My '90 Civic 1.5L d16A6 was going through a little oil when I bought it. It has always had a pretty hot exhaust manifold, but I figured they are just like that. I have kept up with the oil, pretty much, but the other day it started running BAD and I pulled the plugs and #3 plug is coated with oil. #3 gets great spark though.

I pulled the valve cover and the valve adjustment SEEMS ok- nothing horribly wrong from that view anyway.

I turned the crankshaft with a wrench and all cylinders seem to work about equally- (that's my hillbilly compression test) and one more thing: it still runs, fairly well, but the exhaust manifold is as hot as ever, maybe even a little hotter.

Any guesses? Can I lift the head off and fix just ONE tiny little exhaust valve?

Is it safe to drive it as is, or am I going to trash something out down there? Should I take off the #3 sparkplug wire?

Thanks, Joe
'90 civic 1.5L d16a6

 

try doing a compression and leak down test before takin the head off.

 

if its a d16a6 its a 1.6 cowboy. and remove your valve cover, replace your valvecover gasket and your tube seals, there are 8 but only the top usually go bad. this causes oil to get into your spark plug cylinders and can cause it to miss. it could be your problem

 

I dont think he has oil down where his plug go i think he ment that the ground electrode and the center electrode of the spark plug are coated in oil

 

Correct. Oil is on the electrode, not up above.

well I *thought* I had a 1.5L d16a6. Guess not. How do I tell?

I am planning to do a compression/leakdown test this weekend, using an air regulator and gauges I have laying around (got the idea from here: http://www.xs11.com/tips/misc/misc3.shtml )

Then, I guess I will know a little more, but I STILL don't know if it is possible or advisable to take the head off to fix a valve, with the engine still in the car. Can I do this?

Also, is it uber unwise to drive this car the way it is? Maybe with the #3 sparkplug wire off?

Thanks, Joe

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by joetho &raquo;</TD></TR><TR><TD CLASS="quote">
well I *thought* I had a 1.5L d16a6. Guess not. How do I tell?

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ummm... the 16 in d16a6 tells you its a 1.6L. if it was a 1.5L it would be d15somethingsomething

 

Great, now I can't figure out what engine it is.

VIN calls it a 1.5L
vin= 1H6 ED3 547 LL 0021016
USA-Honda-passenger / Civic4Door,1.5L / 4drsedanmanual-DX- / 1990-Ohio

but the sticker on the timing belt cover says D16B23528189

How do I find out for sure what it is? Is there a number stamped on the block somewhere?

 

The DX never came with a 1.6L. Sounds like your car has had an engine swap. Check the engine code to the left of the exhaust manifold.

And ive noticed my engine seems to be really hot all the time, not overheating hot, just you can barely touch the hood after a descent run.

 

COULD JUST BE A SWAPPED TIMING COVER OR HEAD

 

An update.

I am leary about doing this job myself (replacing just one valve) and I have a pretty basic question:

Would I save any significant amount of $ by taking off the head myself, and carrying it into a shop to have them fix the burned up valve?

I haven't done the compression/leakdown test. I started to tear up an old sparkplug to make a tester when it occurred to me that I would have no way to tighten it into the head with a hose coming out the middle of it. Also, I can think of no other explanation for why this motor is doing what it is doing. Bad exhaust valve.

Thanks, Joe

 

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

I am leary about doing this job myself (replacing just one valve) and I have a pretty basic question:

Would I save any significant amount of $ by taking off the head myself, and carrying it into a shop to have them fix the burned up valve?

I haven't done the compression/leakdown test. I started to tear up an old sparkplug to make a tester when it occurred to me that I would have no way to tighten it into the head with a hose coming out the middle of it. Also, I can think of no other explanation for why this motor is doing what it is doing. Bad exhaust valve.

Thanks, Joe

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You would definitly save some money in removing the head yourself. I would recommend doing this just so you feel more comfortable with your car and working on it. It's not that hard of a task either:

Drain coolant....remove intake manifold and exhaust manifold and set aside (keep as many hoses/connectors hooked up to the intake manny so you don't have to remember where they all go)...mark and remove timing belt....remove head bolts in sequence...lift head free (follow your manual to every singe step b/c this is just a quickie).

It is honestly not THAT hard of a job to do. You would definitly save money in removing/installing the head yourself. Just make sure you remove/install everything correctly and by the books...I think you'll be suprised with how simple it actually is (b/c I was my first time!).

And it won't hurt things much driving it with a little oil leaking around 1 cylinder. I drove my wagon for about 3 years with 2 leaking seals and the only thing I would have to do is replace those spark plugs more often b/c they fouled out easy from the oil...IMO your not going to hurt much of anything driving it with it leaking alittle oil around a valvle. Just keep any eye on your oil and make sure it doesn't get low.

 

well the problem is not just oil leaking, the old girl now runs like a tank. I am assuming that the bad valve has gone way bad instead of just leaky.

When I unplug the #3 spark plug it runs just as bad, but it is getting plenty of spark.

The rocker arms and matching cams look fine, and the valve lash was just about the same across the whole head. Both #3 exhaust valves go down manually ok.

If I go ahead and pull the head off, and all the valves look just fine, why, I guess the problem is uglier than I thought. Maybe I should bite the bullet and figure out a way to run a compression/leakdown test anyway?

At the very least, I am going to take the exhaust manifold cover off tonight so I can hopefully read the engine code stamped on the head. This is either a 1.5 or a 1.6 (VIN and timing cover stamp don't agree) and I am thinking I will want to KNOW that...

-Joe

 

No need to remove your exhaust...look to the left (towards passenger side) of the exhaust manifold and you'll see it there. You may have to wipe away the funk to see the engraving. Its a flat spot on the block angling up towards you...search and you can find some pics

 

Oh yea...Have you tried replacing the #3 spark plug with a new one and see if it runs any better? I would have to replace my bad cylinder plugs pretty frequently...

 

you can drive it with the plug fouled with oil it will run like **** though and let gas down past the rings into the oil. you can do the head gasket with the engine in the car its not too hard. takes me about 45 minutes if i dont run into any trouble( not including having the head shaved at a machine shop if it was being changed because of a blown head gasket.).

 

I started to take the head off, and look what I found underneath the valve cover, partially blocking an oil hole:



it's a little piece of beatup rubber, about a fat 9/16 wide:




Is this a valve guide that fell out when someone else was doing a previous valve job? I think I would have remembered taking the cylinder head off.



If that is what it is, what can I expect for damage? Any ideas?

-Thanks, as usual,
-Joe

 

looks like a spark plug tube seal.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by vegas hoe &raquo;</TD></TR><TR><TD CLASS="quote">looks like a spark plug tube seal.
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Did you see the measurement on the ruler? Thats something a little over a 1/ 2 inch wide. Dont think a plug will fit through that

Thats doesnt look like a valve stem seal either because they usually have a metal base and would have a spring around the outside top portion as well. Inner diameter is a little to large too. Cant really determine what it is but definetly none of the previous stated.

 

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

Did you see the measurement on the ruler? Thats something a little over a 1/ 2 inch wide. Dont think a plug will fit through that

Thats doesnt look like a valve stem seal either because they usually have a metal base and would have a spring around the outside top portion as well. Inner diameter is a little to large too. Cant really determine what it is but definetly none of the previous stated.</TD></TR></TABLE>
oh yeah, i'm a dumb ***
i saw it went to about 1.5" but didn't realize it started at 1.

 

Why dont you try replaceing the valve stem seals and see if that helps out. I have the same problem on my 89 civic 1.5. I just replaced the motor with a jdm and it burns a little bit of oil. Going to replace my valve stem seals and se if that works.

 

For reference,valve stem seal
not this

 

maybe it's one of them grommets that hold the valve cover on?

 

I bought a rebuilt head on ebay for $190 shipped, took the old one off, and yep, exhaust valve. Look:



Here's the whole thing:



I left most of the stuff hooked onto the intake manifold. Hope I can get it back on that way!

Thanks for all your help so far, everybody. I don't have a whole lot of time to work on this. It took me like two weeks (five minutes here, five minutes there) to get the exhaust manifold off!

 

holy ****
did you find out what the round thing was?