Josh from the Early Toyota Truck forums, this is about a Honda hence the off topic post...

Got a 90 Honda Accord EX that I've been working on and trying to sell. All of a sudden it's billowing smoke at startup until it warms up, then its just at hard accel. I replaced the head on it due to 4 burnt valves and I don't remember it smoking then.

Each of the injectors are firing, none seem stuck open. There isn't a cold start injector so that is not stuck open. The smoke does not smell like coolant nor does anything drip from the tailpipes. I pulled the plugs (they only had about 50 miles on them) and they looked normal, maybe a bit black around the edges but the electrodes were still clean. The engine runs great even with the smoke pouring out. The smoke is white/blue and when the engine is rev'ed almost gets brown. Get it on the road and it has great power. Just a huge massive cloud that lasts for several minutes. I've never ever seen a vehicle smoke this much. Any ideas would be appricated.

I don't know specifically what would be causing it, but I'll speak of a similar problem on my truck and what it turned out to be.

I'm sure you of all people are familiar with the fuel heater plate in the manifold below the carburetor on 22Rs. It also goes through the coolant bypass passage on the underside of the manifold. What had happened was when the dealer replaced that gasket, they just used a slop 'o' RTV instead of a gasket, and it had degraded to the point where under hard acceleration, it was sucking coolant through in quantities just large enough to make the truck smoke like it had a bad head gasket.

I'd look for things that intersect the intake manifold that contain something other than air... coolant, EGR, PCV, oil, anything that might be sucking in under those sorts of situations.

It's a place to start anyway. <img src="/forums/images/graemlins/confused.gif" alt="" />

I believe that smoke on startup, until it warms up, is usually due to bad valve seals. Smoke on acceleration is due to the piston rings.

Richard <img src="/forums/images/graemlins/patriot.gif" alt="" />

The head is rebuilt out of an outfit on the East Coast. It's got a good warranty but I really don't want to use it. My dad's borrowing my compression tester so I will have to wait until he is up here to test it. (2 weeks from now)

Drove it about 15 miles today and stopped at a few grocery stores. It doesn't smoke much at startup when the engine is warm, only does the bad startup smoke when cold and been sitting for a day or more. I give it a good rev in park and I can get some smoke to come out.

If I backed up the car to the street and started it cold, I could stop traffic it's so bad. It looks like my dual exahast are actually afterburners they way the smoke pours out. Yet it runs fine... I just don't get it.

I have a feeling that the exhaust valves (valves/guides/seals) are bad and the oil is coming in there. That would be why the plugs aren't showing up bad. The oil isn't combusting but still burning in the cat causing massive smoke. It stops when warmed up because everything heats up and expands to seal up better. Viable?

I'd have to say valve seals aswell. Try an oil additive designed to soften oilseal, gasket etc. It may taken a few miles of driving for this stuff to work in.

If it does end up being one cyl is soft due to rings, has anyone ever tried doing a rering in veh? How hard is it to get that piston back in from the bottom?

That's an unoffical trademark on Hondas 15 years or older...buddy of mine had an old 80's Civic hatchback that did the same thing, and it turned out to be from old rings, but it still ran like a champ until the day it got creamed by a coal truck.

Smoke on startup is leaking valve guides. Lots leaks while it sits, and vaporizes (NOT burns) when you crank it off. Bet it smells like oil spilled on a hot exhaust, right?

Bad rings will show smoke on engine braking, as the vacuum pulls oil past the rings. It will smoke all the time, and smell like BURNT oil, but smoke a lot worse on decel.

I'd put a quart of ATF in the oil and get the seals to soften/swell, then change the oil. Run it with the atf about a week or so.

I ran it on ATF for a day or 2 and it got worse about a 2 weeks ago. <img src="/forums/images/graemlins/scared.gif" alt="" />

It's now billowing smoke for about 20 mins if just left sitting.

I'm pretty convinced that I need to change the rings out of at least one piston.

Is it even plauseable to do it without removing the crankshaft? I can't imagine removing the engine with the million wires and hoses this thing has...

Hey Flagstaff... The consinsus of opinion, including mine, is the valve guides/seals! Your supposedly NEW head is not up to specs.
If the guy that rebuilt it is nearby get him to replace it with another one. If a long way off that may be why they sent you such a bad one.
Big Jim <img src="/forums/images/graemlins/pfft.gif" alt="" />