R34 Overheating - Help Please

[nuffsaid]

not losing water

new thermo

recent flush

changed water pump

Hi all

It was about 30 degrees today in Sydney, and I was driving up the M5 motorway and found that my oil temp was slowly hitting 110 degrees.

My car only has a full exhaust and larger SMIC and a boost controller but i dont think those had any effect. Water temp was only halfway on the indicator.

I was driving normally, no boost or anything, just cruising along. It finally hit 110 degrees, I wasnt too concerned, but then I got stuck in traffic (about 15 minutes moving very very slowly). During this time, the oil temp was moving slightly over 110 degrees, and then my water temp started to move past the halfway point, not good!

When the traffic cleared and I was driving through suburbia, the oil temp came back down to around 105-110 degrees, and water temp back to halfway.

Overall, I still feel that the oil temp was high.

I have recent flushed and bled the cooling system myself, replaced the thermostat + water pump with a genuine R34 items (less than 6 months or 5000kms ago)

I find that the oil temp climbs higher than it did when I first bough the car (it never seemed to go over 95-100 degrees) in daily driving. So perhaps I have an issue?

Does anyone know what it could be or how I can TEST for the issue?

- clutch fan?

- blocked radiator?

Thanks all!

[nuffsaid]

I should probably add, when turning off the engine when warm, the fan continues to spin for another 4-5 seconds before it comes to a stop.

I am not losing any coolant either, and now that I think about it, i probably just changed the coolant instead of properly flushing it

I am thinking it is not so much the clutch fan, because I should not be reaching 110 deg oil temp on the motorway with normal cruisy driving right?

Edited September 13, 2009 by nuffsaid

[Moodles2]

Oil temp should be about 85c, I have to go to the track to get it over 100c. A consult cable (I highly recommend one, as you can turn the fan on/off with free consult software) would be handy to check what the ECU reported water temperature is (or even one of those ECUTalk Consult LCDs), even on my R32 the temperature gauge is very vague and can't really be trusted when Ive got my Consult LCD to tell me what the temp really is.

[dori34]

clean and/or replace radiator.

try that

[GTRNUR]

Are you sure youve been bleeding out all the air from the coolant system properly? Even without coolant it should be sitting on 85 degrees when cruising.

Check your service manual on locating the air bleeds on your engine and bleed it thouraghly. You should be using distilled water to, not tap water. Once you get the temps under control drain a little coolant from the top hose, tip in some redline water wetter coolant concentrate and top up.

Your thermo fan has no effect above about 80km/h when cruising, so it wont be that. Your car is new enough that i doubt its a radiator blockage too.

[nuffsaid]

Hmmm car is about 11 years old now, I would not be surprised if the radiator is blocked.

Any chance it could be the thermostat? doubt it as I would see overheating or overcooling issues ALL the time if it waas right?

Edited September 13, 2009 by nuffsaid

[Wacky Dee]

Mate I've been through this recently myself ..'98 R34 GTT.

Changed the thermostat, no change. Flushed coolant, bled everything, no change. Finally got fed up with temps getting up to 100C regardless of driving in traffic or highway so I dished out $340 for a new radiator.

Now she sits at 86c cruising and about 87c in traffic.

The factory radiator fins were all clogged with crap so I'd estimate only about 50% efficiency was all I was getting.

If money's tight or you would like to keep the stock radiator, just take it out and hose out the crap out of the fins so that air can flow through it. Your radiator may also be blocked internally if you or previous owner used tap water and to get it cleaned professionally and top tank replaced is only about $150. I opted for a new 40mm aluminium radiator and couldn't be happier. $340 for a 40mm and I'll betcha she'll drop atleast 25c or so to around 85-86 like mine did.

I'd bought a bottle of that 'watter wetter' Redline crap as well but haven't yet chucked it in. There's just not enough proof that this stuff actually does anything positive. Yes, it may make the water/coolant appear cooler but that could be due to the fact that its reducing contact (and hence cooling) with all the hot engine internals - which is opposite of what they claim it does. I'm yet to see PROOF that engine internals are actually cooler due to this additive and not just the coolant. Plus I read in at least a handful of places of people noticing it leaving some sort of sludge in the cooling system as it breaks down.

Oh and in regards to fan spinning ... yeah mine looked a bit sus too although mechanic said it was fine, I thought f**k it ..might as well and changed the fan clutch as well just to be on the safe side (only $210 brand new).

PS. R34 thermostats only starts to open at 82C so 85-87 is quite normal and optimal for the NEO engines. The older 25s thermostats opens at 76.5 so people might think even 86-87 is too hot but its not. NEO likes a touch more heat in it

[Wacky Dee]

Oh and another thing .. if I were you, I'd make this a priority. 110C is NOT anywhere near healthy. Couple more degrees and you'll boil the coolant (and it will evaporate quickly) and you'll end up with a blown engine. Mine only reached 100C and I was getting nervous already ..

Justjap have those 40mm aluminium radiators in stock if you decide to go down that path .. tell 'em Denis with the black 34 sent ya ;D

[nuffsaid]

do you really need a brand new larger radiator?

or would a professional clean to clear out the internal clogging be sufficient?

[Wacky Dee]

The factory radiator will do the job if its not blocked and the cooling fins are not blocked or bent ... I couldn't justify paying $150 to clean my 11yo radiator plus I couldn't be stuffed trying to straighten out the 5% or so of bent fins. It's a pain in the ass to do as they're so brittle and you have to do 1 by one slowly..Plus I like shiny new things

If money's tight ..get the factory radiator cleaned out. If it's blocked the top tank will probably need to be replaced which is about $40 ..but all up it shouldn't be more than $150. Thing is, for $200 more you can get a thicker radiator that is guaranteed to not be blocked, have all nice straight fins, 3 cores instead of 1 and it just cools better..

[nuffsaid]

So is it fair to say it is looking more like a blocked radiator than anything else?

And is there any downside to fitting a larger radiator (other than cost) i.e. longer warm up times, car running rich as it thinks its cooler etc etc (i am just brainstorming here and am probably wrong anyways)

Thanks dudes

[Wacky Dee]

yes most likely a blocked radiator or your cooling fins are so dirty/blocked that air can't get through it in sufficient quantity..or the fins are bent or a combination of all of those. In other words, its an old radiator that's taken a beating and had a gazillion bugs and road dirt thrown at it....refurbishing it can take time and money and it might still not work anywhere as good as it did when it came out of the factory.

Larger radiator will just cool the water more quickly once the thermostat starts opening ie. once water reaches X degrees (82 for NEO and 76 for other RBs). Bigger rad will cool the coolant better too ie. to lower temps, so your water intake will be colder (not cold, just colder than a smaller radiator) which is good for your engine internals.

And no, it won't affect your warm up times at all..that's why the thermostat is there, it's shut until the water reaches certain temps and only then fresh new (colder) water from the radiator is pumped through the engine..

[Wacky Dee]

I should add I'm no engine or cooling expert ..this is just all the stuff I've learnt over the past month or so, so take it with a grain of salt if you will but I'm sure most peeps would agree with all of the above.

[R34Liner]

PM sent buddy

[EJD001]

Aron where did u get your radiator looked at/ fixed up??

[R34Liner]

MRC in Castle Hill $250 buks, i didn't buy a new radiator for my own reasons...but as long as your car is Manual you should just get a new alloy radiator from Just Jap for 350 or wtvr is =]

[blind_elk]

What's the actual problem? The first post was talking about OIL temps over 100, but all the replies are related to WATER temps. These are 2 totally different systems. Which one is the problem?

A new radiator won't have any effect on water warmup times or "engine too cool" as long as the thermostat is working correctly.

[nuffsaid]

Both.

Oil temps rising to 110 and a tiny bit over, followed by water temp going past the half way point

I assume that there is just a cooling issue altogether causing the rise in both

[nuffsaid]

I dont know what my water temps are as i dont have a gauge for it

I think Denis was talking water temps

[Ultimategtr]

After reading through all replies, theres no mention of the grade of oil being used, or when it was last changed??

What oil are you using? and when was it changed last(inc the filter)?