Roachie's overheating patrol

Trendy

When you say MTQ upgrade, do I make the the assumption that you have had an aftermarket DTS turbo fitted.

If so, did you have the pump removed and calibrated etc to match the turbo including the injectors when the turbo was fitted , or did the turbo fitter just adjust the fuel screw/control on the pump to 'suit/match' the new turbo.

G'day Trevor,
Well, what can I say..... I am still trying to solve my over-heating problem. On top of the tings you've mentioned, I've also cut a hole in the bonnet above the turbo and installed a Nissan scoop (don't waste your money doing that...). I've also fitted an 10" Davies Craig electric fan in front of the air con condensor (don't waste your money on that either....). As for the bigger radiator; great bit of kit, looks fantastic....but it hasn't killed the problem!!!!......

I've ordered a new thermostat (should be here tomorrow) and will try to check the old one when I pull it out to see if it still opens up as far as it should, by immersing it into a sauspan of boiling water and seeing how far it opens. I'm not sure if I'll attack the new one with a 1/8" drill bit like was recently suggested....might leave that til I see if the new one has any effect in standard form.

I'm also in the process of installing 3 more gauges from VDO.... coolant temp (I'm gunna try to get a fitting that I can stick in the middle of the top radiator hose; it shows as being available in the installation instructions, but I haven't seen it in the VDO catalogue......that would save me having to get another special adaptor machined up so the 1/8" NPBT sender unit can be used (as the Nissan has 1/8" BSPT threads......0ne is 27 tpi, the other is 28 tpi !!!!!).
The 2nd gauge is an oil temp gauge, the sender for which I plan to fit where I have the oil pressure gauge sender already mounted, down on the block behind the air conditioner compressor.
The 3rd is a Boost gauge.
I have just got all the gauges today and have installed them on the dash, but haven't hooked anything up as yet.
Pesty, (mate of mine even though he does drive a toyota,,,hahahaha) reckons I should also be getting the timing re-checked. He maintains that if the timing is slightly too far advanced, it could be causing overheating....but I would have thought that might also reflect in the Exhaust Gas Temps......I have a digital gauge for measuring these already, and they seem to be well within the acceptable standards, even when the Nissan' coolant temp gauge is approaching the "H". That's why I wanted to install a decent coolant gauge as I have no way of knowing whether the beast is REALLY getting too hot, or is it just a whacky gauge???? Time will tell.
Rest assured mate, as soon as anything worth reporting is worked out, I'll be posting on here. What I am really hoping is that when I see the Nissan's gauge going into the "H" area, the VDO gauge will be showing only a very small increase in temp.
The other thing I will be doing is installing another bottom radiator hose. I have asked around to see if anyone knows about the stainless steel coil spring wire that I thought was readily available (but isn't!!!!). Another alternative might be to either cut out the centre section of the lower hose and replace it with a length of stainless steel pipe and just have the right angle ribber elbows top and bottom, OR replace the bottom hose with a length of that concertina-type hose (which I thinks has re-inforcing wire moulded into it), like they seem to use on the Chev 6.5 litre V8 conversions).
So there you have it....still a lot of things to check on and try.
Cheers mate
Roachie

hi trendy, no idea about overheating pootrols as i own a LANDCRUISER, but have noticed in the 4x4 trader mag an ad about a triple flow radiator, not to be confused with a triple core radiator, so maybe talking to these boys might be a solution. cant give you the contact details as SWMBO said to clean out my library. hope this helps you, roachie and anyelse in this predicament. regards bob h

Trendy,

Sounds like you have tried just about everthing, but you have not said what coolant you are using. Is it genuine Nissan stuff and is it mixed to the right mix?

The gauge could also be out a bit, a massed produced item may be showing hotter than normal. Like Roachie, a aftermarket gauge might be the answer.

Good luck with the project,

Wayne

Trendy and others, The triple flow radiators are not a good product in my opinion, replaced the radiator in my 2.8TD GQ with one and when the motor $hit it self about 6 months later, the radiator was already corroding??? Also re MTQ turbo mods, have had this mod done to my GU and comparing EGTs with a mates modded GU much much lower and I don't have an overheating problem, been full throttle in 40c temps and no problems. Just my two cents worth. MTQ mods and 3" exhaust have taken kw from 72 to 120 at rear wheels.

I was going to ask if " how sure are you that it is overheating"....but it looks as if your gunna check this out ...

can the pump circulate the required amount of coolant to radiator.
A pump that does give sufficient circulation will allow overheating to happen within the block. (The radiator would/could shows symptons of "general" overheating when the engine stops.)

I would really check temps acurately first though.

Ok guys can I ask when the oveheating shows up?

My4.2 GU also overheats but only when towing and climbing on hot days under big throttle openings. I can generally control it by slowing down a little selecting a loweer gear and lifting the right foot slightly. THe engine revs a bit higher but with a light throttle the temp doesn't climb. This suggests to me that it is a fuel thing. That was definately the prblem when my turbo GQ was overheating. I checked everything on that, even rebuilt the head. A good fuel system service fixed the prob and delivered much improved performance too. The same service also fixed a mates 80 series cruiser with overheating probs.

All the fixes you are talking about sound very expensive, especially if they are not working. The fuel system service seems relatively simple, needs to be done sometime anyway and for me at least, it worked.

The hard part is finding a good fuel system service.

Duncs

G'day Trevor

Could you please send your email addy to Me at

krobbo@optusnet.com.au

Ken Robinson

You can have too much coolant in the system, coolant itself doesn't conduct heat as well as straight water.
There is a product from Redline called Water Wetter which claims to decrease coolant temps by up to 20 degrees.
While I don't have a cooling problem with my truck I have put some in and did notice slightly lower temps and decreased cooling fan cycling.
There are two water wetters, one for diesel (dark grey colour) and one for petrol, (bright red/pink colour)
I've aslo had the problem mentioned about the coolant flowing too quickly on a previous vehicle.
As has been mentioned overfuelling can and will cause heat problems, a lack of black smoke isn't necessarily a sign that all is good.

Hi all
You have covered all the major possibility’s so just a few simple things

Electric water pump is a good idea as if you have fitted a larger radiator the standard pump will have trouble pushing all that extra water around. Also the coolant you are using is it premix? If it is don’t that stuff is s*ht.
Does the Techtalloy 90+ meet Nissan’s cooling system protection standards?

When you mix the coolant make it 30 to 40% coolant and the rest-distilled water anything over 50% coolant and it will overheat on a hot day.

Thanx for everyone's ideas and I will post the solution here when and if I solve this problem

Just a thought do you have a Glind shower under the bonnet connected up incorrectly and cooling water recirculating thru the engine and the radiator

Greenant

sorry should be not the radiator