I've noticed that my '92 BMW 535 has a problem with low oil pressure
when parked at an incline. I made two runs getting sand today, and to
get the trailer in the right position I had to park the car in the steep
area of the driveway. Both times the oil pressure light was on when I
started the car, and the second time it even came on as I was backing
in. I tried restarting the engine, but same thing. It wasn't until I got
the car up on level ground and restarted the engine the light finally
went out. Mind you, both times I had to drive up onto the street, reving
the engine and with the trailer behind, without oil pressure. Obviously,
that can't be good. Is this a design flaw in the engine, or is there
something wrong with my car? I checked to oil level afterwards and it
was perfect, right below max. I've never had any problems with low oil
As you can see in this picture, it isn't even that steep:
Don't mean to scare you but I used to have an '86 535i and was told by
several knowledgeable BMW enthusiasts that the engine was virtually
indestructible. Well, when I bought it (with about 200K miles) it had a
bad leak from the cat which I had rewelded... then I found that I had a
tapping noise from the engine... well next time I had a free weekend I
took it to my parents' house (about 150 miles away) and reset the valve
clearances... noise still there... that's when I started to get
worried. On the way back the oil light started flickering when I
stopped for tollbooths etc. D'OH! Next time I started the car it
immediately spun a rod bearing. Not good. I'd maybe put 2K miles on
the car and I had to spend as much as I paid for the car to have a
junkyard motor put in it.
IOW, get it checked out soon...
replace "fly" with "com" to reply.
Make sure you have the right dipstick and tube length, this is typical
symptoms of oil laying in the rear of the oil pan away from the pick up, try
adding maybe 1 and 1/2 qts and see if it still happens, you can always drain
it back out.
You shouldn't have any trouble pulling it (except if it is very steep), but
stopping in a straight line, that's a different matter and nothing to do
with the towing car*.
* You canna change the laws of physics - McCoy.
Quite often, the limitations on towing isn't getting going, but getting
slowed down again. I gotta wonder if a yard of sand or gravel is more than a
BMW should be working with. It's one thing to drag a SeaDoo or two to the
river, and quite another to to deliver a ton or more of building materials.
Agreed, but it's not like I'm in the construction business... :-)
Speaking of braking, I did have the ABS kick in once when I was braking
for a red light. The brakes on the trailer weren't really that great,
but I guess that can't really be expected on a rental. Then again, the
sand might have weighed a little more then I first thought too. I just
did some calculations and the volume of the bed is about 1.6 m^3, the
question is if the sand would cover the whole area up to the top of the
sides or not. Assuming it would, and with a density of 1.5 tons/m^3,
that's like 3 tons including the trailer. I regret not using the scale
they had where I bought the stuff, it could have been a nice surprise... :-)
In the construction business or not, I can't help but think you are
overloading your car and putting yourself at serious risk. I gotta think the
chassis isn't very happy to have all of that tongue weight hanging off of it
Well, I don't know about "serious risk", driving 55 mph in the right
lane is as safe as it gets. Besides, on a twin axle trailer the tongue
weight is pretty low, anyway. Of course, towing a trailer twice the
approved weight of the hitch still isn't the best idea, so you do have a
Nope. Wrong! It makes no difference if the trailer is a single or
double axle, the tongue weight must *intentionally* be made to be
approximately 10% of the load or you are setting yourself up for some
serious fishtailing, which is a safety concern for you and those driving
There are two weight ratings on hitches, tongue weight and towing
weight. Neither should be exceeded for safety reasons, regardless of
the tow vehicle.
Serious risk comes when the bonehead -- that's a relative term, it is
difficult to find more of a bonehead than the guy with a trailer load of
building materials behind a BMW -- in front of you slams on the brakes for
Tandem axle or single, the tongue weight is a function of where the scoop of
building material is placed, if the material is on the back, then the tongue
weight is low, if on the front then the tongue weight is high. Looking at
the pic you posted, your weight is high. My guess is the trailer weight
exceeds the hitch capacity, and the tongue weight is too high as well.
Frankly, if I was a cop and saw you coming, I'd be dropping in line behind
you and hitting the lights, especially on the freeway. I might give a blind
eye to a surface street infraction if the speed was below the posted limit
and an extremely large following distance to the car in front of you, but on
the freeway there would be know way you could haul that Sanford & Son load
to a halt in an emergency. That load has no brakes. That is, the class of
trailer hitch that would be reasonably installed on a BMW would not take a
trailer brake controller, and therefore even if the trailer had brakes, the
BMW isn't going to operate them.
let compare the load of a car or a boat put on a trailer pulled by a 5
series with regard to the sand load he is trailing.
Is there a serious difference as far as the trailer is suited for ?
You assume that the guy is driving like a mad. You make assumptions about
the way he is driving on.
Why shouldn't a BMW be used for transporting something else than diamonds
or pearls ?
Everything in your reply is subjective.
Sorry, but I find your reply as disrespectful and abusive towards the guy at
the origin of the post.
Are you a sherrif or a judge ? Have you special rights ? Are you superior
because driving a BMW ?
That's a good point. It doesn't really matter what one is pulling IF the
load does not exceed the towing capacity of the vehicle. 5,000 pounds of
sand is the same to the car as 5,000 pounds of boat.
I don't know the towing capacity of the 5 Series, but a casual observation
is that it isn't 5,000 pounds.
I was in the right lane 2 sec. behind a semi both times I drove from the
sand pit. I would have had ample time to take evasive action in case
something unexpected were to happen.
You're probably right. Looking at the other pictures it looks like I got
a much better distributed load the first time, despite a probably higher
If you look at the picture again you'll see that the trailer has surge
brakes so I don't need any brake controller. Also, if you think it's
more dangerous driving on the freeway than on a surface street where
there are kids, crosswalks, speed humps, intersections, traffic lights,
bicyclists, etc., then you obviously don't know what you're talking
about. I don't get what's so terrible towing a trailer with building
materials either. You say recreational equipment is okay, so I assume
you'd approve of me towing my motorcycle, but how about my lawn mower?
Yes, no, or maybe only at night?
Obviously you made it home alive. The problem is, you can't always be in
control of your environment, and if a sudden change in the environment
causes you to loose control of your machinery, then death or serious injury
is certainly within realm of the possibilities that can result.
All right, the surge brakes improves things somewhat.
I think that 35 is safer than 55, but 35 on the freeway is a disaster
waiting to happen. The trouble isn't WHAT is on the trailer, the trouble is
HOW MUCH is on the trailer. Your car has a Max Towing Capacity, and the
trailer you are using probably exceeds the capacity of the car even when the
trailer is empty. A very light weight trailer, say 300 pounds, that has two
jet skis of say 300 pounds each makes a total trailer weight of 900 pounds,
this is a far cry different than what you are towing. Frankly, 600 pounds of
sand isn't very useful and you need a bigger trailer than can haul jet skis
or motorcycles, but this demands you need a bigger vehicle to pull the
And, in the interest of full disclosure, I do lots of stupid things with my
cars and trucks. I am not dinging on you because, if I was faced with the
same dilemma of how to get stuff home from Lowes or the gravel yard, I've
been known to overload my vehicle. Once was a near disaster when a severely
overloaded trailer took control of my Jeep and demanded more of the roadway
than was considered to be available to me.
Back to your original question, if the oil level was low, then the oil
pressure could suffer if the vehicle was on an incline. The oil is pumped to
the top of the motor, then it drips down to the oil pan and starts over
again. When on a hill, the oil can only drain down a few of the available
holes that it would normally drain through, so more oil would accumulate at
the top of the motor. If the oil level was on the low side, and excessive
amounts of oil was accumulating at the top of the motor, then the oil pump
would begin to suck air and the oil pressure would drop. Your oil pump is in
the front of the motor, and on a hill, the oil will flow to the back, and
more of the oil will get stuck at the top since there are fewer drain holes
available. As the oil gets pumped to the top, and flows to the back of the
engine, and the oil level is low to begin with, then you will suffer low oil
My guess is that you are down about 2.5 quarts, give or take. Your car takes
7 quarts to fill it up, but lots of oil change places might only put in 5
quarts because that is what most cars take. If your oil change guy only put
in 5, then you might be thinking that the oil is filled because it was just
changed "last week" or whenever, and the reality is that it isn't full at
all. You need to pull the dip stick and see for yourself ...
Towing my race car (3200 pound Camaro) to the track last year with a
rented 1 ton Uhaul and trailer... we came across bad traffic... caused
by a CHEVETTE towing a trailer that had jackknifed into the ditch coming
down an overpass.
Did I mention the Chevette had what looked like a class III or IV hitch
on it? The trailer was an old truck box loaded with stuff... must have
been 6000 pounds in it...
Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here.
All logos and trade names are the property of their respective owners.