Odd noise when I kill the motor

[mearly65]

Just grabbing at straws here. Could it be the fuel pump? Kind of sounds like a small electric motor coming to a halt.

 

[groumoutis]

Considering the fuel pump is ten feet away from the engine and it is the tank surrounded by fuel I don't think it is the fuel pump. If it is I will eat my hat. If a fuel pump is that loud that far away it would definately be ruined. I still say starter.

 

[mearly65]

Considering the fuel pump is ten feet away from the engine and it is the tank surrounded by fuel I don't think it is the fuel pump. If it is I will eat my hat. If a fuel pump is that loud that far away it would definately be ruined. I still say starter.

That's why I said grabbing at straws. I'm well aware the fuel pump is 10 feet away but who's to say it's surrounded by fuel? If the tank is empty and/or the pump was touching the tank it could make one hell of a racket. My old Suburban's fuel pump was really loud even with a full tank. You can't tell the proximity of the noise based on the video. It would take all of two seconds to rule out the fuel pump. If it was the starter staying engaged it would need a spinning flywheel to keep it in motion. The OP said the noise happens after the engine stops. Plus, if the starter was stuck I would think you would hear it the entire time the engine was running.

 

[87-WE2]

At first I though it sounded like the whine of a bad power steering pump, but I talked my self out of it after listening to it over and over in the dark. I'm not an expert, but that noise sounds like to metal to metal - almost like a low speed grinder. It stops abruptly also like something is spinning with drag on it. Since you just did the front cover, is there any possibility that something inside the cover is rubbing against it with not enough clearance?

Since it only does it when it's cold - maybe put your hand on the turbo to see if you can "feel" the vibration from there.

Did you try removing the accessory belt? That would for sure rule out the PS pump.

This is a true brainstorm.

 

[mearly65]

Can you post a video with the camera under the car?

 

[TType85]

i'll try to get out to the car tonight to get more. There is not a lot that can make that type of noise. I would think if it is the starter I would hear it with the motor running. If it was the turbo it would correlate with the wheel spinning.

The sound really sounds like it is coming from the pass side.

To go over what I did this weekend:

Started the car, pulled the intake hose which killed the car. Turbo was spinning down, noise happened, turbo was still spinning after it stopped.

I removed the inspection cover and shimmed the starter and still got the noise.

I used a screwdriver on the exhaust housing and I think I could feel the vibration from the noise.

I pulled the downpipe and did not get the noise. There was no excess play with the wheel. It spins freely but not quite as much as when it was brand new (<150 miles on it now). spin it by had and it only goes a few revolutions. There was no damage to the blades that I could see.

When I went to put the DP back on I noticed it was not 100% parallel to the turbo (when you look at it from the front) it was off a few MM on the lower front bolt. I loosened up the exhaust and lined it up better. I have not got the sound since then, but the car was warmer.

It doesn't make sense. But nothing about this car usually does

When I did the front cover/oil pan thee parts I replaced:
TA Front Cover (with pump)
Melling cam button (roller style)
RJC Crank Pully
HR Drivers Side Mount
Cork oil pan gasket
E-Bay mini-starter <--- suspect
TR Custom Parts billet filter/turbo saver
New lower hose
New water pump (not rebuilt)

 

[87-WE2]

If you pulled the dp and it didnt do it, AND you felt a vibe in the exh housing, that would make me want to go over the turbo with a magnifying glass.

 

[Amelio]

I like others susspect the starter.....it sounds just like a starter when energizeing one on a bench.....plus the way the noise stops lets me know it has drag......

Is it possiblethe starter motor is getting backfed power some how when you shut the ignition off and it is just spinning the bendix but not engaging it?????????????

have you cycled the key to ignition on "no start" to ignition off just to try?

as mentioned before put your hand on the starter while running and hae a friend shut the car off.

 

[TType85]

Went out to the car tonight. Makes the sound cold. hit the starter running and it grinds (so it is disengaging). Disconnected the downpipe (it doesn't line up again) and the noise is gone. It is the turbo. Looking at the exhaust housing it looks like the blade may be making contact (little shiny bits in the black soot. the blade looks good though and there is almost no play... could the down-pipe be tweaking the exhaust housing and when the engine turns off the bearings unload (no oil pressure) and it hits?

 

[Phoneguy]

what kind of oil pressure do you have? Can you connect an oil gauge to the turbo oil inlet? Loosen the clamp at the end of the DP, connect DP and then tighten the clamp at the end of DP. There should not be any twisting at the turbo, if it doesnt line up you are flexing the center section by forcing it.

Bryan

 

[TType85]

I am seeing 65-70# cold on the fitting coming out of the block. I am using a TR Custom Parts filter with the fitting on the end going to the turbo.

The hot side of the turbo looks perfect.


Tomorrow when I get home I will pull the cold side.

I think I may have been forcing it the last little bit with the downpipe. I need to pull the downpipe out it is a REAL tight fit in the cat.

 

[Phoneguy]

Remove the cat so the downpipe is not in a bind and fire it up, hopefully you havent damaged the turbo already.

Bryan

 

[87-WE2]

It's just weird that it began doing it after a starter change and front cover change. You weren't even messing with the downpipe, right?

 

[TType85]

It's just weird that it began doing it after a starter change and front cover change. You weren't even messing with the downpipe, right?

I did have the downpipe out to get more room to work and changed to my gutted cat. The fit was tight but I didn't tighten up the band clamp or bolts to the exhaust on the back of the cat till after I did the turbo and it is still tweaked a bit.

 

[TType85]

I may have lucked out and not damaged the turbo. Cold side of the turbo looks brand new. Amount of play is minimal (less than a stock turbo I have here).

This is how the DP lines up. The angle is a bit exaggerated as I didn't fully bolt down the exhaust housing fully bolted down it is a little bit closer than that.



I am going to pull the downpipe and cat tonight. Probably have the neck of the cat opened up just a tiny bit so it slips on easier.

 

[HouTX87]

Remove the serpentine belt. That will tell you if it's external.

x2, this will rule out anything belt driven on the front of the motor. Also try unplugging the orange ecu wire near the battery, crank the engine. See how it sounds cranking without the engine running. Should be easier to hear the location of the noise.

 

[HouTX87]

hard to tell from a video but that noise sounds very close to where you were filming. I've never heard a starter make that sound. If the starter sounds normal when you crank it then I doubt that is it.

 

[John Larkin]

The exhaust wheel sits inside the exhaust housing. No way it can contact the DP. Are you bolting the DP to the housing and then bolting all of that to the center section of the turbo? I just can't see how contact is possible unless some extreme twisting of all these components together is happening. The DP has to sit flush against the housing (both sides are flat, machined surfaces) unless it is contacting the header, frame or heater box first. Something is not adding up. Forget the catalytic converter. Lay it on the floor and just hook up the DP with nothing attached to it.

 

[TType85]

The exhaust wheel sits inside the exhaust housing. No way it can contact the DP. Are you bolting the DP to the housing and then bolting all of that to the center section of the turbo? I just can't see how contact is possible unless some extreme twisting of all these components together is happening. The DP has to sit flush against the housing (both sides are flat, machined surfaces) unless it is contacting the header, frame or heater box first. Something is not adding up. Forget the catalytic converter. Lay it on the floor and just hook up the DP with nothing attached to it.

Bolting it on like normal. Attach to the header then attach down pipe.

Dropped the "cat" still get the sound.

x2, this will rule out anything belt driven on the front of the motor. Also try unplugging the orange ecu wire near the battery, crank the engine. See how it sounds cranking without the engine running. Should be easier to hear the location of the noise.

Cranking and running sounds fine. Just get the noise when I shut it off. I pulled the belt and it didn't make the sound.... I could only try twice because my battery was weak. It must be an accessory. When the battery charges I will try it again to make sure.

 

[EYE-OPENER]

Look at the tensioner when it's making the noise. A stretched belt could cause the tensioner to be at a spot where it doesn't want to be. While the belt is off, toy with all the pulleys and see if something feels odd as well. But I truly vote for throwing a new belt on and it fixing the noise.