALOT when the oil touches that header!! WOW.