overheating

[mav]

hi, my '90 maverick has an overheating problem when i push it hard, so far i have replaced thermostat,clutch fan (hub & blades) had the radiator flushed and cleaned out the a/c condensor (bugs & straighten fins) the coolant is 40% glycol and had the injector pump & inectors overhauled and dynoed. it runs a safari snorkle with a finer filter and a ryco paper element as the secondary filter, it has a denco hdf296 fuel filter. any help would be great at the moment i am out of ideas.

mav :(

[wooders]

How about some extra vents in the bonnet to help get that hot air out??

[baby_troupe]

I was thinking to not drive it hard.
Other than that, has the radiator / cooling system been checked to ensure you are getting proper flow?
Even though the radiator was flushed, there still may be a restriction, so a flow test should show this.

[baby_troupe]

Sorry, should have added this b4, check oil.
It may be low or not providing enough "lubrication"
When was last oil change including all filters.

[mav]

Sorry, should have added this b4, check oil.
It may be low or not providing enough "lubrication"
When was last oil change including all filters.

the oil and filters were changed 2500kms ago and the level is fine how do you do a flow test

[mav]

How about some extra vents in the bonnet to help get that hot air out??

good idea, but it shouldbe able to keep cool (it doesn't even have a turbo on it yet) have you heard of other maverick/patrol owner having overheating problems with the 4.2 diesel

mav

[Tlux]

When it's idling, check the radiator for bubbles, if it is, then it could be a blown head gasket or cracked head. It will probably use coolant as well, because it will be pushing out as well as boiling it off. :(

[The Goodz]

I would say the radiator, because simply flushing it isn't enough. You'd be surprised how much crap can be in there, get it properly cleaned out where the pull the thing apart and shove rods through all the pipes, amongst other things.

Also check your fan belts as they may be slipping. How hard do you have to push it before it overheats? And how hot is overheating? Is the temperature just rising a bit or is it going way off into the red?

Alex

[baby_troupe]

how do you do a flow test


You will need to see a Radiator guy.
I had NATRAD do mine & was amazed how poorly it had been working.
Since my recore (straight after his diagnosis) my temp has been much more reasonable.

[mav]

When it's idling, check the radiator for bubbles, if it is, then it could be a blown head gasket or cracked head. It will probably use coolant as well, because it will be pushing out as well as boiling it off. :(

it doesnt blow bubbles in the radiator or use any coolant, which seems to rule out a blown head gasket i was going to use a head checker on it (a device that samples vapour off the top of the coolant in the radiator to tell if it has high CO2 levels.) but apparently they dont work to well on diesels.

mav

[mav]

I would say the radiator, because simply flushing it isn't enough. You'd be surprised how much crap can be in there, get it properly cleaned out where the pull the thing apart and shove rods through all the pipes, amongst other things.

Also check your fan belts as they may be slipping. How hard do you have to push it before it overheats? And how hot is overheating? Is the temperature just rising a bit or is it going way off into the red?

Alex


sorry i meant cleaned out when i said flushed, but i am considering getting it cleaned out again just to be sure. the fan belts are tight and dont squeal/slip when the clutch fan cuts in, pushing it hard is anywere from 3/4 to full throttle on steady uphill sections or towing trailers (usually 500kg up in weight) at 90kmh and faster. The temp climbs steadily into the red until i back off and cruise along at about 60kmh the auxilery temp gauge that i fitted will go to 115-120 deg celsius and has spiked higher.

mav

[Tlux]

Trade in time :-*

[bigbluemav]

Hi Mav

TD42's overheating problems have been discussed ad nauseum on the Patrol4WD yahoo group and some good ideas have been floated.

Most of those with problems have done as you have and checked/replaced all the obvious things. Some have gone to the expense of 4-5 core radiators, one good idea was to send the fan clutch to Berrima Diesel Services whop modify for less than $100. This idea was very popular and well reported to be very positive.

Also, don't take this the wrong way (I'm no diesel tech), but you have to drive it like a diesel. When you give it to much throttle under load, you'll notice HEAPS of black smoke come out the tail pipe. This is unburnt fuel, as you know. Diesels are different to petrols in that that if you enrichen fuel delivery in a petrol vehicle, it will (marginally) cool the vehicle.

In diesels too much fuel in the combustion chamber makes them run very hot, very fast. When you are towing something heavy and/or goping up a hill, ease off on the throttle when you feel the engine catch up with the throttle opening and keep it in its optimal torque range, which is approx. 2000rpm.

If there is anything technically incorrect with this post, please feel free to set me straight, as I'm only passing on what I have learnt in real life and forums such as these.

Regards

[wooders]

Hmm interesting points there bigblue - I'm not Diesel literate so would have never thought of that sort of thing...

One thing in my travels I've heard that a 4-5 core radiator can actually be more inhibative to the airflow (& thus cooling) than a quality 3 core.....Whats the Patrol/Mav stocker - 2 core?....

[mav]

thanks bigbluemav

I'll get on to berrima diesel to find out more about the clutch fan mods, the other day i was told to put extra silicon oil in the clutch hub and saw a vehicle that had it done it had a loud fan roar and ran really cold, i guess the extra oil had just made the clutch lock up all of the time.

mav

[BigDave]

heating problems are frustrating, as you cant see whats going on.

Just a question...are you actually losing water anywhere (visible or not)?

When reved hard a crappy lower radiator hose can suck in and restrict flow...causing overheating...$20 can solve that.

also, in a big old diesel cast iron block the liklihood of a cracked head isnt high, but you can check it easily by looking for milky oil in the sump.

Dave

[mav]

heating problems are frustrating, as you cant see whats going on.

Just a question...are you actually losing water anywhere (visible or not)?

When reved hard a crappy lower radiator hose can suck in and restrict flow...causing overheating...$20 can solve that.

also, in a big old diesel cast iron block the liklihood of a cracked head isnt high, but you can check it easily by looking for milky oil in the sump.

Dave


hi there big dave,
i haven't been losing any coolant and the lower radiator hose doesn't suck in (this is usally caused by a blocked radiator or not enough bypass flow in the cooling system (flow around the cooling system when the thermostat is closed)thats why not all cars come standard with the wire spring in the bottom hose. ;D

[aussietj]

Big Blue is right re the pedal to the metal on hills, having just bought a 92 GQ 4.2 diesel with turbo, I did a sort out run from Newcastle to Lithgow with a medium load, recovery gear etc............

the temp gague sat at the quarter mark for 90% of the trip on the h/way at 100 klm/per /h, but when I hit the Wollimi NP pass with about 5 klm of S bend road along the Bylong road fron sandy hollow to Rylstone the temp jumped to over half way,

It was then i realised I was driving it like the Wrangler, heaps of gas, I didn't pick the diesel slug thing cause the turbo was doing its thing..............

I was probly running 2600 to 2800 rpm in 4th (again a turbo thing) I then gave myself a big kink in the butt, dropped the revs to 2000, and slipped into 3rd, and pulled 2nd for the 25kph hair pins..........

within a couple of klm the temp dropped back to just under half, seeing I was still climbing that was reasonable...and the turbo was more responding better

as soon as the load was off the motor the temp dropped to normal as before.................

on the reverse trip I watched the rpm's and stayed at 2000 max and the tepm gague hardly moved...........

So what I learned was that diesels have great pulling power st low to medium revs and u will not get up the hill any faster is u flog them,

the economy for the trip was 26 mpg or 11.75 L/per 100klm

[mav]

the economy for the trip was 26 mpg or 11.75 L/per 100klm


gee thats not bad economy my non turbo 4.2 gets around 16 l/per 100 kms

ever thought about a king core ?? they make em in qld to my knowedge a friend of mine is a radiator specialist and says you may need a bigger core or to have a radiator mechanic place an outlet on tha other side of tha bottom tank and link the two togeather this allowing to make use of the radiator cooling ability the other he suggested with a few mods wat to some how make it a cross flow instead of up and down
if you want more info contact me
mike4kylie@optusnet.com.au the guy i knows had more than 30 years in the industry and has made many of hot cars run cold when others have failed