R33 Running Too Hot

[nevaan]

Hey guys

I've just purchased my gtst and was wondering what the normal operating water temperature of it is. My factory temp gauge is disconnected, but the aftermarket gauge usually sits at 210F (99 C) and up to about 225 F (107 C) after spirited driving. I have read lots of threads and am aware of the fact that my fmic is restricting airflow to the radiator, and is probably causing this problem. My question is if these temperatures are safe for my car?

[Aleckr33]

That is high, normal temperature is around 75 - 90 C. I don't think it would be your FMIC causing the problem, I'd be checking the radiator. Give it a good flush and see what happens. How's your clutch fan?

[nevaan]

well racq said the coolant concentration is weak and discoloured. Only used the car for a day and is sitting in garage now. I need to do an oil change, air filter change and was planning on flushing radiator this weekend. Still need to do timing belt too....dont want my engine to rip apart haha, its at 112000 Kms

[Mayuri Krab]

well racq said the coolant concentration is weak and discoloured.

Could be that your water is boiling away (if there is low level of coolant mix present in the water & hence it will have lower boiling point), resulting in radiator going low on coolant & hence overheating happening.

also check the other basics

-is the rad cap worn?

-is thermostat worn & not functioning properly?

-Radiator partially blocked? (get a rad place to clean it)

When I had a partial overheating problem (stock gauge is being as useless as ever), the first 2 things on that list fixed the problem.

[nevaan]

ok looks like I'l have to give it a look. Fu** man owning a turbo car costs a fortune to maintain!!! Do you reckon if I just take it to a radiator shop they would obviously be able to diagnose the problem ay?

Edited March 29, 2011 by nevaan

[Mayuri Krab]

Do you reckon if I just take it to a radiator shop they would obviously be able to diagnose the problem ay?

1st easy check is the Radiator cap, just take it off & look, if the rubber appears to be cracked/worn then get a new one (0.8 bar, there is still a debate here on whether a higher pressure cap is better, I personal just stick with the stock pressure one) & see how that goes.

If you are good with working on cars, the next step would be checking out the thermostat & see if it opens & closes properly. The stock Nissan one opens at ~76C if I remember right.

Cleaning the radiator I would recommend a proper Radiator place to do, since its is a bit different from just plain flushing the radiator.

It pays to do a bit of DIY/check yourself so you can save some $$$.

If your coolant is very dilute (you mentioned), I would do a flush & refill & bleed the system just to avoid rusting in the system.

ok looks like I'l have to give it a look. Fu** man owning a turbo car costs a fortune to maintain!!!

Not really to do with the fact that it is a turbo car, but more with the fact that these cars are getting past 15 years (mine is 17...) & bits & pieces are starting to worn out & show their age.

EDIT: BTW is the overheating/high temperature happening all the time or only when stuck in traffic or moving slowly?

If it is the latter, it would indicate the clutch fan is not working as well as it should.

Edited March 29, 2011 by Mayuri Krab

[nevaan]

Thanks for all the helpful info mate. Had a look at the coolant level in the excess tank and it was at about half full. Dads done heaps of work on cars and said a flush would be bad on an old radiator because it could remove corrosion that has formed a seal where it has corroded. So by flushing the system I will remove these corrosion build ups and form leaks in the system. So we just topped up the coolant for now. I will let u know how it runs tomorrow. The temperature is that high all the time man, I thought it would be okay because the temp stayed constant and didn't fluctuate. Hopefully it drops down a bit tomorrow. Thanks again mate, i'l have a look at the cap tomorrow and keep you posted

[datsun_1600]

Just my 2c but wouldn't it be better to flush the rad ? I mean replacing a leaking radiator is a lot cheaper than risking warping a head ect which can happen quite easy running as hot as you are.

If it were me I would just flat out replace the thermostat, water pump and have the rad flushed. If the radiator comes up bad then you can work towards fixing it... Better safe than sorry I think. But that's just me.

Hope you get'r fixed!!

Jeff

[turael]

Well, here is my 2c:

You topped up the coolant - did you use plain water or a brand of coolant? if it was coolant, was it the same type as in there before (guessing you wouldn't know this, as you just bought it)? Mixing coolant is a big no no and can cause rapid corrosion.

What I would do, as soon as possible:

- pick up a timing belt and water pump (may as well change pump at same time, as you need to fiddle with the belt to get the pump out anyway) + rad cap + coolant (i use nulon longlife)

- drain coolant, use the bleed bolt up the top to get as much out as you can

- change timing belt and water pump. will see the quality of the corrosion while changing pump. If there is a lip of rusty corrosion from the old pump on the block, remove that (screwdriver/scrape etc) before fitting new pump, use gasket goo.

- check out the thermostat, replace if necessary

- put all back together, run a few lots of clean water through, keep doing this until running clear - quick way is to leave thermostat out, disconnect a hose, block off on rad and use a hose to push water through rad, block and out the disconnected hose into a bucket. long way is to let car run with water in it, properly bled, heater open, until at temp, turn off, cool it down, drain, repeat until running clear.

- apply the new coolant + rad cap

- enjoy a much cooler car? hopefully.

Still hot after that? try a diff gauge temp sender

new rad

maybe its running lean

glhf

[jjman]

had similar issues. Was the radiator blocking up. They are almost bound to be full of crap if it is the stock radiator after all these years.

[Nanogrip]

Thermostat might be kaput, not opening when it should. Try running with heater turned on to see if it helps a bit. I would change the thermostat and replace all the rad fluid.

[nevaan]

aww ok thanks guys. how do i get the thermostat out? is it in the radiator? I just called a radiator shop and they said it is in the engine...

[turael]

follow the hoses that go from radiator to the engine, I think its the bottom one on RBs with the thermostat housing, looks like this: linky

You unbolt that (After draining coolant), 3 bolts. pops off and inside is the thermostat! good luck

[nevaan]

aite thanks mate ima flush the coolant tomorrow and get a new thermostat from nissan while im at it...hopefully it works

[Mayuri Krab]

Have you checked your rad cap yet?

Mine was worn as sh*t when I noticed overheating problems (stock gauge went over 1/2 way with A/C on).

But I agree with what Turael said with while you are going over the system you might as well change all the bits & pieces just to be safe considering that they are getting over 15 years old now.

[nevaan]

ok guys did oil change and more inportantly coolant flush...

I opened the radiator plug under the radiator, turned on car, let heater run...

Using the radiator outlet pipe (lower pipe), I judged the operation of the thermostat. This pipe only started getting warm at about 95 degrees celcius. Obviously this would indicate the the thermostat is defective right?

Anyway, I let old coolant drain out, only about 5 litres came out even though I had the system running. Maybe this is because the engine plug was still on?

Next I filled some radiator flush that i bought into the radiator; and put some water in. Let the car run for 20 minutes, took it for a drive etc. followed the same procedure as above to drain the cleaner. Car is cooling down in the garage now. Im just gonna fill it with water again, run it through the system, then drain it out and leave the radiator empty overnight. Will that cause any corrosion? I dont want to put new coolant in, because im going to buy a new thermostat tomorrow and put it in, then change the coolant then.

Hopefully this fixes the problem. The cap was in perfect condition. If its not the thermostat, then the radiator could be blocked. Since I did not install the temp sensor myself (previous owner did), the gauge may not be accurate either...

[turael]

From my experience with my RB you'll need to open the bleed valve to get everything out - make sure you are swapping all of it and not leaving any coolant in the engine (sounds like you are doing good so far)

Not really a fan of running the engine while no coolant in it though?

I've left my RB empty overnight a few times, doesn't seem to be too bad.

whats the quality of the water coming out, brown or clear? keep flushing till its clear.

[nevaan]

yh man im not really running the car, was just planning on leaving it in the garage. took the car to my uncle this evening coz hes an actual mechanic. he showed me the radiator is completely blocked. all the little holes that are meant to flow the coolant and clogged with dirt (from japan!). haha the previous owner imported the vehicle, and it has always been running at that temperature. freaked me out, but then i remembered that the compression test showed all the cylinders working at above 90%. there is no leaks and no moisture in oil, so headgasket is not screwed either. my uncle offered to change the timing belt for me, so im taking the radiator to a radiator cleaning shop tomorrow while he takes the belts off, and yh hopefully everything is perfect by sunday!!!

Edited March 31, 2011 by nevaan

[jjman]

as is the usual case with stock radiators...