cja3455

http://www.youtube.com/watch? v=wrh8HIzlh1w&feature=youtu.be

The head gasket is less then 10k old and car didn't overheat afterward, what is this air blowing out of the rad when revving the engine, I bleeded the cooling system many times and still

cja3455

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ezone

Try this




No, you see the liquid movement happen as the internal pressures change due to sudden increase in speed of the water pump impeller.

That alone is not an indication of a head gasket problem. IMO

cja3455

So this is normal, I'm not seeing any HG symptoms except the air that keeps trapping inside the cooling system and the coolant move into overflow tank and the radiator won't suck it back. I need to bleed the cooling system once a week to suck back the coolant. Sometimes when I open the read cap after the car been sitting overnight, some air escapes into the overflow tank as soon as I start rotating the cap. I tried to catch this air through the hose that go to the overflow and feed it into a block tester to check for combustion gases and the test was negative, something is pushing air into the cooling system, is it possible that a water pump push air into the system ? The read cap is brand new from the dealership
Thanks

ezone

I saw exactly what I expected to see in the video when you revved the engine up.
Your problem is the neck of the radiator is not deep enough to contain all the actively moving liquid as you rev up the engine.

You described symptoms of a breached head gasket.
You need to change your test methods if you want to prove something.
Check this video: https://www.civicforums.com/forums/182-7th-gen/352984-idle-behavior-normal-vid-included-redid-thtle-body-clean-worse-now-2.html#post4629441


An easy one for me is to use a funnel-fill funnel in the radiator, that way I don't have to wait for combustion leakage pressure to overcome the radiator cap relief pressure. (as in the video above, that one has the cap in place.)

Or pull the plugs and apply air pressure to the cylinders.



Those block testers won't prove a dang thing on most of these head gasket failures. I don't use them.
No, the water pump is not going to pump air into the system.

No pinholes in the overflow hose?
Neck of radiator isn't burned out from steam erosion? (Can't tell from the video)

cja3455

Looks like I need another head gasket, so for this job what other things I should consider replacing along with the gasket ? Beside sending the head to the machine shop and maybe putting in a new timing belt; is there anything to ask the machine shop to do beside resurfacing the head?
How risky this job is for a diyer to do ? I'll have someone experience to help me with tools and stuff but I'm wondering where people usually screw up when doing this job ? What things to watch for ? Where to be very careful? Its a big job and I don't want to do it to find out something wasn't done right

ezone

Figure out WHY you have it all apart again so soon.
What is the root cause of this problem?

Did it overheat?

I own a precision straightedge. I measure warpage first, then decide if it needs to be sent to the machine shop at all.

0.002" is max allowable warpage. (0.05mm)

I'd ask them to measure for warpage and if it doesn't need milled, then don't touch it. You can have them check the valves for leakage, but I'd think there would have been other issues if it has valve problems.



When you get the head off of the engine, look at the machined surface of the head. Is it nearly mirror smooth, or does it look like it has a belt sander finish? Improper machining can cause the leakage too. The head surface must be smooth, not rough. 30Ra or less. Just like the original finish of the block deck.

Razor blade to scrape, never a whizz wheel.
Suck the liquid out of the head bolt holes, the coolant in there will keep the head bolts from tightening proper, and can crack the block.

More reading here: https://www.civicforums.com/forums/2...ml#post4630314

And here: http://www.rlengines.com/Web_Pages/C...L_Engines.html

Search this site for more.