Flushing Coolant From Block

[Galois]

the heat transfer between hot and cold water is much more effective than it is for air, so to have such a big difference seems odd. hot water rises through cold water, but it mixes better than air due to its physical properties.

it'd be good to know if the temp gauge was at half way kong, you said it was idling for a while but while idling it takes longer for the engine to heat up because there's effectively no load.

[mad082]

and if you have the heater on it takes even longer for it to heat up as it is heating up more coolant which also gets cooled a small amount when it passes through the heat unit

[KrazyKong]

I was idling yes, so there wasn't a load. Also the heater was on for a bit too.

The gauge was sitting at halfway for quite awhile, but reading here I guess that's still not truly at full temperature. I'll have to take it for a drive then, and then feel the bottom hose. But it's weird it's not getting hot. Unless...

unless the thermostat opens not by how hot the water is, but by it touching the inside metal of the block. If that's the case, then it doesn't matter if the hose isn't hot is it, as the thermostat is open and water is flowing in. That's what I'm worried about is that the thermostat isn't opening because no hot water is flowing in that area.

[Galois]

heat transfer between metals is very fast, so a warm engine will heat up the thermostat and thermostat housing very quickly

plus what mad said above, if the heater's on you have to warm up all that coolant too, AND you're effectively cooling the coolant down by "trying" to warm up the car

[mad082]

also the coolant on the engine side of the thermostat will still be warming up, so that would sort of negate the cooling effect of the water from the radiator. plus the radiator core itself has to be heated up before the coolant in the lower hose feels warm. as long as the radiator core itself is still cold at the bottom the coolant coming out of the core is going to be cool. i would suggest going for a drive around the block a few times (with the heater off) to get the car up to temp. once the needle is half way you'll still probably want to drive another 2 or 3km to make sure it is fully up to temp and then pull over and feel the lower hose.

[KrazyKong]

So the thermostat opens by the heated coolant in the engine, so behind the thermostat is what I mean to say? If that's the case it doesn't matter if cold coolant would be flowing in right, as the heat trigger is coming from the block itself. Is that how things work?

I'm experiencing one of this situations where I didn't pay that much attention to something, and now I'm wondering what is "normal" and what isn't lol.

But right now it takes a little while for the heat gauge to get to half way. Idling or going round the block doesn't do it. The weather here also is getting colder, so it might just be it's taking longer to get up to heat.

I took the car for 50km drive today up one of the valleys and when I stopped to check how hot the bottom hose was, it was certainly hotter. Really my only fear is that I've installed the thermostat wrong, or put too much sealant on. Basically just worrying I didn't do it right and now the car isn't running "properly".

If the bottom hose is never meant to be as hot as the top hose, and that's considered normal then I'm probably all in the clear. Will need to monitor it more and see how it goes, but it's certainly not overheating by anymeans. If anything it's taking longer to get up to temperature.

I still have the radiator flush treatment stuff in, so will drop it tomorrow and then replace with proper coolant. The bottle said it wouldn't hurt to run it for a bit, so that's just what I've done instead of the 20min idle routine.

[mad082]

at this time of year my 33 would take about 3kms of driving to get the needle to get close to being about halfway, but before it got fully up to temp was probably about 5km, but it is a bit hilly here. if it was flat i'd probably say about 7 or 8km.

if you drove 50kms and the engine didn't overheat and the bottom hose was cooler than the top hose then you should be fine. if you are really worried then you could always spend a bit of money getting a consult cable (pm newkleer on here) and then hook up a laptop to see what the actual temp of the coolant coming out of the block is. i have one of them and they are great. i was wanting to check the temp in my pulsar and used the consult cable and it showed that it was all good. on a warm day giving it a bit of stick it was sitting on 82 degrees. i wish i'd had the cable when i was having temp issues with my 33.

[Galois]

So the thermostat opens by the heated coolant in the engine, so behind the thermostat is what I mean to say? If that's the case it doesn't matter if cold coolant would be flowing in right, as the heat trigger is coming from the block itself. Is that how things work?

I'm experiencing one of this situations where I didn't pay that much attention to something, and now I'm wondering what is "normal" and what isn't lol.

But right now it takes a little while for the heat gauge to get to half way. Idling or going round the block doesn't do it. The weather here also is getting colder, so it might just be it's taking longer to get up to heat.

I took the car for 50km drive today up one of the valleys and when I stopped to check how hot the bottom hose was, it was certainly hotter. Really my only fear is that I've installed the thermostat wrong, or put too much sealant on. Basically just worrying I didn't do it right and now the car isn't running "properly".

If the bottom hose is never meant to be as hot as the top hose, and that's considered normal then I'm probably all in the clear. Will need to monitor it more and see how it goes, but it's certainly not overheating by anymeans. If anything it's taking longer to get up to temperature.

I still have the radiator flush treatment stuff in, so will drop it tomorrow and then replace with proper coolant. The bottle said it wouldn't hurt to run it for a bit, so that's just what I've done instead of the 20min idle routine.

it all sounds fine mate. the bottom hose has to be colder as its coolant that's been through the radiator, which is the cooler.

from my understanding the thermostat will open when its components are at the right temp, the block and coolant in the will be more than enough to keep it at temp. and if the coolant on the cool side is enough to close it then the block wasn't hot enough anyway. AND throwing cold coolant into a hot block is bad, so the thermostat slowing the flow of cold coolant by partially closing is a good thing

at this time of year my 33 would take about 3kms of driving to get the needle to get close to being about halfway, but before it got fully up to temp was probably about 5km, but it is a bit hilly here. if it was flat i'd probably say about 7 or 8km.

if you drove 50kms and the engine didn't overheat and the bottom hose was cooler than the top hose then you should be fine.

+1 50kms and the engine running fine, all is good.

and yeah my r34 takes 5-ish kms to get to temp

[gotRICE?]

My R33 takes a good while to come up to temp at the moment too. Its pretty cold in NZ at the moment.

Am yet to make up a cold weather shield for my oil cooler too. It cant be helping the situation much.

[KrazyKong]

Did another flush today of the radiator to get the flush treatment stuff out. I had done about 160kms with it in, so figured it had done enough cleaning and was a good time to drain it.

I positioned the car down hill, undid the radiator plug and let her drain. Due to the angle, it looks like the block was draining as well which was nice. After letting it sit for awhile, I screwed the plug back in and started filling it up with new coolant. Once I had put in enough, I turned the car around to then be facing uphill. Unscrewed the bleeder screw, and had my plastic bottle with the bottom cut off to sit in the top of the radiator. Once the coolant was coming out of the bleeder valve without air, I closed it. Then I filled the radiator and also overflow bottle.

I think I'm finally done with my radiator/engine flushing saga lol. All the hoses are clean, the rust and corrosion has been removed from the thermostat housing and the coolant is now free from that scungy rust colour paste. So the flush treatment has worked nicely, as well as all my previous tank water flushes.

The best part is I no longer have to drive around with the heater on full blast to make sure my flush cycle is thorough lol.

Edited June 5, 2010 by KrazyKong

[mystery_kid]

Assuming the bottom hose is the return and the top is feed to the engine,

you assumed wrong, fyi

[Galois]

haha nice work kong, good to see the problem fixed

[gotRICE?]

Your actually better off having the car level when bleeding the system, but whatever works.

[KrazyKong]

Your actually better off having the car level when bleeding the system, but whatever works.

I guess you take the information present on here due to not knowing it yourself. Some had said have the car on a slope facing upwards, have a bottle with the end cut off in the top of the radiator to make sure the coolant was at the highest point. Then fill, bleed until coolant was freely flowing out, close, and fill the rest up.

Having the car level, what difference would I have experienced? Plus after a few drives, whatever air is in there, is going to be forced out anyway right? So in the end, it should I would imagine all be the same.

[mad082]

draining you are better off having it on a slope (unless you were using the drain bolt), however filling i probably say that on level ground.

also when i was reading through the manual the other day it said that when filling up the coolant you should have the bleed screw removed and fill the coolant at no faster than 2L per minute. i'm guessing that this is so the rising coolant is able to push the air it is displacing out the bleed screw hole and not cause as many pockets of air.

[Sparky206]

Couple of questions after reading the thread

Has anyone answered how to get the tap water out of the block once you've flushed it, but before you put new coolant in?

Also with the air bleed screw on the top of the motor, how long does this generally take until all the air is bled? I left mine off for a good 10 mins and all it managed to do was make a mess by spitting coolant everywhere

[mad082]

the drain bolt in the side of the block is the only way to get the tap water from the block. or if you have a heap of spare distilled water then you can tip that through to dilute the tap water a bit. i personally don't think it's all that serious though. i think you'll find a lot of mechanics use tap water to fill top up radiators. i remember seeing in the service manual of my pulsar that the coolant should be changed every 40,000kms i think it was.

[jackdanielz]

hei guys, been trying to read this thread's post one by one,

2 question arises

i have a 34 heres a picture of one bleed valve, but wheres the other one? is it covered under the neo cover?

also where is the drain bolt on the side of the block, couldnt find it eh, it must be down the bottom right and on the engine block but where?

cheers

bly

Edited June 22, 2010 by jackdanielz

[jackdanielz]

btw the pics was from r33, found it on the other thread, but that thingy looks familiar, so yeah i can find it, but wheres the other one?

the drain plug been mentioned really hard to reach is this true at all?

anyone with pictures would be a hell of an awesome guy!! thats for sure

[KrazyKong]

Here's a question...

does it matter than I put in some $5 cheap coolant that needs replacing after 30,000kms? I know it's not as good as the Nulon long life stuff, but I have no problem in draining it near the 30,000kms and refilling.

After my flushing the coolant has remained free from any scunge or rust coloured stuff. So it's been a success for sure. Just wondered really what's the difference between the various grades of coolant other than how many kms they last.