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Hey all. Recently, my old 1993 Accord LX has developed a few small nagging issues that are bugging me, and I was hoping you guys could help me sort her out.
About one month ago, I noticed that when I accelerated hard from a stop, when my engine reached 2100 RPM under load, a quiet chattering noise could be heard from the driver’s side of the vehicle. The noise is hard to describe, but the closest I could come to would be someone shaking a plastic container of marbles. The weird thing about the issue is that is simple to replicate, but very particular. It only happens when the engine is still not fully warm (as in, driven less than ten miles), and the air outside has to be cold as well. It also ONLY happens at 2100 RPM. Not 2000, not 2200, but 2100. It will chatter as long as I hold that RPM, but go beyond or under and it stops immediately. Finally, it usually only occurs if I am accelerating relatively hard. A gentle takeoff will result in a quiet run.
Yesterday, a new and more pressing issue arose. I just took it on a long, hilly freeway drive for the first time in several months. Along the trip, I noticed that the vehicle has started shuddering when I accelerate hard from a dead stop. The shudder is not massive, but definitely pronounced over the normal action of the engine. It only occurs for a moment and only just after starting to accelerate-I originally thought that the crosswalks in the area I was visiting were oddly bumpy, as the shuddering is more like one or two hard but very short spasms, as if my front wheels were going over a bump in the road. It also ONLY occurs when I accelerate hard, but ALWAYS occurs when I do so. There are no noticeable RPM fluctuations or loss of power when this happens-I can still drive up a hill from a dead stop.
The engine performs flawlessly under all other circumstances-no misfiring, no transmission slippage, smooth shifting, smooth idle, proper mileage, etc. Transmission has 210,000 miles and had a fluid change with genuine Honda ATF-Z1 about 5000 miles ago. No CEL codes, and engine timing appears to be within specs (consistent red line at marker). Hopefully you guys will point out something I am missing, because I’m completely lost as of now…
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The first thing that comes to mind with those symptoms is spark knock or “pinging”. Have you tryed a higher octane fuel to see if it disappears?
I have not, as the issue just cropped up yesterday afternoon and my fuel tank is still mostly full. However, isn’t pinging the result of bad engine timing? If my timing light is anything to go by, everything looks good regarding that on my end.
Also, I should mention that it is impossible to get this car to make noise unless I am actually on the move. There is nothing when sitting still, even if I put it in drive and hold the brake, I can stomp it as hard a s I want and nothing odd happens.
[quote=”Lavarider” post=124503]I have not, as the issue just cropped up yesterday afternoon and my fuel tank is still mostly full. However, isn’t pinging the result of bad engine timing? If my timing light is anything to go by, everything looks good regarding that on my end.
Also, I should mention that it is impossible to get this car to make noise unless I am actually on the move. There is nothing when sitting still, even if I put it in drive and hold the brake, I can stomp it as hard a s I want and nothing odd happens.[/quote] Pinging is the result of numerous causes. Carbon buildup creates hotspots and can raise cylinder compression igniting fuel prematurely, cooling system inefficiency can also cause it due to excessive heat. Too hot spark plugs will also cause issues as will a lean running condition. Incorrect ignition timing is a usual cause, but not the only cause. You need to also keep in mind, there are two types of timing, valve and ignition.
I see. I did my timing belt back in June of last year, and both valve and ignition timing looked fine at the time. Will an octane booster give me the result I need to know if it is pinging or not, or will I need to burn off all of my current tank before i can run that check?
[quote=”Lavarider” post=124507]I see. I did my timing belt back in June of last year, and both valve and ignition timing looked fine at the time. Will an octane booster give me the result I need to know if it is pinging or not, or will I need to burn off all of my current tank before i can run that check?[/quote] Heres what I recommend, Seafoam. However to keep the variables down, I would first try a higher octane fuel when you can. Now if the problem goes away, I would use some seafoam in the intake and the gas tank to help clean the upper engines possible carbon buildup. Octane boosters only make a difference if you buy alot of them as they only add .5 a piece if I recall correctly.
On the topic of the shudder under hard acceleration, have you thought to check the integrity of your motor mounts? It’s possible that the torque from the engine movement could cause some vibration or related issue, but only when the engine twists with enough force.
Chevyman21 you are right about the .5 anything higher then that is marked for race use only and can damage all kinds of parts mainly emission stuff such as catalytic converters which is normally what gets damaged first.
I would try what Chevyman21 said first.
This is a long shot but, I would check your PCV valve and shake it see if it still works and if that is the sound you are hearing. I have heard it before but, only on a very well timed extremely smooth running engine. If that is the sound then I would check the hose coming off of it and what it is going into. If you don’t feel like pulling the stuff apart to get to it you can stop at Pep boys they normally have them on display grab the one for your truck and shake it. It may be easier then pulling it. If it makes that sound it is working but, the hose might be plugged up and it can cause the issues you are talking about but, once again its rare.
So a quick update, in case it helps. I’ve been driving my machine around all day burning my tank off so I can add some premium, and I’ve noticed some odd traits about this issue that caught my attention. First of all, it seems to have progressed a bit, Now, it happens every single time I take off from a dead stop, gentle acceleration or not, but ONLY from a dead stop. The problem manifests itself as either one or several rapid, sharp jerks. I have also noticed that the RPM meter freezes while the jerks are going on, which suggests to me that my engine is misfiring during this process and therefore not spinning up.
The spasms last no longer than a single second, whether it is one or multiple in short succession, and the only happen once every time the car moves. I cannot under any circumstances make it happen twice-I have tried gently accelerating until it starts, then suddenly jamming my accelerator down and pushing it hard, and vice versa, but nothing. The car will only act abnormally ONCE, and only immediately after accelerating from a dead stop. Even if I slow down to five miles an hour and then accelerate back up, nothing. it will not occur. However, if I stop, it will, GUARANTEED. The problem also does not appear to have had any performance impact on the car whatsoever. I feel I should also mention that these shakes are not accompanied by any audible noise, at all. No clicks, no pings, nothing.
The tank is almost empty, and I will fill it with premium as soon as I can. I also plan to SeaFoam the vehicle, and I was also recommended to check my EGR system and make sure it doesn’t need cleaning. If the new information I have posted flashes a lightbulb for anyone, I would appreciate hearing it.
[quote=”Lavarider” post=124686]So a quick update, in case it helps. I’ve been driving my machine around all day burning my tank off so I can add some premium, and I’ve noticed some odd traits about this issue that caught my attention. First of all, it seems to have progressed a bit, Now, it happens every single time I take off from a dead stop, gentle acceleration or not, but ONLY from a dead stop. The problem manifests itself as either one or several rapid, sharp jerks. I have also noticed that the RPM meter freezes while the jerks are going on, which suggests to me that my engine is misfiring during this process and therefore not spinning up.
The spasms last no longer than a single second, whether it is one or multiple in short succession, and the only happen once every time the car moves. I cannot under any circumstances make it happen twice-I have tried gently accelerating until it starts, then suddenly jamming my accelerator down and pushing it hard, and vice versa, but nothing. The car will only act abnormally ONCE, and only immediately after accelerating from a dead stop. Even if I slow down to five miles an hour and then accelerate back up, nothing. it will not occur. However, if I stop, it will, GUARANTEED. The problem also does not appear to have had any performance impact on the car whatsoever. I feel I should also mention that these shakes are not accompanied by any audible noise, at all. No clicks, no pings, nothing.
The tank is almost empty, and I will fill it with premium as soon as I can. I also plan to SeaFoam the vehicle, and I was also recommended to check my EGR system and make sure it doesn’t need cleaning. If the new information I have posted flashes a lightbulb for anyone, I would appreciate hearing it.[/quote] Please drive it easy while we wait for the results from the high octane test(get the good stuff in there ASAP). Damaging a piston is a possibility here if you push it too hard.
Ok, so after driving 300-odd miles to empty the tank (first time in my life I’ve regretted my vehicle getting good mileage), I stuffed the car to the gills with Chevron Supreme 91 Octane…
And it had no effect whatsoever. I drove it for 20 more miles to make sure that the new stuff was circulating through the fuel lines, but the stutter is still there and performance has not altered in the slightest.
On another note, I noticed today that the car appears to have sprung a massive power steering fluid leak (as in dripping on the ground), which appears to be coming straight from the pump itself. I don’t know if it’s possible for both these issues to be related, but I thought I would throw that out there, just in case.
Alright here are my suggestions.
1. Still use the Seafoam at least in the gas tank
2. Check your PCV Valve as MDK suggested…might as well change it
3. Check for Vacuum Leaks around the intake and elsewhere(Eric has a video on this)The power steering issue should be addressed, it is possible the chatter was from the pump all along as power steering is engine driven and goes with RPMS. I suspect after you do all these things the problem will be fixed. Without being able to diagnose the car in person with my own eyes and ears, this is the best I can do. The 3 things listed above are to make sure that your engine is clean and tight. The power steering MUST be addressed.
Ok, I have the next few days off, so guess what I’ll be doing. Thank you for your assistance, Chevyman21. I’ll post once I’ve Seafoamed her, changed the PCV valve, gotten a new power steering pump, and cleaned out the EGR passages, and let you guys know the result.
[quote=”Lavarider” post=124719]Ok, I have the next few days off, so guess what I’ll be doing. Thank you for your assistance, Chevyman21. I’ll post once I’ve Seafoamed her, changed the PCV valve, gotten a new power steering pump, and cleaned out the EGR passages, and let you guys know the result.[/quote] Excellent can’t wait to hear! One final note, be sure to read the instructions on the can of Seafoam good because you don’t want to add too much. The amount you add is based on how much gas you have in the tank at the time.
Ok! So, after doing everything and having her spew enough white smoke to hide a battalion…
The car is back to normal! Two of the EGR passages were completely clogged, and oddly, one of the fuel injectors was missing a seal, so there may even had been a vacuum leak involved there as well. Once everything was back together, however, the stutter has vanished completely, and the engine is now purring like a fat old happy cat.
The strange “marbly” noise upon 2100 RPM when cold is still present, however, but as it seems to have no impact on the engine’s performance whatsoever, I am willing to attribute it to vibration somewhere and am sure I will find it eventually. Thanks again for your help, everyone. I am greatly pleased to have my vehicle back to its old self.
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