Motor setup-
B18c1 OBD 2
Mild port/polish
CTR Intake/B17 Exhaust Cams
ITR Valvetrain

I was driving on the freeway the other night and out of nowhere, my CEL started to blink. Immediately, I let off the throttle and exited. As I made my way off, the car sounded like it was running on 3 cylinders, or as others would describe it, like a WRX.

Once getting the car back to my place, I checked the CEL and did a compression test. My CEL blinked a 72 and 74. I checked the compression and blew 215 across all cylinders except for cylinder 4. Cylinder 4 barely blew a reading on my gauge.

I checked the lash on those valves in cylinder 4 and they were within spec, none too tight or loose. I put the valve cover back on and still, no compression on cylinder 4.

Now, is this likely a bent valve or is there a chance that this could be fixed without removing the head? I did not over-rev the motor prior to this happening and no mis shifting at all. The car has been running fine and strong since the headwork was done about 45K miles ago. This is all surprising for me. Any help is more than appreciated. Thanks!

 

Whenever the car sounds like a wrx, its usually a valve. Same thing happened to me. One day my car all of a sudden started misfiring, hadn't overreved or misshifted. I had a chipped exhaust valve in cylinder 2.

 

Yeah, same situation with me as far as events leading to the misfire.

Did you find out the cause of the valve chipping?

 

nope never figured it out. But the car has been running fine since I fixed it back in july *knocks on wood*

 

How much did it all cost?

 

Lets see I have the reciept here somewhere...


1 Exhaust Valve: $26.54
1 Head Gasket: $62.50
1 Timing Belt: $54.08 (You don't have to replace the timing belt, but its the perfect time to if it needs it.)
1 Valve Seal: $2.95
1 Stud for the header $2.38 (stripped it when taking the header off, won't be a problem if you just remove the whole header from the cat)

Total with shipping: 156.58


All parts were OEM ordered from http://www.barancoacura.com Labor was nothing. A couple of friends helped me rip the head off. For getting the valve in and seated, my friends dad did it for me and refused to accept money from me. Then I put everything back together myself. It was a great learning expierence, I had never done anything this in depth before.

 

Could if be a unplugged spark plug wire?.... I drove around for 2 days trying to figure out what the hell was wrong with my car... looked at everything... well except the #3 spark plug wire that connects to the dizzy.... I can't believe I missed it! Also when me and my bro changed his plugs and wires we accedently switched the #3 and #4 wire and it sounded like a WRX, it was awesome but we knew something was wrong because he has a civic si....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Spoon07 &raquo;</TD></TR><TR><TD CLASS="quote">Could if be a unplugged spark plug wire?.... I drove around for 2 days trying to figure out what the hell was wrong with my car... looked at everything... well except the #3 spark plug wire that connects to the dizzy.... I can't believe I missed it! Also when me and my bro changed his plugs and wires we accedently switched the #3 and #4 wire and it sounded like a WRX, it was awesome but we knew something was wrong because he has a civic si.... </TD></TR></TABLE>

Well, if it were that, I should still be getting compression in that cylinder, whichever it may be. But i'm not showing any compression on the cylinders that are misfiring.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EnjoyTheRideDC2 &raquo;</TD></TR><TR><TD CLASS="quote">

Well, if it were that, I should still be getting compression in that cylinder, whichever it may be. But i'm not showing any compression on the cylinders that are misfiring.</TD></TR></TABLE>

Ha ha whoops missed that part of the post

 

usually the sound of a wrx can be a valve or rod bearing.

 

Pulling off the head today, after a leakdown test. I dont see signs of a bent valve yet, since valve lash is still within spec and none of the springs are compressed excessively.

Is it possible the valve could just be stuck somehow? Maybe some type of additive could free up the valve? Or seafoam the crankcase to remove any types of buildup that is causing the valve to stick??

 

i had the same exact problem you did. and it was a burned valve.

 

my poor valve

 

Yeap, the more I continue to analyze this whole disaster, the more fingers point to a burnt valve. I just hope I somehow find a cheap way out on this one..

 

A) Nobody say burnt valve again...a valve with a chunk taken out of it is not burnt. Your exhaust regularly gets to 900*s, so its pretty common that all valves are "burnt"
B) Take off the exhaust and/or intake manifold and look in the port with a flash light....you'll either see a slight gap around the valve or a big chunk missing from it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EnjoyTheRideDC2 &raquo;</TD></TR><TR><TD CLASS="quote">Pulling off the head today, after a leakdown test. I dont see signs of a bent valve yet, since valve lash is still within spec and none of the springs are compressed excessively.

Is it possible the valve could just be stuck somehow? Maybe some type of additive could free up the valve? Or seafoam the crankcase to remove any types of buildup that is causing the valve to stick??</TD></TR></TABLE>

Have you considered a leakdown test to diagnose the leak path?

 

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

Have you considered a leakdown test to diagnose the leak path?</TD></TR></TABLE>

Yes, I mentioned I was probabl;y going to pull the head off following the leakdown test. Its being performed as I type. Once I find the leak path, or if I find a leak path, then i'll begin to move forward. I was just hoping for an easy fix somehow.

 

I had a bad reading moment.

What was the result?

 

<U>Leakdown Results - Cylinder </U>
#1 = 4%
#2 = 3%
#3 = 6%
#4 = 22% (Air escaping out of the tailpipe)

I guess this explains the loss of compression in cyl.#4...

New question - What explains the misfire in cylinder #2??

 

UPDATE - My 18c has now been be-headed...

Ok, pulled the head from my motor, and checked the block...


So far so good, least I didn't have to change a piston...

So next, flipped over the head to check the combustion chambers....


A close up of each combustion chamber helps finding the culprit...


So there you have it, the loss of compression and reason for misfire was due to a chipped exhaust valve in cylinder 4.

<U>NOW - More questions :</U>
-Why do my exhaust valves have all that white build up forming on them?
-Should I just replace the one chipped valve, or all exhaust valves, or all 16 intake/exhaust valves?
-If I change the one chipped valve with a new OEM one, is it necessary to have the seats cut?

 

i'm not sure if that seems healthy at all. just my .02 someone shall confirm this after me. TTT

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Rcp &raquo;</TD></TR><TR><TD CLASS="quote">i'm not sure if that seems healthy at all. just my .02 someone shall confirm this after me. TTT</TD></TR></TABLE>

Not a confirmation, but I didn't think so myself. It really does not seem healthy.

 

Its a pretty common buildup, the exhaust valves are always white buildup like that due to the heat from the exhaust. Buildup is very common....that much buildup isnt though. A little injector/cylinder/seafoam every 10k or so should take care of the overbuildup. I would replace all the valves simply due to the fact that the valve could've failed due to normal wear and tear and I wouldnt chance the other ones doing the same thing.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 95 integra &raquo;</TD></TR><TR><TD CLASS="quote">Its a pretty common buildup, the exhaust valves are always white buildup like that due to the heat from the exhaust. Buildup is very common....that much buildup isnt though. A little injector/cylinder/seafoam every 10k or so should take care of the overbuildup. I would replace all the valves simply due to the fact that the valve could've failed due to normal wear and tear and I wouldnt chance the other ones doing the same thing. </TD></TR></TABLE>

First off, thanks for the insight 95 integra. See, I would agree with you completely, except my previous DB8 lasted 296,000 miles without a problem like this. The builds were both similar in mods, and I haven't changed my way of driving, so i'm not sure why this occurred.

Its just the cost of replacing valvetrain is SO expensive, its hard to consider spending all the money involved in this mod/repair...and at the same time its hard not to consider spending this money with all the time, labor, and parts i'd have to spend again if it did happen again...

 

is that normal for a valve to be white? lol