diagnosing a blocked radiator??

[Bruce Nicholls]

Phosphoric acid in Coke I believe!

[Andy Bennett]

back to the acceptable difference in temperature. I did some tests with a thermal imaging camera a few years back (we made them for firefighters so I borrowed one for a weekend).
I found that unsurprisingly at first the temperature gradient was clear to see, with the hot area by the top hose.
However, after a few minutes it really did even out. Of course for the radiator to be working the temperature at the bottom must be colder than the top, but 80 degrees to 10 degrees suggests a super cooling radiator.

my picture below was after a 15 minute run. 80 degree at top and if i recall was about 60 at the bottom.


  P7030_sn1549(black)_72.jpg (Size: 10.19 KB / Downloads: 433)

[jamesheath]

Time for a bit of an update on how things went, or didn't / haven't yet.....

Following the excellent advice here, I removed the rad and created a flushing system - some adapters to connect hoses, and a pump driven by a drill (allowing it to be run forwards and backwards).
Heat was applied by running a little heating fan pointed at the rad.

I worked up through a number of steps, starting with weak Sulphamic acid (Furnox DS40), then stronger.
I tried it back on the vehicle, with no success.
I began to doubt whether the block was obstructed, so I installed the rad from my other special (different size, but OK while stationary) the result was a nice even temp. gradient in the rad and an engine that sat at around 70 even without a fan.
I then went in heavy with Hydrochloric Acid. Lots of bubbles and nasty smells, but no appreciable improvement in the free flowingness of the rad.
I then thought back to the oil issue....
As I mentioned in a throwaway comment in my very first post, there was a little oil sitting on the top on top of the water when I first inspected the rad...
I tried washing the radiator through with dishwasher detergent & water, and heating it up whilst full of it. This got some gunk out and some small fairly solid lumps of greasy tacky stuff - presumably cooked oil....
The final stage I've got to is flushing it through with "Gunk" engine de-greaser - this comes out a thick dark brown, and on flushing with clean water a fair amount of particulate comes out.
However the rad is not becoming significantly more patent (I can warm the rad, and then fill it from the bottom to see how it cools, and the thermal cam shows that the left is probably clearer and more even than it was, but the right is not great and there are two stripes in the middle with zero flow.
I suspect that Mike was spot on in post #4 - the rad is blocked beyond cure, but has anyone had any luck de-oiling a rad?
I'm wondering whether to fill it with an organic solvent - Meths, Isopropyl alcohol? brake cleaner?

I've learnt a lot and quite enjoyed the battles, though I think the rad may have won the war!!

(follow up posts will be centred on sourcing a replacement rad, and working out where the oil is coming from, but I want to get to the point of condemning this radiator first!!)

Cheers,

James

[JonE]

James - did the rad stlll stay intact in its ability to hold fluid after the hydrochloric acid?
Whatever your angst, these posts are impossibly interesting, so thankyou for posting. (Keep using the same thread for new updates so it is easily findable)
I guess the solvent fill would be interesting but you have to offset cost vs. gain.
What would be interesting to do is to retain the core if and when it is replaced so you can physically section it, and assess?
Like a postmortem.

[A G Wood]

James- If you've got little or nothing to loose, (and I see you've tried a degreaser and dishwash powder) I've seen a recommendation for clearing oil/grease blocked radiators [in the particular case of 'overuse  of the water pump greaser'] whereby the cooling system is filled with kerosene instead of water and the engine run until warm, then the cooling system is drained and refilled with a 'strong solution' of washing soda and the process repeated. No mention of damage to rubber parts, and although kerosene isn't cheap here anymore and I guess its the same in the UK, washing soda is. Might be worth a try? Also do you have 'Alfloc' brand cooling system products over there-they used to make an awesome high pH cooling system cleaner in powder form which you premixed with water that gave some pretty impressive results in some of the junkyard refugees I've dealt with in the past.

[Renaud]

I had issues like that with industrial heat exchangers. The difficulty lies in the fact that there is numerous little parallel circuits like in our radiators. Once some are cleaned all pressure and flush goes that way. The others stay blocked.
I would try to heat reasonably to free it but flushing won't work in my book.
Good luck!

[Parazine]

I used Bardahl Oil Remover when I had to clean up 10 litres of oil and coolant which had emulsified for 18 months in my MGF after a Head Gasket Failure (HGF).

https://www.bardahlindustry.com/rolling-...mover.html

I'm not sure how easy it is to obtain, being a "professional" product but it did an extremely efficient job, leaving the cooling system sparkly clean. It seems to be available on eBay, which is probably where I sourced it.

[Charles P]

Thoro-flush is also very good.
https://www.ebay.co.uk/itm/IRONTITE-THOR...2464815415
If the price makes you wince wait until you see the radiator repairer

[jamesheath]

thanks for the encouragement, and the pointers.
I'm pretty much resigned to a recore or replacement (the filler neck is missing from the header tank, so if I can source a replacement that's preferable!).
But as a last ditch I was going to get this 

https://www.smithandallan.com/products/i...fin-based/ 

 (useful to have around anyway, and I need to order some other oils from them) and fill the rad, and leave it for a few days, warming periodically - it needs to soak right through the blocked bits, though I'm sceptical....

I could try the more expensive things...... I hate buying "specially formulated" stuff, as it's often something totally standard with a posh badge on, though possibly not this time.

[jamesheath]

I felt like I ought to update this thread.
I've filled the rad with paraffin for a couple of weeks, and got some interesting white sludge that settled out of the paraffin, and a little black sludge, though not much, however the rad remains mostly blocked - about a third is free flowing.
So it's time to give up and look for a replacement radiator for a re-core.
   
(this photo is of a hot rad, having cold fluid pumped through it - the left is flowing, the right not)