# Whistling Noise from Oil Dipstick



## Eddy Cruze (Jan 10, 2014)

My 2014 1LT has been virtually problem free. Heard more than normal ticking today, decided to pull dipstick and check new oil, reading is spot on. Noticed an immediate whistling noise from the filler tube and clicking from the valve cover, like something is slapping around. The Idle actually changes when removing the dipstick, and when replacing the dipstick the idle drops and the motor shakes like its going to stall. What can this be? Runs fine with no hint of noise or any engine problems?


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## ChevyGuy (Dec 13, 2014)

Opening up the crankcase with the engine running will create problems. It's not unlike when the PCV valve in the cover ruptures.


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## Eddy Cruze (Jan 10, 2014)

I pulled the Dipstick, is that considered opening the cranckcase? In any case why should the tube make a wine like a teapot, why should the engine idle fluctuate when removing the dipstick and then reinserting it, and why should the valve cover be making a clunking/slapping noise which you can feel by touching the top?


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## NickD (Dec 10, 2011)

Because these new PCV systems really suck, literally, at idle, draw about 19"/Hg of vacuum at engine idle.

The source of this vacuum is where the PCV hose goes into the inlet of the turbo, is a venturi, air from the air cleaner flies over this to create this vacuum. Leaks can be in the camshaft cover, PCV hose, oil filler cap, or the dipstick itself, also has a pressure switch, manual does not say when this trips, guessing around 4"/Hg, if it drops below this point, will set a Type A code, CEL will come on, only way to reset it is with a scanner.

You can't check your engine oil while its running anyway, pumping oil all over the place, will always read low. When I change my engine oil, only add four quarts, take it off the ramps, start the engine to take it off the ramps, and pray the oil light goes off. On level ground, wait about five minutes for the oil to settle,then check it, then fill it to the full mark on the dipstick. Do not want to over fill it, more problems. Always check the engine oil and coolant when cold, both should be at the full mark.

All this stuff is basic, but those kids working at the dealership don't even know all this stuff. But like to call themselves the experts.


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## Robby (Mar 1, 2013)

To simplify, Eddy, the dipstick goes down into the crankcase. When removed with the engine running, the crankcase, which is at negative pressure with the dipstick sealing the hole, is now pulling additional air in through that hole.
Because the volume of air is large, you can hear it whistle as air is pulled in.
Because of that increased volume, the air/fuel mixture becomes lean (more air than required) and this lean condition makes the engine run rough (lean misfire). The fuel injection can compensate for this and once it re establishes the correct mixture (just a few moments) the engine idle generally smooths out.
When you re insert the dipstick, the inverse occurs (rich misfire) and the fuel injection once again corrects the fuel mixture and idle quality is restored.

You are seeing normal operation.....as far as the whistle, just a result of the volume of air drawn into the crankcase through the dipstick tube (hole).

Rob


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## warbed1 (Nov 2, 2020)

Eddy Cruze said:


> My 2014 1LT has been virtually problem free. Heard more than normal ticking today, decided to pull dipstick and check new oil, reading is spot on. Noticed an immediate whistling noise from the filler tube and clicking from the valve cover, like something is slapping around. The Idle actually changes when removing the dipstick, and when replacing the dipstick the idle drops and the motor shakes like its going to stall. What can this be? Runs fine with no hint of noise or any engine problems?





Eddy Cruze said:


> My 2014 1LT has been virtually problem free. Heard more than normal ticking today, decided to pull dipstick and check new oil, reading is spot on. Noticed an immediate whistling noise from the filler tube and clicking from the valve cover, like something is slapping around. The Idle actually changes when removing the dipstick, and when replacing the dipstick the idle drops and the motor shakes like its going to stall. What can this be? Runs fine with no hint of noise or any engine problems?


If its the 1.4 or 1.8 engine then the valve cover needs to be replaced The bladder is cracked and cousing vacuum to leak into the crankcase system. pull dipstick or oil cap off and spray a little carb cleaner in there , if idle changes and smoothes out you need a new valve cover assy.


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## Eddy Cruze (Jan 10, 2014)

warbed1 said:


> If its the 1.4 or 1.8 engine then the valve cover needs to be replaced The bladder is cracked and cousing vacuum to leak into the crankcase system. pull dipstick or oil cap off and spray a little carb cleaner in there , if idle changes and smoothes out you need a new valve cover assy.


Do you really think so? I know Robby and Robby always told it like it was. I miss Robby, he knew the Choo Choo in Des Plaines! No cracked bladder, although I am having male problems I will discuss with my Doctor in a couple of weeks


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