Engine noise/ Power loss as engine reaches its operating temperature

[Thaik]

Hi,
I currently own a Honda Civic 2004 DX Manual and I’m experiencing a problem here.
As the engine gets warm and eventually reaches its operating temperature, I hear a knocking noise coming from the engine
from 2000-2500 RPM and it does only under load and when it’s warm.

When cold, I almost don’t hear it, the colder the engine is, the less noise you hear, there may be other noise, but it’s not knocking like when it is warm. The warmer it is, the louder you can hear it.

Also, when the noise occurs, I’m losing power, when it’s really warm, like after driving for an hour or more, the engine really feels weak and lacking power, it’s still “driveable”, but it feels like, compared to other similar vehicles, the engine isn’t behaving as it should.

Well enough talk.
Here’s a video I made:
http://www.youtube.com/watch?v=KlY6uROQ8uI (don’t know why it won’t show the link)
Paste this on youtube: /watch?v=KlY6uROQ8uI

Feedback will be very appreciated

Thank you.

Topic

[Matt]

Quoted From Thaik:

First of all, thank you for all for responding
and thank you Beefy for you honesty, I appreciate it.
Well, I said it doesn’t sound that bad from a certain point of view. Because many people heard it and thought it was normal.

About the valve adjustment, we just did one last summer, and it didn’t seem to have made any difference, I think gas mileage improved a little but that’s all, knocking noise was still there. I also tried to pin point the noise, it definitely comes from the top, the engine block is totally silent.
I have to say that now the car belongs to us, it’s been very well maintained, oil level is constantly checked and replaced regularly, 5W-20 is the oil the engine is running on.
No, the car doesn’t overheat at all, which is really weird, when I say the noise gets worse, it’s not that bad, but after a long trip, the power loss and the knocking is really obvious.
Timing belt, tensionner, and water pump has been replaced and the coolant was flushed out too.

About the knocking sensor, I heard we normally get a Check Engine Light for these kind of problem, but I don’t have any! I sure would be happy if the Check Engine Light appears from time to time, at least I would have an idea about the problem, but no. It’s as if the car is pretending to be healthy when it’s not, really frustrating. Also ScannerDanner, I can’t see the link you’ve written, all I see is http://www.youtube.com, just like mine. It seems this forum is blocking links or something…
I also forgot to mention that when it’s stone cold, like once when we did the timing belt, the engine was left for two days cold, and when we started all the noises started disappearing, but when the engine picked some heat, noises started to come back all together again.

Here’s the condition of the engine:
-Engine doesn’t overheat
-Engine doesn’t burn oil (using 5W-20)
-Engine has decent fuel economy
-Engine doesn’t produce white, blue or black smoke (coming from tail pipe)
-Engine has good compression test results (around 200 psi for all cylinders)
-Engine timing has been checked and is timed (timing belt done)
-Valve adjustment has been done (0.008 for intake and 0.0010 for exhaust side)
-No check engine light has appeared since the day we have the car, and noise has been present until now(not first owner)

Considering all these, I cannot understand how the engine can be bad.

Also, I forgot to mention that engine noise/performance seems to affected by weather, on cold dry days, it runs fine, on hot humid days, it runs like crap.

Again, thank you for your feedbacks

I just want to say that it’s hard diagnosing noises via internet videos. The mic on your camera may be amplifying noises that aren’t that bad, so stick with the pro’s advice above. Good luck bud.

[Thaik]

Well, the funny thing is, we already replaced the exhaust manifold since it was cracked, and the catalytic converter for this car is already included with the exhaust manifold. There was no apparent difference before and after the replacement, I’m still having the same issue, sure, there is no exhaust leak now.

But I will try removing the primary oxygen sensor, if that is the one I should remove and not the secondary, and see how it runs.

I will keep you guys posted

Thanks

[college man]

keep us posted on your progressC8-)

[Thaik]

Still, this engine seems to be “knocking” quite more than the average other Civics:
http://www.youtube.com/watch?v=tKn4ublp … 8q7c2HekiA
http://www.youtube.com/watch?v=lGX-DhLS … 8q7c2HekiA

My engine doesn’t sound that nice and healthy.

[Thaik]

ScannerDanner, if I unplug the knock sensor and the car does run better, what will I be able to conclude, that the problem is indeed internal and really caused by the sensor?
But, just by hearing the knocking itself and knowing that it comes from the upper part of the engine, do you have an idea what could internally caused that knock?

Thanks

[hbvx]

Could there be spark knock(plugged EGR even?) like the top-end being caked with carbon deposits in the combustion chamber? Could perhaps an injector not be flowing as well as the others, causing that cylinder to make the symptom when more fuel/ignition is demanded?

What I can say is that if it is a bearing causing the sound, you typically will be able to tell with a Used Oil Analysis at your next oil change, allow the oil to drain from the pan and catch the drain ‘mid-stream’ with a sealable container for safely mailing(some labs online offer kits for free in hopes of you mailing to them). You catch the draining oil in your container after it first starts draining freely, but before it goes to a drip. Usually about 3-4 ounces are needed at most. Cost is usually $15-$30 range(at most) for the basic tests which is all you need.

When the results come back you can see if elevated copper/tin/lead (if these are tri-metal bearings) or whatever material these bearings are made of in composition, then it would indicate a bearing that is wearing fast. If you want a recommendation, I can recommend a lab I’ve used for this one time test if you don’t get results or want to go this route for peace of mind. It will give a general idea of engine health, if wear appears normal it’s a cheap way to find out if this sound is internal engine in nature or a bolt on component.

If the UOA comes back okay or at least doesn’t indicate bearings, you could always try cleaning the top end, replacing spark plugs and trying a piston soak with the plugs removed, a decent PEA container fuel system cleaner in 1 full tank to empty prior to this, followed by an immediate oil change to remove any loosen carbon(typically while driving to expel a top-end foam cleaner, you will have carbon leave via the exhaust) and the drain is to get rid of any remaining solvent that is mixed with the oil. That is a general C.O.A. to attempt to reduce carbon if this is a ‘bad’ case of spark/carbon knock.

[ScannerDanner]

Quoted From Thaik:

ScannerDanner, if I unplug the knock sensor and the car does run better, what will I be able to conclude, that the problem is indeed internal and really caused by the sensor?
But, just by hearing the knocking itself and knowing that it comes from the upper part of the engine, do you have an idea what could internally caused that knock?

Thanks

It is hard to diagnose a noise over the computer, but lets say that by unplugging the knock sensor your low power condition goes away. This means there is internal engine problems and you need to drive the car until it dies. If however you are actually having a pre-ignition/detonation problem you could actually cause more harm to the engine by disconnecting the knock sensor.
As some other posters stated there are other causes of pre-ignition/detonation (spark knock). Lean a/f ratio is a big cause, plugged up EGR passages, engine overheating, timing too far advanced, etc.
One clue to whether it is spark knock or not is do you here the noise at idle or when you hold it at 2000 rpm in PARK (no load)? If your engine is noisy during these times then it is probably not a spark knock problem but in fact an internal engine problem. If this is the case, start looking for a used engine and drive it until it dies and try disconnecting the knock sensor (if it has one)

[hbvx]

^I don’t agree with that course of action. Some cars that ‘do’ have a history of overly sensitive knock sensors have disconnected with success, can’t recall those models off hand, but on a Honda if its really a mechanical issue I’d imagine the sensor staying connected would be better as far as ‘lasting’ and not simply pushing ahead with normal timing.

But, he has a manual transmission so the revving is while in Neutral I’d imagine. He obviously isn’t moving the car, that might be more EGR plugging related to have that symptom. A misfire can happen at idle but show itself more under load when demand is higher on the ignition system and the fuel system, of course if a mechanical condition is existing at idle it’s hard to imagine that noise without the car in motion either like the videos show. That said some other tests may have confirmed but I wonder if this is a piston slapping an imperfection in the cylinder wall/bore clearance issue? That wouldn’t be wrist pins, would it? Was it eric that showed in his video the sound of a disassembled engine with the piston head hitting this upper cylinder wall imperfection of sorts, from mechanical failure or not. Might have been in a video I saw of a connecting rod or main bearing that was damaged.

IMO, it’s not worth it just to say trash an expensive engine even if it is mechanical without considering all options. You can ALWAYS run it into the ground later.

.02

[dreamer2355]

Here is a great video ScannerDanner made on knock sensor testing –

http://www.youtube.com/watch?v=vqj2YWbe … xSCeMBQ%3D

[Thaik]

Hi guys,
I just read everything that you guys posted. While reading all this, I felt somehow left out, I didn’t know it the posts was addressed to me or not about some other subjects and I’m a bit confused here.

About the noise, I’ll do some more clarification:
The engine itself is to me, really noisy, especially when I compare it to other Civics. Even when I’m inside the car, with all the windows rolled up, I can hear the noises clearly, so I think the microphone wasn’t really amplifying the noise.
The noise occurs also at idle, but very unnoticeably. Under the hood, when I put my ear right on top of the engine, I can hear a slight clicking/knocking noise.
It also occurs when I’m driving it but not when keeping a constant speed (engine not accelerating) nor does it do it when decelerating.
The engines also vibrates when revving it almost to the red line, I can tell the engine working hard from inside the car.
I cleaned the EGR valve, didn’t do much difference, but I guess if the valve or the passages are really clogged, the Check Engine Light should come on, right?

This problem is really a big hassle to me, the itself is always regular, I think I mentioned previously, it also varies depending on the weather.
I drove it today, the noise wasn’t there when cold (engine still rough and noise in some other way), it appeared when the engine started to warm up (20 min) but after a long driving and revving a lot, the noise seemed to be less noticeable, but power issue was still there.

So yeah, I know diagnosing by the internet isn’t the best way, I just wanted to have some feedback, in case it was a much simple issue that I could solve myself, but it doesn’t seem to be. Btw, thank you everyone for your feedbacks, I really appreciated it.

About what I should do, should I follow Eric’s advice and unplug the O2 sensor, or should I unplug the KS and see how it drives (or that isn’t a good idea considering what you guys said previously) or should I do both one at time?

Thanks guys

[hbvx]

^Based on more information you just mentioned regarding hearing the noise worsen upon acceleration while driving and not holding speed or engine braking/deceleration, someone may be able to point out if it’s more specific symptom.

Other than that, it’s fairly easy to remove the front(pre-cat) 02 sensor and see what happens. The knock sensor response from me to the other post ScannerDanner, was more my gut feel initially, and I created a lot of dialog to get more information. I wouldn’t pull that one honestly, but I’d like to see what eric has to say since this is a different vehicle than the one posted in the video. Not sure if it makes a difference if it’s mechanical in nature to remove the knock, as far as risks, but I simply wouldn’t do that unless it’s a last resort and you have decided on not pursuing an actual repair for this problem after ALL ELSE has been exhausted. That would be my own choice. Now, if someone gives advice on disconnecting the knock sensor temporarily and starting the car/idle it only you’ll know if it had any effect with the noise remaining.

It sounds mechanical in nature to me, but first start with a potential clogged exhaust as eric mentioned.

How long have you owned the vehicle? How many miles driven since owned?

I mean, if the car can drive with the knock sensor in place and it IS a mechanical issue, I don’t see the point in disconnecting if it’s going to be driven into the ground anyway. If you have an interest in fixing the problem, at least you can get to a more complete diagnosis.

Worst case to me is connecting rod bearing or wrist pins at the cylinder head. I know thats what a lot of us are thinking but no one wants to guess at that over 1 video(microphone doesn’t do justice to this sort of thing, IMO) but my ONE suggestion that still applies is a simple Used Oil Analysis.

Seriously, $25 and you know ‘more than likely’ if its your bottom end (crankshaft related) bearings. I would need to know feedback from others as to what your Civic’s bearings are made of.

If the knock sensor disconnect is a temporary thing, check worth a shot I suppose. Not your fix, though, and a UOA may be more revealing to ‘confirm’ wear/worn(at this point if the case) internal engine parts.

[Thaik]

Well, actually, upon acceleration, the knocking doesn’t get worse, but the engine overall feels rough and noisier. That’s why I never rev the car too much since I believe it’s meaningless (I don’t get any more power, and it just hurts when I hear and feel the engine revving that way )and I shift at 3000 rpm.

I know it’s quite simple, although I will probably try removing the O2 sensor, I don’t understand the purpose of it since I already replaced the catalytic converter due to a cracked exhaust manifold (exhaust manifold and catalytic converter comes in one piece for this car).

It’s been almost a year since I owned, I bought it when it had 164k kms (101k miles)on it, and now it has about 184k kms (114k miles) and the problem has been occurring since then. I really regret making that purchase since it seems to me now that the previous owner didn’t really take care/price for his car.

I agree with you about the knock sensor, I never heard anybody disconnecting the KS on this particular car and it’s probably the last thing I would do. Because of that problem, I don’t intend on investing in anything else on the car but it just angers me when I can’t drive the way I want because the engine isn’t running the way it should. I also agree with you when you say that it’s better to fix the engine rather than trash it if the engine is indeed repairable, the engine is running, can produce a certain amount of power, doesn’t consume oil, has a pretty decent fuel economy. I think that would a waste to totally trash it and not resorting to any diagnosis, if that was the case, I wouldn’t have made that video and posted it on this forum. I sure would like to swap in another engine in good shape if that is the easiest and the least expensive way to solve my problem, but still, finding a good, reliable engine isn’t easy either, at least for me, any tips on buying a used engine? where to and how?

If it’s a bearing issue, why would it only make the noise when hot and not cold, I heard bearing noise issue occurs at all time, whether it is warm or not.
Also, I’m curious to know at what point and why does bearing starts to wear quickly. From what I understood, bearing does normally wear and eventually to a point when the engine needs to be replaced, but when and why does it start to wear faster? Let’s see an owner lets his engine oil level drop to a critical level and there’s metal to metal friction. Then, let’s say the owner is more cautious from that point, checking and replacing his oil regularly, the bearings should be safe from that point, does it wear faster than before or…? Sorry if I’m being bothersome, I’m learning just like you guys =)
My point is, I change my oil regularly and I’m trying to understand how the Used Oil Analysis is going to tell me about my bearing’s condition if I’m not and haven’t been running low on oil since I’ve owned the car.

That being said, I’m interested in doing a used oil analysis but where should I send the oil ? I didn’t get that part.

Also, sorry for my English, it is not my first language and some sentences may seem awkward.

Thanks

[hbvx]

Please take the following as an IF scenario(hypothetical), a lot of what I’ve commented on with the other posters is in ‘general’ with an aim at perhaps giving insight. Note, this is NOT a diagnosis, just up for ‘discussion’ . It ‘can’ be a ‘piece of mind’ sort of thing to get a UOA, but it still may not be definitive. It ‘can’ give insight into engine health overall. It will give you a result of wear metals, but not absolute engine wear and larger particles that may/may not be present won’t show up. You could always try inspecting the draining oil OR cut open your oil filter to look for metal pieces. EDIT(that last sentence…this is why you get a Used Oil Analysis, it’s impossible to define wear from the drained oil without something obviously wrong coming out in the drain, just mentioning as a basic observation)

If you do the sample route, you want to get a sample at the end of your ‘typical’ oil change interval. You’ve owned the vehicle for about 15,000 miles and have changed the oil how many times? Use name brand and you usually don’t have a problem.

The sound is louder when the engine is warmer because the oil is thinner when warm, and thicker oil at startup will mute internal engine noise.

I mentioned wrist pins as well, it is possible, but only 100,000…I’d be shocked if it’s an actual bearing gone with oil consumption being apparently so minimal, doesn’t add up to = bearing if it’s using a name brand oil and hasn’t been ran low, or driven abusively or had lapses in maintenance.

Please consider getting your oil pressure tested. That may say a lot right away, faster than a UOA even if you go that route.

One scenario may be running the engine in a race or ‘tracking’ the car, that is to say staying near redline or high speeds for a long time(auto crossing doesn’t count, 1/4 mile times at a drag strip doesn’t count). I’m talking about prolonged lap type racing or driving at a course and not changing your oil afterward or checking the level etc. Usually the oil needs changing after such, if oil sheared enough it may have lead to a contributing factor.

There could have been a bad service job in the past, someone changed the oil and forgot to make sure the old oil filter’s gasket wasn’t removed, drive away and all oil drains out via the filter gasket leak and isn’t caught in time. A drain plug not tightened and/or backs out then spills your oil while the car is driven under load without oil or much remaining lubrication; that is simply an unknown variable to how any 1 engine will respond, etc.

Obviously, if the noise is internal the engine IS currently wearing at an abnormal rate, more than likely. A UOA, if really normal and quiet, would either be somewhat relieving (still need to find the source of the noise) OR it could confirm at least if it ‘is’ a bearing or abnormal engine wear compared to the Universal Averages. The results will have your engine’s ‘wear’ and the same model engine’s ‘typical’ wear or more accurately, the average of all contributed used fluid analysis average out. Basically, Universal Averages = your engine health vs what it ‘typically’ looks like from the same make/model engine in other vehicles.

Please note, this is NOT an actual ‘wear’ test. It’s a general engine health test that may flag wear that appears in ‘typical’/’basic’ UOA results. Mention on the form to the lab you have engine noise and want to look for abnormal wear. They may focus on that end more and give a more detailed report regarding this.

I have gotten UOAs performed and I’m learning about that, trying to catch up on mechanic knowledge, accuracy, and experience. Far behind the other contributors in this thread. To me a UOA isn’t a waste here, and I’m not assuming internal engine wear but this is what I would do if I had a new/unpleasant noise come up that I couldn’t find externally and that really sounded an awful like an internal noise.

On the other hand, certain wear increase may indicate an engine wear but won’t tell you necessarily the contributing condition or factor that may/may not be present. It is ‘only’ a guide.

Here is how to get a UOA from a company I have used, any questions ask me:

[url=http://www.blackstone-labs.com/free-test-kits.php:1ewn5fkl]http://www.blackstone-labs.com/free-test-kits.php

^[/url]A basic UOA costs $25, you have to pay shipping to them but they send you a kit for free.

Curious, have you tried feeling the engine and taking the time to REALLY listen all around your engine while someone else revs to 2,000 RPMs for you? Please, find someone to do that for you and try to pinpoint the sound yourself. That is probably the quickest thing, aside from removing the 02 sensor and/or perhaps the knock sensor for now. You have to wait for the test kit to arrive anyway…

[hbvx]

Quoted From Thaik:
I also tried to pin point the noise, it definitely comes from the top, the engine block is totally silent. /snip/

Also, I forgot to mention that engine noise/performance seems to affected by weather, on cold dry days, it runs fine, on hot humid days, it runs like crap.

/snip/

Okay, definitely doesn’t sound like a low-end bearing noise. The noise itself anyway. I listened to the video again. I went back over your previous post here and didn’t catch this or remember from before.

Have you pulled your spark plugs recently? Please, inspect them and post pictures if you can. It seems it could still be an ignition delivery issue to me(even if inhibited by carbon etc or some other contributing factor), though mechanical reaction in nature as though a spark knock or an extreme condition for carbon deposits to cause this particular noise. Have you tried running higher octane?

Heat/humid = symptoms while cold/dry = none at all OR just less symptoms/noise?

It could still be relative to oil thickness if mechanical, or a noise that is relative to all things coming together at once(closed loop, thinner oil, heat soaked electrical system).

Check out some base line things if you are capable. The UOA is a way to ‘gather evidence’ and can give piece of mind regarding engine health, if the noise is top end it’s possible a bearing is letting go? I don’t know about that, but by itself a mechanical noise top-end could be wrist pins/exhaust related or a mechanical defect.

By the way, regarding the 02 sensor removal: Usually, just unplug the 02 sensor wire, and use a large enough socket that fits the sensor safely without damaging the wires. You can also ‘rent a tool’ from a lot of parts stores and return the loaned tool for money back when finished, I generally do that unless I get into replacing more.

[Mike]

I am not saying you have an internal issues,s but pull a plug wire on each cylinder or kill an injector and listen for the change. This will tell you if and which cylinder is affected. Main bearings are usually affected by load and normally trucks. Rod bearing noise will get quieter with ignition killed to that cylinder, piston pin noise will double in frequency, lifter noise goes away with oil pressure, piston slap is usually affected by temperature so has the engine warms up, and if the noise gets quieter or goes away, then it is probably piston slap. And of course, try to distinguish between upper end and lower end. The lower end with knock twice as fast as the upper end. I learned this from my machining class. It’s helped me out on quite a few occasions.

[Author]

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