ssd

iTrader: (1)

I am going to be as thorough as I can with my description. Please read entire post. I apologize for the lenght of my post.

Car: 98 Honda Civic EX

Motor: d16y8 from 00 Honda Civic EX, unknown miles

History: I recently purchased a bare long block from a junk yard. Original motor had engine knock. Swapped all electrical components to newer d16y8 motor. Therefore retain obd2a. Also swapped intake manifold and exhaust manifold from original motor. Newer distributor also changed at time of swap including water pump and timing belt.

Problem: About two weeks ago, I noticed that the idle was rough especially during start-up but eventually became normal. Then about a week ago, the check engine light came on. I checked it out and it was a code 74 (misfire cylinder 4). That would explain the rough idle. Later that same day, it got worse as I was waiting at a drive thru. The car started shaking and you can see white smoke coming from the tailpipe. Check engine light also flashing as well as noticeable decrease in power. After a few minutes checking the motor, I decide to try to drive the car home (less than 1 mile away). After speeding up a little, the power came back and I was able to drive the car home like normal. A few days later, I try to drive the car again and it was once again giving me the same problems as earlier indicated. I took the car to the mechanic to check out the problem. He tells me that I need new spark plugs. CEL are now cleared and car running like normal. Then just recently, the problem came back. I brought the car back to the mechanic and he said that he thinks it might be burnt valves. I think he jumped to that conclusion pretty quick even though the problem is intermittent. We did a compression test in cylinder 4 and initially he said it was kind of low. Then I did the compression test again in front of him and the numbers came out 160 for the first trial and 140 for the second trial. The mechanic cleared the CEL and told me to tell him if the problems come back. That was two days ago and the car is now running fiine.

Solutions: I am aware of the cost and time to repair burnt valves. I really don't have the money to fix it and the car is my only car. There could be something else wrong with the car other than the valves. It could be the injectors, spark plug wires, cap and rotor, etc. If it is the valves, I don't understand why the problem is intermittent. Wouldn't it be more permanent? I just want to make sure it is the valves before I spend the money on it.

On a side note, if I purchase a rebuilt head, what are the steps necessary to make it work (i.e. new head gasket)? Would that be the cheapest route?

Thanks in advance for any help and again I apologize for the length of the post.

Eclivic

well really you need to do a leak down test on the valve in question. compression isn't that bad, i dont think its a valve issue but more an ignition issue, start with basic, check the rotor button, wires, change plugs anyways they are cheap and check crank sensor.

psychocarne

My daily driver was recently doing the same thing, ended up doing a tune up and hasnt come back. It was a y7 and intermittently had a random misfire. I would start with the cheap parts and work your way to the conclusion. I highly doubt a valve is the culprit especially with it being intermittent.

Fawkinay

hey i dont really give advice cause im still a noob, but when you said white smoke it made me think maybe you were burning water in the engine, maybe you need to replace the head gasket?

ssd

iTrader: (1)

that was one of my initial thoughts also but I checked under the oil cap and there is no mixture of oil and coolant (milky color).

Thanks for the responses guys. I will get a leakdown this this weekend as well as change some ignition components. I'll keep you guys updated.

ssd

iTrader: (1)

I brought the car to a Honda dealership today. They did a block check and said the head gasket is ok. For some reason, the mechanic said I don't need a leak down test. They replaced the cap and rotor and recommend fuel injectors as well as fuel filter. I hope that is the case and not something else.

TravisCadello

seems like either a bad ignition sensor somewhere and at times it gets hot or stops wanting to work and it will not send a signal for the number 4 to spark and will idle rough or the plugs are platnum and are over heating. or maybe all u need is a fuel injector cleaner or maybe you have a weak Coil or bad distributor.


Theirs a lot of reason it could be doing this but ur valves seem good from the compression test's.


What you need to do is next time it has a rough idle is pull over and pop the hood and take one by one off the spark plug wires just pull them off the spark plug and if it idles worse than it was put it back on till u pull one that does not make a difference. put it back on and determine.

1 Is it getting spark? check if it is your good.
2 Next pull the fuel injector clip off and put it back on if its not than check the clip for voltage. if its getting volts than get a microscopic and listen to the injector and hear if u hear it clicking open and closing. or just get a screw driver and hit it and if the idle gets better than its a sticking injector and need some lucas injector cleaner that will lube it up and flush it clean.

Good luck Bro ! and stop wasting money at these dam mechanics. they will guess the problem untill you run outa money man. the more they do to ur car the more money into their pocket. they will know the problem but will tell you its a few other things to make more money outa you. they will find the problem but waay later and 700 bux later.

civic_driver

I had a similar problem on my volkswagen a few years back and it ended up being a cracked ignition coil and it was arcing. So my temporary fix was to glue the cracks so it would stop arcing. Not sure what it could be on the honda but it sounds like a spark issue.