[TEKNO]

G,day all...I checked my coolant reservoir bottle again today and it was low again and then I checked in the radiator and to my surprise when I took the rad cap off I could see the core,coolant way low so I topped it up and checked the obvious areas i.e hoses, tanks,oil...nuffin! So im buggered if I know why it has used so much?
Could a faulty Radiator Cap cause it to do this or is my problem worse? My car is a 2012 so maybe its time to replace rad cap?
Opinions please
Tanku

[Dan`]

Quote:

Could a faulty Radiator Cap cause it to do this

definitely can. i have had similar issues before because of it, but

Quote:

or is my problem worse?

yep also definitely could. blown head gaskets are great for also doing this. there is a test a mechanic can do for combustibles in your coolant which can only get in there if you have leakage between the combustion chamber and the water jacket.

caps are at least cheap and easy to change with no negative side effects, maybe just do that for piece of mind?

it could also be something like a thermostat sticking, have you been keeping an eye on engine temps to make sure htey arent getting high while driving hard? (while accelerating up a hill etc not just while your coasting along on the flat)

[bumstein]

Off the top of my head. If it's getting warm it could be boiling over.

Put an empty drink can on the end of the overflow and see if it's letting it's self out there.

If it's overheating, there's a list of things it could be. Radiator core blocked, water pump, thermostat etc

[TEKNO]

^^ sorry...I failed to mention that the temperature is just fine which is why im puzzled by this.

[Dan`]

bumstein wrote:

Put an empty drink can on the end of the overflow

they said its already got a reservoir, do you mean replace it or add a second res?

[TEKNO]

[qu have you been keeping an eye on engine temps to make sure htey arent getting high while driving hard? (while accelerating up a hill etc not just while your coasting along on the flat)[/quote]




Yep mate....the temps all good,always on 1/4 on the guage

[Dan`]

TEKNO wrote:

Yep mate....the temps all good,always on 1/4 on the guage

from the dozens of times ive blown head gaskets...... its starting to sound more and more like a head gasket.... what happens is tht every time your motor fires it blows a little bit of combustion into the water jacket displacing a little bit of coolant. unlike if it was boiling, once the motor cools this air cant condense again unlike steam does if its getting hot which causes it to suck water back in from your res.

id still definitely head down the radiator cap route, but id definitely think about getting the coolant checked if for no other reason than to rule out a HG issue

[Kor3y101]

Dan` wrote:

bumstein wrote:

Put an empty drink can on the end of the overflow

they said its already got a reservoir, do you mean replace it or add a second res?

Think he means a bottle on the little overflow tube on the res if that makes sense.

[Dan`]

Kor3y101 wrote:

Dan` wrote:

bumstein wrote:

Put an empty drink can on the end of the overflow

they said its already got a reservoir, do you mean replace it or add a second res?

Think he means a bottle on the little overflow tube on the res if that makes sense.

it does, and was kinda what i thought they meant but im not sure what that would actually show over the factory res? specially being so small like a can? i could maybe see the point if you put say a 2L bottle?

if the factory res is showing low/empty anyway which has a fairly reasonable volume (factory one must be well over 500ml? maybe close to 1L?) im not sure what a 375lm can could possibly show above that?

or, im maybe im missing something, hence why i asked. i just cant get my head around what could be different

[Kor3y101]

I suppose it would be a way to possibly eliminate a faulty rad cap, seeing if the coolant is being forced out of the overflow res while operating then being sucked back into the rad when it's stopped, thus giving the appearance of an empty res bottle.

I could be wrong, but I believe that's the idea.

[Dan`]

Quote:

I suppose it would be a way to possibly eliminate a faulty rad cap,

a rad caps design is to allow enough pressure that water/coolant dosnt just boil at the normal atmospheric 100c in the same way that at altitude you can "boil" water at room temp (any decent high school science teacher should have shown how you can "boil" water at room temp in a vacuum?)

Quote:

seeing if the coolant is being forced out of the overflow res

again this is my issue... if the coolant is being forced out of the rad caus of a fucked cap it would stay in the res but as OP has already explained the res has been emptying also. im not saying your wrong im just trying to understand the logic behind how that could be happening with the facts that OP has explained?

Quote:

while operating then being sucked back into the rad when it's stopped, thus giving the appearance of an empty res bottle.

from what OP explained its not getting sucked back into the rad because the rad is also empty enough to be able to see the core?

Quote:

I could be wrong, but I believe that's the idea.

you could well be right. im completely happy to accept that i missed something, its the whole point of my comments. feel free to point out if i missed something, anything, no matter how obvious or not. it is the only way we can learn and the best way to help OP

[bumstein]

Dan` wrote:

Kor3y101 wrote:

Dan` wrote:

bumstein wrote:

Put an empty drink can on the end of the overflow

they said its already got a reservoir, do you mean replace it or add a second res?

Think he means a bottle on the little overflow tube on the res if that makes sense.

it does, and was kinda what i thought they meant but im not sure what that would actually show over the factory res?

Was a quick reply. A Can on end of the overflow isn't as an additional reserve or to retain the fluid. But merely to highlight if fluid is being expelled from the system via this exit.

I've seen vehicles overheat and expel fluid without registering on the cars temp gauge.

Possible the rad cap could allow this too?

[Dan`]

Quote:

But merely to highlight if fluid is being expelled from the system via this exit.

ahh yea, i see your point but the factory overflow would serve this purpose anyway wouldnt it?

Quote:

I've seen vehicles overheat and expel fluid without registering on the cars temp gauge.

yup sadly a cooked a motor and turbo once because it had a sudden complete loss of coolant and the temp guage never registered above "normal" even tho the motor ended up ceasing because of the excess heat. at the time it displayed nothing unusual apart from a bad knock which at the time i assume was a bearing which was why i crawled it home only to find out that if i stopped and checked the coollant id probably have saved myself a few thousand bucks......

Quote:

Possible the rad cap could allow this too?

definitely could, while being unlikely... but is certainly the easiest and cheapest thing to try and in the past ive had similar problems caused by a cap. it is certainly what i would do first before trying anything else.

[murcod]

Check the rubber seals on the radiator cap. My XL-7 went through 2-3 caps in 8 years (all OEM) all due to the rubber seals starting to split.

Also check that you can't easily expel coolant from the system (when it's cold and full) by squeezing the hoses. If there's little resistance then your cap is gone.

[MrRocky]

Change your thermostat to new genuine

[bumstein]

Dan` wrote:

Quote:

But merely to highlight if fluid is being expelled from the system via this exit.

ahh yea, i see your point but the factory overflow would serve this purpose anyway wouldnt it?

Not necessarily.



Anyhoo! This is the topic I meant to find you the other night. There's also a link to another thread on overheating in the first few posts.

viewtopic.php?t=51987

All varying topics but a good scour might give you a few ideas

[TEKNO]

^^good read however it's not overheating YET so I will keep an eye on it over the next couple of weeks and if by the end of this week it's still losing coolant I will try the new rad cap option first and keep my fingers crossed that it doesn't need a head job haha

[THE_DICTATOR]

Get a cooling system pressure tester. Pump it up to 10psi and see what happens, repco sell a good kit for reasonably cheap as long as you can talk them into trade price

[murcod]

MrRocky wrote:

Change your thermostat to new genuine

Yes, OEM is the only way to go for thermostats. The one for my XL-7 was about $55, but some aftermarket options I've tried in past vehicles just caused further overheating issues.

[Paulw]

Is there any dried up coolant(white calky shit) on the side of the reservoir or on PS hoses?
My cap recently started bypassing(as in last week) and you could see the dried up coolant all over the reservoir. I used a friends headchecker but it was ok so I just changed the cap and topped up the coolant.
I paid 31.94 for a new OEM cap and 35.63 for 2.5ltr of OEM coolant.

[TEKNO]

So first thing this morning i checked the coolant before starting the engine and the reservoir bottle was brimming and I could see the core again in the radiator so i simply topped it back up then went and got a new radiator cap and also rang my mechanic who said that yes a rad cap could be the fault BUT if its still playing up in a few days bring it in and we'll do a TK test which test's for exhaust gasses in the coolant which will then confirm if its a head gasket or not so that is what I shall be doing. Its only $25 to do the test so why not I figure!
So its obviously pushing the coolant out into the res bottle but not sucking it back again so hopefully just the rad cap????
We'll see.

[Dan`]

almost word for word what i said originally.

TEKNO wrote:

So its obviously pushing the coolant out into the res bottle but not sucking it back again so hopefully just the rad cap????

as i have already said previously its a 50/50, its just as likely to be a cap as it is a headgasket, hence the changing of the cap first then the testing of the coolant. cap from the local parts joint is only a handful of bucks and there is no bad side to replacing it anyway.

there is 2 probably things happening here, either the cap is not holding pressure and allowing the hot water to boil, creating steam, and pass water through to your res tho when the motor cools again the steam condenses and it should suck most if not all the water back from the res into the rad.
option 2 is the headgasket is allowing the coolant to get pressurised and that is pushing the coolant out, because its not steam but just compressed air once the motor cools there is nothing to condense and thus not sucking the water back in again. this sounds more like what your experiencing

other thing i forgot to ask, do you ever hear any detonation/ping, specially if your givinig it a hard time? if its pinging that will hammer the headgasket seal causing a blown headgasket.

[MrRocky]

Thermostat

[Dan`]

MrRocky wrote:

Thermostat

except OP says its not getting hot so unlikely, tho worth keeping in mind. blocked thermostat will make the temp gauge rise from normal if you go up a hill etc.

[atari4x4]

Dan` wrote:

MrRocky wrote:

Thermostat

except OP says its not getting hot so unlikely, tho worth keeping in mind. blocked thermostat will make the temp gauge rise from normal if you go up a hill etc.

Maybe it's stuck open & not blocked?

[Dan`]

atari4x4 wrote:

Maybe it's stuck open & not blocked?

that would not cause the coolant to come out of the radiator it would simply make the motor run cooler, possibly too cold for the ecu to run it happily (would be running under "choke" conditions, etxtra rich etc). i did this recently while chasing an overheating issue, took the thermostat out completely and took it for a drive, was still overheating and ended up being a blocked rad core. after pulling the rad apart and pressure cleaning all the tubes i put it back together and the temp needle wouldnt move off cold until i put the thermostat back in, but no other adverse driving issues.

[MrRocky]

Ive had the issue surface on a few sierras now where the overflow empties and there are no leaks, seems odd but has been directly linked to the thermostat on numerous occasions and on 1.3/1.6 engines.
An open or removed thermostat will often make a car run hotter due to the fact that the coolant passes through the radiator too fast for it to actually cool down.

[Dan`]

Quote:

An open or removed thermostat will often make a car run hotter due to the fact that the coolant passes through the radiator too fast for it to actually cool down.

completely impossible for an locked fully open thermostat to cause the engine to run hotter because you are only putting the cooling system into its normal mode of operation. unless of course you believe that the manufacturer does not test their engines/cars before mass producing them?

as for removing the thermostat ive heard people say that in the past but the dozens of cars ive run without a thermostat its always made it run cool. in theory at least the faster the coolant runs through the core the more efficient it can cool (greater temp variation between coolant and ambient air temp will improve heat exchanging efficiency.)

sounds like old wives tales to me.

[MrRocky]

I think you have no idea as im sure the vast majority of people on this forum are starting to think also. I dont have an issue with people offering tech advice but quite frankly in nearly every post you make its pretty clear that you have no idea about anything automotive or just like to argue for the sake of it.
The fact you say "ive heard people say removing the thermostat makes the car run cooler" makes me think you should be banned from giving any sort of tech advice on this forum but luckily for you thats not for me to decide
Theres a noob section maybe stay there for 2-3 years

[Dan`]

Quote:

The fact you say "ive heard people say removing the thermostat makes the car run cooler"

read agian, i never said anything of the sort.

you are the one that is claiming that in the normal operation of a factory fitted engine and cooling system that the factory are so sloppy at their job that the millions/billions they have spent in R&D they wouldnt have tested that the factory thermostat does not caus the water temps to get HOTTER at a fully open thermostat position? that is ludicrous. is that really what you are still claiming?

im happy for you to troll away but you cant come at me at an obviously ludicrous position and expect me to take your claims seriously