laack

my compression across 4 cylinders is 125+-5. The civic manual states max 184 min 135. That said, what does the future of my engine look like? My mpg hasnt changed, no startup problems. I just did the test for curiosities sake.

testing procedure used:

drove some errands for about an hour. came in and made/ate lunch (maybe 1 hr)
idled car for about 2 minutes thinking that it was still hot enough to be considered normal operating temp. (coolant temp guage still just under the middle)
all plugs out, wide open throttle and cranked about 7 cranks per reading. tested each cylinder 2 times.

CrewChief

iTrader: (1)

Sounds like failing rings. Do a leak down test to confirm. You could also blow air in to each cyl with all the valves closed and the pistons at top and listen to where the escaping air is coming from. If is is in the intake or exhaust its your valves. If it comes out the valve cover vent its the rings. I would use about 100-120 psi from an aircart for the test.

laack

what are the chances that i screwed up the test by not fully warming the engine up after i came back out? would i get a false low if that were the case? I'm just surprised that my compression is that low. It showed no signs to expect a poor reading. It starts right up, high 40s mpg average, oil loss over 3000miles is roughly 1/2 qt.

CrewChief

iTrader: (1)

I have 8.5:1 low comp pistons and cold my car shows 120-125psi per cyl.

Try this. When you do the comp test add a little oil....and I mean little to each cyl. If your comp rises then you know its the rings.......do the test on a cold motor.

So do a test on a cold motor. Then add a little oil and retest. You should get a significant rise in comp due to the oil filling the leaking rings. If nothing........bad rings man.

laack

clarification-
test for baseline on cold motor then->

if i retest w/ cold motor + a little oil in spark plug tube= rise in pressure (??good rings??) or (??bad rings??)


retest w/ cold motor + a little oil in spark plug tube= no rise in pressure (??good rings??) or (??bad rings??)

CrewChief

iTrader: (1)

A rise in pressure is good rings. No rise= way bad.

Your best test is going to be a leak down test but the oil trick is a good way to test if you dont have a leakdown tester or a way to force air in to the cly and listen to where it is escaping from.

laack

oil added brought psi up to 150-160 across the board. tested each twice again.

I called around to have a leak down test done, price was 90 at the cheapest.. If there is nothing i can do to fix it without a massive repair bill, i would just rather not know until it sh*ts the bed.

CrewChief

iTrader: (1)

If it raised up that much your rings are on their last leg. The only thing you really have to worry about is if the wear on the rings get to much it will cause the piston to touch the side of the cyl walls and then its a new block and pistons.

Piston rings are cheap and if you do the work yourself the whole thing might cost you about 300. Cause while your in there you might as well change the main and rod bearings too. Good part is you dont have to pull the motor to do it. Just the head and oil pan.

Its your call. you could do it now or wait till it blows and buy one out of a junk yard and then rebuild it. Junk yard motors run about 200-400 depending.

CrewChief

iTrader: (1)

Oh and to explain the oil test

If there is no rise at all then your rings are so bad that they cant compress anymore.

If there is a minimal rise then your rings are good and the oil did not have to fill in much of the gap

If there is a large rise then your rings are on thier way out because the oil had to fill in the gap where you where losing your compression.

laack

laack

well... since im guessing i'm f'd on this one... I just need to know what ruined my rings. 6mos ago i checked my compression and it tested at 170 accross the board.

possible cause 1: At some point i started smelling exhaust and thought that it was my exhaust piping and i replaced the cat, b pipe, muffler and gave up. 2 mos ago i changed my oil and say the hose connecting the pcv was disconnected below the intake manifold at teh oil breather. exhaust smell fixed!

2: i drive with fuel economy in mind (52 mpg average, lowest in last 2 months is 48) so most of my shift points are around 2000 rpm and next gear engagement at 1000rpm w/ slow acceleration crusing highway at 65mph.

3: 215,xxx on the odometer. its just time

4: i screwed up all tests( retesting tomorrow with hot engine)

5: i replaced pcv hose to intake 3 months ago trying to beat exhaust smell with vacuum hose. not as rigid and it collapsed at some point. i replaced it 2 wks ago with honda hose.

BlueEM2

iTrader: (1)

Have you overheated the car? Or ran it low on oil at any point? Those are the two main reasons rings fail.

CrewChief

iTrader: (1)

Well with 215,xxx miles it might just be about time. Now you say you checked 6 months ago and got 170. Did you do the exact same process now as before? Ok something does not add up. you would not lose 50psi of compression in 6 months and not beable to tell anything is wrong. Your car would be smoking, you would have worst power and gas milage.

laack

last time i did it the engine was fully warmed up and tested immediately after running around vs driving it then letting it sit while i went in for lunch and ran it for 2-3 min max then tested. my utility car was having some issues so i checked my civics compression while i was working on the other beater.

6 mos = 10000 miles roughly.

I'm going to test again today with a hot engine if i get some free time later.

BlueEM2

iTrader: (1)

Maybe pay someone to do a test so you are 100% sure.

laack

never over heated, i check my oil about once a month. to date, it burns around 1/2 qt per oil change, 3000mi. castrol highmilage if it makes any difference

I'm really hoping that i royally screwed up my compression test

CrewChief

iTrader: (1)

For your sake I hope so too. Good luck and let us know how it turns out.

civicpapi

I am curious, I have 217k miles, no smoke out of the tail. Never ran a compression test, but leaking oil can see it on the top of the engine. How long can you go with just a leak?

Almost afraid to run a compression test. If I decide to run one myself what do I need and what is the correct procedure?

CrewChief

iTrader: (1)

Your leak is probibly coming from your valve cover. Any leak is a bad leak but as long as your not running the car on low oil you will be fine.

Process of a compression check.

Make sure the engine has been warmed up before beginning the test, to ensure that the oil has been warmed up. A cold engine will not test correctly.

Disable the ignition module or coil.

Insert the compression tester into one cylinder spark plug hole at a time.

Hold the throttle to full open position to ensure the engine gets adequate air intake.

Crank the engine continually for at least five to 10 full revolutions to obtain an accurate reading on the compression tester.

Record the reading for each cylinder. If any of them vary 10 percent or more from each other a problem may exist in one or more cylinders. If the variance is greater than 10 percent, specialized testing equipment may be required to fully diagnose the problem.
If all cylinder readings are within 10 percent of each other, no further testing is required and compression is considered

laack

user error! i used a different tester this time from autozone and tested immediately after running around town. highest reading was under 190 (analog gauge) lowest reading was about 170. tested each cylinder 2 times.

all that stress for nothing. it either had to be the gauge i used last time or the engine not being warm enough.

thanks for all the help crewchief

civicpapi

Had the valve cover done, had the distributor o ring done, had the v tec solenoid done, still leaks right in the area below the distributor.

I am curious can the crank or cam seals leak in that area?

Back to your post:

"Hold the throttle to full open position to ensure the engine gets adequate air intake".

Do you mean hold down the throttle as you crank?

CrewChief

iTrader: (1)

Not a problem. Glad to see it work out in the end and didnt cost you any money to fix.

CrewChief

iTrader: (1)

Yes and Yes. when you changed the valve cover seal did you put a little sealant in the corners by the Cam lobe holder. If not they like to leak in those cracks. For some reasom the OEM rubber gasket does not seal completly in that area on all civics new and old.

civicpapi

I had the dealer do it when adjusting the valves, so who knows.

I have attached a pic of the area, oil under the dizzy area, and on top of the trans etc.

any ideas?

Scroll to last post, will not let me post same pic again.

https://www.civicforums.com/forums/7...-oil-leak.html

CrewChief

iTrader: (1)

On that sensor there is no oring or seal. Just pull it out and either wrap the treads in Pipe sealant tape or cover the treads in some Honda bond or gasket sealer and reinstall. If that is the cause it will seal it. I use seal tape on every sensor on my motor religously.

civicpapi

The only thing I read that, is only coolant will come out, not oil?

CrewChief

iTrader: (1)

You sure its not still coming from the Dizzy. we changed a dizzy seal on my boys D16 and that **** would still leak. We had to remove it and add gasket sealant to get it to finally stop.

civicpapi

I had that done at the dealership as well, I should have them look at it again. Also, will that leak a lot of oil?

In your opinion do you think that could be it? and not the cam or crank seals?

Thanks for your help.

CrewChief

iTrader: (1)

It can. I would clean the area with some engine bright or brake cleaner and then run the car and watch for the leak. Let you know exactly where its coming from.

civicpapi

Thanks Crew.