An Engine Noise Mystery Quiz

Old Aug 14, 2012 | 11:06 AM
  #41  
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Originally Posted by stellar
My best guess - Did this car have a bimetalic spring control for the choke? I think choke related anyway. Or the H2O hydraulic screwtinater resivour was low on water. Mind you these require non chlorinated water so it must have distilled water or rain water.
No, not that either. I'll give another hint that the problem was not on the engine.

I was told the H2O hydraulic screwtinator had been replaced when they replaced the piston return springs.
Old Aug 14, 2012 | 11:21 AM
  #42  
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Originally Posted by 69442C
No, not that either. I'll give another hint that the problem was not on the engine.
I was told the H2O hydraulic screwtinator had been replaced when they replaced the piston return springs.
Dang, I guess that eliminates muffler bearings

Seriously if it's not electrical, not vapor lock and not on the engine then I am clueless here I think
Old Aug 14, 2012 | 11:25 AM
  #43  
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Not the good old manual choke being set and then forgotten?
Old Aug 14, 2012 | 11:27 AM
  #44  
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My last guess, then I will wait for someone to get the right answer. The customer was a blonde driving with the emergency brake on.
Old Aug 14, 2012 | 11:29 AM
  #45  
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Hi Seff. Is the flicker gone?
Old Aug 14, 2012 | 11:40 AM
  #46  
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I'll let this go for about another 45 minutes or so since that is when I'll be out of a meeting I'm now walking into and if there are no other thoughts I'll discuss what the problem was.
Old Aug 14, 2012 | 11:40 AM
  #47  
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Okay, I've had time to think about it a bit.

Any "cutting out" problem makes me think immediately of an electrical problem, like a misplaced wire from the recent points / condenser change touching ground randomly, but you said it isn't ignition, so that eliminates that thought.

The next thing is fuel starvation. It doesn't exactly translate to "cutting out," but customers / wives will describe a problem in lots of inaccurate ways.

How about bad / disintegrated fuel intake sock in the fuel tank, combined with some foreign gunk in the tank? When there's a decent amount of fuel pump suction, it pulls in the gunk and blocks the intake, causing the car to stall. After a few minutes, the gunk is released back into the tank and the intake is cleared.
On rainy days, the customer drives more slowly and cautiously, so less fuel flow is developed, and gunk doesn't get drawn in.
A '71 Nova should not have a fuel return line, so flow will vary, as I described.

- Eric
Old Aug 14, 2012 | 11:42 AM
  #48  
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Originally Posted by MDchanic
Okay, I've had time to think about it a bit.

Any "cutting out" problem makes me think immediately of an electrical problem, like a misplaced wire from the recent points / condenser change touching ground randomly, but you said it isn't ignition, so that eliminates that thought.

The next thing is fuel starvation. It doesn't exactly translate to "cutting out," but customers / wives will describe a problem in lots of inaccurate ways.

How about bad / disintegrated fuel intake sock in the fuel tank, combined with some foreign gunk in the tank? When there's a decent amount of fuel pump suction, it pulls in the gunk and blocks the intake. After a few minutes, the gunk is released back into the tank and the intake is cleared.
On rainy days, the customer drives more slowly and cautiously, so less fuel flow is developed, and gunk doesn't get drawn in.
A '71 Nova should not have a fuel return line, so flow will vary, as I described.

- Eric
Eric, you are close in that it was fuel but not the issue you mentioned. I'll give the answer after my meeting.
Old Aug 14, 2012 | 12:02 PM
  #49  
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Okay, fine.

Fuel filter or fuel line clog / obstruction reducing fuel flow to the bare minimum required to drive conservatively in the rain, but when more than that is demanded, the float bowl empties and the car dies. It can be refilled slowly by cranking, and then you're off again.

- Eric
Old Aug 14, 2012 | 12:11 PM
  #50  
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Originally Posted by stellar
Hi Seff. Is the flicker gone?
Hey there, I've yet to check it in the dark; long summer nights. There's a more in-depth reply in the thread.
Old Aug 14, 2012 | 12:18 PM
  #51  
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Wrong gas cap causing the tank to implode?
Old Aug 14, 2012 | 12:20 PM
  #52  
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Originally Posted by J-(Chicago)
Wrong gas cap causing the tank to implode?
And once imploded fuel pressure shoots up to the carb and it runs like a bat out of hell lol!
Old Aug 14, 2012 | 12:34 PM
  #53  
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OK, here is what was going on. A few good thoughts were given and some were close in nature.

This car was driven on a driveway that must not have been paved. It was a little dirty underneath and there was a 2" section of metal fuel line back near the front of the leaf spring that was encapsulated in mud. In trying to figure this out, I was looking over the fuel line and found a very faint stain on the frame rail where the mud was covering the line. As it tuned out, the line had started to rust and it had a small hole in it which became visible when the mud was removed. The hole would cause a loss of suction so the pump wasn't always able to pick up fuel from the tank. When it rained and the dirt was wet it did a good job of sealing off the hole. I suspect when the car sat for a few minutes the fuel would start to run into the line and the hole would leak a little fuel and hence the stain that was somewhat visible. When the line became filled the car would start again. Not sure of exactly why everything worked as it did when the dirt was dry. The bad section was removed and a piece of hose was clamped in place and the problem never came back.
Old Aug 14, 2012 | 12:38 PM
  #54  
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The other one I can throw out there will need to wait until tomorrow. But before I do so, it involves a 1992 Olds Cutlass Ciera. Is that too new or do you guys want to mull this one over? Not sure how much everyone wants to talk computers and sensors etc. Let me know and if there is interest I will do it tomorrow.
Old Aug 14, 2012 | 12:43 PM
  #55  
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Originally Posted by 69442C
When it rained and the dirt was wet it did a good job of sealing off the hole.
Okay. You got me with that one.

A very good diagnostic challenge, though!

- Eric
Old Aug 14, 2012 | 12:55 PM
  #56  
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Originally Posted by MDchanic
Okay. You got me with that one.

A very good diagnostic challenge, though!

- Eric
That one really was a challenge. I was happy to have found it as the gas tank was next to be removed and inspected for the things you mentioned.
Old Aug 14, 2012 | 12:57 PM
  #57  
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I think anything computer controlled is going to give too many variables for diagnosing over the web. Then again, it'd be a cool challenge...As long as it's not something like mud caked fuel line with rust holes that seal on Wednesdays and Fridays when it rains and is sunny at the same time but only when person X is driving and they're eating a Big Mac and a ICEE while texting on the phone to a foreign dignitary about nuclear powered easy bake ovens
Old Aug 14, 2012 | 02:10 PM
  #58  
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Originally Posted by ah64pilot
I think anything computer controlled is going to give too many variables for diagnosing over the web. Then again, it'd be a cool challenge...As long as it's not something like mud caked fuel line with rust holes that seal on Wednesdays and Fridays when it rains and is sunny at the same time but only when person X is driving and they're eating a Big Mac and a ICEE while texting on the phone to a foreign dignitary about nuclear powered easy bake ovens
Bbbbbb bbb buuuu buu......

But I found & bought a single TSB at a yard sale years ago & it deals with those exact issues to a "T"".

Are you telling me now that I finally found an opportunity to use it ... I won't be able to ?.



















Old Aug 14, 2012 | 06:28 PM
  #59  
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Originally Posted by ah64pilot
I think anything computer controlled is going to give too many variables for diagnosing over the web. Then again, it'd be a cool challenge...As long as it's not something like mud caked fuel line with rust holes that seal on Wednesdays and Fridays when it rains and is sunny at the same time but only when person X is driving and they're eating a Big Mac and a ICEE while texting on the phone to a foreign dignitary about nuclear powered easy bake ovens
Aaaahhhh maaaannn, there goes all the fun.

No, it won't get into any crazy computer stuff. Actually, I will spell out most of what was going on and how the various systems worked and what wasn't working and see if anyone has any thoughts. It will be an interesting read.
Old Aug 15, 2012 | 04:41 AM
  #60  
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Here goes with the 1992 Cutlass Ciera. This car was my company car and I picked it up new. 3.3 V6, auto trans and most power options. The car was problem free up to 13,000 miles when I began to experience intermittent (yep..here we go again) torque converter locking and unlocking while driving. I could be driving along at 60 mph and the converter would just start to unlock and then lock. This may go on for several minutes and then not return for a few weeks. One night after a sales meeting/dinner, I was on the way home and I had the cruise set at 50. I was just sitting back, feet away from the pedals (won’t do that anymore) and one car about 6 cars lengths ahead of me. Suddenly, the car just goes full throttle, kicking down into passing gear and I got pretty close to the car in front of me before I was able to jump on the brakes. Since it was dark and the headlights were on, the guy in front of me must have wondered what I was doing. And Toyota thinks they have the market cornered on sudden acceleration. Heck, Olds was 20 years ahead of them…. LOL! Being that it had 13K miles, I was just out of warranty. I took it to the dealer who said they would cover it under warranty given the odd nature of the problem. Since it was intermittent, they had a hell of a time duplicating this. No codes were in the computer either. I did experience the sudden acceleration several more times after that but always had my foot near the brake when I set the cruise. And hitting the brakes always made it stop. One day I was on 95 and no one was around so I thought I would let it go to see how long it would continue. At 80mph I hit the brakes as it was still full throttle. I know this is a tough one to throw out there and I won’t let this hang out there too long. I’ll be busy for a few hours this morning but will check back later this morning to see what thoughts are offered.
Brian
Old Aug 15, 2012 | 05:12 AM
  #61  
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Hold off on this. Let me post some additional information in a few minutes to simplify.
Old Aug 15, 2012 | 05:42 AM
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I think this will lead to more ideas by explaining it in this manner and that will be to give the answer now. So I’ll do this backwards. The answer to this was…there was no solution. Oldsmobile ended up buying the car back as neither the dealer nor the techs in MI who were talking with the dealer techs could figure it out. The car was taken to the dealer about a dozen times over a year’s time and they threw everything at this that they could think of. But they didn’t replace one part that I think may have been the problem. So I’m taking suggestions on what this part was. Maybe it was the problem, maybe not….Olds sure didn’t seem to know. When they bought the car back from my employer, it had 57K miles. They refunded all money less $0.10/mile for the first 13K miles, which was the point when the problem showed up.
The converter and sudden acceleration are related. The way everything works is there is a speed transducer on the back of the speedo. That generates a signal between 0 and 5 volts DC depending on vehicle speed that is sent to the computer. Depending on voltage (and other inputs) certain functions happen. It will know when to lock the converter and the voltage value also represents vehicle speed. One day when it was acting up I went straight to the dealer and the tech jumped in, connected the scan tool and we took a ride. We watched the voltage reading jump all over the place. When it went to 0, the converter unlocked. When voltage came back, it locked. But then we also saw voltage drop to a low number rather than 0. When that happened and the cruise was set, the computer though the car had slowed dramatically which caused the sudden acceleration. Over the year’s time, the dealer installed 3 computers, 2 dash harnesses, 3 speed transducers, 2 printed circuit boards and a completely new speedo with transducer. I was told they were shipping the car back to MI so the engineers and techs at Olds could look it over and I never heard any more about it. The company bought a new 94 Ciera from that dealer and that car was flawless for 90K miles when it was sold for my next car.

As mentioned above, in my mind, there was one more part in that system which controls the torque converter and cruise control functions that wasn’t replaced. Pure speculation at this point. Thoughts?
Old Aug 15, 2012 | 01:07 PM
  #63  
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My thoughts are that this was exactly something like mud caked fuel line with rust holes that seal on Wednesdays and Fridays when it rains and is sunny at the same time but only when person X is driving and they're eating a Big Mac and a ICEE while texting on the phone to a foreign dignitary about nuclear powered easy bake ovens. Only, there is no answer to the problem except to perform a gas cap overhaul.
Old Aug 15, 2012 | 01:29 PM
  #64  
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Originally Posted by ah64pilot
My thoughts are that this was exactly something like mud caked fuel line with rust holes that seal on Wednesdays and Fridays when it rains and is sunny at the same time but only when person X is driving and they're eating a Big Mac and a ICEE while texting on the phone to a foreign dignitary about nuclear powered easy bake ovens. Only, there is no answer to the problem except to perform a gas cap overhaul.
You're thinking too much on this one. My thought was there was only one other device that would disconnect the cruise and also unlock the converter. We're all done this too. If you're cruising down the road and you want to knock the cruise off you can do by turning off the cruise switch or you can do one other thing. That thing has a switch. If the switch were defective, it could have caused the signal to be lost or be restricted. Brake light switch! There was basically nothing else in that electrical system that wasn't changed. We'll never know but that was what I thought it could be.
Old Aug 15, 2012 | 10:27 PM
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Here's a tough one

'68 442
non-std engine- '67 425 HC 4-bbl
TH400
4.33 gears, posi
OAI not hooked up

If I depress the accelerator pedal more than just a little, a loud squeal emanates from the rear of the car. It will continue as long as the gas pedal is held down, usually. Sometimes the entire rear end of the car goes kind of sideways also when this noise is happening. Oftentimes a medium to large quantity of smoke will also be observed at the aft end of the car. Subsequent investigations usually reveal some sort of carbon leakage strips on the pavement, as if black paint or lamp soot has dripped from the car onto the asphalt. Also, this usually correlates to finding black zits or particles adhered to the lower section of the rear quarters, just aft of the wheels.

Letting up on the gas pedal seems to greatly diminish or even stop the squealing. It's so bad that sometimes it even attracts the attention of Law Enforcement Officers.

The tires look ok, if a bit worn. The brakes and bearings seem ok. It doesn't make this noise on the inspection rack, OF COURSE.

Like the 1-legged man said,
"I'm stumped!"

I think the Trunk Monkey is spilling his drink and smoking.

Last edited by Octania; Aug 15, 2012 at 10:31 PM.
Old Aug 16, 2012 | 05:21 AM
  #66  
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Originally Posted by Octania
Here's a tough one

If I depress the accelerator pedal more than just a little, a loud squeal emanates from the rear of the car.........
It must be a '68 thing. My '68 Cutlass S with a 350 HC, 4v, 350TH and 4.10 posi has the same problem. Please let me know if you find a solution.

I might be a case of plumbuminous pede in the steering wheel to pedals connectinator.


Adam

Last edited by arodenhiser; Aug 16, 2012 at 05:32 AM.
Old Aug 16, 2012 | 07:31 AM
  #67  
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Originally Posted by Octania
Here's a tough one

'68 442
non-std engine- '67 425 HC 4-bbl
TH400
4.33 gears, posi
OAI not hooked up

If I depress the accelerator pedal more than just a little, a loud squeal emanates from the rear of the car. It will continue as long as the gas pedal is held down, usually. Sometimes the entire rear end of the car goes kind of sideways also when this noise is happening. Oftentimes a medium to large quantity of smoke will also be observed at the aft end of the car. Subsequent investigations usually reveal some sort of carbon leakage strips on the pavement, as if black paint or lamp soot has dripped from the car onto the asphalt. Also, this usually correlates to finding black zits or particles adhered to the lower section of the rear quarters, just aft of the wheels.

Letting up on the gas pedal seems to greatly diminish or even stop the squealing. It's so bad that sometimes it even attracts the attention of Law Enforcement Officers.

The tires look ok, if a bit worn. The brakes and bearings seem ok. It doesn't make this noise on the inspection rack, OF COURSE.

Like the 1-legged man said,
"I'm stumped!"

I think the Trunk Monkey is spilling his drink and smoking.
I think this comes down to a simple case of a coefficient of adhesion. It seems the rear tires are out of sync at times with the adhesion value of the road surface thus leading to this imbalance and your issues. The solution in my mind is to tighten up a little on the nut behind the wheel or install rear tires that have an adhesion value more closely matched with that of the road surface.
Old Aug 16, 2012 | 07:38 AM
  #68  
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Originally Posted by Octania
Here's a tough one

If I depress the accelerator pedal more than just a little, a loud squeal emanates from the rear of the car. It will continue as long as the gas pedal is held down, usually.
Got it! BOTH front calipers are siezed and the front wheels will not turn.

Adam


But wait..... I am still 4 wheel drums.... Hhmmmmmmm.....
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