Been trying to figure out why I've been burning oil and was trying to figure out if it was rings or vavle seals. Finally had some time to do a compression test, and at the same time put new plugs and wires in. The results are as follows (I don't know the firing order off the top of my head, so I just did them as each side from front to back):
Car has 128,xxx on the clock.

Driver side, front to back:
185
200
200-203
200-203

Passenger side, front to back:
195-200
200
198-200
195

Everything was pretty much even except for the front cylinder on the driver side. Additionally, we noticed something very strange with that plug. It doesn't want to thread in all the way, it sticks out a little farther than the other plugs. It was like that on the old plug we pulled out, on the compression tester tool that we screwed in, and on the new plug we put in afterwards. It just doesn't go in as far. I figure there might be some gunk or something blocking the threads? It doesn't seem to be affecting anything either so I'm not sure what to do about that.

Also, a new thing we noticed was that when I go WOT, there is a big blue puff of smoke that comes out. Tried it twice, did it both times. Hopefully this can help me narrow it down. What do you guys think? Thanks in advance.

 

I can tell by the readings you got lots of carbon build up and the oil usage maybe because the oil rings are pasted. Run a tank of gas with a large bottle of Chevron Techron in it.Will clean uop the carbon and free up the oil rings.

Compression readings should be in the 160 range stock.

 

^^what

 

usually blue smoke when wide open throttle means rings are shot. Blue smoke on initial start up for a few minutes mean valve seals.

 

You looking for no more than a 15% range. You're well within that. If you're still concerned do a leakdown. What is your vacuum at idle and at 2500RPM?

 

wtf? His numbers are fine, it shouldn't be 160 for that compression motor and chevron techron will do nothing for the carbon and oil rings.

Numbers are good. they are less than 10% difference so that's not a problem

 

Yeah, I thought the readings were pretty good. I'm not listening to what that guy is talking about because hes way off lol. Thanks everyone else, and what do you think it is, rings or valve seals?

 

99RTA is generally very off in what he says... There's only one way to really figure out what's going on here and, well, you know what that is. Tear the ***** down.

 

BS!.... those compression readings are too high for a stock motor. That has carbon buildup, I bean doing this a very long time. Try what i said before you waste any more time on this.

 

So you say his bumbers are good no problem??? then why is he here??? LMAO

 

Compression is a relative thing. Two similar engine won't necessarily read the same after a lot of miles down the highway. Carbon build up? Where? On the piston crowns? It would take a heck of a lot of carbon build up to increase compression from 25 to 40 lbs. per cylinder. You can do a leakdown to narrow down the area of leakage. If the leakdown doesn't show evidence of a problem it's not that big of a deal to swap the seals especially using the Vinci/Crane tool. I wouldn't do a spring swap on an LS series without it. Plus this give you a chance to upgrade your springs while changing the seal.

 

F13 = not stock LOL

 

Let's see? If you combine a thin head gasket with cylinder heads that are milled 0.030" along with an 1/8" of carbon on the piston crowns you might increase compression by 40psi.

 

those are in the same area as mine were with my 230/224 cam, stock heads, felpro off the shelf gaskets

I can guarantee you there is not a bunch of carbon in my engine

 

Sorry maybe you guys can convince yourselfs but go check the compression in a new engine........that cam didn't increase the compression. unless that engine was modded with heads or pistons the compression should be in 160 range.

If you think anything else you don't have alot of experience working on engines and you wouldn't be posting for help. If you know what to look for FIX IT!

Do you have any idea how fast carbon builds up in todays engines with the garbage fuel thet sell. PLUS add the LS1 usually puss oil into the intake you have HUGE carbon build ups FAST>

I'll bet that engine is so full of carbon its INSANE like me!

 

Is it just me or do you argue in just about every thread you post in? Correct me if I am wrong but was it you that was going back and forth with LS6427 in his PCV thread not long ago? To post up that somebody has guaranteed carbon buildup as an "internet diagnosis" from compression numbers alone is plain ridiculous and that is what I am convinced of.

 

either agree with me or be WRONG! LMAO

I've been building and working on high perfm engines all my life, you can't BS me about this crap. Yer trying to tell me a engine with over 100k isn't full of carbon BULL PUCKY!

over 128k to be exact!

 

I've checked MANY MANY engines that had 190+ compression readings that read 160 after decarboning the cylinders. Go to GM any dealership and ask for their decarbon service and ask why they would bother to do it if it wasn't a HUGE PROBLEM.

I'll betcha stock LS1 in excellent shape will measurse in the 160 range same with the LS6, the ZO6 maybe in the 175 range.

 

I gotta add something else......engines with INSANE compression ratios that would give you stock readings of 200+ compression DON"T EXIST on the street because the gasoline available would destroy them! GEEZ where do you guys dream up this stuff?

 

So after reading a million of these posts, does anyone actually have anything to add that people agree on? Not just arguing back and forth... lol