Valve noise/Power loss as the car reaches its operating temperature.
 

Hi,

I already started a thread similar to this one. But I'm to re-write it in simple, shorter manner so that it can be easier to understand.

Alright my car is a Honda Civic 2004 DX-SE (Special Edition) which means it has Air Conditioner, Tinted Rear Windows, and a tachometer.
It has 175 000 kilometers on it, car have been bought used at 164 000 kilometers. Problem has been present since then.

Here's what have been done on the car
:
-Exhaust manifold (the model that has a Catalytic converter) has been replaced (it solved valve clicking noise)
-Spark plugs replaced
-Air filter replaced
-Oil have been changed recently
-Battery replaced

Condition of the engine:
-Doesn't consume oil at all
-Engine oil always at full capacity
-Engine not overheating at all
-No blue, black or white smoke coming from the exhaust tip
-Good fuel economy around 600 to 750 km with a full tank
-Compression test done: results were really good, 200-210 psi dry test warm engine
-Valve adjustment have been done (made no difference, maybe better fuel economy)
-Engine timing have been checked during the valve adjustment, but not with a timing light yet. Timing was correct, Cylinder 1 at TDC and cam pulley UP mark pointing up, TDC grooves aligned with engine block.

Here's my problem.
Cold Engine:
-Engine not as smooth and quiet as other Civic but still smoother, quieter than when engine is hot and;
-Power and torque is there at lower RPM
-Power is still there at higher RPM, but it is noisier.
-No clicking noise of whatsoever
-Can feel slight vibration when free revving, but not much
-Engine is more responsive, I don't have to depress the gas pedal by much to get the power I need
-Engine feels lighter too, revs faster and easier

Hot engine (Optimal operating temperature, after highway drive for example):
-Loss of power at low RPM
-Loss of torque at low RPM
-Engine is noisy as I am increasing revving higher
-Engine is revving slower
-Engine less responsive
-Have to depress gas pedal further down to get accelerate as fast
-Tapping/ light knocking noise coming from what seems to be valves around 2000-3000 RPM, happens only when accelerating, not decelerating. Also noticeable when maintaining a constant RPM.
-Vibration, not much but noticeable, from the engine as I am revving higher
-Noise is much noticeable when free revving in neutral.
-Noise can be describe as valves noise but it also seems there is a vibrating noise along with the engine: rattling noise, especially when free revving and when the RPM is going down right after revving to around 3-4k RPM.

Also, car drives much better during cold, dry weather since I guess the engine takes more time to warm up. But eventually, cold whether or not, the engine will lose torque/power. During hot days, engine feels good within 5 min of driving the car, then it starts going down, it's even worse on hot humid days.

Basically, if I have to sum up all this. I'm losing power/torque; engine is vibrating much more as the valve tapping/light knocking noise becomes more and more noticeable and as the car reaches its optimal operating temperature. This is IMPORTANT, really, the car is losing power as the noise becomes more noticeable.

When I talk about vibration and noise, it's really annoying since I don't dare revving the engine close to the redline, the noise, vibration is just unbearable, and the engine does not sound NICE at all.

I'm really clueless right now, what really bugs me is that compression is good but valve noise is present, and losing power as the noise gets louder and as the engine warms up.
People told me:
-Exhaust restriction
-Loose timing belt tensioner

Thanks for reading.
Waiting for feedback and suggestion.

Re: Valve noise/Power loss as the car reaches its operating temperature.
 

Is the MIL(Check engine/Malfunction Indicator Lamp) illuminated? Have you had a valve job done at all? What is the condition of your exhaust system?

Re: Valve noise/Power loss as the car reaches its operating temperature.
 

Like I said, the exhaust manifold have been replaced since it was cracked, so was the catalytic converter since it's in one piece. All the rest of the exhaust system is stock, still in good shape, no holes or anything.

No check engine light either, I've scanned the car few times, nothing

The car drives fine, it's just that I'm a perfectionist and I want the car to run the way it should run. It's not that dramatic, but it's not a simple matter either.

What do you mean valve job? Did the valve adjustment, nothing else. You mean I should rebuilt the head? Aren't Honda engine supposed to last forever? It only has 175 000 kilometers.

Thanks

Re: Valve noise/Power loss as the car reaches its operating temperature.
 

Re: Valve noise/Power loss as the car reaches its operating temperature.
 

By valve job I mean, yes. A valve lash adjustment. Nothing lasts forever either. Honda does have a solid reputation on building some great motors, but that doesn't mean you should neglect them(not saying you are). Noises are really hard to diagnose unless you're right there hearing it.

Re: Valve noise/Power loss as the car reaches its operating temperature.
 

Seriously, the engine strangeness, performance and noise issue is depressing me. So much that I want to swap the engine. But that would be cost me too. I looked around in locals shop, they charge me around 1100$ for non-vtec engine and installation labor.

If the engine is done for, I wouldn't hesitate. But after the compression test, I know that the engine is mechanically in good shape, so I don't want to swap the engine if this one still good. What bothers me is that I don't know what's the problem, good compression test, but noise and loss of power when warm... Hard to diagnose this stuff.:confused:

Unfortunately for me, I'm a perfectionist, that's why it bothers me so much, especially when I compare my car to other Civic running all smoothly.:mad:

Does anyone understand what misery I'm going through? :rofl: XD

Timing is a bit off, is this the problem?
 

Hi,
Since I didn't know what to do anymore.
I just thought, maybe the timing is off.
So I went to Canadian Tire and bought a timing light.

This is when I discover that the timing is off by about 1-1.5 cm between the timing mark on the crank pulley and the the mark on the engine block.

For a gap of 1-1.5cm, what do you guys think would cause that gap?
Timing belt not installed correctly? A tooth off?
Or could it be the timing belt tensioner?

I heard when the timing is off by a whole tooth, it's really something, like the car would not accelerate over 80km/h, but my car can go to 140km/h(haven't tried going over that, because I don't wanna get a ticket xD) without too much effort, sure takes some time, but it is possible.

Also, checking the timing that way, is it accurate?
This might sound stupid, but is there many ways to install a crank pulley. I thought maybe the previous timing belt replacement could have been done not correctly.

What bothers me is that, when I did my valve adjustment, I didn't check the TDC with the timing mark on the crank pulley. Instead, for the first cylinder, I aligned the cam pulley TDC grooves with the engine block (the UP mark point up of course) and I inserted a chopstick in the cylinder and rotated the crank pulley until the chopstick was at its highest point.

However, when I looked at the crank pulley, the marks weren't aligned, about the same gap. I thought maybe I didn't look at it at the right angle. That day I was more focus about doing the valve adjustment than checking the timing. What bothers me is that the cylinder was indeed at TDC, but I also notice there was some play, the cylinder would not move if I rotated the crank pulley just a tiny little bit for some time. Could it be that checking the TDC with chopstick in the cylinder is not accurate?

Damn, I only intended on writing just a little bit, turned out to be a novel haha xD Sorry guys.:rofl:

Btw, any feedback on this?
Thanks

Re: Valve noise/Power loss as the car reaches its operating temperature [WITH VIDEO]
 

I know many of you don't post in these kind of thread since it's meaningless if you can't hear what I'm talking about.

Here it is:
http://www.youtube.com/watch?v=KlY6uROQ8uI
Video is about 3min, it contains a cold start + rev and warm start + rev (when knocking occurs).

Re: Valve noise/Power loss as the car reaches its operating temperature.
 

I'm experiencing the same problem with my 03 EX. Are you also getting poor gas mileage? When the engine is hot it feels like the car is being dragged down? (I thought my brakes were seized at first, I even replaced the calipers). I hear a whining noise when I accelerate now which probably means my alternator is about to go. Would that and a timing belt change fix the problem?? Please help

Re: Valve noise/Power loss as the car reaches its operating temperature [WITH VIDEO]
 

I just heard your knocking. Mine isn't that intense but it's very similar and only when the engine is hot

Re: Valve noise/Power loss as the car reaches its operating temperature.
 

I'm glad I'm not the only one having engine noise / power issue here, not saying that you should =P
Your problem seems very similar to mine, it only occurs when the engine is warm/ hot, power loss, except the fact that there isn't any whining noise when accelerating. Also, I don't have to depress the gas pedal that much to accelerate, but it does not accelerate faster either even if I depress the pedal completely. Mine is a manual, I guess car won't totally behave the same way when driving.

I do not know if our engines share a similar cause, but I posted my problem in other forums, and they gave me few suggestions.

Here's the link:
http://www.ericthecarguy.com/forum/t...ID=2538&PAGE=1

EricTheCarGuy, he has a very useful channel on youtube too.

Re: Valve noise/Power loss as the car reaches its operating temperature.
 

how is your gas mileage?

Re: Valve noise/Power loss as the car reaches its operating temperature.
 

Not bad, but I think it could be better.
With shifting most of the time at 3000 rpm, I get about 300km for half a tank and around 500-600 km with a full tank in mixed driving.
In miles per gallon, that would be around 28-30 mpg, however, I always fill up the tank at half a tank so it's not really accurate.

Also the engine seems to be less fuel efficient during winter so that may explain some loss in mpg.
The best mpg I got in mixed driving was 31 and I still had that engine issue.

UPDATE: Went to garage
 

Went to the garage today.
They did confirm that it was a "rod bearing" causing that noise.
However, they mentioned that the power was completely normal.
"It has power, what's wrong with it?"
They said I could drive it forever and they won't be any problem.
This might be true since I am still driving it since a year ago.
I did test drove other same Civic from the same gen and it wasn't like that.

This might be the last time I go to the garage.
The best mechanics I know until now is you guys :), the internet, and myself.
It's even considered a reputable garage recommended by the APA (Automobile Protection Association).

I have no intention of driving it like that, it's just unbearable.
I intend on swapping the engine with a good used one from a car recycler
with quite a good reputation.