I have a noise in my engine, and I am hoping it is not a rod bearing, like I think it might be. The noise is like a grinding noise, and there is a distinct knocking. It is not excessively loud, but it is loud enough for me to notice it easily. I hear it from idle and as I increase the RPM, the frequency increases. I have babied my accelerator pedal even more since I heard the noise, so I am not sure how it is under load. When I put my head close to the lower end of the engine, I hear it louder.

This morning, I was driving and I heard the noise from my engine. I stopped and didnt see anything obvious and my oil was close to the top mark on the dip stick, so I continued driving to where I was going about 1 mile away. I started diagnosing it when I was finished. At first, I thought one of my cylinders might not be running correctly, so I pulled each of my spark plugs and see if it changed my engine. With each of them, the engine started running rough, so I know that it was not the spark plug wires. I also opened the engine oil filler cap and I could see oil splashing up inside the engine as it ran, so I am pretty sure the oil pump is working.

I always drive slow, I shift under 3k RPM, and I can count the number of times I shift above 3k RPM or drive it fast. The fastest I have ever driven my car was when I was test driving it before I purchased it. I bought it with 83k miles in 2003. It now has 179k miles. I am meticulous about taking care of my car. I have always kept everything tuned and done all the maintenance on time. My last valve adjustment was in January this year.

Over this past weekend, I pulled out my entire dash board, took out my old basic alarm and installed a paging alarm. I have yet to put my dash board interior back together, but the car was in a driveable state.

Could this be a thrown rod bearing? I was hoping that this engine would last me easily to 250k+ miles without problems. I am currently about 2 hours away from home. I am going to try to make it back home this evening.

What else could it be other than a rod bearing?
What would be my options if it IS a rod bearing?
Would I be better off getting a new engine or should I rebuild my engine? Which would be economically better?

Could it be bad gas? I bought gas from the cheapest gas station in town yesterday.


Modified by professorman at 1:42 PM 10/16/2008

 

Anyone?

 

There are several engine noises which can be audible off idle. They could be;
Piston Slap
Wrist pin wear
Rod bearing wear / Failure
Main Bearing Failure
Thrust Bearing failure

most all are usually the result of several different things:
Extended / No Oil Changes
Oil Pressure loss
Excessive loads

Piston slap is usually most noticable cold (when first started). As the engine warms, the piston expands; tightening in the bore and the noise becomes less apparent.
Wrist Pin wear - rare but will show up as a faint double knock - as the piston changes direction.
Rod Bearing wear / Failure - can normally be induced by lightly feathering the throttle during a no-load period. You will hear the condition (rattle type knock) get more and less apparent as you move thru the rpm range.
Main Bearing wear - normally caused by related Rod bearing failure (Debris from rod bearing damages main bearing)
Thrust bearing failure - allows the crank to "walk" forward and back in the main bearing saddles. Only in the worst cases would this be audible.

I hope your discription is in here somewhere
P

 

Thanks for the reply. It turned out to be that the Timing Belt pulley that connects to the cam shaft, the bolt had come up, and it seem like it was either hitting on the timing belt cover plastic shield, or the pulley was wobbling as the car was running, causing the timing to be messed up. When We pulled it off, the timing belt had enough tension and did not seem like it had jumped a tooth or anything. I had the car towed to the shop because on my way to school yesterday, it almost shut off several times, and my Check Engine light came on. I am happy that it was not major engine damage. I do not know how that bolt came undone. I changed my timing belt about 75k miles ago.

 

Failure of that bolt (they sometimes catastrophically fail) can sometimes be attributed to the absense of Locktite. It sees a lot of vibration.

Consider yourself fortunate (and an aware driver) that you addressed this. It could have been far worst.

P

 

Oh wow. I didnt know that this happen to other people as well. My mechanic (friend) put on Locktite when he reinstalled it.

I am not sure if my valves are a little bit louder now. I had them adjusted in January this year. It is not significantly bad to the point where I think I NEED a valve adjustment badly, but I can hear a little increase in valve noise while before, my valves were a bit quieter.

What is the name of the correct tool to adjust the valves? My mechanic friend does not have the right tool, and it is a pain to watch him go back and forth adjusting them. I want to just buy the tool since I want to have the adjusted at the recommended interval. Anyone have a link to where I can buy this for Honda motors?

 

I don't believe (I will most likely be proven wrong ) but I don't believe that Honda Special Tools are available to any but dealers.
It's pretty labor intensive, but Valve Lash can be accomplished witha set of metric open-ended wrenches and a set of feeler gauges.
If you want to go the high-end bragging rights route, see if you can chase down a Snap-on Tool Salesman. They'll sell to anyone with cash.
If not, Craftsman / Sears will do.

It's considered a five beer job. Also expect to invest in more than a few explatives.
But armed with a service manual, (and the correct tools) you should be up and running by the next day.

P

 

I know, I had watched my friend (mechanic) do it on my car in January, and he just did it on my brother's 91 Prelude over the weekend. I was sorry for him for the amount of work he had to do for it because he did not have the correct combination screwdriver metric wrench tool. What is the name of this tool so that I can search for it?

EDIT: Nevermind, I found it.


Modified by professorman at 5:48 PM 10/17/2008