I know this has been asked a thousand time. I searched but couldn't really find an answer to be sure of.

So the story goes.. A year ago my y8 broke a rod in half. I got a y7 rebuilt and just finished the swap tonight. First swap.

Well after finally getting the timing down I get it to crank. First few times it cranks for a few seconds and dies. Now it will crank on its own and run fine.. except for the white smoke coming from the VC vent hose. And i almost think i hear a knock but i just don't want to get into that.

The fans don't come on and the coolant in the resevoir hasn't moved a bit either.

It was suggested that the gas may be bad earlier (keeping it from cranking.. different problem). But there is octane booster in the gas as well if that's at all relevant. Any ideas?

 

you replace the ecu with a non v-tec ecu?

 

No.. still using the y8 head

 

How long has the gas been in the tank? My civic sat for about a year with a the same full tank of gas and I never had a problem with the gas going bad, although it was a concern at the time, when I brought it out of retirement. I really don't think the gas going bad is your problem.

 

cranking or running ????

refresh your gas if it's been standing for a year or more, it may be contaminated or have some water in it .

Did you do a complete or only a partial rebuild ?

Did you rebuild the head or at least check for bent valve stems and install new stam seals.

give us a bit more information to go on.

Let the engine run with the rad cap off to allow it to vent the air from the system and look for circulation inside the radiator .

A new engine shouldnt knock at all, did you have the other rods checked for straigtness and have the crank checked for beinfg bent etc ?

An engine that breaks a rod can have all kinds of unseen problems.

 

oops, scratch some of that last stuff, I thought you rebuilt the dammaged engine.

 

Just started running tonight. has cranked and died a few times before.

rebuild included pitons, rings, honed block, gaskets (including head), water pump, oil pump, tensioner, timing belt

head wasn't rebuilt or checked.. assumed it was fine since i had no problems from it before the rod broke. and i'm a newbie

rods were fine.. didn't have the crank checked

 

no.. the damaged engine has a big hole in the block where the rod hit it

 

So you used the y8 head, did you recon it or check it out. There is a high chance you bent a valve stem or two.

Does it overheat ? you say you don't see any water circulation.
is the head gasket on correectly ( top - front) sometimes I've heard they can be installed wrongly blocking some waterways.

 

nah the head wasn't checked out. is it possible to see while it's on the motor?

I haven't given it the opportunity to overheat, but the temp rises and rises while it runs and smokes.

i made sure nothing was blocked by the head gasket.

 

Ah, may be a big mistake if you didn't check out the head, could be your cause of the knock too. best you can do is a compression test now but a leakdown test is much better to detrmine if the valves are leaking by. Does it run smoothly ? and black smoke or gas fumes from the exhaust.

You can check the valve stem height of each valve, especially the one cyl that had the broken rod is suspect the most. If one is bent it will me stiff in the guide sleeve or lower height than the rest of them.

Make sure the cam isn't pushing them down when you measure.

 

Alright. I'll check it out in the morning. Thanks for the help.

 

you'll need a micrometer caliper to measure the valve spring height.
measure carefully as their may only be a few thou. difference, pay special ettention to the cyl. that broke the rod and compare them with one of the others.

 

the compression/leakdown and valve hight measurement should tell you if there is a problem with that one cyl and save you removing the head.

The no water circ. has nothing to do with this and may be just an air pocket so leave the cap off next time you run it, maybe replace the thermostat.

 

oh, the white smoke from the valve cover breather .... does it smell of coolant (sweet smell) especially from the exhaust ? may be a waterway leak from the head gasket getting into the oilways, check for froth on the dipstick or **** in the coolant. Or it may just be normal break in. I've not seen that on a fresh angine.
Perhaps at the worst the head is cracked somewhere important allowing water to get where it shouldn't.

 

White smoke is nearly always missunderstood, as it is generally "steam" caused by water entering the combustion areas.


Modified by itsmejto at 4:55 AM 10/26/2008

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by UserX826 &raquo;</TD></TR><TR><TD CLASS="quote"> A year ago my y8 broke a rod in half. </TD></TR></TABLE>

How the F did you manage to do that?

 

please don't open two threads on the same subject, it's so confusing.