Towing HEAPS with 325ia (1987)

[warrenp 6]

Hi everyone,

We're moving house from South Island to North (back home! ) and I'm hoping to tow all the stuff in either a horse float or a tandem trailer with my trusty e30.

But... I really don't wanna do this if it's going to ruin (or even damage a little bit) my car!! So here I'm asking for opinions and advice.

It will mean driving over the Takaka and Rimutaka hills (600m and 500m each with some steep bits) and towing probably about 600kg of stuff in a trailer that may weigh 700kg... (ie up to 1300kg of weight behind my little 1200kg car).

As you all probably know, the m30 2.5 has 170hp and the 4 speed auto has a first gear which is like a low 2nd compared to manual, with 2-3-4 having same ratios as 3-4-5 in the manual.

My car is mechanically in order and the engine has 90,000 on a replacement motor.

Now if anyone here thinks I could do this without damaging my car (transmission/motor/chassis/brakes etc etc), then any thoughts on how to best go about doing it (ie weight distribution, which gears to use, appropriate speed, how often to stop, what to check in advance etc) would be very much appreciated!!

[rxsumo 33]

Hi everyone,

We're moving house from South Island to North (back home! ) and I'm hoping to tow all the stuff in either a horse float or a tandem trailer with my trusty e30.

But... I really don't wanna do this if it's going to ruin (or even damage a little bit) my car!! So here I'm asking for opinions and advice.

It will mean driving over the Takaka and Rimutaka hills (600m and 500m each with some steep bits) and towing probably about 600kg of stuff in a trailer that may weigh 700kg... (ie up to 1300kg of weight behind my little 1200kg car).

As you all probably know, the m30 2.5 has 170hp and the 4 speed auto has a first gear which is like a low 2nd compared to manual, with 2-3-4 having same ratios as 3-4-5 in the manual.

My car is mechanically in order and the engine has 90,000 on a replacement motor.

Now if anyone here thinks I could do this without damaging my car (transmission/motor/chassis/brakes etc etc), then any thoughts on how to best go about doing it (ie weight distribution, which gears to use, appropriate speed, how often to stop, what to check in advance etc) would be very much appreciated!!

I dont know what the 3 series towing ratings are but I'm guessing you are probably exceeding them.

I you want to do this, my suggestion is that you would want to get a HD oil cooler installed for your auto trans, and you should have the trans serviced/checked prior.

The trip will probably work the auto trans harder than the engine so you really should know what sort of state its in prior to loading up.

I'd also ensure you have geniune BMW or quality performance brake linings fitted, as I suspect they will take a bit of a hiding.

What are the ratings on the towbar....or who manufactured the towbar.

If the towbar mountings are a little iffy, you may rip the towbar off the car.

The only real concern I would have apart from that ,is to be aware of the trailer. As the trailer is likely to be heavier than the car it will potentially push the car around, especially in the tight corners over the roads you are travelling. Watch your entry speeds into corners

[Napier_E36 0]

Getting the trans cooler kit done is a good idea, but from experience, towing a load that is heavier than the vehicle you are towing with is asking for trouble. You may get away with it, but if the trailer decides to start pushing your little E30 around there wont be much you can do... I recently rolled a vineyard tractor on the road because the load was heavier than the tractor - load pushed going round the corner and I ended up lying on my side on the side of the road. You probably wouldnt end up rolling it, but imagine if you got pushed going down the Rimmutakas or other such place... Its a long way down.

You will probably find it a lot cheaper to hire a light truck for a one way trip. It will save you the risk to your car - and also probably prevent other damage that may come from towing such a heavy load over such a long distance.

[bumpstop325 0]

if the trailer does not have a brake. Then I would not bother with load, or i would make two trips instead of one.

I have towed a medium size boat behind mine. The towbar is only rated to 900kg with only 50kg max on towball on most e30's. I have clearly exceed this. TAKE YOUR TIME

[warrenp 6]

Many thanks for all the very informative replies!

Considering all this wisdom, I've decided to spend a few bucks and send the heavy stuff (fridge, freezer, washing machine etc) with a moving company and get a small trailer to tow the remaining fiddly bits (pillows, clothes, computer, stereo, books etc). So now the tow weight should not exceed about half the cars weight.

I'm much happier with this idea! Provided we take breaks every hour or so I'm guessing that it will not be necessary for me to get a cooler for the trans. Before buying a trailer I will check that the towbar is rated to handle even this weight (cheers rxsumo). I'll also have Haven BMW in Nelson give the car a full check over.

This should make for a far more pleasant trip/adventure...

This is truly a great website!

Edited May 7, 2006 by warrenp

[Bullitt 0]

Ive got a tow bar on my 86 M325i. I cant remember the exact tow weights for an E30 but theyre somewhere around 500kg unbraked 1100kg braked I think. The entry level towbar I could have got was a 1200kg one. I got the uprated 1500kg one as was planning (and have) towed a car trailer with it.

Havnt had any problems with it, though I havnt done anything like the kinda distances and hills youve got mentioned.

Though it seems youve already answered your question so disregard this post

[rxsumo 33]

Provided we take breaks every hour or so I'm guessing that it will not be necessary for me to get a cooler for the trans.

You probably want to have a think about a trans cooler, if the weight of everything you are towing and in the car exceeds the weight of 4 adults and luggage.

If you are exceeding this then the trans will get a workout. Taking a break now and then probably wont help that much, as in my experience the trans only needs one good cooking and the damage is pretty much done. And the time that the heat is really built up is the slugging up the hills.

The normal cooling path through the radiator doesnt really assist to much because because the trans fluid heats sinks into the cars normal cooling system....which in turn will raise the engine coolant temp....which in turn wont cool the trans fluid as much.....and so the cycle goes on....

[OLLIE 26]

i've towed a 16 foot boat behind my 320 from thames over the hills to pauanui.

couldn't have done it in an auto. had to keep the rev's high and definately needed the good brakes i had at the time. so much for the actual tow vehicle! it blew the radiator on the first hill out of thames.

[nazistaffcar 0]

a trans cooler would be a decent idea providing you fit a decent one ie not just the condensor from the back of a fridge, B&M manufactures a nice unit that is cheap and attractive availible from repco/appco at the same time it may pay to add a transmission lubricant such as Translube or Transguard also availible from repco/appco

[bumpstop325 0]

BMW's have a shared radiator anyway.

People, who have only owned manual cars, and MAY have not seen/worked on, this.

There are two hydrallic looking hose's. One at the top and one at the bottom on one side of the radiator. The side will depend on model. e30's are on the Left hand side and M30 auto's most likely have them on the right.

To what effect this does, as in 'does it have to be there or can i do without one' is unknown to me.

[rxsumo 33]

BMW's have a shared radiator anyway.

People, who have only owned manual cars, and MAY have not seen/worked on, this.

There are two hydrallic looking hose's. One at the top and one at the bottom on one side of the radiator. The side will depend on model. e30's are on the Left hand side and M30 auto's most likely have them on the right.

To what effect this does, as in 'does it have to be there or can i do without one' is unknown to me.

ah....thats what I was getting at with my sentence about heat.

The standard cooling for the transmission (with the exception of Borg Warner 35s which are air cooled in some applications), is by heat sinking into the radiator.

Hence the oil feeder lines into the radiator.

As mentioned before, as the transmission fluid gets hot, this may cause the engine coolant to increase in heat, as the water flowing into the radiator is reheated (prior to going through the cooling fins on the radiator) by the transmission cooler (sorta like a jug element).

I wouldnt recommend running without any trans cooling for any distance, but the the fitting of an external trans can improve things as it should sink the heat to air.

The other gotcha, one of the things that can happen over time, is that the trans coolant element can corrode and eventually leak. Radiator water = pressurised hot water that can be blown into the transmission fluid and then thru the trans. Not nice!

An external cooler will eliminate this occurring if the radiator element is bypassed.

Edited May 9, 2006 by rxsumo

[E34er 2]

the m30 2.5 has 170hp

i thought the m30 was the 3.5 litre engine,if not then what motor is in my car,535i 89

[kiwi535 538]

you re right benny but tim has a m30 in his e30 too and he(in your quoted post) meant m20

Edited May 20, 2006 by kiwi535

[E34er 2]

ok i got it cheers for clearing that up