Just got my 1994 CX put back together after the head gasket repair last night, and I drove it around for the first time today. Seems to be driving great, not much power of course, but its rated 70hp at the crank from the factory so I really didn't expect much. The only problem is that it has a small misfire (idle only) and it burns oil at higher rpm's. I don't know what rpm it starts smoking at, because CX's didn't come with tachs, but I'm guessing its around 4500-4700 rpm.

I pulled the spark plugs, and they have whitish deposits on them after being in there for a day. Does that mean its running lean/timing is off? That would explain the misfire, but not the oil burning.. So that kind of leads me to the PCV valve. I completely forgot to replace it when I had the head off. Could the PCV valve cause a small misfire at idle and the oil burning problem? I'd hate to think my piston rings are shot... motor only has 117,000 miles on it.

Any help would be appreciated, thanks

 

ok so you did a head gasket.

did you get the head shaved? could be warped

did you get the valve seals and giuds replaced? Honda dealers told me if thay get a head gasket and the motor has 60,000miles or more that 9 out of 10 time the valve giuds are out of spec and thay leak oil after.

did you have the head magna-fluxed for cracks?
sound odd but a crack would do that but if it over heated a cracked into an oil passage it will smoke at highr rpms as the oil pressure gets higher.

did you still have crosshatch in the cylenders? If no then it's the rings

the idel could be a vac leak between the intake and the head. did you tourqe the bolts to spec and falow thw tourqe pattern?

 

I got the car for $400, so no I didn't do any of the extra work like magna fluxing. Just pulled the head, scraped the gasket off, cleaned everything up, wiped out the cylinders and put everything back together. Intake manifold was torqued to spec. It was doing the misfire before the head gasket repair, so the misfire probably doesn't have anything to do what I did with it... Thanks though.

Maybe it is the piston rings... the inside of the cylinders were looking pretty bad. Hone wasn't too visible and the walls had some corrosion on them from the water/antifreeze getting in there. They were still smooth though, I don't know if that makes a difference :/

Thanks!

 

sounds like bad rings a cylinder damage are the problem. i say runn it till it dies a do a swap for bigger motor.

 

If i did do a swap, it'd probably be for another d15b7/8... don't need any power, just looking for cheap reliability and good miles per gallon

 

true but i was getting 36MPG in my 93 Del Sol with a D16Z6 and a 5 speed and the hatch is lighter then the Del Sol so i could see you getting better MPG with a Huge HP gain

 

I don't need more horsepower though... the 70hp at the crank the d15b8 has been working out fine for me... No real reason to spend twice as much for horsepower I'll never use

 

Alright, a bit of an update.

Pulled CEL, got a code 41, heated o2 sensor. This is probably from the big *** exhaust leak I have right after the cat. This might be what's causing the poor mpg/misfire, but not the oil burning.

Checked the PCV valves. One of them, (in the breather box behind the block) still rattled a little bit when I shook it, but the 90 degree one mounted on top of the IM didn't rattle at all. Is this one supposed to have a check valve in it too?