[Dalaicamel]

I have a question that I have not been able to find a clear answer to. I have a 2000 GU with a 1999 TD42T transplant. I am very happy with it except for a couple of ongoing issues. The first is of course that it runs hot – especially when towing the camper trailer. The second issue is that it is quite dead up to about 2000 revs. (Part of the problem is that I am still grieving for my TB42 which had heaps of get up and go.) The GU boogies along very nicely after about 2300 revs but is very slow to get there.
I still have quite a few parts left over from the conversion including the intercooler off the ZD30. It looks like it would go straight on. What would be the likely positives and negatives, particularly on power and heating, of adding the intercooler to the existing system? Would it run hotter or cooler? Would it overcome the lack of grunt at low revs?

 

[timo_ed]

Factory ht18?

Yes that IC is better than no IC up to about 15psi.

There's a lot if info on cooling system diagnosis already.

 

[Nev]

Adding an intercooler will provide better power, particularly after a tune and can only help overall engine temps. There are plenty of better and more efficient intercooler options around but if money is tight than the ZD30 one will be better than nothing if you can make it fit. Power wise, I'd suggest getting a good tune. 3" exhaust and dump with high flow muffler will help it spool up much quicker too if you haven't already done this. You should be able to get it hitting reasonable boost before 2000rpm although the standard turbo does not spool as quickly as other aftermarket options like a Garrett or Mitsubishi TD05 offering from UFI.

If you're like me though, none of the above will solve your running hot issues when towing. I ended up switching to a PWR radiator which did definitely help but the biggest difference was swapping back to a factory thermostat. Their opening pressure is generally much lower (around 72c from memory) than aftermarket options (often 82c +). This helped a lot on my factory turbo model and I no longer have any issues with temps getting high even when towing. Also check your viscous coupling is operating properly on the engine fan.

 

[Dalaicamel]

Thanks guys. Yes Timo I'm pretty sure it was a factory one but I wouldn't know the model number. You're right, Nev I don't want to throw heaps more money at it, just really wondering if putting the intercooler on it might solve some issues or open some more cans of worms. Being a petrol head at heart, I don't know much about Diesel turbos and don't really want to stuff around with it and cause myself more problems than I already have.
And yeah I've read heaps of information about heating issues with a lot of differing opinions about what works. My last upgrade was to install an oil cooler and I'm in the process of installing VDO temp gauges for both oil and water. That way when I make a change I will know exactly what impact it is having on temperature. I did the Its a Ford Not a Nissan thermostat upgrade so I will compare that to the factory one that you recommend, Nev and also to the standard aftermarket one and see what is actually happening. The old radiator guy here reckons it shouldn't matter what temp the thermostat opens - it's what is happening when the engine is under load that is the important issue.
But this is getting off the point. This thread was meant to be about the Intercooler question.

 

[GQshayne]

I reckon the power issue you have could be well fixed by a decent tune. However, that would really be helped by an intercooler. The cooler may help a bit on its own, but it will allow the boost and fuel to be changed and that would gain the most improvement. If the current tune is factory spec then you should get a significant gain.

 

[CravenHaven]

My TD42t was quite a slug initially, and after doing several "upgrades" including bigger turbo, Water-air intercooler, 3" exhaust, the really big change occurred when I got the injector pump rebuilt. Cost a bit, but it obviously needed doing because the truck pulls away quite easily even when under load. There is definitely a big difference when the turbo finally kicks in at around the 2000rpm mark, but I dont have that worrying feeling that I'm not going to get across the intersection before the lights change again .

 

[DieselTuner]

The factory pump should be more than enough to supply 120-130kw if the rest of the system is built to support it.

If you have not had the injector pump tuned at all, then that is the cause of the lack of power. Factory the td42 is quite undertuned.