Just got my car back from the dealer...


Cyl #1 5%
Cyl #2 5%
Cyl #3 8%
Cyl #4 10%

He says brand new is usually 5% and 20% is allowable by Acura.



Modified by oryanh at 12:17 PM 8/6/2003

 

20% is deffinatly not allowable by honda.........i think you should take your car somewhere else for service/tests.

10% leakdown is alot........especially on a honda engine.......

what engine is this test on?

 

B18C5 with 28k miles.

 

i had less than 3% leak down on all 4 cylinders on my 95 LS engine with over 70k miles........

i would have to say the guy who did the leak down test didn't to it properly or his leak down tester guage is inaccurate.

if thats not the case then your engine is in desperate need of re-building.

 

what exactly is involved when doing a leakdown test? I need to do one soon to see if I can find out why Im loosing so much oil. I already did a compression test and the numbers were excellent, so from what Ive been told a leakdown is the next step.

 

A leak down test involves pumping air (at 100psi) in a cly when it is at
tdc, it measures the %loss of air leaking out. I had one done this weekend
on my car, with 1 or 2% loss on all cly's.

Some more info here
https://honda-tech.com/zerothread?id=438893

Ryan-Who is high from breathing gas fumes all day

 

Not to jack the thread or anything, but does a large loss indicate exactly what the problem may or may not be? Bad rings, bad valves perhaps?
Thanks.
Mark

 

canuck thanks for the info.

how do you know where the air is leaking from?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 01ITR#700 &raquo;</TD></TR><TR><TD CLASS="quote">Not to jack the thread or anything, but does a large loss indicate exactly what the problem may or may not be? Bad rings, bad valves perhaps?
Thanks.
Mark </TD></TR></TABLE>

yah technician should say where leak is coming from, i.e. header, intake manifold, vent, cylinder next to it, etc.

to do the test properly, no adjustment on adj cam gears for overlap or it'll distort. camgears should be 0'rd out.

 

how much does honda charge to get this done...I think i'm in need of a compression, leakdown test.

 

I had my car in for a valve adjustment, and he did the leakdown for free.
I've seen it done for around $80.00

 

10% isn't huge, but definately shouldn't be there with 24k on the clock. They should be about 2-5% with that few of miles. My old motor with 50K of raced miles and daily driving still only had 5% across the board. But the 5% was leaking out of the rings. My new motor is 0-.5%, which is where it should be.

Here is the appropiate way (my version) to do a leakdown test:

Its very similar to a compression test, but like someone said about, you are pressurizing the cylinders to see how much and where air is leaking. You can get a leakdown tester from Snap-On, Summit, or make your own, there were some old posts before about how to make your own. The leakdown tester comprises of a tube that has a female air line fitting on one end and a spark plug fitting on the other. The other part of the tester is 2 gauges, 1 1-100 PSI gauge, and 1 percentage leakdown gauge. On this part of the tester, it contains a **** that allows you to let air pressurize the system or completely shut it off. You will also need an air compressor that holds at least 100psi of pressure.

1: Make sure the engine has been run and was at operating temperature. Turn off engine
2: Remove all spark plugs, and rotate motor to TDC on Cylinder 1
3: Take off intake piping, oil cap, and radiator cap (careful, it may still be pressurized)
4: Thread the spark plug fitting of the tester into the #1 spark plug hole.
5: Attach the air hose from the air compressor onto the other portion of the tester, making sure no pressure is showing on the gauge.
6: Attach the female end of the gauge to the male end of the tube, slowly turn the **** on the tester until the cylinder is pressurized to 100psi.
7: Read the leakage gauge to see what percentage of leakage there is. Record that reading.
8: If there is leakage more than 0%, listen/look for escaping air from the following places:
a)Fully opened throttle body
b)Oil cap hole
c)Exhaust
d)Radiator cap
e)Any spark plug hole

9: After you trace where it is/isn't leaking, depressurize the cylinder, and un-hook the fitting.
10: Rotate the motor to cylinder #3, repeat steps 4-9
11: Repeat step 10 for cylinder #4
12: Repeat step 10 for cylinder #2

Analysis of leakage:
Leaking from Oil Cap hole: Most likely your rings are leaking, if you have air releasing into your crankcase, it means the rings are sealing 100% and there is air flowing passed them.

Leaking from Intake/TB: Air is leaking from your intake valves, probably need a valvejob or new valves depending on whats wrong. I had 11% leakdown from my #3 cylinder at one time, this was due to a bad seal on the valve seats and also one of my retainers was starting to crack which caused it not to full return into place.

Leaking from Exhaust: Bad exhaust valves/seats, on an over-rev, the exhaust valves are usually the ones that get bent. If you use nitrous, the exhaust valves are also the ones that usually get "burnt" or injured.

Leaking from Radiator: Bad headgasket

Hope this helps!

 

was this a dry run or a wet run results?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 98TypeR &raquo;</TD></TR><TR><TD CLASS="quote">was this a dry run or a wet run results?</TD></TR></TABLE>

 

Hmmm. wet/dry? I will find out.

 

Dry.

He said I had some carbon build-up that was not allowing the valves to seat correctly.

 

good info, don't wanna lose.

 

lmao... he is the best acura tech in houston?? what a boner.

 

huh?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by oryanh &raquo;</TD></TR><TR><TD CLASS="quote">huh?</TD></TR></TABLE>

if your "tech" says there is 5% leakdown on new motor he is full of ****. same goes for 20% allowable. can you imagine how much power you would loose if 20% of all the compressed charge an engine made was leaked out of the combustion chamber??