| Howling 1989 BMW [message #781954] |
Fri, 21 July 2006 22:37 |
|
I have a problem with my 1989 BMW 325i. Lately I will be driving down
the freeway (rarely but does happen on surface streets) and the car
will suddenly lose all power. There is no indication that it is about
to happen but when it does the is a howling sound coming from the
exhuast. If I pull over it will still be idling and I can slighly rev
it if I press on the gas. This increases the howling sound. If I don't
pull over and I press on the gas, the car doesn't rev and continures to
slow down (with other cars passing me on right and left). While on the
freeway, I have to put it in nuetral (it is an automatic), turn it off
and then re-start it, put it back in drive, and continue on. Restarting
it seems to cure the problem. If I have been driving for a while and it
happens, it is much more likely to do it a second and third time. This
isn't very safe. I took it to a repair shop and they couldn't replicate
the problem and said it was probably a transmission problem. I didn't
think it was but I took it to a transmission shop anyway and they said
the tranny was in perfect condition. I am not sure if it is an
electrical problem or something mechanical in the fuel system. The
other day, it did it after went over a major bump. But it happens on
smooth road as well. The howling sound is unlike anything I have heard
from a car. Sounds like a dog howling coming from the exhuast. Last
night I replaced the fuel pump and then it did it again this morning. I
also added some fuel system cleaner but I doubt it will solve the
problem. I was thinking maybe it could be the fuel pressure regulator
since it will still idel but won't rev. Although I don't know why it
would be howling. PLEASE HELP ME!!!!!! I don't want to get ride of
this car because when it isn't doing this it runs beautifully and get
up to 27 mpg even with 186k miles. Any suggestions would be extremely
helpful.
|
|
|
| Re: Howling 1989 BMW [message #781957 ] |
Fri, 21 July 2006 23:28 |
|
MechEMike wrote:
> I have a problem with my 1989 BMW 325i. the car
> will suddenly lose all power. There is no indication that it is about
> to happen but when it does the is a howling sound coming from the
> exhuast.
======================
Excessive back pressure from catalytic converter?
If the exhaust is becoming blocked as the unit warms, that would
explain the noise from the exhaust and also lack of power.
Also it is possible for a muffler to collapse internally.
Check for excessive back pressure (intake manifold vacuum drop at
steady throttle opening)
|
|
|
| Re: Howling 1989 BMW [message #781959 ] |
Sat, 22 July 2006 01:07 |
|
MechEMike <Michael.W.Shafer [at] gmail.com> wrote:
>I have a problem with my 1989 BMW 325i. Lately I will be driving down
>the freeway (rarely but does happen on surface streets) and the car
>will suddenly lose all power. There is no indication that it is about
>to happen but when it does the is a howling sound coming from the
>exhuast. If I pull over it will still be idling and I can slighly rev
>it if I press on the gas. This increases the howling sound. If I don't
>pull over and I press on the gas, the car doesn't rev and continures to
>slow down (with other cars passing me on right and left). While on the
>freeway, I have to put it in nuetral (it is an automatic), turn it off
>and then re-start it, put it back in drive, and continue on.
Pull over. If you can get it up partly on a curb, do that. Now find out
where the howling sound REALLY is coming from.
It COULD be coming from your fuel pump. If you have replaced that, and
you are sure the pressure regulator is good, you should replace the filter.
If you didn't replace the filter recently you should do that anyway just
in case, even though that's almost certainly not the problem.
I bet you find it isn't coming from the fuel pump or anywhere near there,
and it's entirely possible it's coming from the tailpipe. If this is the
case, try banging on the converter and muffler some time when the engine
is cool and see if you don't have junk floating around inside them that
occasionally clogs the thing up.
But don't throw any money or any time at the thing until you figure out
where the sound is really coming from.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
|
|
|
| Re: Howling 1989 BMW [message #781973 ] |
Sat, 22 July 2006 09:23 |
|
Perhaps O2 sensor needs to be replaced or is covered with crap
--
There are no words that can be heard unless someone listens....
"MechEMike" <Michael.W.Shafer [at] gmail.com> wrote in message
news:1153514266.932454.33730 [at] b28g2000cwb.googlegroups.com...
> I have a problem with my 1989 BMW 325i. Lately I will be driving down
> the freeway (rarely but does happen on surface streets) and the car
> will suddenly lose all power. There is no indication that it is about
> to happen but when it does the is a howling sound coming from the
> exhuast. If I pull over it will still be idling and I can slighly rev
> it if I press on the gas. This increases the howling sound. If I don't
> pull over and I press on the gas, the car doesn't rev and continures to
> slow down (with other cars passing me on right and left). While on the
> freeway, I have to put it in nuetral (it is an automatic), turn it off
> and then re-start it, put it back in drive, and continue on. Restarting
> it seems to cure the problem. If I have been driving for a while and it
> happens, it is much more likely to do it a second and third time. This
> isn't very safe. I took it to a repair shop and they couldn't replicate
> the problem and said it was probably a transmission problem. I didn't
> think it was but I took it to a transmission shop anyway and they said
> the tranny was in perfect condition. I am not sure if it is an
> electrical problem or something mechanical in the fuel system. The
> other day, it did it after went over a major bump. But it happens on
> smooth road as well. The howling sound is unlike anything I have heard
> from a car. Sounds like a dog howling coming from the exhuast. Last
> night I replaced the fuel pump and then it did it again this morning. I
> also added some fuel system cleaner but I doubt it will solve the
> problem. I was thinking maybe it could be the fuel pressure regulator
> since it will still idel but won't rev. Although I don't know why it
> would be howling. PLEASE HELP ME!!!!!! I don't want to get ride of
> this car because when it isn't doing this it runs beautifully and get
> up to 27 mpg even with 186k miles. Any suggestions would be extremely
> helpful.
>
|
|
|
