D40 towing problems

[bob evans]

Hi guys, we are towing a jayco work n play around. weighs about 2.5t fully loaded. we have towed the van a couple of times now up to Cessnock 2hr drive with no problems. bit sluggish on the hills but just let it sit at 2000-2500rpm and work up the hills. just yesterday we ventured up the blue mountains via bells line of road. after climbing Bellbird hill (very long steep hill). the car went into a sort of limp mode. pulled over and tried the old turn the key off and on agian. had to do this a few times with the fuel pressure sensor thingy. but that did not do anything. was real sluggish, so we pulled over for a while. the car got to about 108'c according to scanguage. and no temp lights come on. we took off and still had the same problem car didnt respond to acceleration and auto gearbox started to shudder a little bit on some of the hills.scangauge had no fault codes.
any ideas guys or has it happened to anyone.
on another note had it serviced two weeks ago, and since then have to reset it whist driving on freeway as it goes into limp mode with the fuel pressure sensor ( i think)
thanks Bob

 

[Old.Tony]

At a guess I'd say it could be your tranny is too hot, but knowing that it's happened since the last service, it could easily be air in the fuel system, caused by a careless installation of a fuel filter (or using an aftermarket fuel filter). If you leave the car sit for 12+ hours, how many times do you have to press the primer bulb before it's really firm? Is it now harder to start in the mornings? If you answer more than 5, or yes to the second question, you've got an air leak.

When your gearbox gets a little too hot, certain things will happen differently because the oil (as light as it already is) becomes less viscous, which will cause the following:

* You'll notice that you have to rev the car a little harder to make it go
* You'll notice that the revs drop more when the TCC locks
* Gear changes may not happen at the usual time, and may not be as smooth
* The car may kick back a gear earlier than it normally would

There are two 'tricks' you could use with your transmission (I've done both, and it works like a charm towing our New Age Manta Ray 19' bunk van 2550Kg).

1) Have a trusted mechanic bypass the transmission cooler in the radiator and instead mount a much larger cooler in front of the air conditioning condenser. This will not only assist in cooling the gearbox more, but it will prevent any cross-contamination between the cooling system and the auto transmission (radiator damage or corrosion might cause the two fluids to mix, leading to a massively expensive rebuild).

2) Use the gears. We actually climbed Cunningham's Gap with a broken fluid coupling and didn't see the temp go over 102C. Sure, at 20km/h we were overtaken by Volkswagens and even a Hilux (admittedly the Hilux was on a flatbed but it still went past us) but everything stayed cool. Yes, we got into first on some of those climbs - and if you think Bells Line Of Road has some steep sections, try the climb from Gloucester to Walcha one day.

 

[bob evans]

thank you Tony for your awesome reply.
i thought maybe fuel, and this morning after it was sitting for more than 12hours i tried pumping the little bladder. it took 5 0r 6 pumps till it was firm. i havnt really noticed it getting hard to start in the morning. but it has had the with having to stop and turn the car off then on again since i had the service. havnt had that problem for a while as i dont tighten up the fuel cap to tight.
i think i will get that oil cooler bypass done as well. what oil cooler did you use??
thanks again

 

[Old.Tony]

If you're getting some joy from loosening the fuel cap, your SCV might have a little dirt in it. Washing in petrol and rinsing in diesel will fix a dirty SCV but if it's pitted, scored or worn it will need replacing.

Not sure what brand of cooler was chosen by the mechanic, but it is large enough to extend all the way across the front of the radiator area. If you're in the Newcastle area, he's well worth going to see.

 

[fatboy]

Old.tony
I live in Newcastle and would like to know your mechanic so I could have a chat with him.
Cheers

 

[Old.Tony]

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