Cooling Issues

[Roscoe]

Hi guys, just a couple of things, Re the cooling, remove the bottom hose off the engine and the same with the top hose but twist the top one around so you can pour into it , use a bucket or something with a high flow and dump water into the top hose, there should be no restriction, ie, the water should come out the bottom hose as fast as you can pour it into the top.

A radiator core has a higher flow capacity than the hoses do so if it backs up in the top hose then the core is partially blocked.

If the core is ok and everything esle checks out, think about an auxillary electric fan in front of the rad, these work very well and are designed to compensate for extra loading on the motor that was not factored in by the manufacturer.

Ive heard of air con rads being moved elsewhere to help with air flow into the main core as well and this has proved to be successfull.

The Injector nozzles should be the very first items to get attention in any quest for more power, at least pop them out and get them tested, you may be surprised at the results. Normally though, you will see black smoke under load if they are starting to get a bit tired but even a clean out by an injection speciaist will reap you power benafits.


Cheers

[Roscoe]

Something else I meant to mention, If you have increased your boost and have also re calabrated your pump to suit or have an Anaroid diagphram fitted, this will increase your combustion temp quite a bit so you may just be exceding your cooling systems design limits.

Those electric fans can also be hooked up via a temp probe too so they only run when a certain temp is reached.

I used to have a Toyota Landcruiser swb and I ditched the standard fan and just ran with the electric one. It was a hell of a lot quieter and I gained a bit of power because of the normal power loss with an engine driven fan. No probs with over heating.

Cheers

[JustinW]

This may be a dumb question, but have you managed to block the outside of the radiator, ie between the fins? I had exactly the same symptoms (OK around town but very hot if worked hard) after playing in the mud at Mamaku. After several attempts to clean it insitu, it looked clean but was still getting hot, I took the radiator out and hosed it through the fins. I was horrified at the amount of mud that came out of what looked, in the vehicle, to be a clean radiator.

JustinW

[draganlada]

As roscoe mentioned,I have 12 inch electric fan instoled in front of aircon core to inproove airconditioning in city heavi trafic standstill condition.I'm switching it manualy so it can be used in off road conditions.Last january I drove over stockton dunes at just under 40 deg. C and my temp. didn't moove at all.

In my other car ( lada niva - known for overheating in ausye climat ) I remooved belt driven fan and instoled two electric ones.One is thermo switched and second is manualy + conacted to brake pedal switch.Since than no cooling issues and I allso gained couple ponyes + much beter for water crossings ( belt fans create lots of drag and splashes water allover engine bay ).


Dragan

[justin]

Finished the flush through and changed and checked the thermo & belts, certainly a bit of crap came out. Interestingly I asked for a thermo & gasket for a 4JG2 and it was nothing like the one in there. So went back and asked for the same for a 4JB1T and they were a perfect match. I will post the part no. on the NSW site soon and so far I have floored it in every opportunity and not managed to get the gauge to move. Will test it on a trip to Jervis bay in the next few weeks. J

[MattMU]

I have a good feeling our bullbars have alot to do with it J.

I chased this problem for ages when I was towing my camper trailer through Central Aust in Summer. My rad cap was stuffed and the hoses were getting on and I had repaired a few tubes in the radiator, even replaced the water pump and thermostat. I bit the bullet and recored the radiator and all that helped but didnt cure the problem.

I have now resigned after trying everything else that the rad capacity and airflow just isnt upto the task if you are giving it hell ie towing in 40 deg heat!!

Mine has the Rodeo ARB bullbar with winch and a set of Hella Rallye 4000's so airflow is a tad restricted.


The origional bumper has air scoops in the lower skirt and I never had spotties on either, never had a problem. Although in fairness the only time I can get my needle to climb without a furniture trailer etc on the back is in high heat with aircon on climbing a large hill or speeding!

Your rig never had a problem before fitting the bullbar J, so if all the hoses, cap and rad all clean and good. Then I think therein lies the problem!

I hope you get it sorted though, or just have to be a tad easier in the VERY hot days!

Matt.

[Roscoe]

Have you considered relocating the air con rad with its own electric fan. Ive heard of this being done where there has been an air temp problem entering the main core.

A booster fan on the front of the air con core may help too.

If the Injectors are over fueling, this will creat a lot more heat in the combustion chambers which the cooling system also has to try and deal with.
I know the nozzles are bloody expensive but thats just part of owning a Diesel.

Cheers

[PeterSchurms]

G'day,

I have not read the entire post closely, I’ve been away for 3.5 months and just catching up on some reading. So if I duplicate others info, sorry.

I spent 1.5 yrs and $5000 plus in cash looking for my heating problem. This is before I found it. Almost funny thing was, it was the first thing I checked the radiator core was the root cause. The thief I took it to never checked a thing and charged me for it. 15 tubes were blocked… There was other things I did that improved it, but not fixed it. One of those could be the root cause for you. Temp has not moved since, even towing 2T on hot days makes no difference.

The I got plenty advice, lots of bad and good stuff. A really good rule was, if the temperature gauge rises quickly, and falls quickly, there is a good chance there is a serious issue with the cooling system. If the temperature rises slowly, there may be other contributors.

Some other points to try:
- Cooling liquid concentrate increased to %75 – small improvement
- Throw away the second thermostat behind the engine block (if it has one), mine was stuck partially open. – small improvement
- ½ cowling on fan was missing on mine, replace this. – small improvement
- Installed transmission cooler - small improvement
- I never used to be a fan of oil treatments but… I tried ‘Roil’ oil treatment and for 4 weeks in summer I though the problem was fixed – big improvement. I still use the stuff and am a fan of it. Its Not teflon based filter blocker.

Apparently you one need to restrict the cooling air by 15% and heating issues may arise. So Matt sounds like he is on to something with the bull bar.

Good luck,

Pete

[justin]

Well after a day up at Stockton on Saturday my temp still rises under load. I fitted a 10" fan infront of the aircon rad which stopped it from getting too out of hand but I think the next step is a new radiator. I have replaced the thermostat, hoses, coolant, (more times than I can remember), full descale, Rad cap, and added the fan. The truck is becoming unusable off road now so anyone brought a new rad recently? Is it a straight rodeo swap and what are they worth. I was tinking of getting it recored but its the time off the road which is a pain where I could throw a newy in there in an hour or so. J

[Witchdoctor]

Justin,
Should be getting the oversize rad from PWR tomorrow
made to drop in, they quoted me $850.00x GST will know more then. Was quoted $650 for a new Rodeo from the local rad joint. The PWR is all alloy,they also quoted $260.X GST for a 16"skew thermo fan.
Hope this helps.

Dave

[justin]

Thanks for the info Dave, I found a real helpful company in Sydney who checked out the existing rad and went through the entire catalogue to find out the identicle replacement one was for a 97+ Rodeo? Anyway they are getting one in for $350. So I'll stick that in at the weekend and if I still have temp problems I'm going to give up driving it, just keep it in the garage and polish it on weekends....

[Witchdoctor]

Just picked up the new rad this thing is masive ;D & polished dont think i will touch it . Total cost was $1100.00 with the flash thermo. Will install on the weekend & photograph it with compero shots of the old & new.
Fingers crossed this stops the heating problems.

Dave

[Jimmu]

I have been told that swapping to a thermo gives you about another 5Hp...


So when are we going 4WDing? ;D

Jimmy.

[Witchdoctor]

Fitted the rad, it is one mother over rad. 1st tests look good without trailer old temp was in the range of 180 around town to between 180 & 210 if high speed or hills were involved. She now sits on 140 around town, high speed running at 160.
Will be testing with the trailer to day looking good so far. Was told about putting a engine oil cooler will also reduce the heating on the system, this is a much cheeper option than replacing the rad.
More info coming ;D.

Dave

[justin]

Dropped my new rad in this morning, straight swap the only difference was the transmission cooler outlets were at a slightly different offset. That just meant an extra 6" of hose. The old one had a nice fan impression in it, obviously during some radical manover. Tested it up a long steep hill under hard acceleration for about 3 mins and the temp hasn't moved so looking good for now. J

[Witchdoctor]

Still having problems
Going to investigate an engine oil cooling rad

Dave

[justin]

U R Kidding Dave
I was sure the monster rad would have fixed the issue.
Mine seems fine now, I have hammered it up some really long hills and it hasn't moved. I will go on a trip to Jervis Bay next weekend and try the 130 on the freeway test as a final effort. Let me know how you go with the oil cooler, that sounded interesting. J

[JustinW]

Still having problems

Just how far do you have the fuel pump and boost wound up?!

[Witchdoctor]

It's all stocko Justin W.
Have drilled 3 4mm holes in the thermostat will try that.
Could anyone direct me to the rear engine thermostat as i have read that some MU's have them?
Thanks guys

Dave

[PeterSchurms]

G'day Dave, The second thermostat, was located at the back of the engine block, just left of center. It sends water to the oil cooler. It is an inline thermostat approx 3 inches long. Maybe reach behind and run your hand along the hose you should be able to feel it. I was not able to see it .

Do you have a boost gauge? If so, does it loose boost/power when it gets hot. If it does it could be turbo related.

When tackling my heating problem I did heaps of research. Spent heaps of cash, many, many days of frustration. But when you solve iit, be sure to go to the pub and celebrate as i did. The beer tasks better. So I hope your drinking soon.