- Thread starter mylesdw
- Start date
then I think the problem is down to your radiator and/or fan
I looked back but couldn't see a decent photo of the radiator fins... but I'm guessing they're decent enough or you'd have changed it already/said something
colin posted above as I was typing... I was going to say there must be enough flow through it for the outlet pipe to be hot.... but it could be mostly blocked so the water is rushing through a small area instead of slowly through the whole radiator?
I'd check for cold spots above, and check the fan... how much air does it pull through the radiator? (it should be a lot)
does the fan have any numbers on it? amps/watts? any chance you have a dc clamp meter so check how many amps it's pulling in use?
mylesdw
Member
- Messages
- 794
Thanks guys.
I think the core is OK. I took the rad to the shop when it was out, they flushed it and pressure tested it and said it was OK. They described the core as 'OK but a little soft'. I think they meant that the fins a bit bendy but there were none so bad that airflow would be affected.
I think the fan is the problem - simply not powerful enough.
I think the core is OK. I took the rad to the shop when it was out, they flushed it and pressure tested it and said it was OK. They described the core as 'OK but a little soft'. I think they meant that the fins a bit bendy but there were none so bad that airflow would be affected.
I think the fan is the problem - simply not powerful enough.
- I have ordered another similar fan that I could run as a pusher on the front of the rad
- I could ditch the original shroud and mount the puller fan directly to the core (or on small brackets)
- I could seek out an original fan and shroud but I don't really want to do that - there are definite advantages to electric fans (when they work!)
- I will try and measure the fan current
- I've ordered (yet) another https://daviescraig.com.au/thermatic-electric-fans 16" fan. This time not an eBay cheapo one. It draws 9.5A @ 24V and shifts over 2000 CFM. I really need to get this sorted out over the Xmas break so I'm throwing a bit of money at it.
Just a thought,I remember many years ago I had a same problem, I bought a smaller Rad the type that can be used on a race saloon type of Car. I also fitted an electric fan to it , I extended the Hose from the main Rad to the second Rad I had installed underneath it worked kept the temp down a treat.
james butler
Member
- Messages
- 1,517
- Location
- birmingham england
this is very true!
on my datsun the temp would soar when booting it so i ordered a new radiator made by mishimoto and to my suprise it was a good 10cm shorter than the old one although thickness and width was the same.
the new rad had three cores compared to the old ones 2 core and it made a massive difference!
slim_boy_fat
Member
- Messages
- 29,540
- Location
- Scottish Highlands
DAPPH
as dyslexik as I'm daft
- Messages
- 7,181
- Location
- Near to Cross Hands Llanelli SouthWales GB
Myles as a quick fix ..... have you tried cleaning he cooling system & back flushing the rad yourself ? One ounce of citric acid crystals in a pint of hot water poured in the rad . run the engine for 20 min or so to get to working temp for few minutes to mix the citric acid solution & get it all circulated . Leave it overnight .
Do a 20 min run of the engine in the morning to loosen any crud then turn it off & drain the rad Now back flush the rad from the bottom hose for a few minutes.
It's handy to make up an adaptor to pipe the dirty water off from the rad filler neck . Let it cool by itself for a coupe of hours then refill the rad adding a small 250 ml can of radiator weld just incase you have un blocked a tiny leak .
Often people take a rad to a workshop for it to be cleaned but forget that the block is also likely to be silted up or have flow rduced due to mineral deposits in the coolant and / or oil from the occasional partly blown head gasket .
I can't remember if you sprayed the rad with something like Gunk engine cleaner from both sides left it for a couple of hours and power washed it out with warm water from the engine side keeping the lance nozzle at least 15 inches from the cores . Then using a bit of thin plastic cut to size redress any bent over fins if possible .
One other thing that came to mind just now . Have you actually checked the temperature & operation of the thermostat using a bucket of hot water and a thermometer or isn't there one in the system .
Do a 20 min run of the engine in the morning to loosen any crud then turn it off & drain the rad Now back flush the rad from the bottom hose for a few minutes.
It's handy to make up an adaptor to pipe the dirty water off from the rad filler neck . Let it cool by itself for a coupe of hours then refill the rad adding a small 250 ml can of radiator weld just incase you have un blocked a tiny leak .
Often people take a rad to a workshop for it to be cleaned but forget that the block is also likely to be silted up or have flow rduced due to mineral deposits in the coolant and / or oil from the occasional partly blown head gasket .
I can't remember if you sprayed the rad with something like Gunk engine cleaner from both sides left it for a couple of hours and power washed it out with warm water from the engine side keeping the lance nozzle at least 15 inches from the cores . Then using a bit of thin plastic cut to size redress any bent over fins if possible .
One other thing that came to mind just now . Have you actually checked the temperature & operation of the thermostat using a bucket of hot water and a thermometer or isn't there one in the system .
Last edited:
Farside
Badly Welded Man
- Messages
- 5,842
- Location
- Ireland
One of the biggest killers of radiators is the habit of topping them up with tap water, whether mixed with anti-freeze or not.
It's a haphazard affair, as most people don't know or care about the quality of the water coming out of their tap, but given the likelihood of hard water being introduced to any given old radiator at some or many times in its past, it's quite possible that scaling up has happened.
This is why I've been keen to find sources of soft water local to me, and have developed the habit of storing the condensate from my dehumidifiers. It soon adds up and right now I've got enough to refill a dozen cooling systems.
It's a haphazard affair, as most people don't know or care about the quality of the water coming out of their tap, but given the likelihood of hard water being introduced to any given old radiator at some or many times in its past, it's quite possible that scaling up has happened.
This is why I've been keen to find sources of soft water local to me, and have developed the habit of storing the condensate from my dehumidifiers. It soon adds up and right now I've got enough to refill a dozen cooling systems.
DAPPH
as dyslexik as I'm daft
- Messages
- 7,181
- Location
- Near to Cross Hands Llanelli SouthWales GB
Rain water caught off a plastic sheet or non metallic or cement tiled roof is also fairly soft water .. filter it through a fine cloth o remove any crud before you pop it in the cooling system . I have a 310 litre rain barrel to play with if needed .
slim_boy_fat
Member
- Messages
- 29,540
- Location
- Scottish Highlands
We're lucky up here, no scaling from our soft water - that's also why whisky is good for you...in moderation
Never seems to need topping up anyway, so I'm lucky on 2 counts
.Our water used to have a slight brown tinge from being filtered by peat, then simply run through filters to remove any contamination. It tasted absolutely beautiful, then the 'safety' crowd got on the case and spent millions on a water-treatment plant up in the hills, pulling water from a loch. Sadly they overlooked dry Summers and their intake pipes didn't reach the water when the level dropped through evaporation.
Cue much more expenditure with bottled water deliveries for weeks. You couldn't make it up. 
The installed 'automatic chlorine dosers' which used to go in the huff occasionally, rendering the water undrinkable - cue more bottled water...... Eventually it all seems to work OK, but in no way tastes as good as before.
DAPPH
as dyslexik as I'm daft
- Messages
- 7,181
- Location
- Near to Cross Hands Llanelli SouthWales GB
We're lucky up here, no scaling from our soft water - that's also why whisky is good for you...in moderation
Never seems to need topping up anyway, so I'm lucky on 2 counts
Our water used to have a slight brown tinge from being filtered by peat, then simply run through filters to remove any contamination. It tasted absolutely beautiful, then the 'safety' crowd got on the case and spent millions on a water-treatment plant up in the hills, pulling water from a loch. Sadly they overlooked dry Summers and their intake pipes didn't reach the water when the level dropped through evaporation.
The installed 'automatic chlorine dosers' which used to go in the huff occasionally, rendering the water undrinkable - cue more bottled water...... Eventually it all seems to work OK, but in no way tastes as good as before.
Wanna buy a steam activated charcoal element with ultra violet light filtering system to remove 99.9% of all contaminants from your drinking water . ( You can't store the filtered water for more than 2 days in the fridge ) ? 
And your clothes and washing machine go mouldy without the chlorine!
mylesdw
Member
- Messages
- 794
Thanks for the detailed instructions Daphh and my apologies for not replying sooner.
I did have the rad flushed and they said it was all good. I put a new thermostat in and the bits of the water ways that I could see looked fairly good too. The core of the rad was what they described as 'soft'. The fins bend very easily and although I spent a while unbending them as you describe there a still a lot of bent areas. I may just bite the bullet and pull it out this winter and get it re-cored with something more modern. My brother-in-law who as done most of the driving so far found that opening the side flaps on long climbs made a lot of difference.
It still uses a certain amount of water, probably a pint a day and we're puzzled where it is going. Also, one of the hoses collapses when the engine cools, suggesting that there is air present. Do you have any clever tricks for bleeding the heater matrix?
