Aidy

[Aidy]

Hi I'm wondering if anyone can help
I have a e46 325ci and recently my car had a slight whistling sound(sounds like a supercharger) and smoke is coming from the engine bay when up to temp and stood idling....the smoke smells more of a water/steam smell n I've noticed that it's slightly using water,this both happened just suddenly btw......it's also running a little rough on idle when I start the car
Also with it been auto...once I select drive n very lightly touch the accelerator(sounds like a slight suction of air) it tends to stall n I have to give it a bit more throttle
I took off the oil cap and there seems to be a lot of suction n quite hard to take cap off

Is this problem/problems down to the ccv crankshaft ventilation n hoses that require replacing
Pls help

[parkerbot]

Welcome to the forums! You've come to a good one as the guys and gals on here are some of the most knowledgable I've seen in my years of navigating car forums.

First so more information would help diagnose your autos problems. How many miles are on the vehicle? Are there any lights showing on the dash (check engine like, ! marks, etc.)? If so what are they? Have you had a BMW compatible code scan done on the vehicle? If so what were the codes and description? Have you noticed a change in your exhaust...does it seem more water vapor saturated? Does it smell sweet almost like coolant?

I suspect you have a vacuum leak causing the rough idle/sucking noise and stalling. You'll need to get a smoke test done to see which components have failed. I would suspect intake boots have cracks and CCV as these are the most common problems but a smoke test will find all the leaks.

As for the smoke/steam you very likely have a coolant leak especially with the car losing coolant. I'd have them check for coolant leaks when you get the smoke test done. If you prefer a more DIY approach...I'd remove the lower engine bay cover and place a large piece of cardboard under the engine bay overnight after using the car. This will point you in the general area of the leak if its not readilly noticable (if you don't see coolant leaking from part X)

Also watch for oil or brown residue on the exhaust manifold. If you look on the passenger side of the engine you'll see the exhaust manifold and heat shield. If has oil or a dark brown burnt looking residue on it you most likely have an oil leak from the valve cover gasket. This notoriously causes smokey engines in the E46.

[marcva]

Agree that it sounds like a couple different items

1) Coolant leak - You might have a coolant leak that needs to be ficed fairly soon, you might have a leak that could fall apart in your hands leaving the car immoble.

How many miles on the car? how many miles since the last cooling system update? There is a lot of brittle plastic that needs to be replaced about every 60-80k on these cars. The neck of the reservoir for the radiator can get brittle and snap off if you grab the cap. The plastic thermostat cover can get brittle and start leaking. the reservoir itself can get brittle and crack. The gasket bahind the thermostat cover can get dry and leak.

Look specifically for telltale puddles under the car to give you hints of where the leak is. Also look for any white residue (dried coolant from leaks). Check the coolant cap and hoses as well as the plastic elbow behind the fan which is the thermostat cover. If those areas are dry, peek under the car ad the front left corner of the bottom of the engine where the water pump is. It will be on the main drive belt. See if there is any indication of coolant leaking there. If nothing obvious comes up, have a shop to a pressure test. Also if the system is over 60-70k, just buy and replace the radiator and hoses, thermostat and cover and water pump. (or have it done).

2) Whistling - Regarding your whistling. start the motor and squeeze the intake tubing around the elbow to expose any non-obvious cracks. look for leaking oil around your valve cover gasket that might indicate a leak and possible vacuum leak there. If you don't find anything obvious to replace based on dry rot or other failure, then see about a smoke test from a repair shop.
Regarding your whistling. start the motor and squeeze the intake tubing around the elbow to expose any non-obvious cracks. look for leaking oil around your valve cover gasket that might indicate a leak and possible vacuum leak there. If you don't find anything obvious to replace based on dry rot or other failure, then see about a smoke test from a repair shop.