318is M42 Engine Hesitation

[PrinceE30]

So after I replaced my fuel pump, fuel filter, and did an oil change on my 1991 318is, I was hanging around the engine and listening b/c I thought I heard something weird. There's a slight hissing sound (which I found a BEN article on about the timing chain, tensioner). Can anyone confirm this will fix the sound?

More importantly is the slight hesitation when I push down the accellerator when the car is at idle. It pauses for a second and then accellerates the engine as usual. When the engine is under a load there isn't the same pause, only when the car is accellerated from idle.

There seems to be a lot on the M42, so let's see if anyone can help here.

Thanks all!

-Prince

[E30Driv3R]

Ive been noticing the same thing any info would be great.

[Rob]

check all your vacuum hoses, as well as the intake boot, for leaks.

[el_4ever]

There's a slight hissing sound (which I found a BEN article on about the timing chain, tensioner). Can anyone confirm this will fix the sound?

-Prince

Can you post the link??

[e9nine]

Best concise site for m42 related fixes http://www.esatclear.ie/~bpurcell/index.html

This hissing sound you speak of... Is it related to engine revs as in getting louder when you rev or it's just a slight hiss? Does it sound like the fan or the belts or something on the front end is just sounding funny?

[E30Driv3R]

My "weird" sound sounds like the fan, and i checked it..... seems normal. That sound also goes away at ~3-3.5k rpm so i looked on BP's site and it says it is the timing chain tensioner so i guess ill check that next. Any More ideas?

[PrinceE30]

Can you post the link??

http://www.bmwe30.net/cgi-bin/datacgi/database.cgi?file=articles&report=view&ID=00160&Section=08

-Prince

[PrinceE30]

My "weird" sound sounds like the fan, and i checked it..... seems normal. That sound also goes away at ~3-3.5k rpm so i looked on BP's site and it says it is the timing chain tensioner so i guess ill check that next. Any More ideas?

Mine is about the same...where it goes away at certain RPMs and above. However, I have to check the hoses still. In car I do hear a whistle at a certain RPM.

I think this may have to do with the timing chain tensioner some.

-Prince