VT V8 5.0 Radiator issue

[Salada]

So i checked the coolant the other day and turns out it was full of brown sludge.
I gave it a flush and just topped it with water and just after a half an hour drive it's all brown again.. i noticed when i dropped it to have a bit of a red tinge so I'm assuming its the trans cooler in the radiator thats gone? Was just wanting to double check before i purchase a new radiator..
Also it takes considerably longer to reach operating temp compared to my v6 (a good 15, maybe 20 minutes idling) is that normal? (stuck open thermostat?)
And what is the correct radiator cap for the 5l, it currently has a 100kpa, (would've been put on by the mechanic) and I'm lead to believe this isn't the right one.
Any help would be greatly appreciated, cheers.

 

[accentstencil]

Looks to me like it hasn't seen coolant in quite some time, just water, therefore that brown sludge is most likely rust which in turn has probably also seized the thermostat in the open position causing the lengthy heat up time.

 

[Nut Kracker]

Mines 19 PSI (135 kPa).

My VT 5 litre takes a good while at idle to warm up.
So I assume it's normal.

If you aren't using coolant (just water), never have or you haven't changed the coolant for a good while,
I'd say the sludge build up would be inevitable.

The red tinge may be auto fluid, but it also could be the remnants of red coolant.

 

[Nut Kracker]

Just had a look at the Factory Service Manual and Holden
say to use the 100 kPa cap, as you have.
Might have to change mine.

 

[Salada]

It would've always had coolant in it as it's been left to the mechanic for the last 15 years, was literately slop before i flushed it and i only put water so i wasn't wasting coolant as i know there's an underlying problem.. isn't it meant to be run with green coolant as it's an iron block? shouldn't be anything red in there haha

 

[Salada]

Mines 19 PSI (135 kPa).

My VT 5 litre takes a good while at idle to warm up.
So I assume it's normal.

Just had a look at the Factory Service Manual and Holden
say to use the 100 kPa cap, as you have.
Might have to change mine.

Oh right, sounds all good then.. thanks heaps for that.

 

[colourmesilver]

Just wanted to add my bit into this thread, I've flushed my radiator out and the block and even removed welsh plugs etc, no matter how much you clean and refill with the hn2045 I think coolant and use demineralised water with a 115kpa cap and do all the right things (it's apparent never to use radiator flush from super cheap I don't in my opinion it's not good or nessacary) you will always get that sludge after few grand worth of kms. I reckon it's just the Aussie climate or to agitate the more ocd type of people there is always a slight possibilitiy that the tranny chamber may have a hair line leak into the coolant but let's not go there

 

[Salada]

Just wanted to add my bit into this thread, I've flushed my radiator out and the block and even removed welsh plugs etc, no matter how much you clean and refill with the hn2045 I think coolant and use demineralised water with a 115kpa cap and do all the right things (it's apparent never to use radiator flush from super cheap I don't in my opinion it's not good or nessacary) you will always get that sludge after few grand worth of kms. I reckon it's just the Aussie climate or to agitate the more ocd type of people there is always a slight possibilitiy that the tranny chamber may have a hair line leak into the coolant but let's not go there

hmmm interesting.
i've actually got myself some radiator flush from supershit hahaha, i don't see a problem with it. i'll run it this weekend and clean it as best as possible, top it with coolant this time and see how it goes!

 

[gm1961]

Hi All

Ok from new these cars had coolant - typically green

A proper working car should warm up in say 5 mins - 10 max , out of the blue in 3 , then at say the 1/4 mark

This is still cool, but for all purposes the car is warming up fine

My VT SS used to get into the 1/4 mark in 10 mins in summer, but winter took almost a hour ( thank sydney traffic for 1 hour drive in the morning )
So in winter that was say 45 mins with no heater

Turns out i removed the thermostat and it had 3 small 1/8 holes drilled in it , now i personally do use the 1 x 1.8 trick myself just in case the thermostat ever seizes stuck, you dont want to boil the engine, but 3 was a overkill.

So with a new thermostat it works fine, heats up quick enough and has never hit close to 1/2 mark, the thermo fan kick in at about 33-40% hot

You mechanic may have simply been checking the water level and topping up as needed ( my WH statesman has not had a cup full added in the last hmm 8 years , i am there every time it is serviced)

So either he has toped it up , or totally changed it with plain water - which i doubt

Probably what has happened is over the years the original coolant additive has broken down and totally dissolved becoming useless, you car now has plain water

Plain water rusts engines, causing the brown sludge , more importantly it will easily clog the cooling fins in the radiator as it is very thick

Old traditional radiators yo can take the top and bottom tank off and clean them ( rodded ) then reweld them together, but that only works on old school copper radiators

Modern radiators are either all alloy or alloy with plastic tanks , most shops cannot weld alloy

So the only fix is really to take of the radiator hose and just flush out the radiator, plug the bottom hose outlet with a sponge or rag , fill it up with water then remove the plug , do that about 4 or 5 times until the radiator is all clean

The engine and heater hoses will still be dirty , so you may have to remove the thermostat as it will close with cold water, for the engine just stick the hose in the thermostat and run the hose for 5 mins

Eventually you will get most of it out, the heater hoses you will need engine running so that you can get vacuum to open the heater tap to circulate the water , but that has about 5% of the water anyway

Once the entire engine is close to as clean as possible, then drain 1 more time, flush out the overflow and add coolant , then most of the water run the engine for a while with the radiator cap op and then top up as necessary

some shops or radiator placed have a machine that looks like a small fridge called a power flush or similar , i tired one a few years ago ( 10 or 15 ) , dont knwo what it really done as the car i used did nto have any issues, i just wanted it done before i change the water and additive

Remember that radiator additive and brake fluid have a shelf life, the book will say 2 / 3 /5 years or so to change entirely

regards
george