Recently acquired a whiny whistle sound from my B18A1 and it starts right after the car is warm. Thought it was a vacuum leak but after looking at everything it seems fine. Finding the source of it has been difficult but it seemed like it was coming from the bottom of the transmission where it mates with the block. Thought it was maybe the throwout bearing and it does change volume when the clutch is pushed in but not much. Also when you turn off the car and the engine is stopped, you can hear the whistle slowly die out so and it changes pitch each time so it sounds like air escaping somewhere.

But here's the good part, I read somewhere the PCV valve could be the culprit so I popped the valve out while the engine was running and boom, it stopped whistling. Went to my auto store and got a new PCV valve thinking it was the valve and nada, still whistles. We checked round the hoses but it doesn't seem like air is escaping. Guess the echo of it in the firewall is what got us thinking it may be the transmission. We sprayed carb cleaner down the pcv hose but nothing changed too.

Has anyone had this problem and how to remedy it? It's most annoying at a stoplight but when driving it's not as loud but constant.

 

I have somewhat an issue like that. except i can only hear it when I turn the car off, and it slowly dies. But it's not a whistle, more like air just escaping somewhere.

 

Use brake parts cleaner to find the source of the leak. Engine RPM will generally increase if a leak is present. Try cleaning the throttle bore out where the plate rests, known to make noise on a lot of sludged ones.

 

Sounds good, I'll give this a try. But it sounds more like a crankcase problem now. What does it mean if you take out the dipstick while it's making the noise, a ton of air will escape with a whoosh sound? Where could this pressure be building up at? Once you put the dipstick back in it seems to take about 20 seconds before the pressure is built back up.

 

Some reason your crankcase is not venting like it should. are the hoses on the back of the motor hooked to the black box right? is the PVC valve on it good and a hose running from it to the intake manifold? How are your valve cover vents? are they hooked to the intake tube like they should be?

 

All hoses and lines seems okay, PCV valve was just replaced and looks good. I went ahead and took off the breather box to only have the top line connectors to it break. So after a trip to lowes, I found some fittings to replace and when it installing it, I ran an extended hose from the PCV connector hose straight through the intake runners to the top of the engine. Now having the an open hose, I ran the engine and of course the pressure was relieved. I ran it like this for a couple of days but the oily/gas smell was strong and I hooked the pcv back to this hose. No whistling and it seems the new piece of hose is helping. maybe the old hose was clogged or was restricting?

Whatever the case, I'm running the same setup but with only an extended piece of braided hose unlike the original one molded onto the intake runners. Works for now and I appreciate the help guys.