hey!
I am running a rebuilt engine and my compression tests:
1. 180
2. 190
3. 180
4. 180

This is in my gsr with 9:1 JE pistons. Car runs quite good.
I noticed while retuning my car today that at idle every once in a while, I get some grey smoke coming out the exhaust. Clears once I have been driving and I don't see it in full boost (up to 13psi) and I am tuned quite well.

I pulled the plugs and notice that in the #2 cylinder the plug had a slight oil stain and if I look inside the cylinder I can see the top of the piston and it looks like there may be oil on the top. There is no oil in the plug chamber (meaning its not dripping from around the valve cover seals).

I had my head reworked with the valves polished and lashed and new valve seals put in.

How can I narrow down where this is coming from? What should the tops of the pistons look like when you peer down into them with a flashlight from the spark plug hole?

I'm assuming its the head. I'm tempted to buy a head and have it totally reworked by portflow.


It seems like its just one thing after another
Thanks!

Torin

 

ttt
oh, also, after 1000miles I change from castrol gtx 10w30 to mobile 1 10w30 and that made the smell of burning oil noticeable on rare occasions. especially coming off throttle to a stop. is that diagnostic of anything?

 

have you changed your spark plug gromet things on your valve cover ? my friends b18 did the exact same thing ..had his spark plug soakd to the electrode!!! we changed em now its fine

 

wouldn't i find oil in the spark plug chamber itself if that were the case?

 

ttt

 

I'm thinking head. Do a leakdown test. valve seals ???? Are you checking hot or cold ?

 

are you sure it`s oil ? it may be a slight head gasket leak .

 

i'm sure its oil. i can smell the difference. mobil 1 in particular has a unique putrid odor when burning.

I can see the one plug has a little oil on it. I'm assuming that its the valve seals. they are new but the valves were polished and perhaps there was just enough wear that allows a little to get by.

 

Is it on top of the plugs to or just the bottum where the electrode is

 

just the bottom where electrode is

 

Well, what size pistons are you running (any overbore? like .025 or .010 over) Did you have your cylinders re-bored and honed when your pistons were installed, and also what rings are you using. It could be a problem if it waas not bored at least .010 over and honed just to clean up the bores a little. I have an LS running with Custom JE 8.5:1 Forged Pistons built for 28lbs. of boost. now when it is cold and my pistons haven't expanded with the heat the pistons get a little blow by. Part of this is because of the simple fact that it's forged, it expands more during heat and therefore is smaller in bore when cold so blow-by on a cold motor with forged pistons is not that uncommen and not all that bad. However if you are getting it when it is warm and when you are under boost a little than you might have to look at the following reasons. Another reason is that your rings may not be sealing all the way. A lot o people think that it is the "springiness" (if that's a word) or the ring that seals the pistons. That is far from the truth. The actual thing that seals your piston rings to the bores is the compression. Now you are running good compression at 180 or 190 but sometimes that poses a problem with people running really dropped compression: however, it shouldn't be a huge problem for you. One last reason is a far stretch but still possible. When I was putting my rods onto my pistons and re-installing my pistons my buddy (works with a race shop / machine shop) in the area was there and told me that whenever you install pistons make sure that your ring openings are in opposite directions. Like if you have 1 oil ring and 2 compression rings the bottom oil scraper of the oil ring would go to the left, the top one would face the right, the first compression ring to the left and the second to the right. get what I'm saying??? Make sure they are on opposite ends of each other. Just make sure they are not lined up! they rotate a little as soon as they go up and down the first time, but if they are all lined up there is a possibility that it can dig into the bore... thus causing a small little oil leak to the top of your piston. I wouldn't think its in the head there are way too many things that can go differently with forged pistons and especially if you replaced all of the head parts like you said you did. Everything should be good with the head. I would check the block. I hope this helps at least a little if you have any questions shoot me an email at b18cvtecls@hotmail.com I will help you in any way possible. I know how it was when I had questions... . Good Luck.

Later,

Sean C.

 

thanks for the reply,
i have .020 over pistons and the bore was done to JE's specs sheet. my rings are clocked as per JE.

I checked my new plugs again today and they look ok. i have not seen any oil burning but its amazing that with mobile1 i seem to get a hint of oil smell vs running the castrol gtx.

 

Now I'll check when I get home, but as I remember, JE recomended a very loose Piston to wall clearance, and with the XC file-to-fit rings when you gapped them to their specs it left them a little loose. (nothing that you can really notice) it's so minute that it's rediculous (not sure if that's spelled right...) but my machinist wenta hed and left them a little tighter than they recomnded for that reason. I will get you the specs I used. The reason that the synthetic oil may leave you with a slight burning smell is becasue the oil even though the same weight (10w-30) it is a slicker oil that can get through your rings easier if they are loose. and that will leave you with a little bit of blow by. Here, try this. Take a baby food jar, empty it all out, and rinse it out. now put the cap back on and drill a hole in it. put your Breather tube (from your valve cover) in that and seal it off with a little clay then run your car like normal for a day or so. and see how much blow by you are getting if there is some in there (well more than an acceptable anmount), than you might have a blow by problem and then I'll let you know how to remedy that if that's the problem. I hope this helps.

Later,

Sean C.

 

did you change from regular oil to synthetic? i have heard that when u first change to synthetic, it burns a little....(smells)

not sure about this tho..

good luck dude!
mike

 

Synthetic oil smells like it's burning because the molecules are smaller, allowing it to pass into places regular dino oil can't. That why I don't run tynthetic on a turbo motor.

As for the baby food jar thing.... hooking that up to the 'breather' tube will always get blow by. ALL motors create blowby thru that tube to the intake tract... it's normal. what would you be looking for here ? Seeing a little oil and residue would mean nothing as oil and vapors are constantly dribbling out of that tube anyway.

Get those valve seals checked... are they new or the originals ?

 

i run a catch can between my pcv and my manifold. i have a breather filter on my valve cover.

catch can never seems to accumulate anything!

 

valve seals are all new.

 

That's because when you're under boost the pcv valve is closed. The pcv valve only opens when there is negative pressure in the IM. When you're at negative pressure on a boosted car you're usually at low rpm and produce little or no blowby. Your blowby gases will come out of the breather tube of the valvecover at high rpm and boost. Connect the catchcan there to catch blowby.
Oh and Sean, this is Ray! Call me this weekend. I'm putting on my kit!

 

The baby jar is nothing but a catch can that you can see through very easily, nd on top of that it's cheap. What you would be looking for with the baby jar though would not be everything that comes into it, as I stated if there is more tahn usual blow by than you could be worried about some things and yah, rayis right about the placement of you catch can, try it where he said, and tell me what happens.

Later,

Sean C.

P.S. Ray I'll give you a call a little later, I might be going to LA, cali to hookup with some car people in the near future so I'll let you know. Also, did you ever get your oil line tapped and did tony ever get his fixed and is he now boosting... Let me know.

Later.