ItsaHonda,

I too have this strange noise in my 1994 Accord EX Sedan. I have only used Mobil 1 5W30 since I bought the car back in July of 1994 new.

The knocking noise can be heard when I am in neutral or park around 2000 to 2500 rpms. If I goose the engine to this rpm you can really hear it. It sounds like a diesel engine. At faster rpms it goes away. I really don't notice it when I am driving, except when I listen carefully at a slow acceleration.

I first noticed it around 110,000 miles about a year ago. I now have 122,000 miles and the noise may be getting louder. I am now using Mobil 1 15W50 at the advice of the Service Manager of my local Honda Dealer. They can not tell me the exact cause of it without taking apart the engine! They checked a few common things that it could be and it wasn't. The car runs fine otherwise, doesn't burn any oil, and the exterior of the engine looks like it just came from the showroom.

The car has been to two dealerships for a diagnose. One said it was probably a misalignment of the balancer shaft belt. The other anything from a bad conrod bearing to a main engine bearing. Maybe when the car was assembled they picked parts with excessive tolerances???

I myself last year checked and cleaned the EGR Ports, and did a valve adjustment, expecting a miracle.

I wonder how many more people have this problem with this engine and just don't notice that it existS???

Michael

 

MichaelT1960,

I can be fairly certian they didn't pick excessive tolerance parts. In case you haven't checked out the service manual, bearings come in A, B, C, and D...well maybe not exactly but it's been awhile, but they are coded per tolerance. In anycase this same attention to detial is even shown at the engine plant. Each block and mating crank/cam have the tolerances computer checked then the computer hand picks which bearings should go in each slot. It's unlikely to be a slipped rod bearing from poor assembly.

In anycase I find it hard to believe you could put thousands of miles on a bad bearing, you would start to find oil shavings in the filter and crank case at some point.

You could always change the oil and have the filter analyzed to see if you have a high degree of metal shavings from bearing failure, etc.

Have you had a new water pump or timing belt tensioner installed with a new timing belt...a bad set of either could lead to a bad rattle.

 

MrChad,

Thank you for the reply. My timing belt was done at the dealer at 92,000 miles.
I know they replaced the water pump. They did not replace the tensioner...but I think they checked it when I complained about the knocking noise about a year and a half later. The service manager got in touch with me and asked me to leave it for the day so that they could check a few things. When I picked it up they had told me that everything checked out ok. I think I recall that he said the tensioner was a little loose.

The last time I drained the oil I passed it threw a strainer and did not find any particles at all.

What about "wrist pin knock"?

Michael

 

Hhmm, well I think the Honda has a floating wrist pin. I can't recall ever hearing of a wrist pin knock?

I'd still send the filter to a lab and have to oil analysed to see if you have any elivated levels of metals in the fluid, just in case. It should run about 20 bucks. If all the noise came after the belt change I would seriously concider having the belts and goodies redone again. Maybe the tech from the first round did something a tick off and left the belts too tight or something. I would have also never reused the tensioner it's so cheap to replace once and do it right when all the belts are out.

 

The knocking noise can be heard when I am in neutral or park around 2000 to 2500 rpms. If I goose the engine to this rpm you can really hear it>>>

Yep! Same here. We're definitely hearing the same noise.

I really don't notice it when I am driving, except when I listen carefully at a slow acceleration>>>

When I'm driving, I'll notice it right before 2nd gear kicks in during slow acceleration...which occurs at about 2k rpms.

They can not tell me the exact cause of it without taking apart the engine! They checked a few common things that it could be and it wasn't>>>

Do you know if they dropped the oil pan and checked the bearings?

I wonder how many more people have this problem with this engine and just don't notice that it existS???>>>

I remember when I posted the last thread a while back, there were several other 5th gen owners who said they had it. Basicially, they were given the same list of things it 'could' be. In any case, I haven't heard of it causing an engine failure yet (knocking on wood) and at 143k miles, my engine is still going strong. I'll still go ahead and set an appointment with the dealer to have them diagnose the car for the heck of it and see what they say about it. Definitely good to know I'm not alone with this!

 

The service manager said he didn't want to take my money. He said the knocks cause wouldn't be that easy to find. Apparently the clearance that causes it isn't all that much? He basically said to use a heavier weight oil and live with it.

The only other problem I have had with my car is the rusting of the back of the rear wheel well, after 6 years or so which I patched up myself with autobody filler. The finishing touches could have been better (along with the matching of the color), but so far the rust isn't coming back. Seems like the inside of the sheet metal wasn't coated properly from the start.

Michael

 

Micheal, the rusting of the rear wheel well can usually be solved by removing the black rubber lining along wheel well edges. This lining will trap water/salt that gets splashed up in there by the rear wheel, and will eventually cause that area to rust. I removed mine during the two years I lived in Michigan and never had a problem. As further precaution, I always ran the car through a good car wash at least once or twice a week...especially if I got caught behind a salt truck on my way to work. Fortunately, I'm back in Florida now . I do have a little surface rust on the underside of my hood, but no where else on the body. My original exhaust B-pipe did have to be replaced back when I had the t-belt done, because it had pretty much rusted out. The muffler is still original, though it's getting rusted pretty bad as well. This seems to be common, as Honda decided against stainless steel exhaust systems. Other than that, a pair of CV axle shafts/joints @ 130k miles, one radiator @135k miles, an 02 sensor @ 140k miles and routine maintenance and upkeep... I've had no other problems with the car in nearly 100,000 miles of commuting.

 

This may be a dumb suggestion but have you tried premium fuel? In some areas, octane is lower and you need to compensate for it by switching different brands and/or grades. I hear this is especially true in mountainous and I guess also in higher elevation areas where air is less dense.

 

Okay, I made an appointment at the dealer, but they can't look at the car until Monday of next week. In the meantime, I drove around looking for 5th gen Accords for sale at used car lots. I found a 94 EX model w/ 115,000 miles that was in overall excellent condition. Michael, you might feel a bit more comfortable (I know I did) knowing that this car made the exact same noise that we've been hearing from our engines. I wonder if it's unique to the VTEC engines? I'll have to find an LX and listen. I think this completely rules out a spun bearing, it just wouldn't be that common (IMO)
I'm going to check for TSBs.

 

wow guys..I too have been hearing this on my car since 122k. I bought the car at 122k and changed the timing belt and water pump because the owners neglected the car. I took it to a friend mechanic and he told he's hearing funning noise from the enigne due to old oil running in engine for a long time, and he said to change my oil often, which I change at 2500. The car makes a funny grinding, knocking noise around 1.5k-2.5rpm and I've been wanting to do a valve job. I have always thought that my engine was worn out because of negligience in changing oil but it seems there are other ppl with this "problem"