1992 Accord Rough Idle

My wife's 1992 Accord EX 2.2 has developed a nasty vibration when the engine
is cold at idle, even more noticable when in gear. Only vibrates during cold
idle and not at higher engine speeds or when engine is up to temperature.

Searched through Google Groups and found MANY people with the same problem,
stating it's a common problem with this era of Accord. I've seen suggestion
about doing "this that and the other thing" to remedy the problem.
Including, but not limited to, intake and injector cleaning, valve
adjustment, plugs, cap, rotor, wire, O2 sensor, EGR cleaning/replacment,
engine mount check/replacement, idle control valve, etc, etc.

My problem is I haven't found any thread stating the problem had been
remedied by doing any number of these, except for the motor mount. The
people that had a vibration due to a bad motor mount had the vibration all
the time, not only when cold and not only at idle. Ours is only at cold
idle. The people with the cold idle vibration don't seem to have the problem
solved, or haven't posted what their solution was.

The car is due for a tune-up anyways, so that will be done in a couple of
days. I'll also check for vacuum leaks and do a compression test while I'm
under the hood. It also has an exhaust leak at the centre pipe to muffler
flange that will be repaired soon. If the vibration doesn't go away, what
should I do next?

Steve Mackie

 

Steve,
You mentioned that you plan to get a tune-up in a couple of days. I advise
you to tell the service manager or mechanic the problems that you are
having. He may be able to fix the problem. It's fairly easy to find
problems when a car is placed on a lift. Ask the mechanic to place the car
on a lift and check for any problems--esp. the engine mounts.

 

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All is speculation without knowing the mileage. I'd guess it's the valve
adjustment. CR-Vs are terrible when the valves get too tight, with
stalling during the warm-up, but they go on to burn valves, like the
integra. If you're in Canada, run a couple tanks of Mohawk Ethanol gas
thru it and see if it smoothes out.

'Curly'

 

You mentioned that you plan to get a tune-up in a couple of days. I advise

I am the mechanic. But I will check the engine mounts.

 

All is speculation without knowing the mileage. I'd guess it's the valve

160,000kms. What do you mean by the valves getting too tight? What will the
ethanol gas do? The last experience I had with ethanol gas I put it in a
Cavalier I used to own and it ran like shit until that gas was all gone and
I got regular gas in it.

Steve

 

Since you mention "worse when in gear" I assume it is an automatic
transmission. In that case, the rear mounts should be electronically
controlled hydraulic mounts designed to solve exactly that problem.
According to the Haynes manual, section 2A-18, "any diagnostic work must be
done by a dealer service department or qualified repair shop."

Mike

 

According to the Haynes manual, section 2A-18, "any diagnostic work must

I'm going to assume you posted that quote for a laugh.

 

I just report it, not write it.

The system doesn't look that complex, just well buried. FWIW, the Haynes for
our Volvo 765T says the same thing about the A/C system. (Not that it has
electronically controlled hydraulics - that it should only be touched by the
dealer or holy scribe. "Oh Wah Ta Goo Siam")

Mike

 

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The valves on the Integra / early CRV engine get tighter as the engine
ages. If they're not adjusted in time, they will start burning.
Unfortunately the manual says to ignore them unless they get noisy :-(
In the North American manuals it says to wait till 105,000 miles for a
valve adjustment. UK manuals apparently say 50,000 Km, (30,000 miles).

Ethanol is a great cleaner and remover of moisture. It cleaned up a
sticking injector for me, and might absorb water lurking in your tank
and filter. Sure it's not great as an engine fuel, but it does fix a
couple of other problems that sound like what you're asking about.

'Curly'

 

Always start with the basics. Have the plug wires and cap and rotor EVER
been changed? When a car comes into our shop and it is 13 years old with OEM
wires on it and running ruff, we start with that. So first put new plugs,
wires cap and rotor (the basics to the ignition system) and see if the
problem is gone. If not, then we get into advanced diagnostics.
Yesterday a 1986 Chevy Caprice Classic came in with misfire and ruff
running. (As the engine "loads up" when placed in gear it always will seem
worse) The car had the original spark plug wires on it. We did all the
basics ant it left running fine. Now the front brakes were at the squeelers
and the radiator is about to blow but it ran good!

 

Always start with the basics. Have the plug wires and cap and rotor EVER

Everything was changed about 5 years ago. The plugs were changed and a valve
adjustment was done about a year ago. I am about to change the rotor, cap
and wires, PCV, air filter etc. Also fixing the exhaust leak, check the
valve clearance, check compression and plug gap. This will most likely fix
the issue, if not you will hear about it. When I changed the plugs last
year, I inspected the cap and rotor. They were worn, but didn't seem in need
of a change, no maybe they do.

Steve

 

So I changed the ignition consumables. The engine has smoothed out with
increased power, or according to my wife "pep." No longer sounds like a tank
with the new pipes/muffler. However, the rough idle/vibration is still
present. Since I only drive the car once in a blue moon, I drove it around a
lot today, to and from work, running errands, etc. I noticed that the rough
idle/vibration is intermittant. It'll be rough, shut the car off, come back
5 minutes later, restart and all is smooth. Doesn't vibrate as much when
engine is at temperature, but it's guarunteed to vibrate when cold (below
freezing).

I got the ALLData information on the rear motor mount, description and
diagnosis. I will check it out later.

Steve

 

Run a can of fI cleaner in the tank

Steve

 

Good tip.....will do.....

 

really? that's contrary to most other cars that get looser with age.
the only way that could be happening is if the valve/valve seat
interface is wearing at a greater rate than the cam/cam follower.

true! but they burn for other reasons as well.

 

I'd have to agree with you there. As an engine wears, the valve
clearances will increase....not decrease. Also if the valves are too
tight, they won't close against the seats. The cause of burnt valves
(related to valve clearances), is because the lash adjustment is too
sloppy, thus not allowing the valves to open completely, and therefore
causing the valves to stay closed and hot for too long and then burn
(usually the exhaust valve because it is hotter than the intake). There
is combustion occurring in the cylinder, but the exhaust is staying in
the cylinder too long, and thus you get burning.

Regarding the rough idle.....when is the last time you had your
transmission cooler flushed ? Over time, the same crud that pollutes
your transmission also takes up residence in the small confines of the
cooler, which in turn creates a back pressure in the cooler hose coming
from your transmission, which in turn causes the oil pump in the trans
to work harder, which in turn puts extra, unnecessary load on the
engine, and so on and so forth. It's worth a shot as nobody ever thinks
of doing this (usually only done when a trans is replaced at the
dealer), and it does cause rough idle. I know a lot of people have trans
flushes done, but I don't think that the cooler is included in the
flushing circuitry.....just hooked up to the trans cooler lines.

D.Mills
Licensed Automotive Technician.