Fresh motor lost a cylinder

[arcadiacb7]

Ok well my fresh built h23 vtec came close to the 500 mile mark and while going 75mph on the freeway one cylinder went dead. When i got home I did a compression test and cylinder 1 had nothing, 2, 3 and 4 had about 240.
I am getting no smoke out the exhaust oil is full, coolant dropped a little but i don't know if it is really enough for to say blown head gasket. I pulled the valve cover and everything looks tight up there and all the valves on all cylinders seem to move about the same. The only thing I really think it could be is the cometic gasket is shit (I worked there, i seen what comes out of that place) or a valve bent. Just wondering if any of you guys have a suggestion. Also I haven't taken this motor past 6500 rpms. ok well once it saw 7k. but just once.

well any ideas?? help please

[quickangel93]

piston ring? did you do a valve clearence check?

[NAiL05]

IT could be a valve bent. To make sure its not your rings put some oil and redo the test. Numbers should go up. If it still stays 0 probably your valves. You can also do a leakdown test to further confirm this since you should be able to hear where its coming out from if its the valve.

[Bboy_Trevstuh]

That's what happen with mine I got lucky and only had 1 bent valve on the exhaust side!

[AllWhiteCoupe]

Personally, i dont think you should rev it that high with only 500 mi. When i got my fresh f22, i let i break in. I didnt rev passed 4000 untill i got 2500 miles on it. But it does sound like your rings could be bad. But first, deff. check out the valves. Good luck

[arcadiacb7]

Yeah i tried the oil thing and i got no difference. so i think its a valve or possibly a head gasket. If a ring went it would smoke like a bizzitch right?

6500 is no big deal on a h23 vtec. My motor is designed to rev to 7800 safely.
I rev it high though because at 75 on the freeway my car is revving at 3500-4000 rpms and it has vtec so it is supposed to be used. How a motor is treated during break in is important to its longevity. If i only rev the motor to 4k during break in then it is going to not be used to 8k when i'm racing it. so if I push it a little during break in then it will be more likely to last longer when i start driving the shit out of it when it is "broke in". I'm going to take a couple of days to cool down so i don't go and get pissed and do something stupid to it. Then i'll tear the head off and see what i got.

If anybody else has some suggestions please throw them up.

[blackcb7]

a leak down test will tell you what you need to know

[almostJDM]

i have the same problem as you but my comp was around 150 for 1,2,3 and 0 for #4 i did a leak down an still same so im in the process of tearing the head off i hope i find good valves lol mine would take a month to get from japan hope its not the valves

[mugenaccordlx]

Carefully check everything , especially for bent valves or any cracks.

[Fake Thug]

Yeah i tried the oil thing and i got no difference. so i think its a valve or possibly a head gasket. If a ring went it would smoke like a bizzitch right?

Any dark blue smoke? Because you should see a shitload of it behind you if rings are gone. Did you pull that plug to see if it was covered with oil? I think that engine might have overevved. looks like you have to pull that head and check those valves.

[almostJDM]

im wishin for the best 4 ya i just go the head off my f20b and need new pistons now good luck altho i bet its only minor

[arcadiacb7]

hey thanks for the good wishes, they are appreciated. Yeah i pulled the plugs to do a compression test. I have denso iridiums in there and they were all a little on the dark side. No there was no smoke. I figure its gotta be a bent valve. I noticed that it wasn't hitting vtec when i noticed the problem so that may have caused the head to over rev. I'll probably pull it apart on wednesday cuz i have it off of work. I really hope to see that cuz i'm going to buy full skunk2 valve train. hehe