M35 Overheating

[scotty nm35]

Bloody thing is still overheating, now its getting worse.

Last night, even though the water temp was around 90, the heater wasn't working at idle. As I started driving, it worked again. Driving down the freeway the temperature hovers around the 89 degree mark but as soon as I slow to under 60, the temps shoot up to 108 or more. This should not be happening on an 8 degree night. I am guessing the water pump is on the way out as I have already replaced thermostat, I installed a mishimoto race radiator and i'm running the motul additive.

Anyone know how to change the pump? Looks like I now have a reason to fit the new silicone radiator hoses I bought.

[GoldZilla]

Does your new radiator have the factory fan shroud re-installed, Scott? It's pretty surprising how much this can affect airflow through the radiator.

[scotty nm35]

Does your new radiator have the factory fan shroud re-installed, Scott? It's pretty surprising how much this can affect airflow through the radiator.

I couldn't fit it. I was going to make an alloy one eventually, but that wouldn't explain the heater not working. Looks like they only last around the 100k mark on the 350z. If they run the same pump, they are around $125us shipped.

The pump runs off the timing chain so it will be a big job, i'm not looking forward to it.

[Jetwreck]

I couldn't fit it. I was going to make an alloy one eventually, but that wouldn't explain the heater not working. Looks like they only last around the 100k mark on the 350z. If they run the same pump, they are around $125us shipped.

The pump runs off the timing chain so it will be a big job, i'm not looking forward to it.

I still reckon you have an airlock.....DON'T BUY A WATER PUMP.....I have a brand new JDM one that has never been used....I bought it when I was having the same problem as you.

If you don't think it's an airlock still I'll sell it to you for what I paid.....I have something going down to VIC tomorrow so I can put in in that parcel if needed.

As far as changing it........apparently it's a huge job! Have a look at the V35 manual.....If that doesn't show you get Ian to scan the jap manual for you.

[Duncan]

I think it's much more likely they system is not bled properly - the heater is not working because there is a big air bubble there probably.

Have you replaced the coolant, and if so what procedure did you follow to bleed it. You should run the heater on hot while bleeding, prefeably with the nose of the car pointing uphill. There may also be a bleeder on the engine block you should open, certainly is on rbs

[scotty nm35]

This is about the 20th time I have bled it. The bleeder is at the back of the block on the heater hose. I cracked the bleed point last night when I was having the issue and coolant came out so unless there is an airlock elsewhere in the system I am stumped.

There were definitely air or steam bubbles going into the overflow when it got hot.

I still don't get why it runs fine when the revs are up, points to the impeller loosing a couple of blades doesn't it? I need to refit the low temp thermostat and silicone hoses so if there is a special "bleed while upside down with your tongue to the left" procedure post it up Craig and I will follow it.

[Jetwreck]

so if there is a special "bleed while upside down with your tongue to the left" procedure post it up Craig and I will follow it.

Tongue to the left procedure:

1. Go to the bottle O get 6 pack of beer(or a shandy in your case Scott)

2. Drink beer before arriving back home( Also know as the 6 pack holiday)

3. Contemplate not doing it at all....also know as the "she'll be right mate" symptom.

4. Go to walk inside house figuring out the wife is there and she'll make you do house chores.

5. Call a mate to pick up some more beer as the one's that you bought 10 minutes ago were gone before you got home.

6. Wait for mate to arrive with new supplies

7. Get mate to take you for a spin in your car as you are too drunk to drive....also a useful task to get the heat right up in the radiator.

8. Open bonnet and bleed while car is still running with tongue hanging out to the left.....probably burning your hand in the process....you wont feel it till tomorrow though!

9. Drink more beer winging about how much you hate the car ATM while the car cools.

10. Repeat process's 5 - 9 three more times.....you will know that the car is properly bleed when you cannot get anymore mates into the car for a spin around the block.

11. Next day....try to remember whether you did it right....if car overheats again start the whole process again.

cheers

Craig

Edited May 17, 2010 by Jetwreck

[scotty nm35]

I'm guessing that's the Australian way buddy but what do the Japanese do?

[Jetwreck]

I'm guessing that's the Australian way buddy but what do the Japanese do?

replace the beer with sake

P.S. Do you want this water pump?

Edited May 17, 2010 by Jetwreck

[Duncan]

ahh OK sounds like the right procedure....just make sure the heater is on full as well.

[scotty nm35]

Let me try a bleed AGAIN.... Im getting sick of the smell of coolant.

[scotty nm35]

Seems better... The only thing I did different this morning was bleeding it while cold. I will see how it goes.

It definitely had air in the system, I put about 200mls in the bleeder with a large syringe and it seemed to do the trick. I will check it again later.

I have never seen a system so hard to bleed before.

[pipster11]

this is how i bleed most rads (31 is a bit of a pain to do)

grab a 600 ml coke bottle (or any soft drink)

cut off the bottom

tape up the top till its a snug fit inside the radiator filler

squish it in a bit so it seals off

pour water into it

turn car to "on" position but not started

crank heater onto hot as a mofo setting

open that bleed bolt and take it out

squish the rad hoses and the heater hoses if you can reach them

i had a problem with a few mates cars after we drained the coolant, got a massive air lock in the system and it didn't wanna come out

eventually it did and it needed about another 2 litres of coolant putting in

can you remember how much you put in?

[iamhe77]

Seems better... The only thing I did different this morning was bleeding it while cold. I will see how it goes.

It definitely had air in the system, I put about 200mls in the bleeder with a large syringe and it seemed to do the trick. I will check it again later.

I have never seen a system so hard to bleed before.

Couldn't agree more.

If it still ain't right, try parking with the nose downhill and finish filling using your "Dandenong" syringe via the bleeder.

I have found it is the most thorough way of getting all air our of the system. It does take some time though

EDIT: pipster11's method will usually work though and is the same method I use to change the coolant (although I DID get a small air lock last time)

Edited May 18, 2010 by iamhe77

[pipster11]

i usually god for a quick drive and watch the temps then crack (but not remove) the bleeder bolt while hot (although the jap sticker says not too) and wait for the bubbles to piss off

[scotty nm35]

i usually god for a quick drive and watch the temps then crack (but not remove) the bleeder bolt while hot (although the jap sticker says not too) and wait for the bubbles to piss off

That is what I have been doing but it doesn't seem to work. Like I said there was fluid at the bleeder when hot but 200mls down when cold. There doesn't seem to be any leaks, it just holds a lot of air in the block obviously. I will keep bleeding it when cold and see how that goes.

[nickcorr]

My citroen BX GTi 16V needed some wierd arse additional expansion bottle to be fitted when the cooling system was bled.

Because the top of the engine was physically higher than the normal models they used this additionl bottle. It had a bottom like a radiator cap, that fitted into the top of the expansion bottle. They filled it with water, now some 20 cm higher than normal, and then started the engine with the heater on melt down setting. Once the thermo opened, they would bleed it, wait for the engine to cool down a bit, remove the extension bottle, suck out a bit of the water to get it back down to the correct level, and send you on your way...

I'm pretty sure that something similar was required for the Rb30 in the VL, because the radiator cap was "too low".

[Duncan]

yeah same sort of solution pipster11 said, that's how we do the race car too but its easy without a heater box.

to be honest i think its just luck sometimes....these systems are very complex and big air bubbles can form