Outer Limits 4x4 Board

hi - i hope someone can help me - i have a 4.2 deisel, a GQ 88, 230k on the clock, oils are done ever 5000kl. Over the last 3-4 months I've been trying to cool the motor back down cause if i sit on 100 km the temp sits on about 1/2, when it used to sit on about 1/4. When it starts to do some work, in sand mud rocks, it gets really hot - fast ! So what I've done is replaced the water pump, new thermistat, new fan (the right one for the motor), pulled out radiator and back flushed it (looks clean), hosed out the fins of the radiator, also added two thermo fans to help the air blow thru the airconditioner condenser - still same problem - now I'm about to replace the silicon in the fan clutch mechanism (whatever it's called), but it all looks ok - see pic attached. If someone can tell me if the pics look normal or if I need to replace the oil in fan clutch mechanism ? Or is there anything else someone can think of as to why it's getting too hot ? cheers

Hot is over 3/4 on gauge.

Ensure no crap in rad fine. REMOVE to clean.

Bazzle

hmmmm whats is the rad fine and where would i find it on the motor ???

bazzle wrote:Hot is over 3/4 on gauge.

Ensure no crap in rad fine. REMOVE to clean.

Bazzle

FINS Saw you already tried that ..

Top silicone up to top edges of holes.
Dont get that fluid within a MILE of anything you want to paint.

Bazzle

so that silicone is a little low ? where is the cheaps place to get the silicone from ? As nissan part here is like going to the ZOO

bazzle wrote:FINS Saw you already tried that ..

Top silicone up to top edges of holes.
Dont get that fluid within a MILE of anything you want to paint.

Bazzle

Grt thr stuff that toyota sell is good and cheap, should cost less than $20.
I have to do the same to mine this week

does anyone have the part number for this silicone stuff for the viscous hub? i did search, but couldnt find it,

help greatly appreciated.

http://www.off-road.com/~estegall/tech/ ... lutch.html

Bazzle

bazzle wrote:http://www.off-road.com/~estegall/tech/fanclutch/fanclutch.html

Bazzle

thanks for that Bazzle, now i have the part number, im off to the shops, (when they open)

thanks skippy

skippy's GQ wrote:Grt thr stuff that toyota sell is good and cheap, should cost less than $20.
I have to do the same to mine this week

cool thanks

bazzle wrote:http://www.off-road.com/~estegall/tech/fanclutch/fanclutch.html

Bazzle

The clutch hub should be higher up the list of things to service.
Sometimes the radiator needs to come out and have the tanks removed to "rod out" the core, particularly with high kms, no inhibitor, poor water quality.
Next, if all else fails, can be the head gasket.
J Top

thanks mate - serviced the fan clutch today, not sure how much silicon to put in but got rid of the old stuff & filled the holes to level. Rodded out the radiator today - they told me it only had a 80% flow rate. So we'll see what the go is when all back together & on the road. (which is 10minutes as its a nissan

J Top wrote:The clutch hub should be higher up the list of things to service.
Sometimes the radiator needs to come out and have the tanks removed to "rod out" the core, particularly with high kms, no inhibitor, poor water quality.
Next, if all else fails, can be the head gasket.
J Top

ok guys - really getting into trouble now - it's now boiling !


this is what I've done:

flushed radiator & engine - was at 80% flow rate, now at 100%
replaced thermistat - twice - one standard, one high flow
replaced all radiator heater hoses
replaced water pump
repacked silicon in fan clutch
replaced fan
replaced fan belts
installed 2 new thermo fans
taken back fuel pump to be retimed & calibrated - it was 1mm out
removed bull bar, removed spot lights to increase air flow

what the f**k is going on with this piece of shit - I though Nissans were good ??

have u had an exhaust gas test done on ur radiator?

get some one to rev ur engine up and watch ur hoses
make sure they arn't getting sucked shut... think its the bottom one that does it

if that fails .. suggest u get a pro to look at it

dude no i have not had the exhaust gas test done how do you go about it so i can get it done and what do i ask for, and what do i look for ???

as for the hoses closeing up i put new hoses on and i did do a test to see if they where closeing up and all good

Hoonz wrote:have u had an exhaust gas test done on ur radiator?

get some one to rev ur engine up and watch ur hoses
make sure they arn't getting sucked shut... think its the bottom one that does it

if that fails .. suggest u get a pro to look at it

just a CO2 test on the radiator fluids ... see if ur head gasket maybe leaking

H@MMeR wrote:dude no i have not had the exhaust gas test done how do you go about it so i can get it done and what do i ask for, and what do i look for ???

Your local mechanic is ya friend here......

CO2 test on the radiator means they stick a clear tube about 6" long into the spot where ya radiator cap lives, this tube has some liquid in it that reacts with any CO2 and changes color to signify its presence..... in laymans terms it "tastes the coolant for exhaust gas presence"

A positave result in a CO2 test shows that the head is cracked or the head gasket is leaking and allowing exhaust gases to pass from the cylinder into the water jacket sorounding the cylinder head either via the head gasket or a crack in the head.

A blown head gasket or a cracked head WILL cause overheating, it will also show up in the coolant level as the collant is forced out and replaced with exhaust gas, obviously exhaust gas doesnt cool that well !!!

No mention anywhere in your posts of a low coolant level once its overheated ?????

Suggest you run it till it becomes near hot then shut down before it boils..... allow it to cool and then check collant level in radiator, you will need to disconect the "overflow bottle" prior for an accurate test.
If the collant level is low then its head time !

There are CO2 test kits for sale at some auto shops for the DIY guy, but best to get it tested by a mechanic with the right knowlege and gear.

Also you mentioned that you had done a power flush on the radiator..... did you also do one on the engine aswell ???
An 80% flow on the radiator means a lower percentage for the actual engine.

Kingy

thanks V8Patrol ( kingy) i'm now starting to think it is the head aswell :(
i'm just a little pissed at that i have work on the head as i dont know any of the setting with TD42 :(

but will do test abd let you know

V8Patrol wrote:

H@MMeR wrote:dude no i have not had the exhaust gas test done how do you go about it so i can get it done and what do i ask for, and what do i look for ???

Your local mechanic is ya friend here......

CO2 test on the radiator means they stick a clear tube about 6" long into the spot where ya radiator cap lives, this tube has some liquid in it that reacts with any CO2 and changes color to signify its presence..... in laymans terms it "tastes the coolant for exhaust gas presence"

A positave result in a CO2 test shows that the head is cracked or the head gasket is leaking and allowing exhaust gases to pass from the cylinder into the water jacket sorounding the cylinder head either via the head gasket or a crack in the head.

A blown head gasket or a cracked head WILL cause overheating, it will also show up in the coolant level as the collant is forced out and replaced with exhaust gas, obviously exhaust gas doesnt cool that well !!!

No mention anywhere in your posts of a low coolant level once its overheated ?????

Suggest you run it till it becomes near hot then shut down before it boils..... allow it to cool and then check collant level in radiator, you will need to disconect the "overflow bottle" prior for an accurate test.
If the collant level is low then its head time !

There are CO2 test kits for sale at some auto shops for the DIY guy, but best to get it tested by a mechanic with the right knowlege and gear.

Also you mentioned that you had done a power flush on the radiator..... did you also do one on the engine aswell ???
An 80% flow on the radiator means a lower percentage for the actual engine.

Kingy

you will find, if its the head leaking gasses into the coolant, there should be conitinous bubbles when you have the radiator cap off

yer i seen it befor , but it is not with this my motor i wish it was then i would know just just pull of the head off :((

thanks anyway any more suggestings
would be good !!!
Michael

ozy1 wrote:you will find, if its the head leaking gasses into the coolant, there should be conitinous bubbles when you have the radiator cap off

As Bazzle said, 1/2 on the guage is not hot. Scribed mark on the injection pump should line up with the corresponding mark on the injection pump mounting surface to initially set pump timing. After that, it can be set more accuratly if req with a dial guage for correct amount of plunger lift at TDC. Check pump is not over fueling and tappet clearances are set properly. Injectors may need checking also.What grade oil are you using?

When refilling radiator, fill slowly to allow system to bleed as the bleed hole in the thermostat is very small. Also another thing to check is that there is no corrosion inside the water passages in the front aluminium timing cover which could produce bubbles causing pump caviation. There are a few hidden spots where the aluminium and steel meet causing white rust. I noticed this during my TD42 rebuild last year--caught it just in time. Make sure grounding strap from thermostat housing to body is in position. Make sure radiator shroud is sealing to radiator securly

Nick

I assume you did the flushing yourself. Honestly take it to a radiator place and get them to have a look at it before pulling heads etc off. Mine did the same thing. I back flushed it etc, looked good, but still hot, ie on the highway towing around 3/4. In the end I said F@#K it, pulled it out, had the tanks pulled off and BAM, there was a blockage in the core. New core and it now sits on 1/4 towing and lucky to get to half, maybe just under when up a big hill on a hot hot day. I'd be getting a radiator mob to get into first. Once you pull the head you may find more that needs doing. Radiator first THEN look at other things IMO

heheh dude i did it my self at fist after i did all the list above i pull it out agian and got them to flush out the radiator they pulled the top tank off and flushing all the cores out it helped a little only a little tho :(
the only thing i have not really done get them to flush out the motor and i dont know even if they do that
re your temp. that whats what was doing about 4 month ago

thanks for your help

Red Rover wrote:I assume you did the flushing yourself. Honestly take it to a radiator place and get them to have a look at it before pulling heads etc off. Mine did the same thing. I back flushed it etc, looked good, but still hot, ie on the highway towing around 3/4. In the end I said F@#K it, pulled it out, had the tanks pulled off and BAM, there was a blockage in the core. New core and it now sits on 1/4 towing and lucky to get to half, maybe just under when up a big hill on a hot hot day. I'd be getting a radiator mob to get into first. Once you pull the head you may find more that needs doing. Radiator first THEN look at other things IMO

hey Injectors checking i have not done them as there no smoke really only when working
- oil ever 4-5 k caltex Delo 400 SAE 15-40
- tappet spacing can you give the size of the spacing and i will have look
- timeing of the fuel pump is right as a pro did it but i have not look my self

Woop wrote:As Bazzle said, 1/2 on the guage is not hot. Scribed mark on the injection pump should line up with the corresponding mark on the injection pump mounting surface to initially set pump timing. After that, it can be set more accuratly if req with a dial guage for correct amount of plunger lift at TDC. Check pump is not over fueling and tappet clearances are set properly. Injectors may need checking also.What grade oil are you using?

When refilling radiator, fill slowly to allow system to bleed as the bleed hole in the thermostat is very small. Also another thing to check is that there is no corrosion inside the water passages in the front aluminium timing cover which could produce bubbles causing pump caviation. There are a few hidden spots where the aluminium and steel meet causing white rust. I noticed this during my TD42 rebuild last year--caught it just in time. Make sure grounding strap from thermostat housing to body is in position. Make sure radiator shroud is sealing to radiator securly

Nick

I tell you what else is worth checking, a compression test. When they are down on compression they run hotter. Do that before pulling the head off. I could suggest a three core, but if it didn't do it before hand it won't be the right solution. Has it started burning oil. If you cook a diesel it normally F@#ks the rings and therefore you can and most likely lose compression in turn running hotter. If you haven't touched the timing it won't be that. My MK started to run hotter and hotter. It then a ticking noise so I pulled it out and had it rebuilt. Ran cool after that. But get the compression test done first before pulling it apart, as a suggestion.

Cheers

here in the tropics backwashing is not enough most of the time. in cases that the water starts to boil. this means that the radiator is not able to cool enough water. and backwashing may not be enough. you might want to do a complete overhaul of your radiator. in other words the radiator shop will take off the top and bottom of you radiator exposing the ends of the radiator tubs and unclog the tubes manually. cuz once the tube is completely cloged. no chemical can unclog them.

it also happend to me that my cylinder gasket needed to be replaced. a simple test is take off the radiator cap before your first start in the morning. make sure radiator is filled up. then start the engine. if you notice water spewing out. that means there is a leak from the gasket or cylinder head. but if your not loosing water. i'm 90% sure a lot of the tubes in your radiator are just cloged up.

mate thanks for that i got the radiator shop to overhaul the radiator and 2 of the tubes was a little blocked and i am losing some water and i'm getting a CO test done soon as i can. Now starting to think the cylinder gasket is stuffed or i have a cracked head

when you did your was the head ok after ??
was the cooling all fixed ???

Mintoy wrote:here in the tropics backwashing is not enough most of the time. in cases that the water starts to boil. this means that the radiator is not able to cool enough water. and backwashing may not be enough. you might want to do a complete overhaul of your radiator. in other words the radiator shop will take off the top and bottom of you radiator exposing the ends of the radiator tubs and unclog the tubes manually. cuz once the tube is completely cloged. no chemical can unclog them.

it also happend to me that my cylinder gasket needed to be replaced. a simple test is take off the radiator cap before your first start in the morning. make sure radiator is filled up. then start the engine. if you notice water spewing out. that means there is a leak from the gasket or cylinder head. but if your not loosing water. i'm 90% sure a lot of the tubes in your radiator are just cloged up.

Tappets 0.35mm. Timing mark is difficult to see from above--i use a mirror to get timing mark right on.

Nick

mate thanks for that
Michael

Woop wrote:Tappets 0.35mm. Timing mark is difficult to see from above--i use a mirror to get timing mark right on.

Nick