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Discussion Starter · #1 ·
I got a 2g gst, afew days ago when i was driving home when i noticed that my car started making this weird knocking noise around 2k rpm. it sounds like its coming from cyclinder 1. i changed the plugs but that didnt do nothing
the engine dosent hesitate to start or seem to have lost any power, it drives fine except for this knocking noise at around 2k rpm, it goes away above and below that number. i havent thrown any codes yet.

about a week ago i put in fuel injector cleaner in a full tank of gas, when it got 3/4ths down this is when it started making this weird noise
 

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Harmonic resonance?
 

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Use proper grammar, please. Your post is hard to read and understand without going over it a few times.

If you can get a recording of the sound, that would help a bit. How do you know it's coming from cylinder 1? The thing about sounds in an engine is it can be very hard to tell where a sound is actually originating from. This, I believe, is what Prozium451 was getting at.

Your definition of "knocking" could be quite different from others, and might only be a "tick" to someone else, which could be as simple as a noisy lifter or noisy injectors. It could be a "knock" which might be a bad rod bearing or something completely different. We can't really tell from what we've been given, because just putting injector cleaner in a tank of gas should not cause ill effects; a full tank of gas, or almost gone wouldn't matter. This sound may be something completely unrelated.

I had a spun bearing that made a racket at around 2200 RPM, but it was quiet below that, and it seemed to disappear after 2300. But, as I stated above, there is no way we could know from what you've given us that this could be your issue. It "could" be anything.
 

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Discussion Starter · #5 ·
Sorry, but maybe if you read it slower you would see that i used proper english. I just abbrevated certain things. Each break down or paragraph is just alittle insight of the different things that I encountered in these last couple of days. I through in the gas part ( or section) because I heard of some people using an additive in there fuel, (like a cleaner) that they started to have problems.

I understand that my knock definition may not be what others are thinking, that is why I threw in such broad explanation, its so that i can start to rule things out. It helps me to get ideas on where to start.

I'm asking for help, I'm not in class so I dont think I need critizism on my grammer.

If you have a question pretaining to my car then ask. If I didnt add something in there that you might think is important then ask and I'll be more then happy to answer.
 

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A video clip of the knock would help.

Like Esky said it could be a ton of things, is it coming from the top or the bottom of the motor? If its coming from the top pull the valve cover, if its coming from the bottom pull the oil pan..

You got it two days ago and its knocking??:confused: :eek:
 

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Discussion Starter · #7 ·
I'll try to get a video clip or something in the morning. Its hard to say exactly where its coming from.
Sorry, i got the cylinders mixed up, it sounds like its coming from the first cyclinder on the drivers side (#3 cylinder). I cant tell if its upper or lower but its a constant knock at around 2000 rpm, it doesnt seem to increase when giving it gas. Someone suggested cylinder slap because the sound was coming from the upper portion to them.
 

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My car actually had the same kinda isssue for a while. I figured it was a rod bearing. I took it easy and the car was fine for a long time then it started to get worse. It did however turn out to be the rod bearing.
 

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I didn't mean to offend you on your grammar. I'm just trying to help you out on how posting works here. The rules on this board are very thorough and are also thoroughly enforced, which is why I'll link you to them before a mod does. Rule number seven is usually the biggest:

http://www.dsmtalk.com/forums/announcement.php?f=22

Your other posts were much cleaner. :cool:

Although piston slap is definitely a possible noise maker, I wouldn't guess it's what you're hearing. Piston slap can be common among forged piston user's, or in a fresh rebuild where the wrong piston size was used, or the bore is incorrect. You could get it from normal wear...but odds are not too great, especially when it started out of the blue.

If the sound "sounds" like it's coming from the first cylinder on the driver's side, then it is indeed cylinder one. They are numbered in order, starting at one at the timing side of the engine. Unless you're talking about firing order, then it's a little different, but these are strictly firing orders, not cylinder numbers.

It could be rod knock, which can lead to a spun bearing and other problems that will require a rebuild/replacement. A spun bearing will sound like a slappy-knock when revved.

Does it sound like this?
http://youtube.com/watch?v=SlZvtcZ6uSA

EDIT:
You can definitely drop the oil pan and check the rods for play and pull the bearings to check them out, just make sure you only do them one at a time. They would have to go back in their correct spots. But, if your bearings are blown, they may have chewed up your crank, which will chew up your new bearings in a hurry. Typically, if you wanted to change out your bearings, you would also have to remove the crank and have it serviced, and would have to get matching bearings for the "new" crank measurement.
 

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Discussion Starter · #11 · (Edited)
no harm done, I'm just alittle frustrated with the whole thing.

I'll check the oil pan either today or tommorow, and I'll also try to get some type of audio or video of the engine.

I cant tell with that video. I'll compare it when i get back alittle later today,
and let you know. thanks for your help.
 

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this very same thing happened to me except i down shifted into 2nd going 80 and spun a rod bearing.....no fun, but my knock is the very same. starts at 2 grand and stops around 2500

now im stuck pullin out my engine, but in the long shot it'll pay off. while your in there you mine as well put some new rod and pistons in.... maybe ross or wiseco
 

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You need to read the link that Esky just put up, "rule number 7.."^^

To the op, I had the same EXACT problem not to long ago and if you searched you would find my video clip and an bunch of suggestion and pics..
I did however end up changing my bearings and not touching the crank because I couldn't see any scratches or wear on the journals what so ever.
When my car started to knock it was right down the street so I only ran the car for less than a mile and diagnosed the problem. When I pulled the oil pan and rod caps I found that I did infact spin a bearing and there was a bunch of bearing material in the bottom of the oil pan from the little amount of time that the car ran... Its been running strong since I've replaced the bearings but there's still a really faint knock, that leads me to believe its coming back... Most people will tell you that you need to get your bottom end rebuilt and there right, tihnk of all the metal running through the oil pump etc... If your tight on money and you want to try replacing the bearing I say go for it but you will not be able to beat on it, if you want it to last more than a couple days.. Like said above you can drive with knock for a while depending on how bad it is but you will have to BABY IT!
 

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Discussion Starter · #14 ·
Trying to upload the video. Cant really tell where its coming from, but on further listening it seemed that the noise was coming from cylinder 4. I noticed the smell of gas. When i inspected fuel rail, gas was coming from around the fuel injector and now I have a check engine light with cylinder 4 misfire.
 

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Discussion Starter · #15 ·
This isn't my week, I'm just having a hell of a time getting things goin, the video is have trouble uploading, the god damn e-brake cable snapped and the car rolled into the the back of the garage where the f-in garden tools fell on my car. nothing like have a F-IN rake fall on your rear quater panal and putting a foot long scratch into a new paint job. F-it, I'll be back tomorrow.:mad:
 

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This may be a weird question but is the rail fully tightened down? You said that fuel was coming from the suspected cyl, is there any deposits around the inj? Like from combustion. You may be hearing combustion from that cyl. It's a long shot but check it anyway. The combustion process at low RPM may not be enough to vibrate the inj. and the combustion at high RPM may be a constant stream not making noise.
 

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Discussion Starter · #18 ·
So after some time away from the car i finally decided to work on her. The fuel injector had a torn o ring so that was a simple fix (no more leak). On the other hand I did in fact spin a rod bearing, dropping the oil pan I found metal chips, for a second there i thought my car was making gold (just kidding).
Number 3 cylinder rod bearing completly gone and number 4 was starting to mess up. I figured that something like this happened because my car was sitting for over a year and the oil wasnt changed, so yes I was a dumbass for that move.
Luckly under inspection ther was no damage to the crank shaft and/or anyother part.
I got some ideas from a few mechanics in how to change the bearings without taking my engine out. So when I get it professionly inspected and they tell me its fine, that is when i'll work on it.
Thanks for all the help it gave me a lot of insight into what I need to look at.
 

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Discussion Starter · #19 ·
I've been trying to do research on rod bearings and ACL keeps coming up,
but these are race bearings which are fairly cheap compared to autozone, but nothing on standard bearing.
Does anybody here have any comments on his company or are there better ones out there?
 

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Luk909 said:
I figured that something like this happened because my car was sitting for over a year and the oil wasnt changed, so yes I was a dumbass for that move.
Oil doesn't break down from sitting unless you had contaminants in it. Oil will remain on the bearing surfaces for long periods of time. I pulled a motor apart that had an engine fire, sat in a yard for 8 years and STILL had oil on the valves/guides.

Something else caused the motor to go, could be oil pump, could be foreign material/water.
 
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