North American Turbocoupe Organization



NVH - Vibration at Idle
88turbomajor Offline
Junior Member
#1
Most cars idle pretty smoothly, but this T/C has a mean vibration at a light, in Drive. I know the 2.3L wasn't a particularly balanced engine and had NVH issues but has anyone run into this issue? I have to put it in neutral to minimize the vibration. I've only had the car a few months and am trying to fix the things I can. Are they susceptible to bad motor mounts/trans mounts or exhaust/any turbo parts touching the frame that would cause this?

Any ideas?

Thanks!
1988 Turbo Coupe, Blue on Blue with Cloth Interior, Moon Roof, A/T - Bone stock.
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anasazi4st Offline
Senior Member
#2
(08-15-2020, 12:42 AM)88turbomajor Wrote: Most cars idle pretty smoothly, but this T/C has a mean vibration at a light, in Drive. I know the 2.3L wasn't a particularly balanced engine and had NVH issues but has anyone run into this issue? I have to put it in neutral to minimize the vibration. I've only had the car a few months and am trying to fix the things I can. Are they susceptible to bad motor mounts/trans mounts or exhaust/any turbo parts touching the frame that would cause this?

Any ideas?

Thanks!

Assuming the timing is correct and you have no vacuum or exhaust leaks, the first thing to check should always be the motor mounts.

I replaced mine in 2015 and was surprised to find really nothing except the engine’s own weight holding it in place. The difference in the engine’s smoothness at both idle and acceleration after the replacement was kind of shocking.

I don’t care if you have 22,000 miles on it and it’s kept in the garage all the time, the simple fact is pretty much any rubber or similar compound is constantly under attack from ozone and other chemicals in the atmosphere. Also, unless they have been replaced before, these are now at least 30 years old, and there is a half a ton of engine bearing down on them constantly.

Whether or not they are the cause of the problem, they are likely contributing to it in even a small way, and should probably be replaced anyway.
Another proud dues-paying member.

1987 Turbo Coupe w/T5OD, 8.8 axle, grey smoke; most options. Got it in 1991 with 41K miles: 3 turbos, 2 heater cores, 1 T5OD full rebuild, 5 clutches, 1 head gasket, 2 Teves II ABS units, etc. later....
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88turbomajor Offline
Junior Member
#3
(08-16-2020, 06:24 AM)anasazi4st Wrote:
(08-15-2020, 12:42 AM)88turbomajor Wrote: Most cars idle pretty smoothly, but this T/C has a mean vibration at a light, in Drive. I know the 2.3L wasn't a particularly balanced engine and had NVH issues but has anyone run into this issue? I have to put it in neutral to minimize the vibration. I've only had the car a few months and am trying to fix the things I can. Are they susceptible to bad motor mounts/trans mounts or exhaust/any turbo parts touching the frame that would cause this?

Any ideas?

Thanks!

Assuming the timing is correct and you have no vacuum or exhaust leaks, the first thing to check should always be the motor mounts.

I replaced mine in 2015 and was surprised to find really nothing except the engine’s own weight holding it in place. The difference in the engine’s smoothness at both idle and acceleration after the replacement was kind of shocking.

I don’t care if you have 22,000 miles on it and it’s kept in the garage all the time, the simple fact is pretty much any rubber or similar compound is constantly under attack from ozone and other chemicals in the atmosphere. Also, unless they have been replaced before, these are now at least 30 years old, and there is a half a ton of engine bearing down on them constantly.

Whether or not they are the cause of the problem, they are likely contributing to it in even a small way, and should probably be replaced anyway.



Thank you for the help. The other thing I forgot to mention was it does it more with the A/C on. I'll see if there is something loose there too. TY!
1988 Turbo Coupe, Blue on Blue with Cloth Interior, Moon Roof, A/T - Bone stock.
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Kuch Offline
Senior Member
#4
TurboMajor,
When you put it into neutral, try to rev the engine, does it still vibrate? You should try to isolate the vibration from either the engine or the transmission. If in drive, hold the brake and give it some gas, does the vibration come back, or go away, or no change? Is it only in drive, or other gears? What RPM does it idle at? Does the rpm's drop or raise with the A/C on? It should raise a little to compensate for the A/C load.
1988 Turbo Coupe, Black/Black, 5 Speed, Moonroof,  T3/T4 50 trim, ported E6, 255LPH, Kirban, 3" DP dual 2.5" w Hooker Maxflows, MGW shifter, K&N, Gillis valve, RR cam, Koni's
1964 Ford Galaxie 500XL, 390 6V, 4 Speed, Vast and fast
1960 Ford Starliner, 292 Y Block, 3 Speed, slow and low
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anasazi4st Offline
Senior Member
#5
(08-17-2020, 12:15 PM)88turbomajor Wrote:
(08-16-2020, 06:24 AM)anasazi4st Wrote:
(08-15-2020, 12:42 AM)88turbomajor Wrote: Most cars idle pretty smoothly, but this T/C has a mean vibration at a light, in Drive. I know the 2.3L wasn't a particularly balanced engine and had NVH issues but has anyone run into this issue? I have to put it in neutral to minimize the vibration. I've only had the car a few months and am trying to fix the things I can. Are they susceptible to bad motor mounts/trans mounts or exhaust/any turbo parts touching the frame that would cause this?

Any ideas?

Thanks!

Assuming the timing is correct and you have no vacuum or exhaust leaks, the first thing to check should always be the motor mounts.

I replaced mine in 2015 and was surprised to find really nothing except the engine’s own weight holding it in place. The difference in the engine’s smoothness at both idle and acceleration after the replacement was kind of shocking.

I don’t care if you have 22,000 miles on it and it’s kept in the garage all the time, the simple fact is pretty much any rubber or similar compound is constantly under attack from ozone and other chemicals in the atmosphere. Also, unless they have been replaced before, these are now at least 30 years old, and there is a half a ton of engine bearing down on them constantly.

Whether or not they are the cause of the problem, they are likely contributing to it in even a small way, and should probably be replaced anyway.



Thank you for the help. The other thing I forgot to mention was it does it more with the A/C on. I'll see if there is something loose there too. TY!

The small nut on the A/C compressor clutch Cover Plate can work itself loose, despite the lock washer that is behind it. I was sitting at a red light some years ago when the A/C suddenly shut off. I popped the hood (it was not a busy street) and sure enough the nut holding on the cover plate was missing. I looked on the ground under the car and there was the nut and lock washer. WHEW! Very fortunate!

Also check the compressor mounting bolts—but it sound like you are already going to do that.
Another proud dues-paying member.

1987 Turbo Coupe w/T5OD, 8.8 axle, grey smoke; most options. Got it in 1991 with 41K miles: 3 turbos, 2 heater cores, 1 T5OD full rebuild, 5 clutches, 1 head gasket, 2 Teves II ABS units, etc. later....
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Kuch Offline
Senior Member
#6
Wow dude, that is a strange thing to happen. I've had parts fall off before, but that may be the most interesting one
1988 Turbo Coupe, Black/Black, 5 Speed, Moonroof,  T3/T4 50 trim, ported E6, 255LPH, Kirban, 3" DP dual 2.5" w Hooker Maxflows, MGW shifter, K&N, Gillis valve, RR cam, Koni's
1964 Ford Galaxie 500XL, 390 6V, 4 Speed, Vast and fast
1960 Ford Starliner, 292 Y Block, 3 Speed, slow and low
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andrewjs18 Offline
Administrator
#7
if you're going to replace the motor mounts/trans mounts, I'd suggest you use the ones we sell as they're much stronger than factory and have polyurethane bushings: https://tbirdcougarparts.com

do note that polyurethane bushings do transmit some vibration, though usually low and tolerable.
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anasazi4st Offline
Senior Member
#8
(08-19-2020, 08:45 PM)andrewjs18 Wrote: if you're going to replace the motor mounts/trans mounts, I'd suggest you use the ones we sell as they're much stronger than factory and have polyurethane bushings: https://tbirdcougarparts.com

do note that polyurethane bushings do transmit some vibration, though usually low and tolerable.

WOW! Well, ya sold me! When it’s time to replace mine in a couple of years, looks like I’ll be going with yours. Probably order them sooner to make sure I have them.

I didn’t see the notch you’re talking about on the site until about the 6th photo; aren’t the mounts different anyway? Well that makes it even easier to spot.

And, it looks like you got the Editor issue here on the site fixed, which is great to see.
Another proud dues-paying member.

1987 Turbo Coupe w/T5OD, 8.8 axle, grey smoke; most options. Got it in 1991 with 41K miles: 3 turbos, 2 heater cores, 1 T5OD full rebuild, 5 clutches, 1 head gasket, 2 Teves II ABS units, etc. later....
Reply

88turbomajor Offline
Junior Member
#9
(08-19-2020, 05:53 PM)anasazi4st Wrote:
(08-17-2020, 12:15 PM)88turbomajor Wrote:
(08-16-2020, 06:24 AM)anasazi4st Wrote:
(08-15-2020, 12:42 AM)88turbomajor Wrote: Most cars idle pretty smoothly, but this T/C has a mean vibration at a light, in Drive.  I know the 2.3L wasn't a particularly balanced engine and had NVH issues but has anyone run into this issue?  I have to put it in neutral to minimize the vibration.  I've only had the car a few months and am trying to fix the things I can.    Are they susceptible to bad motor mounts/trans mounts or exhaust/any turbo parts touching the frame that would cause this? 

Any ideas? 

Thanks!

Assuming the timing is correct and you have no vacuum or exhaust leaks, the first thing to check should always be the motor mounts.

I replaced mine in 2015 and was surprised to find really nothing except the engine’s own weight holding it in place. The difference in the engine’s smoothness at both idle and acceleration after the replacement was kind of shocking.

I don’t care if you have 22,000 miles on it and it’s kept in the garage all the time, the simple fact is pretty much any rubber or similar compound is constantly under attack from ozone and other chemicals in the atmosphere. Also, unless they have been replaced before, these are now at least 30 years old, and there is a half a ton of engine bearing down on them constantly.

Whether or not they are the cause of the problem, they are likely contributing to it in even a small way, and should probably be replaced anyway.



Thank you for the help.    The other thing I forgot to mention was it does it more with the A/C on.  I'll see if there is something loose there too.  TY!

The small nut on the A/C compressor clutch Cover Plate can work itself loose, despite the lock washer that is behind it. I was sitting at a red light some years ago when the A/C suddenly shut off. I popped the hood (it was not a busy street) and sure enough the nut holding on the cover plate was missing. I looked on the ground under the car and there was the nut and lock washer. WHEW! Very fortunate!

Also check the compressor mounting bolts—but it sound like you are already going to do that.

Thank you!  I'll look at that too!
1988 Turbo Coupe, Blue on Blue with Cloth Interior, Moon Roof, A/T - Bone stock.
Reply

88turbomajor Offline
Junior Member
#10
(08-19-2020, 08:45 PM)andrewjs18 Wrote: if you're going to replace the motor mounts/trans mounts, I'd suggest you use the ones we sell as they're much stronger than factory and have polyurethane bushings: https://tbirdcougarparts.com

do note that polyurethane bushings do transmit some vibration, though usually low and tolerable.

Thank you!  I'll look into it....  I'll have a better look at those by early next week.
1988 Turbo Coupe, Blue on Blue with Cloth Interior, Moon Roof, A/T - Bone stock.
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