trying to improve towing performance of 3l di auto

[watto1416]

We have had the patrol for 3 years now as the tug for our caravan.
It is not a light van at 2400kg inc towball mass.
We are slowly leaning the peculiarities of the automatic transmission.
As most would be aware it 'hunts' constantly with overdrive on.
Also locks and unlocks constantly in 3rd with o,drive switch on (even though it is not overdrive) but stays locked better in 3rd with o-drive off.
Up a more than a modest hill i shift the lever back in 2 and stays locked even under acceleration.
So when we are towing we usually keep overdrive off and stay in 3, locked if possible. But this means higher engine revs and more noise especially over long trips.
On fairly level terrain i can usually keep the transmission locked in overdrive until i cant maintain speed above 77 to 80 ks.
I dont think there would be a large difference in the economy of towing locked in 4th or locked in 3rd as obviously the engine (and trans) has to work harder in 4th.
But which is better in the long run for the motor and transmission?
Do torque lockers make a discerable saving in diesel due to lower engine revs, longlivity of transmission oil and transmission itself due to cooler temperature of the transmission fluid?
Any comments, advice or personal experiences both positive or negative would be appreciated.
I plan having a transmission oil temperature gauge installed soon, so any advice along this line would also be appreciated
Cheers
Peter

[paulyg]

Do you have an EGT gauge? I think you may find that the EGT will be lower with the OD off, it is with mine, and My camper is lighter at 1500kg.

[watto1416]

No EGT gauge

[watto1416]

I imagine by questioning if i have an egt gauge fitted implies that generated exhaust temperatures are more of a concern. I think the exhaust was upgraded or the turbo t off upgraded to 3" .
Sorry both were upgraded, so I'm told!

[4bye4]

I don't tow a caravan or camper, but a trailer with all our camp gar on board. I have had the same issues that you talk about and find it best to always switch off the od, especially when passing, even more so on a hot day with the aircon running. I have had a couple of wake up calls half way past a truck on a hot day uphill, when it decided it didn't know which gear it wanted to be in. It's like going into limp mode and is really quite interesting. I get about 12 to 13 ltrs per 100 k and it doesn't really change much with or without od, although when the road is good and there is no traffic to navigate I put it in od. Seems to work ok for me. 2005 3ltr auto.


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[paulyg]

The ZD 30 can be prone to high EGT, which may shorten its life.
Mine will go over 550c which is a safe limit, when towing up a hill, I also tow with the OD off.

[watto1416]

So it seems the way i am driving at the moment is about the best way, economy is about 18l/100, so not the best. That really doesnt trouble me though i would like a little better, especially on the planned loop in a couple of years.
I gather by reading some forum topics that there are both pros and cons of the installation of a torque locker. Read mention of installing a resister, or changing the current one to help maintain lockup. But whereas this keeps the transmission fluid temperature down it would seem to have a negative impact on the exhaust temperatures?
Sorry if i sound naive but i am on a (steep) learning curve,!
Thanks paulyg and 4bye4 for your replies

[4bye4]

So it seems the way i am driving at the moment is about the best way, economy is about 18l/100, so not the best. That really doesnt trouble me though i would like a little better, especially on the planned loop in a couple of years.
I gather by reading some forum topics that there are both pros and cons of the installation of a torque locker. Read mention of installing a resister, or changing the current one to help maintain lockup. But whereas this keeps the transmission fluid temperature down it would seem to have a negative impact on the exhaust temperatures?
Sorry if i sound naive but i am on a (steep) learning curve,!
Thanks paulyg and 4bye4 for your replies

I would agree that driving it the way you are is probably the best way. Think about fitting a EGT gauge and a boost gauge and also a NADS before your big loop. The 3 ltrs seem to be prone to self destruction particularly on long towing trips. I say this in complete honesty in that I own one. I believe that looked after properly they can be as reliable as any other engine, but you should help it as much as you can. When reading the horror story's about these motors, remember that the people who have no problems seldom write up on the forums about it.

[BigRAWesty]

See my father inlaw has the converter lock up installed in his Prado and he locks it in 4th (5 speed auto box).
Hills etc he turns off the lock off but flat open road it's on..
This is with his 17' van..

Maybe worth installing a manual converter lock up and lock it in 3rd when towing..

[GeeYou8]

I would have thought that you would never have the over drive on when towing.
I have a manual, I chose it because I tow a boat or car trailer, I never use 5th gear when towing.
A lower gear makes sense, less torque on input side of the gearbox for same power.
Graham

[watto1416]

Thanks all, comments taken on board. 4 bye4 do u suggest i ditch the idea of transmission fluid temperature gauge and ivest in an EGT gauge first up.
Cheers

[threedogs]

I tow my camper with the OD on as I can hardly feel the weight.
Next trip I'll try with the OD off and see how it goes.
fuel wise I get about 15ltrs per 100 ks.Towing a bit less around town
Next trip the weight of the trailer will be distributed better too
as its a bit front heavy as it is, but Ill sort it our

[4bye4]

Thanks all, comments taken on board. 4 bye4 do u suggest i ditch the idea of transmission fluid temperature gauge and ivest in an EGT gauge first up.
Cheers

Sure do Extra high EGT and boost will kill the motor for sure.



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[threedogs]

Maybe a larger trans cooler to keep the temps down when towing.
Pack the van correctly too not too much on the ball

[watto1416]

Will chat to my mechanic . Id assume a trip to a specialist muffler exhaust workshop is needed for install of an EGT?

[Bigcol]

you Mechanic should be able to fit the EGT & other gauges

as 4bye4 said, get all the NADs fitted, better to be safe than sorry

and
as you tow with an Auto, I would suggest the Trans Temp gauge as well, but after the other gauges are fitted
why....?
same same as EGTs, better to know what its doing on a long run towing

[GeeYou8]

A workmate fitted Dawes/needle valves & reckoned it improved the way his auto "felt".
He was not happy with the hunting before the modification.
Graham

[steve4377]

If ya towing I would ensure that your simple things are taken care of first. Ensure that your radiator cap is serviceable, towing with a compromised cooling system is probably a major killer of any engine (Bill Hewitt of Powerstroke Help on Youtube does a great example video of Ford Powerstroke engines destroying themselves simply because the pressure cap is stuffed. Towing creates serious additional heat in the system and this is where you don't want your coolant boiling inside the engine. Ensure that your coolant is protected by the highest boiling point possible.

My 2004 3litre auto has an overheat warning light for the transmission oil on the dash; think it shows up as ATP or similar - I wouldn't bother adding another.

Always better to hold an auto in a lower gear (multiplies torque) rather than letting it hunt. A lower gear will save you money as you have a smooth use of continuous power when hill climbing. On the flat tow in top with overdrive off unless it feels light load and then let it take it's head. Overall when towing lower gear the better when heavy loads are concerned. Remember too that the ZD30 develops max torque fully by about 2400 rpm - so aim for 2400 to 2800 max for good fuel economy.


Auto trans will heat up mainly when there is no forward movement but the fluid transfer is occuring. This is mainly such as being stopped but in gear. If one side of the torque converter is spinning and the other side is resisting (the vehicle is stopped or moving slowing - typically a FWD trying to drag itself out of deep sand etc) then the fluid heats up quickly. Using the transmission to hold the vehicle on a hill is the worst possible scenario. If you stop while FWD put it in neutral and hold it with the brakes - this allows the fluis to cool off. When I drove auto 50 seater buses, I saw drivers holding full buses on hills with the transmssion and they complained the overheat light would come on and there was this burning smell. Geese I wonder why! Also while u are going slow there's precious little cooling air going through the little cooler up front.

I reckon u are right to hold it in a lower gear when ever it is hunting gears. The converter lock up is a good thing as when it is locked (it must be a mechanical lock) the stator and rotor are travelling at the same speed and the trans oil is not even being used or heated.

If u think you've done a big hill and the whole units worked hard with a 2.5 tonne van on the back, pull over somewhere safe, look at the view and smell the roses for a couple of minutes - let the engine and transmission (in neutral) run at idle to cool down everything down - including the turbo. It's the old rule - Look after the gear and it will look after you.

As an aside you should never tow a heavy van in a manual in 5th gear (overdrive). Fourth gear is usually a straight through the gearbox drive shaft coupling - max rorque can be applied. 5th is usually a small side shaft with a physically small gear. This means all power is diverted through this side shaft and when towing the gear or shaft can easily fail. Many old Holden Ford Toyota sedan owners used to find this out - much to their expense!

I towed my boat from Cairns to Onslow last year about 5400km, (weight about 1.6 tonnes all up - but low profile no wind drag). Averaged about 14 l/100 - but on a hilly stage went to to 16 l/100.
I was happy with that. So yeah have a look at Bill Hewitt - great food for thought.

Finally make sure you have clean cool air going in the front of the car. When towing ensure there is a good space btwn you and the car in front - smooth laminar air hitting your radiator and transmission cooler is great for low temps. Stopping for just 5 minutes (idling) to take in a view - will lower all oil temps heaps, and give ya time for that great selfie!!!

Cheers and happy trails...

Steve

[steve4377]

Just noticed that post by 3 doggies...Tows with OD on as he can feel it's light load. Great stuff, he's feeling the load and driving accordingly...Like a horse in the old days, they know when they wanna run, give the vehicle it's head and let it go...

[4bye4]

you Mechanic should be able to fit the EGT & other gauges

as 4bye4 said, get all the NADs fitted, better to be safe than sorry

and
as you tow with an Auto, I would suggest the Trans Temp gauge as well, but after the other gauges are fitted
why....?
same same as EGTs, better to know what its doing on a long run towing

Hey Col we should set Ropes up for an NADS installation trip. Just sayin[emoji1]


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[threedogs]

you might also think about getting a rear coil tower
brace fitted to seeing you plan on lots of towing

[watto1416]

Threedogs, the previous owner installed heavy duty coils and airbags, does this achieve the same as a coil brace?

[Bigcol]

you Mechanic should be able to fit the EGT & other gauges

as 4bye4 said, get all the NADs fitted, better to be safe than sorry

and
as you tow with an Auto, I would suggest the Trans Temp gauge as well, but after the other gauges are fitted
why....?
same same as EGTs, better to know what its doing on a long run towing


Hey Col we should set Ropes up for an NADS installation trip. Just sayin[emoji1]


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an interesting idea

I think it would have to be a 2 part "trip" though

1st part
explaining what is required and why - and what bits and bobs are needed

2nd part
actual fitting

sounds good to me

[the evil twin]

Threedogs, the previous owner installed heavy duty coils and airbags, does this achieve the same as a coil brace?

No they are seperate issues but bracing should be done for heavy loads and you should check if it was.

Heavy coils/airbags are to assist in suspension levelling which intimates heavier than average load on the rear towers
Patrols are known to develop cracks in the rear towers even with factory spring set up.
If you fit heavy coils and airbags and load the vehicle accordingly it is pretty much a 'must do'.

Fixing the cracks is waaaaay more hassle and expense than fitting the braces prior to having an issue

[jff45]

Please don't advise people that the factory trans temp light in the dash is ok to use as an indication of trans temp being ok.
That light comes on at 140 degrees C which means you're in the process of shorting your trans life if you're using non synthetic fluid. It's widely accepted that fluid temps over 120 are doing damage.

If you're towing with an auto, get a trans temp gauge, a larger fluid cooler and manual TC lockup fitted.

[threedogs]

Being new to diesels,,,, Im used to towing with my chev Petrol V8 troopy sitting
on 2000 rpm, thinking the lowr the the revs the better,,,,,,,,,,,,,,,,,,,,,,,,now Im
Towing with the ZD30 sitting on 2200rpm with an auto are you saying I should
take the OD off and cruise at 2600 rpm

Hear ppl here saying the were towing stting on XXXX and EGTs were very low
maybe they had the OD off.
What revs does a manual ZD30 sit on at 110 kph ?

[watto1416]

I could Google it but i would undoubtedly get a better reply here....whats is NADS?

[the evil twin]

I could Google it but i would undoubtedly get a better reply here....whats is NADS?

Slang acronym for "Nissan Anti Detonation System"

Possibly lowers the risk of burning holes in #3 or #4 Piston
It involves taking boost control away from the ECU plus a few other things.
Generally speaking it involves Dawes Valve and Needle Valve to control boost and optionals like Catch Can, EGR block, etc

Again, generally, considered as not needed for CRD's altho EGR blocks and Catch Cans are great for reducing soot and contaminates in any engine

About the one thing everyone agrees on is that dirty MAF sensors are a major problem and definitely have a part to play in poor performance and possibly premature engine failures due to incorrect fuelling or boost

[threedogs]

Please don't advise people that the factory trans temp light in the dash is ok to use as an indication of trans temp being ok.
That light comes on at 140 degrees C which means you're in the process of shorting your trans life if you're using non synthetic fluid. It's widely accepted that fluid temps over 120 are doing damage.

If you're towing with an auto, get a trans temp gauge, a larger fluid cooler and manual TC lockup fitted.

could you suggest a bigger trans cooler size wise please
more to the point what size does a ZD30 have now,and would a fan
assist whats there now

[jff45]

could you suggest a bigger trans cooler size wise please
more to the point what size does a ZD30 have now,and would a fan
assist whats there now

The ZD30 factory cooler is actually pretty good. It's easily twice the size of the factory cooler on the TB45.
I would fit a trans temp gauge first along with a manual TC lockup to limit the locking/unlocking that generates heat and let the gauge tell you if you need better cooling.
No different to a good engine temp gauge telling you that need to enhance your cooling system..

[GeeYou8]

What revs does a manual ZD30 sit on at 110 kph ?

Ok 100 km/h is max for towing here in WA, 100 on the GPS is 105 on the dial from memory 2700 rpm in 4th (CRD).
110 on the GPS is 2700 rpm in 5th (CRD).
110 on GPS is 3000 rpm in 5th (DI).
Graham

[threedogs]

Ok so what revs are you pulling in a ZD30 manual @ 100 kph
My auto pulls 2200 @ 100kph I feel thats a tad weak for towing
other than dead flat towing,
I think mine will go to 2400 rpm with the OD off @ 100kph

[threedogs]

Ok 100 km/h is max for towing here in WA, 100 on the GPS is 105 on the dial from memory 2700 rpm in 4th (CRD).
110 on the GPS is 2700 rpm in 5th (CRD).
110 on GPS is 3000 rpm in 5th (DI).
Graham

That doesn't sound right to me unless they are from a manual patrol
110 from 5th in a Di sounds wrong too

Going up the Murray sitting on 110Kph cant for the life of me remember see any of those numbers
Will be going again soon when Roofys on the road so I'll take more notice then

[the evil twin]

Speed versus RPM comparison between different vehicles is problematic unless the tyre size is also known.
1 inch diameter nominal (nominal as hardly any tyre dia are what the manuf say) will give as much as 4 KPH and 200 RPM

[threedogs]

I understand my best options are to fit std 265 tyres, But I dont always go with my best options lol
Most here would run 285s and Im hoping I can get RPMs that way

[threedogs]

We have had the patrol for 3 years now as the tug for our caravan.
It is not a light van at 2400kg inc towball mass.
We are slowly leaning the peculiarities of the automatic transmission.
As most would be aware it 'hunts' constantly with overdrive on.
Also locks and unlocks constantly in 3rd with o,drive switch on (even though it is not overdrive) but stays locked better in 3rd with o-drive off.
Up a more than a modest hill i shift the lever back in 2 and stays locked even under acceleration.
So when we are towing we usually keep overdrive off and stay in 3, locked if possible. But this means higher engine revs and more noise especially over long trips.
On fairly level terrain i can usually keep the transmission locked in overdrive until i cant maintain speed above 77 to 80 ks.
I dont think there would be a large difference in the economy of towing locked in 4th or locked in 3rd as obviously the engine (and trans) has to work harder in 4th.
But which is better in the long run for the motor and transmission?
Do torque lockers make a discerable saving in diesel due to lower engine revs, longlivity of transmission oil and transmission itself due to cooler temperature of the transmission fluid?
Any comments, advice or personal experiences both positive or negative would be appreciated.
I plan having a transmission oil temperature gauge installed soon, so any advice along this line would also be appreciated
Cheers
Peter

Back to basics ,,,Peter what tyre size do you run?

[4bye4]

Hey Peter, we are going away with the club to Denmark over Easter. My vehicle is similar to yours, although my trailer is not as heavy as your van. i will take some notice of RPM in different gears and also with OD on/off and try and give you some feedback next week. Cheers Tony.

[paulyg]

My ZD30 DI auto with 285 tyres, OD of = 3000 rpm at 100kmh.

[watto1416]

Threedogs, my daughter has the patrol, when i get it back i will post, but quite certain standard size. Paulg at 90 k i think around 2900 unlocked, about 2700 locked n in 3rd with the o-drive button off. If i can lock in overdrive at 90 the revs come down to about 2300 i think, but dont take that as gospel! Thought 2300 would be a good range to be in for torque?
Cheers

[watto1416]

Finally have the patrol home,tyres are 265/75 R16.
My mechanic has decided he doesn't wish to put in the auto trans fliud temp gauge as he has never done one and not comfortable with doing it. So has someone any recommendations for the installation of above and also a EGT gauge?
Cheers

[jff45]

If you get the Wholesale Automatics trans temp gauge they will supply you with a trans banjo bolt that has a short VDO temp sensor in it. This banjo bolt replaces the banjo bolt on the right side of the trans.
All your mechanic needs to do is remove that banjo and fit the other with the temp sensor in its place with 2 new 14mm copper washers.
You will lose almost nothing in fluid.
There's a single wire that then needs to come down through the tunnel above the trans.
A mechanic who can't do that should shut up shop..

[the evil twin]

What he said ^^^^

It is so somple you can DIY in less time it takes to do, say, an EGT or Coolant Temp

[Kimbo63]

You should really think about investing in a tranny temp gauge just so you can keep tap on when your oil is due for replacement here is why it important http://www.thetransmissioncentre.com.au/general-information/ I would also look at running some two stroke oil in the fuel great read on this here http://www.nissanpatrol.com.au/forums/showthread.php?37067-2-stroke-oil-in-common-rail-diesels-new-article-(brief)
Cheers Kimbo

[watto1416]

Actually i may get the unit from wholesale automatics and have a look n see if i could do it, been 30 years since i did any mechanical work on vehicles. Perhaps instructions included. Would an exhaust place be capable of doing an EGT fitting. Any hints on where the EGT kit is available from?
Thanks

[watto1416]

Ordered transmission temp kit today. I have a client who is a diesel engine mechanic, i will ask him if he's interested in installing such. I will then look at an exhaust temp gauge. Any hints where to obtain such a unit?
Cheers

[watto1416]

Installed the temp sender this afternoon, just need to wire everything up.

[Warwick89]

All this thread has done is completely prove to me I've been towing wrong all along. I usually tow with OD on and drive through the gears with the stick from 1st to drive. 285 size tyres and the rig cruises at around the 2000 rpm range at 100kph fuel usage is around 17lph around town and 21lph towing, ok so my car is very heavy compared to most and I constantly have the car loaded as nowhere to empty the stuff out like (spare tyres and draws). I understand that every car is different in wieghts and fuel usage and such.... But my figures sound a lot high than everyone else's.


Edit: Auto

[watto1416]

Warwick,
I have at times returned 4.7k per litre towing which would be close to 21l per 100, headwind is an enemy. Usually get closer to 5.5 to 6 k per litre towing 2.4t. Your every day usage is high though.

[threedogs]

All this thread has done is completely prove to me I've been towing wrong all along. I usually tow with OD on and drive through the gears with the stick from 1st to drive. 285 size tyres and the rig cruises at around the 2000 rpm range at 100kph fuel usage is around 17lph around town and 21lph towing, ok so my car is very heavy compared to most and I constantly have the car loaded as nowhere to empty the stuff out like (spare tyres and draws). I understand that every car is different in wieghts and fuel usage and such.... But my figures sound a lot high than everyone else's.


Edit: Auto

I tow in OD mainly going to the Murray river which is slightly up hill all the way.
The HWY is 110 kph which I set my cruse control to about 105kph no rush. eh
My 2004 Di auto will return 15ltr/100Ks. Never had any issues, that was with 285s and sometimes 305's
Picture shows my camper ,which is a 2010 Hilux single cab tub Ive converted to a camper