TD42 cooling issues

[leroy123]

Hi all,

Ive got a 91 LWB Safari Kingsroad. I have had it for about 6 months when i got it it had a leak between the front plate and the block so ended up striping everything and replacing all the seals that i could find. I also bolted on a TD05, custom airbox, modified intake, 4" snorkel.
I replaced the water pump, thermostat 82 deg and rad cap (all genuine) flushed the radiator and also added a water feed from the top of the thermostat housing to one of the welsh plugs on the back of the head (https://trundlesautomotive.co.nz/products/td42-cylinder-head-coolant-bypass?_pos=1&_sid=20afa97b3&_ss=r)

No my problem is it still creeps up in temp when climbing a decent hill most I've had is 105 deg where i stopped and let it cool down, etg's don't go above 450 deg post turbo (14 psi and about 1/2 turn on fuel screw).

Normal highway driving it sits at about 80 degrees but it fluctuates from 70 - 90, is that normal or should it just site around 80?

The thing i don't understand is that after reaching the top of a hill and start going down the other side temps drop pretty quick but they drop down to 60 on a long down hill.

Also i switched out the thermostat for a modified one, longer to stop the recirculation of coolant thru the engine.

What should i look at next? new rad?

Regards Leroy
80190

[0-TJ-0]

All sounds pretty standard to me. Mine runs very similar and I'm about to try a new thermostat to try and settle the needle down a bit.

I put a new hub and fan assembly in mine recently and it has given me a bit more room to play on those up hill runs and recovers much quicker as soon as you're off the throttle.

I don't think you'll ever fully solve it. Unless someone knows something I don't.. I've even toyed with trying to fit another radiator somewhere just to see what it actually takes to keep up.

[MudRunnerTD]

There is some interesting research here mate. have a read.

http://www.nissanpatrol.com.au/forums/showthread.php?46028-TD42-All-Variants-Aussie-Water-Thermostats

[mudnut]

Are the radiator shrouds in place?

[mudski]

Hi all,.....

No my problem is it still creeps up in temp when climbing a decent hill most I've had is 105 deg where i stopped and let it cool down, etg's don't go above 450 deg post turbo (14 psi and about 1/2 turn on fuel screw).



This tells me to go get the Patrol properly dyno tuned first. It could be as simple as a bad tune. If its still the same after a dyno, then look at everything else I think.

[leroy123]

Thanks for the input, shrouds are in-place.

I will get it tuned at some stage but no one does it locally and i want to finish off a few things. Too much diesel would mean the etg's would be running high? mine sits at about 250 - 300 while cruising and pushes 450 up a long hill, is this pretty standard?

I still don't understand why going down long hills the temp drops down to 60deg, shouldn't the thermostat close and stop the coolant from going thru the rad and hold the temp around 80?

[mudski]

Cooling down fast means your cooling system is ok, mine does the same, and believe me, I've done everything known to man on my cooling system to make sure its right. But I hit a hill and the temps will sky rocket, but will cool down pretty fast on the down side.

I've had mine at two different tuners now and its running at its optimum, but still gets hot real easy. Only in the last week I think I have narrowed it down. My injectors are high crack pressure injectors, ever since getting them installed, I've had cooling issues, only to be told by tuners its normal. I know its not, as it never did this before, and my EGT's are great, I rarely see over 300c.
So a customer of mine who owns two TD Patrol and is very knowledgable on this motor just installed high crack pressure injectors. He said on his first drive it ran hotter. It got hot very easy hitting hills, but would cool fast on the down side. Just as mine does. He removes the injectors, all back to normal. Bam! Theres my issue!
He's advanced the pump timing on his Patrol say said in doing this you have to sacrifice some power. Not sure on the hows and why's of this but it seems this is the issue.

So maybe you have injector issues? Not sure, might be worth checking out though. I will be buying a new set of stock squirters for my TD once I have the money to do it thats for sure.

[leroy123]

That could be it then, i put a reco set of injectors in when i did the turbo with the higher crack pressure. I don't have any idea of how it was running before as i put the temp gauge on after the turbo install.

Is it worth looking at a new rad to try to minimize the temperature creep on the long ascents?

how would this increase the operating temp?
What does the higher crack pressure actually achieve? do they inject the diesel a little later than stock but get it in there faster, better atomization? so advancing the timing offsets this?

[mudski]

That could be it then, i put a reco set of injectors in when i did the turbo with the higher crack pressure. I don't have any idea of how it was running before as i put the temp gauge on after the turbo install.

Is it worth looking at a new rad to try to minimize the temperature creep on the long ascents?

how would this increase the operating temp?
What does the higher crack pressure actually achieve? do they inject the diesel a little later than stock but get it in there faster, better atomization? so advancing the timing offsets this?

Hows that!? your experiencing the same as me also with higher crack pressure injectors.

From my understanding, the higher crack pressure means the injector will release the measured amount of fuel at a higher pressure than standard to atomize the fuel better. In doing this however the injector pump need to push more fuel in "per squirt". So the slight extra fuel I take it per squirt is eventually equating to higher temps when under load.

I'm just excited to see you are in the same boat as me. I was so sure from day one when these were fitted to mine that this was it. The mechanic thought I was a idiot.

As for changing radiators etc etc. Don't bother. I've had a triple core ally rad in, big fat copper rad in, now had the OEM rad back in with zero difference. Also fitted to mine, JPC high Flow water pump, Infinity G35 fan with extra oil in my viscous hub so now its locked 100%, a water rail feeding coolant into the cylinder head and the Tridon Hi Flow thermostat. ALL have made zero difference to helping with this issue.

Hodge! Check this thread out. Sounds familiar?

[0-TJ-0]

Mine acts all very similar although my injectors haven't been touched (as far as I'm aware) but it also hasn't had a tune since the new pump went on.

[Cremulator]

Interesting reading everyone's experiences. I've not had trouble with my cooling system (so far luckily) but I read an article when researching fitting the 82° thermostat (which I'm planning on installing) which covered air flow.
Do you guys have this air dam fitted still?
http://www.nissanpatrol.com.au/forums/images/imported/2020/02/114.jpg mine is broken along the bottom where the three bolts are but stays in place.
Also the foam along the top of the radiator?
http://www.nissanpatrol.com.au/forums/images/imported/2020/02/115.jpg again mine is partially in place but coming away on the left had side of the photo.
Both those elements assist moving the air though the radiator.
Also mentioned in the article is checking you have a 1.1 bar rated radiator cap, not a 0.9 bar, as that’s the pressure it will allow before it vents to your overflow – a touch more pressure in a 1.1 bar cap will stop it venting (and boiling) sooner..

Here is the article; https://www.unsealed4x4.com.au/breaking-the-kettle-td42-cooling-tech-tips/

[0-TJ-0]

A lot of interesting info in that article.. Along with some things I may try.

Although, I notice he appears to be running the wider gq radiator? Any of you parts gurus know if any of the gu's came standard with that wider radiator?

If he has swapped it.. Just makes me a bit skeptical about some of the statements made.

[mudski]

A lot of interesting info in that article.. Along with some things I may try.

Although, I notice he appears to be running the wider gq radiator? Any of you parts gurus know if any of the gu's came standard with that wider radiator?

If he has swapped it.. Just makes me a bit skeptical about some of the statements made.

The wide radiator was used in the GU until around late 2004 from memory. My 01 GU uses the wide rad. I’ve also put new foam seals around the radiator and also the a/c condenser and also have the plastic air dam fitted. All to no avail.


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[0-TJ-0]

The wide radiator was used in the GU until around late 2004 from memory. My 01 GU uses the wide rad. I’ve also put new foam seals around the radiator and also the a/c condenser and also have the plastic air dam fitted. All to no avail.


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Mines a 2003 and has the skinny one, but you've answered my main question anyway. Thanks for that.

I find it interesting that Nissan states 118deg is safe yet puts in a 76deg thermostat. Maybe I'm worrying too much. I've never even seen it get to 110.

[Hodge]

Mine hasn't got that air dam fitted. Maybe it had in the past? I have a plate with slots in it, I believe it was a part of ARB bullbar assembly?

I believe this tune / injector business has a lot to do with thermal behaviour of the ol' TD. I think mudski is onto it.

My injectors have never been touched. But each time my car was tuned, the temperatures altered. It's black magic this diesel tuning stuff...

First time it got dynoed and tuned, I believe it was just a flat-head screwdriver fuel screw job... I gained a bit more go, and a bit more smoke behind me and temps were up a little bit...
Second time was after intercooler and exhaust were fitted. Again I believe he just monkeys around the screw. Power was the same, a gained LOTS more smoke at the back and I had to really PUSH the car to get egts and/or coolant temps up to warmer areas... This tells me a lot of unburnt diesel was being sent out the rear choking the poor sods behind me.

Last time was a proper tune @ dieseltec. Car was best its ever been in my possesion. More response and GO throughout MORE of the rev range and gained a incredible sweet spot between 1500-2800 ish rev range. And NO smoke at the back. But THIS time around the drawback is that my EGT's and Coolant temps went up considerably when car is pushed and I can get to those temps quiet easily.... Perhaps maybe now the car is burning the diesel properly and MORE of it to gain that performance and thus the temps are up. Maybe how it should be ???I remember the guy at diesel tec told me I had my gauge alarms set WAY too low. My EGT alarm was at 400 and coolant at 88. And he said thats where the TD begins to sing.


http://www.nissanpatrol.com.au/forums/attachment.php?attachmentid=80209&stc=1

[mudski]

Mines a 2003 and has the skinny one, but you've answered my main question anyway. Thanks for that.

I find it interesting that Nissan states 118deg is safe yet puts in a 76deg thermostat. Maybe I'm worrying too much. I've never even seen it get to 110.

Ok. I thought the skinning rad starts in the series 4's. Cheers.

[leroy123]

Thanks for all the help, temps are getting a bit better now.

I have replaced the radiator with a alloy one as the old one had a small weep.
I also replaced the rad cap with a 1.1 bar one.

Now i can make it up a nearby ski field access road foot flat most of the way and it only got to the high 90's at the top, before it would got past 100 after about half the climb while taking it easy.

So i am pretty happy on the over heating issue, I am still not happy about the over cooling.

So once turning around the the top of the access road the temps drop really fast down to 70 , then continue to creep down to about the mid 50's by half way down.

My thoughts are that the thermostat is not closing properly but I have tried 3 thermostats (the one that was in it, a new genuine and a modified 4mm longer one)
Does the head coolant bypass hose allow circulation thru the radiator bypassing the thermostat?
Could it be the injectors? should i look at getting second hand ones and reco to factory spec or look at advancing timing on the pump and keeping high crack pressures ones?

Cheers.

[MB]

G’day Leroy, in regards your last question of over cooling downhill, do you know if any of the thermostats you have trialled to date had jiggle pins installed mate?

As per the link to another thread in post #3 here kindly added for you by Mudrunnertd, I did some fairly extensive testing on 3 available Nissan OEM thermostats.

Mine was behaving almost exactly like yours is described above and installing one of the OEM higher rated thermostats instantly solved my problem.

In summary:
OEM 76.5C does not have a jiggle pin.
OEM 82C does have a jiggle pin.
OEM 88C does have a jiggle pin.

I have been personally running the 88C throughout Victorian winter 2019 and summer 2020 to find almost no difference on the maximum water temperatures the same as the OEM 76.5C was doing.

What I did find was that the new lowest temperatures hugged very close to its 88C setting unlike the jiggle pinless 76.5C that allowed extra circulation I now believe even when fully closed as pot tested its settings for clarity.

An added bonus was finding after so many years that the old TD42T ran its best fuel economy ever if I could get it singing along on the highway at 92C or near enough.

Worth a quick read of the linky in post #3, some great input from top members helping me with my 56C downhill winter issue too.

Cheers
Marky Mark & The Funky Bunch :-)





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[mudski]

Thanks for all the help, temps are getting a bit better now.

I have replaced the radiator with a alloy one as the old one had a small weep.
I also replaced the rad cap with a 1.1 bar one.

Now i can make it up a nearby ski field access road foot flat most of the way and it only got to the high 90's at the top, before it would got past 100 after about half the climb while taking it easy.

So i am pretty happy on the over heating issue, I am still not happy about the over cooling.

So once turning around the the top of the access road the temps drop really fast down to 70 , then continue to creep down to about the mid 50's by half way down.

My thoughts are that the thermostat is not closing properly but I have tried 3 thermostats (the one that was in it, a new genuine and a modified 4mm longer one)
Does the head coolant bypass hose allow circulation thru the radiator bypassing the thermostat?
Could it be the injectors? should i look at getting second hand ones and reco to factory spec or look at advancing timing on the pump and keeping high crack pressures ones?

Cheers.

I've decided myself to go back to stock injectors. To be honest I dont even know how much better high crack pressure injector are than stockies. Ive just had them in my car since the motor got built so I dont know any different. And from my understanding, advancing the timing should solve the issue of heat, but it comes at a cost of power, again, not sure how much. But it just seems pointless to me to lose power just to have these injectors in. I might aswell have stock injectors, plus plenty of people getting around with stock injectors running more power than I am.

[MB]

Back on track Leroy Mate from your other thread brother.
Have you trialled either of the OEM 82C & 88C thermostats as yet?
http://www.nissanpatrol.com.au/forums/images/imported/2021/01/45.jpg
Left one in the picture is the 76.5C OEM and I would definitely not recommend that for New Zealand year round ambient temperatures much like us Southern Victorian Hillbillies.


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[MB]

http://www.nissanpatrol.com.au/forums/images/imported/2021/01/46.jpg


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[MB]

mudski :-)


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[mudski]

mudski :-)


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Yes?..........

[MB]

Was trying to refer you back to Leroy’s original thread here mate. It gets confusing when two threads are started on the same query, I give up [emoji23]


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