hope you honda gurus can
help me out. First of all, allow me to give you a little background
info about my car.
93 Civic Ex, D16z6 Manual Transmission.
I bought this car one year ago as my daily driver, it has about 95K
miles on it. The car overall was in an "OK" shape, but I felt the
engine was not very smooth, so I decided I want to do as much Tune-Ups
as I could to make it a reliable car.
So far, I've done
New NGK plugs and Wires
New Fuel Filter
New Air filter
New Distributor
New Brake Master Cylinder
New pcv valve
New Exedy O.E clutch
New PCV Valve
Throttle Body Cleaning
Coolant Flush
Valve Adjustment
KYB shocks and Integra Type-R spring
Mobile 1 Synthetic oil and Filter every 3k
New Honda MTF

Now the car has 124k miles on it.
Generally, The car sounds very smooth and healthy. However, after I
drive for a while, like 20 minutes of city driving, the smoothness is
gone. Engine begins to sounds like crap, and i mean it. It sounds like
it's gonna break apart when I rev it over 3k rpm. The sound is even worse if A/C is on. Checked my coolant and oil, full and clean. The water temp was normal as well.
And this doesn't happen when car is cold or just warmed
up, it only happen when car has been driven for a while.
I went to a shop that do Honda engine swap. A mechanic test drove
my car, said it might because the engine has been over-heated before,
So some bearing on crankshaft might be loose, hence the crappy noise.
I dont know if he's right or not. Hope you guys can give me some clue
Even though the car doesn't cost much, I really want to know
what's wrong with this little D16Z6, cause I like this civic alot.
Honda gurus, please give me some help, I will be appreciated.

P.S. if any Honda Guru happen to be in LA or Orange County area care
to test drive my car, I would love to meet you up.

 

ttt opinions welcome

 

exactly what kind of noise is it. Sounding like crap doesnt help diagnosing an engine problem. Is it a rattle, grind, sputter.....

 

sorry about bad description. It's not rattle, grind, or sputter. Sounds more like some parts of engine are loose, hence the crappy sound. And this only happen when car has been driven for 20-30 min. Before that, it's smooth as my friend's 00 D16y8
It's really hard to describe. The mechanic testdrove my car said "Doesn't sound right for a Honda" when he heard the noise. We went back to his shop. He thought it might be timing belt rod at begining, but after endless throttle pressing, he came to a conclusion that engine has been overheated before, so some bearing is loose and caused noise. However, we both found the noise is ONLY obvious when car is moving, when it's parked, it is very difficult to hear same noise. He didn't know why, and told me to use 20-50 weight oil to cover noise, which helped a little.
Honda Tech Gurus, please give me your opinion, greatly appreciated.

 

hrmm..timing belt rod...interesting, still could be a bearing, just gotta get in the high revs to make it jiggle

 

Actually I would love to let any Honda-Tech gurus test drive my civic, if they
happen to be in S.California area. Heck! I would even pay for it if needed.
What I really concern is the ACTUAL cause of this noise, because I've spent so much time and effort on this small civic(with the noise ), it's like my good buddy . Fixing it or not is more like secondary to me, for now.

Any more feedback? Honda-Tech gurus?

 

Replace your timing belt. When the timing belt ages, it stretches and gets loose. When the belt gets loose, it can sound like your engine is going to rattle itself to pieces. Sometimes it can sound like a bad distributor or loose valves. If yours is so loose that its making that much noise, it won't be long before it breaks.

 

haha, wtf is timing belt rod. something your engine has but mine doesn't? i suggest going to another mechanic.

 

lol.

Bonga..
Is your car making a 'knocking' noise?
from the sound of this, it seems to be your block.....you should look into buying a used Z6 block or long block. they're only about $200 or so.

 

Heh, 5th Gens and AC do not mix well. Heh

 

thanks guys, i really appreciated your feedback.
About the TB rod thing, I really didn't know, maybe it was another typical
S.California Honda mechanic B.S. thanks for pointing that out though.

Here's a quick Q for b19coupe.
To my surprise, your discription exactly fits my car symptoms. I feel like to call
my body's store and order the timing belt now. However, what do you think about
that noise only comes after car completely warms up. Is this also a symptom
of bad timing belt? If yes, I will fly to the store and get a new timing belt tomorrow. Your responses are greatly appreciated.

 

I don't know if the t-belt will only cause noise when the engine is warm. I have heard the noise warm and cold on cars that had really loose t-belts. I never really compared the noise hot vs. cold. But if I was in your shoes, I would replace the t-belt just for peace of mind.