Hey guys i own a honda s2000 and it burns alot of oil between oil changes..
engine mods..
-Berk racing header
- k&n drop in filter
-test pipe
- chinese catch can hooked up pritty much to the breather hole on the valve cover
stock exhaust

when i come to a red light it usually smokes up blue smoke and the back bumper usually gets dark black sut all over it...

we did a compression test and the numbers were around 175 all the way across.. the motor has about 90k miles on it .. never re built.. only thing i did when i got the car was change the valve spring retainers to ap2 because i heard the ap1 ones crack... just wanted to get some info on if this is a common problem or if its normal?
Thx for all the help and ideas in advance..

 

what kind of oil do you run? i know when i switched from mobil one to castrol with lucas oil stabilizer my oil consumption pretty much stopped...but 175 compression seems a tad low from my experiences...and AP1 retainers only crack if you mechanically over-rev the motor, i.e. going from 4th to 2nd at redline...i have almost 100k on my retainers and theyre perfect

 

i totally think the issue may be from the mobil 1 10-30 fully syn im using.. the next oil change im going to switch to castrol fully syn 10-40 and c if it helps... i know that mobil 1 is junk oil and the only reason im using it is because of the price difference... i did the retainers just to be on the safe side i do run the car hard spirited driving.. the retainers were just peace of mind.. and for my 175 compression would it be inaccurate if i was using a cheap compression tester? the car runs great and the motor seems like it has power..

 

i wouldnt run 10w40, i think thats too thick, id stick to 10w30 or 5w30 depending on your climate...and mobil 1 is junk in AP1's, they tend to just eat that ****...i was going through a quart every 1000 miles which is unacceptable to me...as far as the compression tester goes, it very well could be the cause, it could also be you didnt crank it long enough...rule of thumb for that is about 7 to 8 cranks...but if the numbers are consistent with no one cylinder being 10% off from any other one than you should be fine...i just tend to see most AP1's in the 200 to 220 range...hope this helps

 

do you think it may be my valve seals?

 

possibly...does it seem to smoke more when you take off from a light after sitting idling for a minute or so?

 

Good advice being said here. Valve seals is what everyone hopes for because they are easy to change but the chance of that is extremely slim..

 

yes thats when it usually smokes or right when i get to a red light..

 

Valve seals typically smoke if the car sits overnight and puffs first thing in the morning. Conditions such as decelerating OR idling, will introduce vacuum from the throttle body all the way into the cylinder. I find 95% of the time there is an issue with bottom end ring seal. Many online diagnosis or wishful thinking has brought valve seal replacements into my hands. I haven't had one fix this problem yet...

Mobil 1 is also famous for being consumed at a much higher rate than other oils. Your compression numbers seem a bit low for the f20c but there is quite a few variables to that. Compression tests are not the end all be all like many make them out to be.

 

if you want a quick easy way to see if its the rings, take the plugs out, drop a couple drips of oil down into the cylinder and redo the compression test...if your numbers go up, youre probably looking at rings...but like stated before, its hard to really diagnose over the internet...i can just tell you from my experiences building honda motors for the past 10 years...leakdown test would be a little more definitive to be honest

 

alright thanks

 

try replacing pcv valve and run amsoil full synthetic (signature series)
that worked for me after changing from mobil1

 

will try

 

if you have access to a borsocope. check to see if the cylinder walls are scored in any way. regardless change to a different brand of oil.

typically in an ap1 when they start to burn oil it is from scored cylinders from what i have found. though they can still run for a very long time in this condition.

 

what causes the cylinder wall to get scored?

 

could be different things. run to lean, bad rings, bad rings lands on piston, oil starvation, car beat to **** and back. like i said if they are scored its no the end of the world. ive seen f20c engine run forever with scored cylinders, just need to be on top of checking oil. i recc checking it every 500 miles at least. especially if you like to stay in vtec all the time.

 

not only do i run the car hard.. the car also does have a 4.77 in it.. and i drive it on the freeway like 25 min every day back and forth .. so about 50 min of driving at 80 mph thats somewhere around 5k rpm ... i know this must abuse the engine somehow

 

Check

 

Weird... I use Mobil 1 Full sync and My ap1 doesnt burn that much of oil... been using it for the past 40k

and my comp its between 210-220 on all cylinders you might want to check that too

 

i can tell you youre one of the few people who run mobil 1 in an AP1 and not burn much oil...the vast majority of AP1's drink that stuff like water...it took me 4 oil changes to finally decide to switch oil and i might burn through half a quart between oil changes and i heavily track my car

 

Your compression #'s are definitely low, which points to worn piston rings. The cylinder lining(frm) in these cars is not kind to the piston rings....

 

This the reason I didn't install 4.77 gears and went with the 4.44 gears.

My S2K's engine was losing oil but leakdown/compression tests determined it wasn't the piston rings but the PCV. I was losing a 1 1/2 qt a month. I just switched to a thicker oil, 10w-40, and it barely loses a quart over 3 months.

 

Hate to say it, but I've got 135K miles and no soot. That said, my little baby (an AP1) gets redlined a lot and will burn through about a quart of Mobil 1 every 4500 miles. I've got an older Integra GSR that does the soot thing and I've traced that to tired rings...though that lil fella's got 200K miles...

 

Its kind of hard to pinpoint oil usage for me in this car as it doesnt really follow a noticeable trend.

-I used to think cleaning the pcv valve helped, but its just a one way valve that opens with vacuum is all it is. I guess if it was stuck open all the time you may suck a bit more through the intake manifold at idle. A few times I have had some smoke blow out the rear from take off. What I think is happening is that the combustion gas byproducts are collecting in the valve cover, and then once you take off its pulled through the intake manifold.

-Like others have said, I seemed to have cut consumption in half by using castrol edge fst. Lucas oil treatment is JUST thicker oil. look for VOAs of that stuff, its just a 60w, nothing special :s

-catch can, I am currently experimenting with a homemade catch can using an water/oil separator from a compressed air setup. Cost is $10. after 100 km already caught a few drops of oil.

-how you drive seems to affect it greatly as well. cruising on the highway wont burn any, low vacuum situation?

 

Can you take a picture of this please?

If I'm seeing this right, you don't have your PCV hooked up right?
You only have the Chinese can hooked up to your valve cover right?
Does the can have a filter and hole?
Does it have a hole at all?
How big is the hole?
Is it bigger than the valve cover outlet?

If it doesn't, well, you're having too much crankcase pressure build up in your bottom end and it's forcing oil past the oil control rings.

If the catch can is good, proceed to rebuild your bottom end as the oil control rings are shot.

I'm with Runnerdown (Hi Paul!) on this one. People usually have hopes and dreams that valve seals will fix their issues, but they never do.