Ongoing cooling saga on my 4.2 GU

Submitted: Thursday, Apr 28, 2005 at 21:46
ThreadID: 22465 Views:2306 Replies:15 FollowUps:19
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Okay....finally got the last piece of the jigsaw today, for what I hope will be the end of my cooling issues.

1)....I replaced the thermostat (thanks for the gasket Ken; a beer was opened for you here tonight, but when you didn't turn up, I had to drink it myself). Before installing the new one, I did a test. Using the large glass bowl from a turbo oven (the lid with heater unit has long ago gone to the tip), I placed just enough cold water in it so that the 2 thermostats would sit on the bottom in their upright position. I placed a gas ring underneath, taking care to ensure the whole lot was centered so they would heat up equally. They are both marked 76.5 deg and both cracked at the same time. I was almost going to end the test at that point, but decided to let the heat continue to build up and lo & behold, the new one opened up about twice as far as the old one!!!

2)... Bottom hose was removed and placed to one side. I introduced the new hose to the Patrol. This new hose has been cobbled together as follows: At the top where it joins the motor, I used a piece of top radiator hose. I cut it about 4" from the end that attaches to the thermstat end. Both standard hoses have 38mm on the motor end and only 32mm on the radiator end. With the 4" I cut off, I was able to get a section which fits nicely onto the motor. Yesterday I got a piece of 32mm stainless steel pipe bent to 90 degrees; about 1 foot long overall. I joined it to the 4" bit of hose with 2x clamps. The stainless pipe points downwards (just like the OE Nissan hose does) and onto this I have attached a 23" long Vulco-Flex hose I got from Repco. (thanks very much to Hugh from WA for all your help to get me this far.....much appreciated). This hose is bendable, it has reinforcing wire moulded into the rubber as well as a s/steel coil spring wire on the inside. This had to go down between the air-con compressor and the chassis and then bent forwards to connect onto the radiator. That connection sits underneath the a/c pulley.

3)... I refilled the radiator, (after flushing it out as much as possible including the heater), with rain water, about 2 litres of techtalloy 90+ and a bottle of Water Wetter...(see.: www.redlineoils.com.au).

After all that I had to have a couple of brown lemonades, so I'll have to wait till tomorrow or the weekend to see if the temp gauge gets back into it's hole.

If it doesn't solve the problem, I might have to save the pennies and do the "MTQ hussle".....hahaha

Cheers

Roachie
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Reply By: Des Lexic - Thursday, Apr 28, 2005 at 22:01

Thursday, Apr 28, 2005 at 22:01
Young Billie, just a single piece of advice to overcome the problem once and for all.
50'S NEVER OVERHEAT
PS thanks for the good wishes. The old chook is resting comfortably in her pen.
AnswerID: 108696

Reply By: AT4WD ADVENTURES - Thursday, Apr 28, 2005 at 22:04

Thursday, Apr 28, 2005 at 22:04
Roachie,

My mate has a 4.2gu Tray Top which had cooling problems. All sorts of things were tried to solve the problem including a trip to MTQ in Sydney and I would have say I wouldn't touch em with a barge pole. (its a whole other story why)

Anyway the fix for his rig was a new and completely different radiator, can't remember which one but can find out if your fix doesn't work.

Regards,

Stuart M
AnswerID: 108697

Follow Up By: trendy - Thursday, Apr 28, 2005 at 22:17

Thursday, Apr 28, 2005 at 22:17
I would love to know the radiator mob you talk about. Many have been tried without success, but one more name to the list to do research on would not hurt. Thanks in advance Trevor.
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Follow Up By: Member - Roachie (SA) - Thursday, Apr 28, 2005 at 22:21

Thursday, Apr 28, 2005 at 22:21
Thanks for that Stuart. I have already done the new radiator thing....an $1100- all aluminium unit from PWR in Qld. The standard radiator has 2 x 12mm cores. This one has 2 x 26mm cores.
I've also fitted an extra electric fan in front of air cond, fitted a bonnet scoop over turbo, replaced the original fan hub with a new one ($300+) etc. I've fitted a new radiator cap (same pressure as original).

Another thing I may have to do is see if I can changeover my bullbar for one with more flow available; or else cut some large holes in the one I've already got.....but the winch is right in there too and probably a waste of money/effort.

Another thing I need to get checked again is the timing and fuel pump output....could be overfuelled.

Cheers

Roachie
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Follow Up By: Member - Roachie (SA) - Thursday, Apr 28, 2005 at 22:22

Thursday, Apr 28, 2005 at 22:22
Trevor,

PWR = Paul Weel Racing.....they have a V8 supercar.

Check their website....www.pwr.com.au

Cya mate

Roachie
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FollowupID: 365469

Follow Up By: AT4WD ADVENTURES - Thursday, Apr 28, 2005 at 22:53

Thursday, Apr 28, 2005 at 22:53
Roachie,

I am pretty sure it wasn't a PWR radiator and I will find out tommorrow and post back here. It fixed the problem and he had tried lots of fixes like you before it being fitted.

Stuart M
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Follow Up By: trendy - Thursday, Apr 28, 2005 at 23:25

Thursday, Apr 28, 2005 at 23:25
Thanks Stuart I'll look for that 2 morrow.
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Reply By: trendy - Thursday, Apr 28, 2005 at 22:14

Thursday, Apr 28, 2005 at 22:14
Hi Roachie,
I read with interest as you know it reflects what I'm going through up here in Queensland. I have talked with a well known 4x4 reporter regarding the MTQ upgrade he had done on his 4.2T patrol, but his has not stopped the overheating completely ( now happens only on hot days 32 c plus ). There will be a PWR radiator going into this vehicle in a couple of weeks to see if that helps his situation. I got to tell you with all the input going on by individuals around the country surely someone will crack this puzzling phenomina. No doubt with the input you have made it will have to be you, good luck and keep me posted as I will you if anything changes up here. PS still haven't tested mine in a real serious manner yet but not long now. Kind Regards Trevor.
AnswerID: 108700

Follow Up By: muzzgit (WA) - Friday, Apr 29, 2005 at 00:54

Friday, Apr 29, 2005 at 00:54
Puzzling phenomina it isn't.

BLOODY NISSAN IT IS !!!!!

This is a vehicle made a few years ago, not decades ago. What the bloody hell is Nissan doing ???????????
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Follow Up By: Michael ( Moss Vale NSW) - Friday, Apr 29, 2005 at 16:25

Friday, Apr 29, 2005 at 16:25
Funny how Nissan can make great diesel trucks ,,, for years and years.. you think they could get cooling right..
Patrol 4.2TDi 2003

Retired 2016 and now Out and About!

There's time to rest when you're dead,
Get out and do something instead!

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Reply By: Sand Man (SA) - Thursday, Apr 28, 2005 at 22:14

Thursday, Apr 28, 2005 at 22:14
Hey Bill,

I thought you were practically a teetotaler!

Now lets see....if I read you right, you started off at number 1 with a couple of beers prior to tackling the challenge.

Then after number 3 you had another couple of beers.

Or were the before and after actually one in the same?

You haven't told us whether the containers were glasses, stubbies, or longnecks.

Actually I'm selfish. I hope you haven't resolved the over heating problem because your updates make for a bloody good read:-)

Na! just kidding Roachie. The thermostat comparison itself must give you a certain level of confidence? Hope you have resolved your problem once and for all, then you can spend your hard earned on some new toys.

Bill 2.
Bill


I'm diagonally parked in a parallel Universe!

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Reply By: Exploder - Thursday, Apr 28, 2005 at 22:36

Thursday, Apr 28, 2005 at 22:36
Gday all.

Yeah you would hope that this has finally fixed it.

Just out of curiosity, as I am no Nissan diesel expert.

Was something changed in the internal’s of the engine from the GQ to the GU Patrol’s smaller water jacket or different flow path? With all the cooling equipment you have tried it should be having more trouble warming up than keeping cool.

How much does your rig way fully loaded with camper and all? Is it possible that you r just trying to move to much weight? Or does it do it when you r just driving around normally.

I am not having a go. Just interested as to why nothing seems to be working for you.

P.S I know a couple of people with GU T/Top’s (non Turbo) and no cooling prob’s Is it only the turbo models that have this problem?
AnswerID: 108710

Follow Up By: Member - Roachie (SA) - Friday, Apr 29, 2005 at 11:23

Friday, Apr 29, 2005 at 11:23
G'day mate,

Weight is probably a factor.....even just sitting in the driveway in it's "unloaded" state, it is over 3tonne due to all the shyte I've got on/in it. Things like the heavy rear storage draw full of recovery gear; the fridge is in (and 'on') permanently; the roof rack is a fixture with rear lights and air horns all permanent; the dual wheel carrier and heavy steel rear bar; bullbar with winch; dual battery; long range tank which I keep filled up most of the time etc.

Once I load it up and hang the camper off it, I reckon I'd be looking at 4.5 to 5 tonnes all up.
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FollowupID: 365518

Reply By: awill4x4 - Thursday, Apr 28, 2005 at 22:36

Thursday, Apr 28, 2005 at 22:36
Roachie, I've found something to be aware of with our PWR radiators. I'm assuming that yours is the same core thickness as mine (2 rows of 26mm tubes, 57mm total core thickness) I know that yours is a GU and a diesel while mine is a GQ and a petrol but when your doing river crossings there is a potential for the fan blades to hit the back of the radiator.
It happened to me over the weekend during a (not particularly deep) river crossing, I didn't notice anything until a few minutes later when my coolant temps started to climb and got up to just under 3/4 on the gauge and my petrol GQ never gets this hot. The group of us stopped and when the bonnet was opened we saw the fan blades weren't turning. What appears to have happened was the blades were drawn to the core by the water and just ever so slightly skimmed the core marking the fins in a circle slightly but not damaging the tubes (very lucky there, phew!!!! ) One of the blades has then hit the top centre shroud bolt, bent the blade and jammed it against the shroud, cracking the shroud in the process. We tried straightening the blade, but no luck there as it was still hitting the shroud and rubbing the radiator core so we cut out the top centre secion of the shroud and cut the bent section off the offending blade and it was then fine. The temps returned to normal and has been no problem since.
Obviously the thicker radiator is closer to the fan so the margin of safety in regard to water crossings has been reduced. I'm thinking at the moment whether to remove the fan and cut back each blade a distance of approx 15mm to 20mm to get the clearance somewhere to what it was originally.
It's something to think about.
Regards Andrew.
ps this would apply to all thicker radiator cores, not just aluminium.
AnswerID: 108711

Follow Up By: Truckster (Vic) - Friday, Apr 29, 2005 at 01:20

Friday, Apr 29, 2005 at 01:20
wow, you went offroad? :o
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FollowupID: 365486

Follow Up By: Member - Roachie (SA) - Friday, Apr 29, 2005 at 11:29

Friday, Apr 29, 2005 at 11:29
Thanks for that Andrew....I'm all too well aware of the reduced gap between the rad and fan. Water crossings are pretty rare over here in the country's driest state, but I do carry a placcy sheet to use as a blind when doing any crossings. Is yours a plastic fan? I would have thought it would have been and that it would have snapped back to it's original position. I'd be cautious about cutting any material off the fan blades (not sure if it would reduce their effectivness and/or balance.
Cya
Roachie
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Follow Up By: goldfinder - Friday, Apr 29, 2005 at 18:26

Friday, Apr 29, 2005 at 18:26
I also have a PWR Rad in a GU and have completed several water crossings since it was installed with no problems at all. Originally it was installed to cure air cond cutting out when loaded, towing a van and when temps were in the high 30's +. No problems since the installation. From memory I had discussions with Roachie back in the early days when I first installed it. Keep us informed Roachie on your progress and I hope you have cured it.
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FollowupID: 365576

Reply By: snowman - Thursday, Apr 28, 2005 at 22:57

Thursday, Apr 28, 2005 at 22:57
Hi Roachie,

Its most probably to late to offer advise but usually you look at easy problems to fix first. Thermostat should have been number 1. If that didnt change anything then i would have fitted a different temp gauge for comparison. Next would have been to pull radiator out and get it serviced. If that didnt work i would have pulled water pump out and checked the impellar for damage.
I think now that you have found a problem with the thermostat your problems will be solved as it wouldn't matter what else you did, without the water flow it would never cool properly.
Cheers Dave
AnswerID: 108719

Reply By: Member - Bradley- Thursday, Apr 28, 2005 at 23:39

Thursday, Apr 28, 2005 at 23:39
i hope you had each end of the stainless tube 'ribbed' to stop the hoses blowing off.... dont want another piece in the puzzle down the track.
AnswerID: 108729

Follow Up By: Member - Roachie (SA) - Friday, Apr 29, 2005 at 11:34

Friday, Apr 29, 2005 at 11:34
Bradley,

Thanks for your concern and I did thinks about doing that. However, I didn't get the ends 'ribbed'. The tubing goes into each hose by about 3" and I have put 2 clamps at each join. Also, as the bottom hose is a 'suction' hose, there should not be the same pressures involved as is the case in the top hose. However, I will keep an eye in it.

Thanks

Roachie
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FollowupID: 365521

Reply By: trippin around - Friday, Apr 29, 2005 at 01:00

Friday, Apr 29, 2005 at 01:00
hi roachie, now i know why i bought a toyo. towing 2.5t at 90/95ks in headwinds and absolutely N O overheating problems. did you investigate the triple flow radiators advertised in "just 4x4" or something like that mag regards bob h
AnswerID: 108740

Follow Up By: Member - Roachie (SA) - Friday, Apr 29, 2005 at 11:52

Friday, Apr 29, 2005 at 11:52
G'day Bob,
Please refer to my response to Keith (below)...... I am concerned for you toyo blokes cos your gauge/s might not be telling you the whole truth. I hope I am wrong, but have come to the point where I don't trust factory gauges; especially ones that just show "C" at one end and "H" at the other.
As for the triple flow radiators, I haven't investigated them as yet. I reckon I'll need a triple by-pass if I have to spend too much more $$$ trying to keep this thing cool!!!! lolololol

Cheers mate

Roachie
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FollowupID: 365523

Reply By: Outnabout David (SA) - Friday, Apr 29, 2005 at 07:14

Friday, Apr 29, 2005 at 07:14
Hi Roachie,

Can't remember everything you have done but from memory you have done the basics radiator thermostat etc. I think I remember you doing something to the shroud. Apart from keeping your fingers out the blades the shrouds actually help cooling by concentrating the air flow over the engine, so if they have been removed I would put them back on.

Have you tried removiong driving lights, winch and finally bull bar to see if the problem still exists? Some vehicles are highly susceptable to changes in air flow not sure about the Nissan. Also the fact that you have a big suspension lift could have some aerodynamic effects.

Good luck.......you will be so happy when you find the cause. You may not fix it but at least you will know.
AnswerID: 108743

Follow Up By: Member - Roachie (SA) - Friday, Apr 29, 2005 at 15:09

Friday, Apr 29, 2005 at 15:09
G'day David,
Yeh mate, I've done most things....but as far as airflow goes, the only thing I've done is to try putting the big Lightforces up on the top bar of the bullbar. That didn't help.
As for the idea of taking the b/bar right off or at least removing the winch, I don't think is terribly practical. Maybe I could remove the winch without too much hassle, but as for the bar itself, there are too many other considerations....not the least of which is that i no longer have the standard bar and it would be illegal to drive without a bar of some sort.
I may have to consider buying a different sort of bar maybe. The newer ones that suit the GU all seem to have a full width gap of about 3" right across between the 2 main uprights which should let more air flow through. Mine does not....it is just one large slab of steel with a couple of small cut-outs down low.
Cheers mate
Roachie
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FollowupID: 365541

Reply By: Keith_A (Qld) - Friday, Apr 29, 2005 at 09:28

Friday, Apr 29, 2005 at 09:28
On by 2 x 1.5 (corolla), the temp Sensor/SENDER was the problem. As it turned out, the actual coolant temp was fine all along. The gauge just showed the wrong temp. It was the sensor unit that screws into the block - gave the wrong resistance as the temp rose. Do you know for sure if the coolant temp is too high?
my 2c worth................regards......Keith
AnswerID: 108763

Follow Up By: Member - Roachie (SA) - Friday, Apr 29, 2005 at 11:48

Friday, Apr 29, 2005 at 11:48
G'day Keith.
Strange thing that you mention. I was concerned because I see the standard gauge going up to near the "High" zone when working hard. However, wanting to know what the real temp is, I have fitted a VDO gauge; the sender unit is in the top radiator hose.

Only fitted this a week or so ago. The results really surprised me. On a trip to Mildura and beyond last weekend, I noticed that when the Nissan gauge reached it's normal position of just under half way, the VDO gauge was sitting on about 75 degrees. As I pushed harder, the VDO gayge rose to almost 110 degrees, and the Nissan gauge DID NOT MOVE. This suggests to me that rather than being overly sensitive, the Nissan gauge is actually "stuck" at normal when in fact the coolant temp is getting quite hot. Is was not until the VDO gauge showed just over 110, that the Nissan gauge got to just on half way. I did not go up any big hills etc , so was unable to get the Nissan gauge to show it's maximum reading as I had shown a few weeks earlier.

This is the thing that 'concerns' me about the many Toyota owners who consistently say that their gauge never moves off normal..... I'm not having a go at anybody, but they could be being lulled into a false sense of security, thinking that their motor is working at "normal" temp (whatever the hell "normal" actually means), whereas it could really be a case (like with my Nisan's gauge) that the Toyota gauge is not showing what is really happening.

Cya mate

Roachie
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Follow Up By: Member - Roachie (SA) - Friday, Apr 29, 2005 at 12:01

Friday, Apr 29, 2005 at 12:01
Sorry, forgot to add that these results were the opposite to what I was hoping/expecting to find with the new gauge. I thought the new gauge might sit at around 80 to 90 degrees and that the Nissan gauge was going "over the top" for no good reason.
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FollowupID: 365526

Follow Up By: Stew53 - Friday, Apr 29, 2005 at 19:08

Friday, Apr 29, 2005 at 19:08
Roachie, when you asked what threads the senders were I new what would happen when you installed them (sorry), its a bit involved, so here goes, I only know the theory in imperial measurement, as everybody knows water boils at 212deg F but for every PSI pressure on the Radiator cap the boiling point rises 3 degs F so in a system with a 10 pound cap the boiling point rises to 232deg F a 15 pound cap would raise the boiling point temp to 257deg F, I have heard of some corvettes with low profile bonnets and small radiators with 27PSI caps which raises the boiling point to 293deg F. I figure the reason manufacturer don't put graduation marks on there temp gauges is to not alarm their customers when the water / coolant rises above 100 deg C or 212 in the old money.
Know you have a thermostat in the car that you have proved is working correctly compared to the original dont do anything else and test the car out it may be fixed.
Stew
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Reply By: AT4WD ADVENTURES - Friday, Apr 29, 2005 at 17:00

Friday, Apr 29, 2005 at 17:00
Roachie,

As mentioned in previous postings the radiator my mate had installed that solved all his problems was a copper radiator from Hotham Radiators in Atarmon Sydney.

Check them out. It solved his cooling issue.

Regards

Stuart M
AnswerID: 108810

Follow Up By: Member - Roachie (SA) - Friday, Apr 29, 2005 at 19:12

Friday, Apr 29, 2005 at 19:12
Thanks Stuart.........I'll salt that info away for possible future reference

Cya

Roachie
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Reply By: Exploder - Friday, Apr 29, 2005 at 17:13

Friday, Apr 29, 2005 at 17:13
Hay Roachie This may be the dumbest question ever posted on this forum and I am probably up for a Darwin award just for asking it but hear it goes

Your patrol wouldn’t be the same one that was In 4WD monthly last year would it I Just spotted that issue on the magazine rack at home and had a flick thru

If so what a MACHINE and do the shu-roo’s work I have heard conflicting reports about them.

Go easy guys I am only new to the forum and don’t know this sort of stuff.
AnswerID: 108812

Follow Up By: Member - Roachie (SA) - Friday, Apr 29, 2005 at 19:22

Friday, Apr 29, 2005 at 19:22
G'day Exploder................not a stupid question at all. Don't ever think you're asking a stupid question.....bloody hell, you should see some of the pearlers I've asked on here.

Yep mate, that was the old girl that they did the article on. Thanks for the compliments.

The ShuRoo seems to work......all I can say is that I live in the country and do 99% of my driving on country roads. I used to live around Cooma, NSW and there are heaps of roos around there in several directions. I've never hit a roo yet with the Shu Roo switched on. As you approach them they seem to just hop away and provide clear passage. I liken it to if a person is walking along the road side and hears a siren coming from behind.....we're not scared of it and run away; we just become aware of it and make sure we stay out the way of the emergency vehicle. That's what the reaction of the roos is like in my opinion.

Cya mate and enjoy your time here in the EO madhouse.

Roachie
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FollowupID: 365591

Reply By: Stew53 - Friday, Apr 29, 2005 at 22:12

Friday, Apr 29, 2005 at 22:12
ROACHIE, when you asked what threads the senders were I new what would happen when you installed them (sorry), its a bit involved, so here goes, I only know the theory in imperial measurement, as everybody knows water boils at 212deg F but for every PSI pressure on the Radiator cap the boiling point rises 3 degs F so in a system with a 10 pound cap the boiling point rises to 232deg F a 15 pound cap would raise the boiling point temp to 257deg F, I have heard of some corvettes with low profile bonnets and small radiators with 27PSI caps which raises the boiling point to 293deg F. I figure the reason manufacturer don't put graduation marks on there temp gauges is to not alarm their customers when the water / coolant rises above 100 deg C or 212 in the old money.
Know you have a thermostat in the car that you have proved is working correctly compared to the original dont do anything else and test the car out it may be fixed.
Stew
AnswerID: 108870

Reply By: Peter 2 - Friday, Apr 29, 2005 at 22:27

Friday, Apr 29, 2005 at 22:27
A trick to stop the fan blades chopping into the radiator core is to get a circle like a large washer made the same diameter as the fan blades at the point where they will hit the core. It only needs to be approx 10-15 mm wide and while the blades might hit it they will just slide on it rather than digging in.
Peter
1996 Oka Motorhome

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AnswerID: 108872

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