"Piston slap" / diesel sound in '94 Accord

I've been Googling for info about my '94 Accord EX 4-cyl VTEC sounding like
a diesel engine, especially when cold. I found lots of references to it, and
even discovered a term that was new to me: "piston slap."

Possible solutions include valve adjustment, piston adjustments, getting a
new short block, etc. All good, but a number of the posts suggest that this
noise is indicative of engines that haven't been well cared for. My car has
133,000 miles on it, is on its third timing belt, has had regular oil
changes (every 3K miles, and sometimes less) and basically every time it
farts in the wrong direction I take it to the mechanic.

So is this diesel sound, or piston slap, merely a characteristic of this
particular model car? (The vast majority of the posts relate to my
generation Accord.) It's really a rather rude sound to come from such a
wonderfully engineered engine, but I will live with it if need be. The car
performs as fine as it ever did and my gas mileage is excellent. I just want
to know what you guys think. Thanks for your input.

 

I thought the 'piston slap' was caused from those driver that would load a
cold engine without giving it a chance to warm up. (e.g. driving off smartly
immediately after starting the car in the morning without letting it idle
for a minuet).

Pars

 

How long does the noise last after starting engine?

Professor
Check out FlashAlert at www.telstar-electronics.com

 

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It's fairly common, same for Odyssey. Nothing you can do, but find a
sticker that says DIESEL and put it on the back of the trunk. People
will stare, and really wonder where you imported it from . . . Just
smile wisely . .

'Curly'

 

A very loose spark plug will make a knocking sound, shortly before it
pops out. At least mine did.

 

If it is any consolation, my 97 makes the same noise. I believe it is
in the same engine series as yours. I also have a 90 and had a 82 and
the noise used to bother me because it is so un- Honda like compared
to them. But it has 143K miles on it and it hasn't come apart on me
yet.

 

Thanks for all the input.

It goes away SOME after the engine idles down after warm-up, but does it
pretty much all the time, just louder when the engine is cold. I take it
easy on the engine when it's cold, letting it warm up before driving.

 

-----------------------

You're supposed to warm it up WHILE you drive it. Read the Fine manual.
Save fuel, reduce pollution, make engine last longer.

'Curly'

 

I've got 240,000km on my 1998 DX Engine which has been used hard (in city
delivery, redlines and hustling at 170km/hr across the city is norm). My car
doesn't exhibit any piston slap issue (even in the winter), In fact it has a
smoother startup then my wife's 2000 DX Engine (and that engine only has
70,000km on it). There's two things I can attribute to the favorable
results, one being the life time use of Mobil-1 oil (started at 30,000km)
and letting the engine warm up before going hard on it. I recently switched
my wife's car to Mobil-1 0w20 and she's seen drastic improvements in fuel
economy as a result. It might be worthwhile to switch to the synthetic oil,
which helps with lubrication during cold startup (and flows better which is
an extra insurance if the problem is an actual engine defect). If you do
decide to go synthetic, let us know if it reduces the noise level of the
'piston slap'.

Pars

 

you definitely have a point regarding oil quality affecting engine
noise. running ford oem 5w-30 in my civic, the motor sounded like it
was five fourth's ready to die. putting it back onto castrol gtx, she
quieted right up again.

 

im considering switching all the vehicles i have to shell rotella synth-
5w40. 2 vehicles spec 5w30, and 2 spec 10w40. i figure 5w40 will be a
happy compromise. any reason not to, other than it not having the
"energy conserving starburst" label?

 

My '96 Odyssey started the "slap" at about 40,000 miles. It was always
treated to Mobil-1 oil changes at 3000 mile intervals. We were religious
about proper warm up, etc. I don't think the oil makes any difference.
Some of them do it and some of them don't.

 

For my next oil change, I'm going to switch to Mobel-1 0w40. If it
returns the same gas mileage as the current Mobel-1 5w30, it's going to
become my summer oil (and I'll switch to 0w20 for the winter).

Pars

 

Considering that the 96 Odyssey was Honda's first attempt at making a
Minivan with Isuzu help, it could have some reliability issues. 40,000miles
seem extremely early for 'piston knock' to occur. If so, it should have been
a warranty issue.

Pars

 

i repeat what i said earlier - some of this /definitely/ depends on the
oil. i changed the oil on my civic this weekend, and she went from
being borderline rattly to utterly quiet. castol gtx 5w-30. 5k miles
since last oil & 10k since last filter. the change before the last
filter was motorcraft 5w-30 & she made a noise like a bag of loose
rattly things from day 1 [and leaked oil like crazy]. with castrol you
get a few thousand miles before it gets noisy, and you need to leave it
in there a /long/ time before it sounds like the ford stuff.

motor oils are /not/ all the same. they /do/ effect how the engine sounds.

 

how much did isuzu actually "Help"? isnt it pretty much a standard
accord platform, with a minivan body? i know it was branded as the isuzu
oasis, but i really dont see any isuzu in the design, unlike the
passport, which was a simple rebadge.

 

I don't think that Isuzu had any part in engineering the Odyssey. The
only connection with Isuzu was that they got some Odysseys to rebadge
(Oasis) as part of the deal that gave Honda the dreaded Passport and
some equally forgettable SUV for the Acura line.

The original Ody was based on the Accord platform and the piston slap
is an occasional problem on a number of Honda models of this vintage.
The first generation Odyssey actually had better reliability than the
second generation minivan.

 

the SLX/trooper! and youre right, i totally forgot about it.

kinda sad to see how isuzu practically doesnt exist in the states any
more. in their heyday, they had a wide range of smaller, useable SUVS,
along with the amigo, and a decent minitruck. now? nothin but a rebadged
GM clone.

i live close to the cerritos auto square in southern california. on the
main strip are all the important dealers. off to the side is a converted
paint store that now sells isuzu/suzuki/mitsubishi. none of those
marques can afford to stand alone. i call it the "kiss of death"
dealership. before that, they sold daewoo

 

What is it about Castrol that makes it such a favorite with Honda
service centers? I mean as log as -- say -- a Chevron brand oil has the
same API rating that is specified by the Honda specs it should make not
diffeence, should it? Yet I noticed that the Honda shops always uses
Castrol.

Rudy

 

Was that after the Yugo shop closed?