[FadedBlue]

Last summer I thought my IMA battery was dying and bought a grid charger, but it turned out the problem was actually a broken ground strap, so I could have fixed the car for like $10, but spent quite a bit more with buying the grid charger.

Also to get my car to pass inspection last summer, I had to have the one of the motor mounts replaced. Perhaps the broken motor mount was the reason for the broken ground strap.

Anyway since I had the car inspected and the motor mount replaced, I have been noticing a noise during acceleration. Once I am at a steady speed I don't notice the noise. I thought the noise might have been related to the motor mount being replaced, like maybe one of the other motor mounts is shot and the motor is moving around during accleration. However I just took it to the shop to have the oil changed and asked them to check out the noise. The mechanic thinks it is the transmission. I was hoping it might be something cheaper, but thought I would ask the forum for an opinion. Do you think this might really be the transmission? Is this a common problem? Or do you think it might be something else?

If the transmission is going bad and making a noise during acceleration is that something that needs to be addressed soon? The reason why I ask that is a bunch of years ago, I had a 1995 Civic that was noisy in 5th gear, but I just ignored the noise in 5th gear for at least 100K miles, until I needed to get the clutch replaced. Anyway with that car, I bought a rebuilt transmission from a place in California, I think it was called Synchrotech transmissions. So is a noisy MT in an Insight something that is just a slightly annoying noise, but you can ignore it (like I did with my 1995 civic) or is this a sign that the transmission might fail at any moment and leave me stranded? Also if I were to replace the transmission, what would you recommend? A used transmission? A rebuilt transmission from say Synchrotech? Or rebuilt by a forum member?

 

[retepsnikrep]

It depends.. Is it noisy in neutral?

Does the noise change/go away if you press the clutch in neutral.

Is the noise related to engine rpm or road speed?

Input shaft bearing (ISB) failure is very common.
Lots of info on here about that.

 

[mike103192]

I agree with retepsnkirep here, we need more info.

 

[FadedBlue]

It seems like the noise is only while accelerating, related to engine rpm. Not while idling. Not at a constant speed. Maybe only in low gears?

I will drive it later today. Would it help, if recorded what the sound? Maybe video from my phone?

 

[mike103192]

Perhaps pop the car in neutral while rolling down hill picking up speed to see if the sound persists. If you could catch the noise via recording it wouldn't hurt.

 

[joeaax1j]

It might also help to try and describe the noise. Is it a grinding noise? Or more of metallic rattling sound? A steady whine? Or...

 

[FadedBlue]

Not a grinding noise. More like a bumping noise that increases with engine rpm while accelerating. There is no trouble shifting into any gear. On rare occassions the transmission may pop out of 2nd gear.

 

[Rainsux]

That sounds like a CV joint. See if any of them are loose and replace the axle if you need to. I’m surprised that your mechanic didn’t check this. It’s pretty obvious.

Sam

 

[FadedBlue]

Video of car making sound

I am accelerating to get the noise, so hopefully the exhaust noise is not drowning the mystery noise out.

 

[Rainsux]

I’d surely like to know if it’s NOT a CV joint. But is your power down? I’m not ready to rule out an engine problem. Clutch? Your upshifts sound crunchy.

Sam

 

[FadedBlue]

Let's see if I have a clue of what a cv joint is.

I got the car in the garage out of the snow for a while. I turned the steering wheel to left lock. Here is the driver's side by the wheel.

Here is the driver's side by the transmission.

Here is the passenger side by the wheel.

Here I tried to use an inspection camera on the passenger side by the transmission.

Well at least for the first 3 pictures I can see the boots pretty clearly. I don't see holes or grease leaking out.

So if we suspect a cv joint, but the boots appear intact, how do you tell if a cv joint is bad?

 

[FadedBlue]

That sounds like a CV joint. See if any of them are loose and replace the axle if you need to. I’m surprised that your mechanic didn’t check this. It’s pretty obvious.

Sam

What do you mean by see if any of them are loose? With the car on the ground and the steering at left lock, I tried tugging on the axles to see if there was any play and they did not move. But maybe I can't check to see if they are loose with the wheels on the ground?

 

[FadedBlue]

I was looking at some videos on youtube about how to tell if you cv joint is bad. One suggestion was listening for clicking when driving in a tight circle. I tried driving in circles slowly at full lock (both left and right) in a cul-de-sac and did not notice a clicking sound.

 

[Bull Dog]

I could be wrong, but I kind of got the impression that the clicking noise I could hear in the video seemed to be more tied to engine RPM than the speed of the vehicle.

 

[FadedBlue]

I could be wrong, but I kind of got the impression that the clicking noise I could hear in the video seemed to be more tied to engine RPM than the speed of the vehicle.

The noise does seem to be related to engine rpm. I hear it during acceleration. It seems to be louder with harder acceleration. I don't notice the noise during constant speed or deceleration. I would say the "crunchy" upshifts are due to sloppy shifting on my part as I was trying to accelerate quickly. Shifting is normally smooth when driving normally.

The cv joint problem is a theory here. I am not sure if that is the actual problem here, but it does not hurt to see if that might be the real problem in case my mechanic might have misdiagnosed the problem. However, the cv joints seem intact and I don't hear a clicking noise when driving in tight circles, so I am not sure a cv joint is the problem.

The Insight has been used infrequently with me working from home for the past 2 years and not having the long commute. I have been driving my Civic Si mostly. Actually the Insight was not driven for several months, which is probably bad for the battery. I thought I should start driving it again since I may need to start commuting to work again and it is much cheaper to drive the Insight 80 miles a day than my Civic Si when I commute to the office. When I took the Insight out the past couple of days, I also noticed a noise when coming to a stop. It reminded me out a brake noise, but maybe it is related to this clicking noise?

It seemed like the clicking noise may have started when I got the car inspected last summer and the engine mount needed to be replaced to pass inspection. But with me infrequently driving the car, maybe the clicking noise was already there and it is just a coincidence that I think it started about the time the engine mount was replaced.

 

[FadedBlue]

I have a feeling that this might be the ISB tranmission problem.

If it is the transmission, should I just take it to a transmission shop for a rebuild? Or see if I can get a used rebuilt transmission, like I did years ago from Synchrotech?

 

[Bull Dog]

It's exceedingly hard to diagnose noises from long distance. So I can't say for sure what the culprit is. However, I would be inclined to believe your mechanic. If you decide to go the transmission rebuild route, here's some food for thought.

Scott (KLR3CYL) and I specialize in rebuilding Insight transmissions. I'm confident in saying nobody does it better than we do.

Every transmission gets completely disassembled, thoroughly cleaned and inspected. We replace all of the bearings. We do the 1st and 2nd gear syncro tab-ectomy. This permanently fixes the downshift grind issue. We restore the ball detents on the shift forks if they are excessively worn. There's more, but you get the idea.

We also do core exchanges where we send you a fully rebuilt transmission and then you send us your original transmission back.

 

[FadedBlue]

I have a feeling that this might be the ISB tranmission problem.

If it is the transmission, should I just take it to a transmission shop for a rebuild? Or see if I can get a used rebuilt transmission, like I did years ago from Synchrotech?

Well I tried calling Synchrotect and they don't do Insight transmissions.

 

[ChooCanDoIt]

It's exceedingly hard to diagnose noises from long distance. So I can't say for sure what the culprit is. However, I would be inclined to believe your mechanic. If you decide to go the transmission rebuild route, here's some food for thought.

Scott (KLR3CYL) and I specialize in rebuilding Insight transmissions. I'm confident in saying nobody does it better than we do.

Every transmission gets completely disassembled, thoroughly cleaned and inspected. We replace all of the bearings. We do the 1st and 2nd gear syncro tab-ectomy. This permanently fixes the downshift grind issue. We restore the ball detents on the shift forks if they are excessively worn. There's more, but you get the idea.

We also do core exchanges where we send you a fully rebuilt transmission and then you send us your original transmission back.

I am interested in knowing more about you and Scott’s fully rebuilt transmission service for my G1 MT Insight. Please PM me with more information. Thank you.

 

[*sean*]

I do not think that it is a CV joint. The sound matches the RPM, not the wheel speed. And I question the transmission diagnosis for the same reason.

Start with the simple, cheap stuff (which will make your car sound nicer anyway) before replacing transmissions. The following are easy to check and do if you do them yourself, the first being, to me, the most obvious and the most challenging (because of rust.)

• The amount of sound the car makes vs the road noise makes it sound like the donut gasket between the first and second catalytic converters is shot. I would start by verifying, then replacing that. The frequency of the note sounds like it is 1/3 of the ignition rate, which makes me wonder if another engine issue is contributing (see second and last bullets)
• Do a valve adjustment - which is really easy - to see if this changes the idle smoothness and exhaust note.
• Also verify that the air filter box is solidly connected to the engine. The rubber bushings may be shot.
• Doesn't sound like loose catalytic converter covers, but check those too.
• There are three engine mounts. Verify that all are in good shape. (Examine them visually, don't take a mechanic's word that they were done correctly.)
• The engine harness is attached to the frame on the cross-bar that also holds the battery. This frequently breaks and may squeak or rattle when it hits that bar.
• Verify that all spark plugs are tight, though if one is so loose you could hear it at all you would probably hear it a lot.
• Is there a problem with a spark plug or ignition coil? Verify all are good and the gap is proper.
• Do a compression test while you have the plugs out.

The fact that your car failed an inspection because of an engine mount suggests one of the above is quite possible, since the engine would have been shaking more. Replace the remaining motor mounts, so that whatever you fix doesn't get trashed again by a bad motor mount.

Exhaust pressures will be greatest when the engine is under load, which is pointing me to the exhaust donut gasket as the first item to check.