to make long story short - last winter my 97Se auto developed turbine like whirrrrrrrr sound coming off from the EGR valve area.

First i suspected timing chain tensioners , or even tranny but simple troubleshooting ruled those two out.

The noise sounded like bad valve train and could be heard in 1st and 2nd gear when accelerating hard - only when the engine was cold , once it got up to normal temp , things were quiet and smooth.

today i was able to pinpoint location of the noise and most likely its coming off the dish looking valve that sits right below the EGR valve

The Hayens and Chilton's manulas list it as EGR Backpressure Transducer EGRC-BPT.

does anyone have similar experience ???

should I start to take things apart and start some major carbon build up clean up ???

I'm just so unconfortable with all those little vacum hoses !!!!

or just take it to the dealer , play dumb and let him pinpoint the noise ???

BTW - No ECU codes , no driveability problems ( bit sluggish thou )



Thanks in advance
Nick

 

You mention that the noise happens when the engine is cold. The EGR system should not operate when the coolant temperature is low. The ECM will not open the solenoid to let vaccum get to the EGR valve and EGRC-BTP valve when there is a "low engine coolant temperature".
I would start by double checking the solenoid if I were you.

Stephane

 

would bad solenoid give me whirrrring sound that is heard inside of the car ??? and not throw CEL ???

just a thought

Nick

 

The EGRC-BTP is a bypass valve. It lets the opens the vaccum to the atmosphere if there in no backpressure in the exhaust. That cause the EGR valve not to open because it doesn't get any vaccum.

But you mention that the noise is coming from the EGRC-BTP valve and only when cold. If you are right, then the solenoid might be open all the time (ie no 12v current reaching the solenoid or defective solenoid) According to the Manuals, this solenoid stays closed until car is warm, engine running etc...

I wouldn't take it apart yet. If you are quite sure that this is the part that makes the problem, I would diconnect the vaccum hose that goes from the solenoid to the EGRC-BTP or if you prefer the one between the solenoid and the charcoal canister to cause the vaccum to be lost in the atmosphere and hear if it is still makeing the noise when cold.

If it still does, then it is not the EGRC-BTP valve.
If it doesn't make the noise anymore, then your solenoid "send" vaccum to the EGRC-BTP when it is not supposed to.
If you try this, please keep us posted on the results.

Anybody else has any idea?

Stephane

 

thanks a lot , will give it a try !!!!

Nick

 

well today during my college engine rebulding class i asked our instryctor to listen to the noise -

first thing he said - you have an exhaust leak !!!
than i told him about about my aftermarket Y-pipe
he said thet those ring gaskets are causing the leak and the noise .

when things are cold - metal shrinks and makes noise , when things get worm it expands and noise stops

I will put the car on the lift and i will try to retighten
those bolts that connect Y-pipe to collectors

hopefully this will take care of problem

Nick

 

Good luck.... Lucky to have access to a lift!