GTT running hot...

[NismoR34]

Hi folks I will try to keep it short. I have noticed my Oil Temp running really hot this summer and the radiator coolant / engine temp has also gotten up to dangerous levels on a couple of occasions.

Today for example, it was approx 33 degrees outside and a bit humid, I cruised on a 30 minute journey and by the end of it the Oil Temp gauge was up to about 112 degrees factory gauge, Engine Temp rose minimally above normal - factory gauge has no numbers, a mm or 2 above normal range, about midway.

After the car cooled off for at least 30 minutes the Oil temp was back to approx 90 degrees when I started it up for the return journey home. Oil Temp got back up to 110 without much fuss and after running the A/C [set to 18 degrees] for 2-3 minutes the Oil went up further to nearly 115 and the Engine Temp shot up to around 2/3 or 3/4of the gauge - not quite overheating but getting into the worry zone! I wasn't driving hard either.

Oil is Motul 4100 Turbolight 10w40 and was put in 1000 kms ago - and the correct amount is in there.

1 Week ago I flushed the radiator and put in Nulon AntiFreeze/AntiBoil at approx 50% mixture...

The previous coolant 'Tectaloy' stuff actually boiled over [a few weeks ago] to the point where a litre or 2 was spat out of the overflow reservoir. At the time I had the standard radiator cap on but have since put my nismo 1.3 bar one back on as I believe this raises the boiling point of the coolant.

Any ideas on why its overheating so easily on a warm day?

I don't recall the Oil Temp getting up to 110 last summer or the summer before that, and up until a couple of months ago the Engine Temp gauge had NEVER gone past the half-way mark!

Last summer I was possibly runnning a different Brand Oil but it was the same 10w40 rating anyway...

I don't have a FMIC on the car, boost is around the stock level, is it maybe the thermostat? I may just replace this anyway and see. What about the water pump? Wouldn't this be leaking if it was stuffed? My heater & aircon work fine and so does the thermo fan!

According to the Nulon bottle of coolant I should have protection up to 127 degrees or more but wtf is up with the Oil Temp and what can I do? I would like to use my car AND the aircon in summer

Thanks for taking the time to read it! Let me know if I have left anything out

Cheers

Dale

[blacky]

Hmmmmm strange that both fluids (oil and coolant) are overheating at the same time. Can someone clarify if R34's have combined coolant/oil radiators. If they do, which i think they probably dont, then the radiator could be to blame.. but i dont know enough about 34 coolings systems to be able to say much. Sorry mate!!

someone will help you out. Come on fellas!

[gtst25]

Thermostat, waterpump, cracked cylinder head - did you bleed the system????

Very strange for such a new skyline to have such problems.

Have you noticed in the morning before you drive any white stuff in the oil when you take off the rocker cover screw?

Any brown colour in the coolant?

I've never heard of any skylines under normal circumstances crack a cylinder head, or blown head gasket, but coolant shooting out of the overflow bottle could be that, or it's just getting bloody hot.

If you have any doubts take it to a cooling specialist as it shouldn't be boiling - I wouldn't drive it in that condition.

Good luck.

[aKTiVE]

yeah damn.. !

i would hope its not a cracked head / head gasket - but thats the general direction i would be looking.

[NismoR34]

Thanks for the advice so far

I did bleed the system after flushing the radiator - for the first drive after new coolant the Revs were up & down like a yo-yo, not sure why but a look at the R33 Service Manual says to do what it was pretty much doing on its own:

Section 11. Coolant

Paragraph 9. After checking the thermostat injection valve, race the engine 2 to 3 times with 10 seconds interval between each @ 2500 rpm.

Coolant and Oil are separate systems on the 34 also.

I am thinking of replacing the Thermostat as it could still be the original one in there for all I know...

Never noticed any white stuff in the oil - oil looks fine.

There was some brown when I flushed out the old stuff last week, haven't seen any since though.

Btw. most of the year the Oil temp sits between 88 and 92 degrees for normal everday type driving. Driven hard it occasionally gets up to between 95-100 but very rarely in the 2 years I have owned it have I seen above 110! And likewise with the Engine temp for over 2 years it has pretty much sat just under the half-way mark, only recently has it gone to 3/4 only a couple of hot days...

Thermostat, waterpump, cracked cylinder head - did you bleed the system????

Very strange for such a new skyline to have such problems.

Have you noticed in the morning before you drive any white stuff in the oil when you take off the rocker cover screw?

Any brown colour in the coolant?

I've never heard of any skylines under normal circumstances crack a cylinder head, or blown head gasket, but coolant shooting out of the overflow bottle could be that, or it's just getting bloody hot.

If you have any doubts take it to a cooling specialist as it shouldn't be boiling - I wouldn't drive it in that condition.

Good luck.

[wrxhoon]

It sounds like you have a cooling problem . Check to make sure there is no air in the system , thermostat to make sure it opens (take it out and put it in hot water it should open 80-85 C degrees ) . when you first start the engine in the morning ( cold engine only or you will burn yourself ) , take the radiator cap off then rev the engine say 3-4000 rpm and see if the coolant shoots up , if it does then you may have a blown head gasket and or cracked head . look for milk like stuff on the oil cap after you been running the engine for say 20 or so minutes and look for oil in the radiator ( never take the rad cap off in the engine is HOT or even warm ) . If you find any milk in the oil or oil in the coolant =bad news .

The reason the oil is hot is because the coolant is hot . coolant ciculates to cool the engine , in your case it doesn't do that so the oil is just as hot as the coolant , as it would normaly after you drive for a while .

[IanH]

The R34 Radiator is rubbish, it's only 1cm thick with very narrow channels at the top. I changed mine (well I got a new core fitted) to a Modified GTR core which is 1inch thick (20fins/inch instead of the standard 8fins/inch) and mine never goes above 94'c on the PFC commander (with 240rwkw). Alothough bleeding the new radiator was a bitch, got coolant everywhere

[666DAN]

Definately a worry...generally the temp should sit so you can just see the little screw above the needle. Only once has my engine temp ever got to the top of the gauge, that was due to stop start traffic for 30 mins...with a road temp of around 55C

Seeing that both fulids are heating up may be related to 2 things...either a bearing is starting to go...more friction heating the oil up. Or the fact the coolant system isn't working to capacity, the heat from the oil isn't leaving the engine as quickly.

Sounds like it may actually be as simple as the thermostat though...similar symptoms to my old corolla.

[RB30-POWER]

Very rare for a genuine thermostat to fail.

I reckon something else is the problem, especially if has boiled before. My guess is the head or gasket.

Also 50% antifreeze seems way to much to me, is that what the recommended ratio is?

I would have though 33% in our climate, doesn't freeze here, and adding to much can have a negative effect on cooling efficiency.

[3R1K]

change oil

[NismoR34]

I believe the Thermostat is working because the return hose to the Radiator gets warm which means the Thermostat is opening to let it back through. Whether it is working at the correct temperature or not I will need to test - by removing it. Went to Nissan today but none in stock, will test mine and order one if its stuffed.

BTW The Oil [on a hot day] gets warm well before the Coolant heats up. In fact most of the time its just the Oil that gets up to higher than normal.

Today driving the car around in 20 degree weather the Oil was fine, it never got above 92... the coolant stayed under halfway!

While I was at Nissan I checked their coolant bottle which recommended a 30-50% mix but no higher than 50. I was under the impression that adding a higher mix provides greater protection in both extremes: Hot & Cold weather, hence I did 50%.

Perhaps their is still Air in the cooling system? What is the best & most thorough way to get it out? By opening the nut which has "Do no open when hot" written next to it? Then pumping the hose or something? Does the radiator cap need removing to bleed air out or should it stay on?

Thanks

[wrxhoon]

To fill the cooling system you have to undo that nut, turn the ignition on ,put the climate control on the highest seting ( hotest ) , undo the radiator cap and fill to the top .

fill the coolant bottle to the line that says max . Take it for a run until it reaches operating temp then when it cools down undo the radiator cap and top it up .

You cant tell if the thermostat works by the radiator hose , its always going to be hot .

You dont know how hot the coolant is by looking at the factory temp gauge either . They go to the middle when you reach about 75 deg and stay there until about 105 , when they start moving up its geting very hot . If you had an aftermarket gauge or better still a power f/c commander you could see what i mean .

50 % coolant mix is fine , i use 33% ready mix , 50 % is more expensive and not needed in sydney .If you use a 50 % mix it will last a bit longer , say 3 years instead of the normal 2 .

I think you will find that the oil temp will go up even on colder days if you drive it hard and for long periods , say 1 hour or so but of course it will get hot quicker on a hot day .

[NismoR34]

Just checked the Oil again and there's no milk No sign of white whatsoever in the oil and likewise with the coolant, there is definitely no Oil in there.

wrxhoon - I did follow that procedure when I changed the coolant a week ago, thanks.

I also attempted to try your other test with running the engine with the rad cap off but I noticed the level of coolant slowly rising to the top just on idle and thought I had better not rev the engine to 3-4K!

The engine wasn't COLD as I had been driving it around earlier, but it had cooled down for about 2 hours...

I Still havent tested the thermostat, looks like a bitch to get out! I may get my mechanic to have a look at that...

Cheers

[NismoR34]

It's possible that the mix is higher than 50% due to not getting ALL of the water [and possibly some traces of previous coolant] out. Water was used to flush / clean it out, prior to new coolant.

I poured about 4L of the coolant in first and then added demineralised water afterwards but I did not get 4L of water in, according to specs there should be around 8.7L for the system and .7L for the overflow reservoir [total 9.4L]. I only got around L of d-water in, is this a big concern?

I thought about emptying the .7L reservoir which is mainly coolant and filling up with d-water...

[RB30-POWER]

Just premix it before it goes in, in a bucket or something.

If you flush the block, you either have to undo the drain plug, which is under the coolant feed line to the turbo on the block, or remove the thermostat, or else the old coolant won't run out of the block properly.

[wrxhoon]

your problem is not the concentration of coolant i don't think , its a good sign that there in=s no contamination in the oil or the coolant . The other thing to do would be to check for steam coming out of the exhaust pipe when the engine is normal operating temp.

Are you sure that your clutch fan works ? Fan belt is doesn't slip ? what about the electric air cond fan ?Are you loosing coolant ? the thermostat should be fairly easy to remove .

To flush the cooling system you must undo the plug on the block and while the ignition is on put the climate control on the highest temp , then you get most of the coolant out .

[AFRO]

[NismoR34]

The other thing to do would be to check for steam coming out of the exhaust pipe when the engine is normal operating temp.

Are you sure that your clutch fan works ? Fan belt is doesn't slip ? what about the electric air cond fan ?Are you loosing coolant ? the thermostat should be fairly easy to remove.

No steam out the back. Not losing any coolant. Maybe thermostat just looks hard to remove cause there are so many things in the way of getting at the bolts! The AC / Thermo / Electric fan works just fine too.

I am assuming the clutch fan is the main fan attached to the radiator and sucks air through to the engine bay. This works, however, I must say that I have been getting some belt noises recently, sort of a squeaking sound. I have visually inspected the belts and there does NOT seem to be any noticeable damage to any of them - tension is tight, possibly too tight? Maybe it is slipping? I don't know how to apply 10 Kg of pressure by hand to check if its within recommended tolerances?

When I did the coolant flush/change last week I couldn't find the block drain plug [i now know where it is] so I used a creative method to get rid of the engine block fluids. Firstly I ran the engine [heater also set to 32c] with the radiator drain plug off and the rad cap off whilst running water through - this helped extract a fair bit of coolant etc that didn't already drain from the rad. Next I proceeded to blow out the remainder via the "blowhole" at the top of the engine - the air release [bleed] plug!

[NismoR34]

Thanks Afro but I already have that doc, I quoted it earlier:

Section 11. Coolant

Paragraph 9. After checking the thermostat injection valve, race the engine 2 to 3 times with 10 seconds interval between each @ 2500 rpm.

[NismoR34]

bump