Percolator sound.

[BeSerious]

Hello everyone,
I'm Justin.
New 87 GN owner.

I have read a lot about the car, it's internals as well as understand the general principles in it's mechanics.
Since I've had it, I drive the car casually and only give it the juice every once in a while.
I did notice though, that when I let go of the gas after "giving it some turbo", I get a kind of percolator coffee machine sound.

It almost sounds like it's coming from under the hood closest to the drivers side.
Is this the knock sensor?

It's all stock save for the exhaust, and some really brutal wiring issues left by the previous owner.
Other than that, the car runs really well, and has been looked over by three separate good mechanics that say the car is sound.
Their experience with turbos not-withstanding, I am still skeptical. I have held off driving it until I know my engine wont explode.

Sadly, my scanmaster has not arrived yet.

Thanks in advance.

Justin

Oh, and here it is on it's first day home.
(Yes I have since changed the tires and rims to their original glory.)

 

[earlbrown]

That's commonly referred to as 'turbo flutter'... oh and don't do that.

 

[BeSerious]

That was vague enough for me to google it. Thanks.

 

[BeSerious]

I'm going to replace the wastegate actuator. I had a feeling mine was wonky when I saw the shaft was slightly bent.

 

[earlbrown]

You'e kidding, right?

 

[SHADOWII]

WELCOME PILGRIM!!!
Always glad to meet a new TR owner. You can learn more about your vehicle by going to these site and reading up on them.
www.vortexbuicks-etc.com and www.gnttype.org
The weak link in the stock system is the fueling and the fluttering is the turbo beating back the air it is no longer requiring to produce the higher horsepower levels needed at a given time. Very difficult to avoid causing the sound but not destructive, easing back on the gas pedal will reduce it somewhat. Should you happen to spin the turbo prior to parking allow it, the turbo a few minutes cool down time, to stop spinning so as not to coke the oil to the bearings. Which will intern impede it's performance and eventually seize the shaft.
As far as the fuel system is concerned we due recommend installing a new upgraded fuel pump and hot-wire kit as added insurance against detonation (knock).
Please continue to ask questions and do a lot of reading to better educate yourself and you will be a happy GN owner/board member!
Again Welcome!

 

[TurboDave]

The turbo flutter as it's called is normal when coming off boost. No need to be replacing anything just yet.

Sent from my QMV7A tablet via Tapatalk.

 

[Pronto]

Yup, a lot to learn. I would be suspicious of the "brutal wiring". You may have a car that was once more modded than you think and then brought back to "stock". If there is a non stock air filter on the car, you will hear the horse sneeze if you suddenly get off the pedal while in boost. It's common with these cars. I use it to intimdate Mustangs and fart pipers. Post a picture of that "bent" actuator.

 

[krom]

The flutter is a great sound, I like when people in the car next to me or walking down the street are startled.

 

[BeSerious]

Yup, a lot to learn. I would be suspicious of the "brutal wiring". You may have a car that was once more modded than you think and then brought back to "stock". If there is a non stock air filter on the car, you will hear the horse sneeze if you suddenly get off the pedal while in boost. It's common with these cars. I use it to intimdate Mustangs and fart pipers. Post a picture of that "bent" actuator.

Thanks for your input. I guess it is entirely possible the car was modded, then put back together with "original" parts.
Here is a picture of the actuator.


Thank you for the warm welcome SHADOWII.

Justin

 

[Chuck Leeper]

They bent the rod in order to get the actuator body to bolt up???

 

[Pronto]

Not a stock actuator, the stocker is not adjustable. One more clue.

 

[earlbrown]

looks like someone hung a wrench on the jam nut and yanked the crap out if it.

 

[Pronto]

How about a few pics of the engine compartment to see what else is going on. Is the under hood wiring messed up or under the dash?

 

[BeSerious]

Here are some pics.






Just some randomly cut wires.


This thing is just unplugged altogether.


More unplugged.


Random Button and Hideous radio


Random button and switch.


Then there's this. One of the switches lights up if I turn it on.

The reverse lights don't come on. The directionals will work sometimes, and other times just stay solid. (Mainly the right turn signal)
The dome light doesn't come on. (I've checked the fuses and changed all the bulbs.) There is some pretty harsh static that comes out of the front left speaker which seems to coincide with the vehicle moving,
which will stop when you come to a halt. The clock on the radio will revert to 12:00 sometimes, but the battery is never dead.

From what I was told by the mechanic, and he very well could be wrong, is that the car doesn't seem to have been altered, just that someone started an electrical project, then gave up halfway through.

Anyway, I got the car for a really great price, so I'm not too bummed about any repairs I will need to have done.

Justin

 

[Pronto]

Seems pretty stock. Could use a nice freshing up. The unplugged green plug is an external tap for a tack. No problem with that not hooked up to anything. The one on the fender is your MAP sensor. They tapped into the line for an aftermarket boost gauge. With that unplugged, your dash boost guage will not work. Your going to need a wiring schematic to check the stock wiring locations and confirm you have good clean grounds (extremely important with these cars!!!). The wires can get corroded under the insulation and look OK but be broken and give intermittent power. Electrical issues can be frustrating. I'll let others with more experience give more info.

 

[Nascar83Fan]

Someone definitely had some aftermarket stuff in the car, that center console ashtray that is housing a bunch of switches is for some good fast goodies. Looks like someone took a mild build-up and put most things back to stock-like form and left a small mess for the next owners.

 

[BeSerious]

Seems pretty stock. Could use a nice freshing up. The unplugged green plug is an external tap for a tack. No problem with that not hooked up to anything. The one on the fender is your MAP sensor. They tapped into the line for an aftermarket boost gauge. With that unplugged, your dash boost guage will not work. Your going to need a wiring schematic to check the stock wiring locations and confirm you have good clean grounds (extremely important with these cars!!!). The wires can get corroded under the insulation and look OK but be broken and give intermittent power. Electrical issues can be frustrating. I'll let others with more experience give more info.

So what you're saying is take it to a professional. lol.
After looking at the forums, there seems to be a shop in Queens pretty close to where I live that specializes in these cars,
I probably will take it to them. As much as I am confident in my ability to loosen nuts and bolts, electrical stuff is probably
better handled by people with experience.

The A-pillar gauge is not functioning, so I guess that answers why it isn't.

Would that green plug have anything to do with my Tach on the dash always showing full?
The boost gauge on the dash seems to be functioning normally, just not the tach.

Thanks for your help, it's really appreciated.

Justin

 

[Nascar83Fan]

The digital tach gauge on the dash doesn't use that green plug, the tach gauge on the dash reading the same whether it's maxxed out or stuck at like 2000 ( which the later example is the case for mine ) is due to some eletronics on that tach circuit board having gotten corroded and it doesn't function properly once that happens as it lost calibration. Happens with the boost gauges as well sometimes, but common with the tach gauge circuit board on these TR's.
You either need to send off that tach gauge unit to be refurbished by one of the groups that specialises in doing that for a fee or acquire one that is already refurbished and replace the one in your dish with the refurbished one.

If you want the dash tach gauge to function properly again, go the route of getting it refurbished or you can go the route of hooking up an aftermarket external tach gauge and use the green plug to supply signal to the aftermarket gauge. The scanmaster also has the ability to display rpm's on it's display panel, ultimately the choice is yours on how you want to proceed with the tach issue.

 

[BeSerious]

If you want the dash tach gauge to function properly again, go the route of getting it refurbished or you can go the route of hooking up an aftermarket external tach gauge and use the green plug to supply signal to the aftermarket gauge. The scanmaster also has the ability to display rpm's on it's display panel, ultimately the choice is yours on how you want to proceed with the tach issue.

Thanks, I had read up on the refubed tachs/turbo gauges, I was just unsure if they could fail independently of each other. I think I'll have it done even after I get the scanmaster hooked up, mainly because that full bar of lights just annoys me.