98 GSR 154k miles
#1-4
Compression is 222, 222, 220, 223
Leakdown is 2%, 2%, 2%, 8%

The numbers above are great except #4 has more leakdown than the rest, still not bad though. I use 10w30 conventional and in a mix of driving (mostly easy driving) burn 1 qt every 1000 miles. Is this anything to be concerned over? It has burned at least a qt. every 2000 miles oil since I bought it at 117k miles.
I figured due to the oil burning the leakdown would have shown an issue but that does not seem to be the case...

 

I haven't performed a compression test on my 98 gsr (120 k miles) but mine also burns oil. I know 1 qt every 1000 miles is within spec. However, you are running a thicker oil, recommended in the car is 5w30. Sometimes I need a qt (using 5w30) after 900 or so miles. Kinda makes me wonder whats going on but I still get excellent gas mileage (30-31 freeway) and have plenty of power. Just thought I'd bounce that off you.

 

its possible that the compression rings are fine but the oil scraper rings are shot so oil is still on the cylinder walls when combustion happens

 

oil entering the combustion chamber will raise compression, by your #'s sounds like your ready for a overhaul, or just keep addin oil.

 

I was using 5-30 for 2 years but haven't noticed a difference either way with the 10-30.

If oil was entering the head would it boost the leakdown numbers as well? I guess there is an arguement if the b18c1 is *suppose* to usually burn some oil or not. The car still runs great so I'll be just adding oil either way, but this is making me curious. I don't see any wet oil on the plugs after idling either, just black soot.

 

no, the engine is not cranking durring a leakdown test so oil cant get past the rings.

 

do you get into vtec often? that will burn oil

 

Not much...once in a while. I might touch redline 2-3 times in a week.

 

could be valve stem seals. you could have great compression numbers, but still burn oil.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MatHadder &raquo;</TD></TR><TR><TD CLASS="quote">could be valve stem seals. you could have great compression numbers, but still burn oil.</TD></TR></TABLE>

Good point. Does it smoke at startup?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MatHadder &raquo;</TD></TR><TR><TD CLASS="quote">could be valve stem seals. you could have great compression numbers, but still burn oil.</TD></TR></TABLE>

That's the first thing that came my mind when I looked at the compression #'s versus the leakdown #'s.

 

No smoke at startup. Only some at WOT 4-8k rpm.
I guess it's just, on average, worn for a 150+k mile car.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DarkDragon &raquo;</TD></TR><TR><TD CLASS="quote">its possible that the compression rings are fine but the oil scraper rings are shot so oil is still on the cylinder walls when combustion happens </TD></TR></TABLE>

Yes, this is possible, and often overlooked. the fact that a car has decent compression does not say anything about the oil rings.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by firewalkerr &raquo;</TD></TR><TR><TD CLASS="quote">I haven't performed a compression test on my 98 gsr (120 k miles) but mine also burns oil. I know 1 qt every 1000 miles is within spec. However, you are running a thicker oil, recommended in the car is 5w30. Sometimes I need a qt (using 5w30) after 900 or so miles. Kinda makes me wonder whats going on but I still get excellent gas mileage (30-31 freeway) and have plenty of power. Just thought I'd bounce that off you.</TD></TR></TABLE>

5w30 and 10w30 are both 30w oils. It is the second number that you care about.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DarkDragon &raquo;</TD></TR><TR><TD CLASS="quote">its possible that the compression rings are fine but the oil scraper rings are shot so oil is still on the cylinder walls when combustion happens </TD></TR></TABLE>

I agree