overheating gq

[tuffzook]

all fixed???....no?... i have seen this more than once. you will find that your head is cracked there is no cheap way of fixing this but to buy a new head. sorry to say i have seen people buy massive radiators oil coolers... the list goes on if you are still having probs feel free to send me a pm i can help on price

[bogged]

all fixed???....no?... i have seen this more than once. you will find that your head is cracked there is no cheap way of fixing this but to buy a new head. sorry to say i have seen people buy massive radiators oil coolers... the list goes on if you are still having probs feel free to send me a pm i can help on price

I think you will find overheating issues more common than a cracked heads on TD42s.. Yes on a TB42, most crack, but not often you hear of TD's cracking
I know bare heads for TB's are round $1300 from Nissan new. be interested to see the difference in price for DIesel.

[dirtyGQ]

i cooked the living guts out of my last motor(td42) and melted pistons etc. But no cracked head at all,td42 heads are heavy cast and are very resistant to cracking.
But if you want a new head be prepared to sell and arm or a leg.

[Rogue Patrol]

This'll fix it.......
http://www.outerlimits4x4.com/phpBB2/vi ... p?t=132029

[PGS 4WD]

You said it had been dynoed and the mixture was perfect, how was that checked? You could get a pyro, if you are running a stock GU turbo setup they run about 8.5psi, try upping the boost to 10psi, this will lower the exhaust temps, most of the heat in your engine is transfered to the water jacket via the head and exhaust port, or turn down the fuel.

Alternativly get back on the dyno as they should have a K type thermocouple (pyro)
What dyno were you on? On a dyno dynamics dyno the ranp rates are so fast they dont simulate real life, the engine dosent have the time to generate the heat it does on the road, I use a DTS dyno and ramp at rates that simulate a 4rd gear pull up a hill, over about 10-15 seconds as this is far more representative of real life, even a fast car will need 10 seconds of Wide open throttle ramp to simulate a 1/4 mile. There is no point doing a 3 second ramp unless you happen to be driving a 5000 HP top fueller.
Heat builds up over time, drive up a big hill and time how long it takes to heat up the engine, go back to the dyno load the car on the dyno at similar load and rpm for the same amount of time as timed on the road and see what your EGT's are. If thet go over 550 C within 4" of the turbo outlet you need to make some changes.

Joel

[purplebus]

it was on my mates dyno on the coast. not sure what type but do remember them loading it right up in 4th. so presume it must be the same.they race 4x4 and do most the tough cars up here. the rad guy almost garantees that the rad and block flush will fix problem. will be done on tues.will let you all know how she goes. starting to really sh1t me now, but staying positive.

[tuffzook]

did one last week i would post pics if i could be bothered got a pile of worthless cracked cast iron here. cracked on 3 cylinders all pre comp chambers cracked eroded the block from coolant entry are you getting extra coolant in your overflow ?

[coxy321]

I had a bit of an overheating problem with my NA TD42, mainly due to a 60% blocked, half corroded core. Had a brass core put in - bloody beautiful.

Just FYI, V8 supercars dont have fans, just a huge alloy radiator. Thats why they dont let them sit stationary too long.

In my experiences, i've generally found that when i have heating/cooling issues, that a radiator workshop are the best people to solve the problem.

My upper radiator hose used to FULLY compress after driving it. Had never seen it before - couldn't beleive my eyes!!!

Through all the stuff you said you've done, i keep thinking the exact same thing that Joel just said. I've seen plenty of turbo diesels get cooling problems from poor fuel mixture. Two of my mates bought TD42T GU utes, both of them fiddled with the injector pump, both of them had cooling issues. The usual reply after someone commented on the huge plumes of soot coming from their truck was "Yeah, its a piece of shit to drive under 2700RPM, but goes real good after that!". The saying "A little bit of knowledge can be very dangerous" rings true here.

I had the same issue with one of my old MK SD33T's. Renewed the whole cooling system (at a rad. shop), still had issues on big long hills. No issues in town/40 degree days/AC on. Poor fuel mixture was the problem. Do yourself a favour - take it to a proper diesel mechanic for a dyno tune, someone that only specialises in turbo diesels.

Good luck - hope you get it sorted!!

Coxy

[purplebus]

here is the latest progress report. full rad and block flush. all came out as very clean no problems. put a small box trailer with a 35" rim and tyre to check her out and absolutely no change. more $$$$ down the shatshute.

fuel isnt wound right up as i cant stand the soot blowers and drive mine in town occasionally.
spoke to rad specialist and he has organised an aluminium 4 core ally rad to come up. we will fit it and put the car trailer on and tow it through town then up the biggest hill i can find. as to check both senarios.
the rad supplier gaurantees it will fix the prob, if so pay for rad if not send it back. thought that sounded like it is worth a try. costing nothing other than my time.
went to cruiser on fri nite as it was cooler and headed home sat arvo in the rain to keep it cool. cant drive a car like that everywhere.

will keep all posted.

[purplebus]

just remembered when i went to grab a coldy that the rad man was jibbering on about fins per inch or something technical like that. if it is down on fins it will effect the efficiency on the same percentage. eg down 10 percent on fins down 10 percent on cooling capability.

curiousity kicked in so i just though i would check my brand new rad against 1 i have out of a 2.8 diesel gq under the house. for starters exactly the same fittings eg hoses in/out ,bolt to rad supp etc. thought for sure they would be different.
grabbed the ruler to compare this fin thing the rad man was on about and he obviously knows his stuff. my new 3 core rad if you measure horizontally 4cms, it has 10 tops of the fins so to speak and measure 4cm down it has four rows. the 2.8 rad has the same 4 rows down but has an amazing 17 fin tops in the same 4cms horizontally.

QUESTION: WILL THIS NEAR DOUBLE FIN COUNT MAKE THE RAD NEARLY TWICE AS EFFICIENT.???
WHAT FIN COUNT DO OTHERS HAVE IN THEIR RADS.???
WILL BE TRYING THE NEW RAD AND THIS ONE AFTER IT IS CLEANED AS I OWN IT AND WILL KEEP IT AS A SPARE..

IMAGINE IF ALL THE OVERHEATING GQ'S WERE JUST A FIN COUNT ISSUE. I ACTUALLY SELL PARTS AND HAVE NEVER HEARD OF FIN COUNT BEFORE ONLY CORE NUMBERS............

ANYONE HEARD THIS BEFORE...................

[cmcd]

ANYONE HEARD THIS BEFORE...................

Snaffled from elsewhere:

Increasing the radiator fin count, or number of fins per inch, provides more surface area for the transfer of heat to the cooling air.

However, increasing the fin count increases the restriction of the radiator to cooling airflow. Lower cooling airflows result in lower heat transfer. In every installation there is an optimum combination of fin performance and core restriction that will produce maximum heat transfer.

Increasing the core restriction from this optimum point by increasing fin count will reduce the heat transfer performance of the radiator. On the other hand, if the original radiator has a very low fin count, increasing will improve heat transfer.

In general, for high performance applications, fin counts from 12 fins per inch to 16 fins per inch are optimum. Increasing the fin count above 16 fins per inch will almost always result in reduced heat transfer performance. Since, as we have seen, in a given installation under “steady-state” conditions the radiator must transfer the given heat load no matter what, the reduced heat transfer performance resulting from an excessively restrictive high fin count must be compensated for by increased coolant temperature, possibly to the point of overheating

[xenith]

Well well well was wondering when this thread would start. Well mine has had same overheating problem. Ok when driving normal. Push hard up hills or put something on the back and bang straight to hot. well after some years that’s right years of moding this and moding that I come to this well let me tell u a story last weekend i towed mates comp truck 3T car+ float 850 Kg & spares around 200Kg worth from Newcastle to land cruiser park for the XWC round one so that’s 200+850=1.05T+3T add my car 2.8T=6.85T u must be kidding u say it is the truth this is behind a truck that up until last week could not handle a box trailer on the back that’s serious weight so i took serious steps to fix my prob. on way up was night sitting on 90 to 100KMh 1/3 a gauge all good 1000+k's. on way back sat on 110 to 120 2/3 u say what did i change to fix the over heating prob new rad u say well not this week went 3 cor years ago no change . I know u say header tank well tried that one long time ago no good took it back off .Ahh u say must have remounted rad to suit body lift well did that one long time ago to and guess what no good. All that’s left is raise back of bonnet u say well I can say never tried that one but after last week end I can say try it good idea paul44b who was in the car on the way up and drove for awhile so can verify all this what u say . ok I will tell u what I did I thought it has come down to AIR FLOWso i had this old alloy bar out the back took my steel winch bar off fitted alloy bar. Went to the shed and got out the grinder cut middle of the grill out. off u say well look at it half of the area is blocked off with plastic. Then I cut out middle bar off the bull bar . then cut out top and front of RHS at the bottom and welded in a piece of alloy plate on an angle as a scoop then thought well that’s only going to push the air over the top of the bonnet. So I welded another piece at the top on an angle down into the rad .stepping back to admire my work. Lifted the bonnet and said all that work and the air can just go up between the bonnet and the rad support. Well I cut and folded a plate to blank that off.
took it for a run down the high way which at 120 KHm it would get to 3/4 a gauge and there it was 1/4 a gauge and unbelievable more oil perisher, less noise, cooler gear box tunnel all good so there u have it. It is not the fact that that the cooling system is no good and can’t cope it’s just the air goes around it (the rad I mean) not through it so as I type slow this has taken me longer than it did to fix those mods on the bull bar and the problem as well. Will post pic’s when I get a chance looks evil now to .

[GUJohnno]

I use some sheet metal to lower the radiator shroud to match the body lift and line up with the fan better. Dropped the temperatures by a 1/4 but can get up to 2/3rd's when pushing hard up a long up hill. I think a dyno tune will help that a bit more.

[full-boost]

got pics yet?

[xenith]

soon mate flat out sorry

[Yom]

No overheating here. Gets up to over 1/2 on the gauge on steep climbs but at the moment I'm having trouble getting it hot.

Unless its a really hot day it doesnt move from just above the cold line.

I'm assuming this is bad for it.

[purplebus]

my fancy rad will be arriving tomorrow to see if it will fix it. will keep all posted on the result. going to be a bit hard as it is cold and raining now.
apparently yom it is bad to run them cold as the bores can glaze up. not sure what that means but all the mechanics and forum members advise against it.
heres hoping.........

[Rogue Patrol]

As some of you may know, we had a scorcher here on the weekend and heading out to Rover on saturday lightly loaded my guage was a shade over half except for downhills.
I was a little concerned about it for a while but when it got no higher I settled in to normal driving mode.
It seemed to go a fair bit better at that temp than cooler.
Coming home Sunday it sat on 1/4 th whole way.
Ambient temp was about 5-10 deg cooler on Sunday and many more downhills.

I'm now thinking of installing a higher temp T'stat to keep it up there.

Opinions?

[Yom]

itsafordnotanissan has done that to his and I dont see a problem.

part of making these old diesels more emissions friendly is to make them run hotter. I know mine really purrs along when the temp gauge is at half (until the viscous fan kicks in :p).

has to be better for the engine as long as the oil can cope with it!


i wouldnt be suprised if nissan have some higher temperature thermostats available.

[paul44b]

Well well well was wondering when this thread would start. Well mine has had same overheating problem. Ok when driving normal. Push hard up hills or put something on the back and bang straight to hot. well after some years that’s right years of moding this and moding that I come to this well let me tell u a story last weekend i towed mates comp truck 3T car+ float 850 Kg & spares around 200Kg worth from Newcastle to land cruiser park for the XWC round one so that’s 200+850=1.05T+3T add my car 2.8T=6.85T u must be kidding u say it is the truth this is behind a truck that up until last week could not handle a box trailer on the back that’s serious weight so i took serious steps to fix my prob. on way up was night sitting on 90 to 100KMh 1/3 a gauge all good 1000+k's. on way back sat on 110 to 120 2/3 u say what did i change to fix the over heating prob new rad u say well not this week went 3 cor years ago no change . I know u say header tank well tried that one long time ago no good took it back off .Ahh u say must have remounted rad to suit body lift well did that one long time ago to and guess what no good. All that’s left is raise back of bonnet u say well I can say never tried that one but after last week end I can say try it good idea paul44b who was in the car on the way up and drove for awhile so can verify all this what u say . ok I will tell u what I did I thought it has come down to AIR FLOWso i had this old alloy bar out the back took my steel winch bar off fitted alloy bar. Went to the shed and got out the grinder cut middle of the grill out. off u say well look at it half of the area is blocked off with plastic. Then I cut out middle bar off the bull bar . then cut out top and front of RHS at the bottom and welded in a piece of alloy plate on an angle as a scoop then thought well that’s only going to push the air over the top of the bonnet. So I welded another piece at the top on an angle down into the rad .stepping back to admire my work. Lifted the bonnet and said all that work and the air can just go up between the bonnet and the rad support. Well I cut and folded a plate to blank that off.
took it for a run down the high way which at 120 KHm it would get to 3/4 a gauge and there it was 1/4 a gauge and unbelievable more oil perisher, less noise, cooler gear box tunnel all good so there u have it. It is not the fact that that the cooling system is no good and can’t cope it’s just the air goes around it (the rad I mean) not through it so as I type slow this has taken me longer than it did to fix those mods on the bull bar and the problem as well. Will post pic’s when I get a chance looks evil now to .

Yeah it worked well but fook it is ugly :lol:I say

[its aford not a nissan]

As some of you may know, we had a scorcher here on the weekend and heading out to Rover on saturday lightly loaded my guage was a shade over half except for downhills.
I was a little concerned about it for a while but when it got no higher I settled in to normal driving mode.
It seemed to go a fair bit better at that temp than cooler.
Coming home Sunday it sat on 1/4 th whole way.
Ambient temp was about 5-10 deg cooler on Sunday and many more downhills.

I'm now thinking of installing a higher temp T'stat to keep it up there.

Opinions?

as yom said i did this to mine by adjusting the thermostat so it doesnt open till around 90 or so deg , it now runs smoother and seems to have a bit more power , the fan doesnt cut in as often so saving power
and as i said before diesles like it hot and unless you are losing water/ coolant you dont have an overheating problem

[patrol man]

I was talking to a bloke today and he was telling me about water deflectors in the block that direct water around the cylinders this allows the coolant to follow the correct path through the block, if these have corroded, or perished then the coolant wound no be flowing correctly. this could be a cause of over heating in older diesels. ( pays to keep the coolant at the correct concentration!
food for thought.
Cheers Phill

[Yom]

as yom said i did this to mine by adjusting the thermostat so it doesnt open till around 90 or so deg , it now runs smoother and seems to have a bit more power , the fan doesnt cut in as often so saving power
and as i said before diesles like it hot and unless you are losing water/ coolant you dont have an overheating problem

How did you "adjust" your thermostat?

What would I be looking at to have your skills make mine run warmer? Slab of golds? Night with big gq? Reasonable cash incentive?

[Rogue Patrol]

As some of you may know, we had a scorcher here on the weekend and heading out to Rover on saturday lightly loaded my guage was a shade over half except for downhills.
I was a little concerned about it for a while but when it got no higher I settled in to normal driving mode.
It seemed to go a fair bit better at that temp than cooler.
Coming home Sunday it sat on 1/4 th whole way.
Ambient temp was about 5-10 deg cooler on Sunday and many more downhills.

I'm now thinking of installing a higher temp T'stat to keep it up there.

Opinions?

as yom said i did this to mine by adjusting the thermostat so it doesnt open till around 90 or so deg , it now runs smoother and seems to have a bit more power , the fan doesnt cut in as often so saving power
and as i said before diesles like it hot and unless you are losing water/ coolant you dont have an overheating problem

How do you adjust it?
Dropped in to R.E.P.C.O. th smornin, the hottest they have is 180 deg F which I think is about 80 deg C.

[purplebus]

does anyone know the nissan running temp for a 4.2 diesel in degrees??
or what do other run on with aftermarket temp guages??

[its aford not a nissan]

As some of you may know, we had a scorcher here on the weekend and heading out to Rover on saturday lightly loaded my guage was a shade over half except for downhills.
I was a little concerned about it for a while but when it got no higher I settled in to normal driving mode.
It seemed to go a fair bit better at that temp than cooler.
Coming home Sunday it sat on 1/4 th whole way.
Ambient temp was about 5-10 deg cooler on Sunday and many more downhills.

I'm now thinking of installing a higher temp T'stat to keep it up there.

Opinions?

as yom said i did this to mine by adjusting the thermostat so it doesnt open till around 90 or so deg , it now runs smoother and seems to have a bit more power , the fan doesnt cut in as often so saving power
and as i said before diesles like it hot and unless you are losing water/ coolant you dont have an overheating problem

How do you adjust it?
Dropped in to R.E.P.C.O. th smornin, the hottest they have is 180 deg F which I think is about 80 deg C.

with thermostats it isnt the spring that controls the temp but the pin in the middle on the other side , so where this pin sits is normally curved and is held in by two tags either side , what i did was to straiten the curves abit by squashing it and thus making it higher , i also took out that pin and shaved a little off the top

it is hard to explain witout pics but once you look at it you should understand

and yom if you just come around ill do it for ya

[Rogue Patrol]

with thermostats it isnt the spring that controls the temp but the pin in the middle on the other side , so where this pin sits is normally curved and is held in by two tags either side , what i did was to straiten the curves abit by squashing it and thus making it higher , i also took out that pin and shaved a little off the top

it is hard to explain witout pics but once you look at it you should understand

and yom if you just come around ill do it for ya

With one in my hand I might be able to work that out......

Where is 90deg on the factory guage? Is half guage about right?

[Yom]

and yom if you just come around ill do it for ya

Legend.

[its aford not a nissan]

with thermostats it isnt the spring that controls the temp but the pin in the middle on the other side , so where this pin sits is normally curved and is held in by two tags either side , what i did was to straiten the curves abit by squashing it and thus making it higher , i also took out that pin and shaved a little off the top

it is hard to explain witout pics but once you look at it you should understand

and yom if you just come around ill do it for ya

With one in my hand I might be able to work that out......

Where is 90deg on the factory guage? Is half guage about right?

nissan guages are pretty shitty and in reality 90 deg could be any where between 1/4 and hot they all vary , but mine sits about half way

[Rogue Patrol]

Might be time to get a good guage then as well.....