TD42 Overcooling

[leroy123]

Hi,

I have a 91 GQ Nissan Safari. I am having issues with it not getting upto temp and then when pushed will overheat.

About the truck:
Aftermarket Kinugawa TD05 water cooled
top mount inter cooler
custom air manifold, air box, 4" snorkel
4" straight thru exhaust

Things I have tried:
New radiator
New nissan rad cap 1.1 bar
new nissan water pump
new nissan thermostat. Tried a tridon 82 deg, tried a 88 deg nissan one for a terrano, tried a aftermarket modified one with a longer bottom section to block the re-circulation better (from Trundles automotive in NZ)
re oil fan hub
new fan blade
has shrouds around radiator

I only had the truck for 1 month before I removed the entire front plate due to a small water leak by the injector pump at the same time I removed the head and did the turbo ect. so I don't know if the issue was already there or not.
I didn't actually remove the injector pump from the front plate as I didn't want to play with the timing.
All new nissan seals, head bolts ect.

I think the overcooling can only be caused by a faulty thermostat? what other things could cause this?

I have also put reco higher crack pressure injectors which I did read somewhere could affect the temps?

Just went on a camping trip with the trailer about 4500kg GCM and it did sit at about 82 deg consistently but would sometimes drop right down to 40 deg when on level road and any hill would see the temps rise, never went above 100 deg but the hills weren't that big. Pyro was sitting on 350 ish and upto 500 max on hills (100mm after turbo in dump pipe)
unloaded it struggles to get above 60 deg unless going up long hills where it will go up to 100 so I stop and turn around it drops to 40deg rapidly.
Just went for a run without the thermostat in and wouldn't go above 60deg up a long hill and when heading back down temps dropped slowly at a steady pace.

This makes me think the rad and most other bits are working but the coolant must be bypassing the thermostat somehow?

Is there only one type of water pump that will fit this motor?

I have also noticed that the rad hoses don’t seem very firm when the truck is running. Should the only be hard when at operating temp?
No water in oil or bubbles in overflow and water level doesn’t drop over time.

Sorry for the long post but better to get all the info on the from the start.

Cheers
82746827478274882749

[PeeBee]

Sounds like you have a problem a few on here would envy!

[jay see]

Just thinking out loud here.

Could there be an issue with your gauge, sender or wiring.

Sent from my CPH1979 using Tapatalk

[MB]

G’day again Leroy Mate!
Might be best to keep on track in your original thread brother:

https://r.tapatalk.com/shareLink?share_fid=16273&share_tid=48147&url=http%3A%2F%2Fwww%2Enissanpatrol%2Ecom%2Eau%2Ff orums%2Fshowthread%2Ephp%3Ft%3D48147&share_type=t

It still wreaks to me of too much water flow by way of thermostat, it doesn’t take much to achieve the lower temperatures you describe and 100C in a TD42 is not overheating IMHO.



Sent from my iPhone using Tapatalk

[leroy123]

Im pretty happy that the gauge is reading right.

I forgot to look back at that old thread recently, i have tried most suggestions on there now and the problem is still there.

I did run it yesterday without the top rad hose on, when cold there was a small amount of water flowing out which must be coming thru the jiggle pin hole.

I might braze the hole for the jiggle pin closed, will this cause any problems? is it there to assist with removing air from the block side while cold?
Otherwise the last thing i can think of is change back to stock injectors?

[MB]

You’ll see in the other thread mate that the missing jiggle pin on the OEM Tropical 76.5C was found to be my colder climate low temperature issue. As soon as I changed to the OEM 88C with jiggle pin included the issue disappeared immediately. I guesstimated at cold idle the jiggle pin-less thermostat was still letting through up to a litre or so per minute idling.
With the OEM 88C out of a TD27 it now runs year round in Southern Victoria between say 86C idle up to say 93C highway and a max of 99C hot summer towing.
Best highway fuel economy was found at 92C and this was confirmed by one of our TD42 experts on here as their “Sweet Spot”
If you feel the 88C setting is too high for your needs the OEM 82C also comes including a jiggle pin [emoji106][emoji106]


Sent from my iPhone using Tapatalk

[mudski]

Just thinking out loud here.

Could there be an issue with your gauge, sender or wiring.

Sent from my CPH1979 using Tapatalk

Yeah sounds odd that the water temps will drop that low. The old TD is a cast iron block, once they get hot the block gets nice and warm and will usually stay warm to an extent.
I'd be checking the gauge first. Cheaper than swapping out injectors.

Bit of an update with my TD and the injectors. I had mine reset to factory spec as I was convinced this was the cause of my issues, it did squat. Made it slightly worse if anything. I then spoke with the pump builder, who also originally at the time build the injectors aswell. According to his data, the pump he built for me, the injectors required are high crack pressure injectors, 150bar high. So I took them into him, he reset them to his spec, and my temps seem more stable now, still gets up there a bit bit I haven't had the chance yet to really test it out.

[MB]

“More stable” come on Mr Mark Mate, real world numbers or it never happened [emoji23][emoji106][emoji106]


Sent from my iPhone using Tapatalk

[mudski]

“More stable” come on Mr Mark Mate, real world numbers or it never happened [emoji23][emoji106][emoji106]


Sent from my iPhone using Tapatalk

Haha. Ok. Took it for a blast down East Link. Ambient temps circa 20c, car empty, 100kph temps eventually got to 90c, unladen. Took a while but once the block had some time to soak in the heat it stayed there. Until I hit an incline. lol.

Before It would act the same but get there earlier. I still need to get the pump timing done. Haven't had a chance with this yet.

[MB]

.....Until I hit an incline. lol.

Before It would act the same but get there earlier. I still need to get the pump timing done. Haven't had a chance with this yet.

Apologies Brother Mark, much like the McTrol.com.au Photograph Rulings, Numbers pretty please or it never dever happened Legend [emoji106][emoji106]



Sent from my iPhone using Tapatalk

[mudski]

Apologies Brother Mark, much like the McTrol.com.au Photograph Rulings, Numbers pretty please or it never dever happened Legend [emoji106][emoji106]



Sent from my iPhone using Tapatalk

Bit hard to take a photo whilst driving. :SNruQWn369624407:

[mudski]

Apologies Brother Mark, much like the McTrol.com.au Photograph Rulings, Numbers pretty please or it never dever happened Legend [emoji106][emoji106]



Sent from my iPhone using Tapatalk

The real test my friend is on Friday towing the camper to Omeo. I’m optimistic mate.


Sent from my iPhone using Tapatalk

[MB]

Which Thermostat you running these days Old Mate?


Sent from my iPhone using Tapatalk

[mudski]

Which Thermostat you running these days Old Mate?


Sent from my iPhone using Tapatalk

Latest purchase was the Dayco DT79A. 82c opening temp, spaced out the bypass as per interwebs advice. Made F.A difference, went back to the Tridon Hi Lfow 78c stat, which was removed to fit the DT79A. Slightly better with the Tridon, ever so, than the Dayco...

[Rossco]

The real test my friend is on Friday towing the camper to Omeo. I’m optimistic mate.


Sent from my iPhone using TapatalkLast climb coming up there will give it good test lol .

Sent from my SM-G930F using Tapatalk

[mudski]

Last climb coming up there will give it good test lol .

Sent from my SM-G930F using Tapatalk

Yeah it’s been a while since I been there. I know it’s hilly so it will be a good test. Just looking forward to chilling out more that anything.


Sent from my iPhone using Tapatalk

[MB]

I’m surprised you haven’t trialled the OEM 82C as of yet mate, it was your helpful findings of the part number back in 2019 [emoji106][emoji106]
http://www.nissanpatrol.com.au/forums/images/imported/2021/01/64.jpg


Sent from my iPhone using Tapatalk

[Wizard52]

Im pretty happy that the gauge is reading right.

I forgot to look back at that old thread recently, i have tried most suggestions on there now and the problem is still there.

I did run it yesterday without the top rad hose on, when cold there was a small amount of water flowing out which must be coming thru the jiggle pin hole.

I might braze the hole for the jiggle pin closed, will this cause any problems? is it there to assist with removing air from the block side while cold?
Otherwise the last thing i can think of is change back to stock injectors?

I have a VDO temp gauge and it took 3 to get it right. The first one had readings too high and then low issues like yours. The second one just kept going up and not stopping until it went off the dial. The third one appears to be right and goes up and down in different conditions.

[mudski]

I’m surprised you haven’t trialled the OEM 82C as of yet mate, it was your helpful findings of the part number back in 2019 [emoji106][emoji106]
http://www.nissanpatrol.com.au/forums/images/imported/2021/01/64.jpg


Sent from my iPhone using Tapatalk

I put the Dayco DT79a in. Same stat but with the longer bypass. Did FA.


Sent from my iPhone using Tapatalk

[MB]

Bugger Mate!
So you’re still overcooling down hills? I seem to recall yours getting as low as 46C cruising downwards over winter where mine was also getting as low as 56C but all good now.


Sent from my iPhone using Tapatalk