hear some evil, smell some evil. (need help)

[wudini]

i have a 95 ex/D16Z6 and when i start the motor from cold, i hear what i believe is a valve tap. how dangerous is this, should i be concerned, and what can i do to remedy it? (apart from the obvious changing of the valvetrain) it quiets out for the most part once warm, but can be heard if you're listening for it. could this be a sparkplug arch? i recently changed my plugs/wires.

second, when i get on the gas real good and get into the high RPM's, i notice a rotten egg smell (best way to describe it). i've always been told this was a bad catalytic converter, yes?

which brings me to my final question, also coming from the area around the cat i notice a random pinging noise that becomes faster, but still very random, the higher the RPM's. almost as if something metal is being bounced around in my exhaust. any help on any of these questions is appreciated, and thank you in advance for anyone with advice.

[BullShifter]

Originally Posted by wudini

i have a 95 ex/D16Z6 and when i start the motor from cold, i hear what i believe is a valve tap. how dangerous is this, should i be concerned, and what can i do to remedy it? (apart from the obvious changing of the valvetrain) it quiets out for the most part once warm, but can be heard if you're listening for it. could this be a sparkplug arch? i recently changed my plugs/wires.

second, when i get on the gas real good and get into the high RPM's, i notice a rotten egg smell (best way to describe it). i've always been told this was a bad catalytic converter, yes?

which brings me to my final question, also coming from the area around the cat i notice a random pinging noise that becomes faster, but still very random, the higher the RPM's. almost as if something metal is being bounced around in my exhaust. any help on any of these questions is appreciated, and thank you in advance for anyone with advice.

Your engine requires manual valve adjustments about every 30,000 miles. This could be your noise if the valves are loose. Honda's don't like cheap tune-up parts*

Rotten egg smells usually relate to a bad cat.

There are heatshields all over the exhaust that come loose. When cool hit the exhaust to pinpoint the loose one. You can either rip it off or try to save it with a large hose clamp.

[wudini]

Originally Posted by jackasssi

There are heatshields all over the exhaust that come loose. When cool hit the exhaust to pinpoint the loose one. You can either rip it off or try to save it with a large hose clamp.

yea ripped the heatshields off a while ago, lol

[heucuva]

Well, this could be a simple thing or a multi-part cascading problem.

It is probably one or more fouled fuel injectors, although, it might be a bad catalytic converter, bad EGR valve, or bad PCV valve. Worst case scenario is that a compression ring is broken on a piston and oil is blowing past it. It's very bad, but thankfully, a compression check can determine that quickly.

All you need to check the fuel injectors and PCV valve is a ratchet with a 10mm or 12mm socket and a 3 inch extender or so.

1. Find the intake manifold (silvery set of pipes sticking out of the engine head, towards the back) and look on top of it, there should be a black bar sitting on top of a silver bar that has 4 plug-looking things shooting into the engine's head. Those 4 plugs are the injectors. undo all three of the nuts holding the silver part on the intake manifold. this will also free the injectors from the head.

2. inspect the injector nozzles. if they're black, that's bad. if they're mostly silver, then cool. You might want to use the high-grade (91 octane) fuel... unless you already are, then you might want to change fuel stations, because they're obviously selling you bunk gasoline.

3. while you have the fuel distributor bar off, on the far right side of the intake manifold, there should be a hose that connects the intake body to a black or gray piece of plastic that rests in the air pipes coming down from the intake body into the engine head. that's the PCV valve (Positive Crankcase Ventillation). Removing it will destroy it, but thankfully, it's a $4.00 part that is regularly stocked by your local auto parts store. Pry it loose and replace it just for the sake of doing so. That will likely fix any residual problems related to poor fuel/air mixtures.

4. If all that doesn't fix it, then... um... bad Cat or EGR Valve (Exhaust Gas Return)... only way to check that is hook it up to a special machine that figures that stuff out. You can probably go to your local muffler shop and get one of their "free" $30 estimates. It beats a broken engine for sure.