Overheating on a long uphill

[Tony]

This past long weekend I took a drive to a game farm in the Waterberg, after doing a 160 000 km service on the 30 TDI. Just after Wambaths we turned on the aircon, and after 15 min or so noticed that it was not getting cold and shortly thereafter, on a long uphill I realised that the temp. gauge was climbing up fast - As soon as I slowed right down at the toll gates, the aircon suddenly got cold again untill I picked up speed and then got warm again. Once over the crest and on the level, all was fine and water temp went back to normal. Once in Naboomspruit I had no option (no Nissan dealers in the vicinity) and drove into the Toyota's workshop to check the engine out! I must say, that (after lots of joking and passing of comments!) the guys were very friendly and helpful - however nothing seemed to be obviously wrong and the only thing the mechanic could point a finger at was my visco fan, which has a fair amount of play when moving the fan blades back and forwards. He seemed adamant that this would affect the aircon at speed as well as engine overheating on long hills, and not when driving slowly and in traffic (she does'nt heat up in slow moving traffic)

Another problem I encountered over and above these on my way home on Monday, towards the end of my trip, was that when gunning the engine (which I never normally do) in order to try and get up and over the uphills as quickly as possible, she lost all power very suddenly on 3 occasions and only after repeatedly pumping the accelerator a few times did she recover. Can anyone shed some light on my woes !!

[gifgat]

Goeie dag Tony, se gou vir my toe die voertuig so warm geword het wat het van sy water geword. Bly die bottel en radiator vol of raak die water weg. As die water nie weg raak nie glo en hoop ek vir jou dat daar nie n gasket probleem is nie. Dit kan die waterpomp wees, want die wiscusfan is deel van hom. Ons het al n paar vw gekry wat die waterpomp impeler loskom en as jy dan die voertuig hard laat werk pomp hy nie meer die water nie. Dj het my trol nou eers kort so ek kan nie vir hou verder iets se nie. Hoop net dit is nie ernstig nie, myne was n duur episode, maar hy loop nou baie leke, danksê vir almal hier se goeie hulp en raad. Hou ons op hoogte

[davejones]

I'm sure there is a similar post on this forum, just can't find it.

I have a td42 which does exactly the same... Well the overheating bit... I never have power on uphills

It actually ends up serving as an early warning... If the air on gets warm then I know the engine temp is getting dangerously high.

[Peter Connan]

Tony

1) There should be no forward/backward play on the viscous fan, and this could well be pointing toward a problem.
2) If the engine overheats, the air-con will switch off automatically.
3) The loss in power sounds like overboost. There is a lot of info here on the forum about it, please familiarize yourself with it before you break that engine.

The type of driving you describe is the best known way to destroy a turbo diesel engine, and I sincerely recommend that you fit an EGT gauge and drive according to it before you do that again?

[ricster]

Here is another option/opinion....ha ha

When last did you replace the water and antifreeze? This plays a HUGE role in cooling that motor. If the levels (ratios) are not correct there will most probably be some gunk cruising its way around the cooling chambers. Over time the thin cores of the radiator start to block up reducing heat transfer which causes overheating. Don't use cheap antifreeze!!!!! Either use genuine Nissan or Silverton Radiator product. I have had good experiences with Silverton, and radiators are their game so they should know what they are doing.

Grant has a 96 4.2TD and often had a temp gauge climbing high when working the motor with the standard radiator. In my 99 4.2 TD, the previous owner fitted a huge radiator, probably double the thickness and slightly longer than standard, I assume to counter the same problem. My water temp NEVER goes past half. In fact it sits a fraction before halfway, even if I'm climbing a hill under load with EGT's sitting on 590 - 600 deg C. Grant has now had a radiator built for his Patrol, and the difference is unbelievable. The temp is steady and stable under load.

So before opening up the motor, take it to Silvertons, let them do an exhaust gas test on the water in the radiator. If all is good there, let them take out the radiator and give it a revamp/recon. Remember to flush out the rest of the cooling system inside the motor !!! While you are at it, replace the thermostat and radiator cap too, and check quality and condition of the hoses. Refill with correct ratio of water/antifreeze.

This may be a bit lateral, but how clean is your air filter??? Restricted air, power loss, higher egt's causing higher water temps......

Hopefully there is no gasket leak or crack in the head due to overheating !!!

[Izak]

If the 160 000 km service was done correctly then the air cleaner should have been replaced. I have never had this type of problem with my 3.0 Diesel. This last weekend coming back from Kruger we drove the Schoemans kloof road, due to the roadwork’s on the N3. The EGT went up to about 550 which is te most I will allow it to go, but even then the air con was on, and with the load as described in the post the water temp stayed very constant never going past the half way mark.

I had a new Isuzu 3.0 LX Double cab in 2006 that did the same towing a off road trailer on steep inclines. Aircon would switch off and she would be a little "pap" op the uphill. That Isuzu had a chip fitted and the only conclusion I could ever reach after speaking to "experts" was that it was due to ever fuelling.

In your situation I would flush the radiator system, clean the MAF and as Peter said, fit a EGT as a matter of priority.

From my experience with my Patrol, the EGT is essential, going uphill in 4/5 gear the EGT temp will skyrocket to way above safety levels if you do not have and watch the EGT.


Regards

[davejones]

thanks Cedric - i've just had my radiator flushed checked etc... will monitor if my engine temp has improved.

[ricster]

EGT gauge is THE most important thing you must have. Unfortunately, and i say this with respect, even more importantly with the ZD30, previous history being my guide. But this doesn't exclude the 4.2 TD !!!

[ricster]

Dave, there should be a bit of an improvement. But due to our Patrols being fitted with aftermarket turbos, my feeling is that the standard radiator is a little too small to handle the heat transfer. Grant's new radiator is slightly smaller than mine, and on his madman ETG gauge his water temps (I stand corrected) hardly reach 95 deg, which means his thermostat is working a little harder to regulate the water flow through the radiator. It may not be a cheap thing to do getting a radiator built, but I was told that my radiator is from a Cabstar truck, which I'm sure can be sourced cheaply from a scrapyard.

Check this post out for a little more info
http://www.patrol4x4.co.za/viewtopic.php?f=44&t=2961

[Tony]

Wow thanks for all the info, guys. The radiator was flushed about 20 000km's ago, and yes all filters have just been replaced - with regard to the overboosting, I did have a problem about 2 years ago which you guys pointed out and that was remedied by Rob Green and sorted. EGT gauge is next on my list and the visco fan is being checked out next week so hopefully will get to the bottom of this one soon.

Thanks everyone for all the valuable tips and information it really helps especially if one is a little challenged with motors !!

Cheers.