General - Rydlyme

Just noticed Guy's useful comment on Rydlyme (old bulletin 2682), which I'm keen to explore. Any problems noticed in practice by members with internal corosion of aluminium alloy bits as a result of the cleaning cycle ? Will core plugs need to be replaced after the flush? What dilution are you using ? Min order volume is 4 gallons from their website. Is that enough with suitable dilution for a 3 liter engine ?  Material data sheet on Rydlyme company website a bit scary regards potential corosion, if you leave the circulation going too long ! Posted by valman 13/06/2012 09:41:05

Michael,I replied yesterday but thought it necessary to add a few thoughts.  Rydlyme recommend a 50/50 solution. Alvis technical spec. say that the cooling system is 3 gallons = approx 14 litres. I use about 7 litres of Rydlyme and this seems to do the job. Run the engine until it reaches 75 degrees and allow to soak overnight. Guy suggests 5 hours and as he has done many more of these than I have, you may wish to be guided by his experience. The Rydlyme representative suggests overnight. If the cooling system has not been cleaned for some years, it is likely that the alloy parts will need to be replaced. The easiest way of doing this is to check the condition of the oulet at the thermostat/ hose elbow (when you insert the sock or stocking) and if this is corroded, certainly the rear plate at the back of the head will need replacing as this one seems to deteriorate faster than the others. As a matter of course I replace the elbow, bottom connection and the rear plate as these can be accessed without needing to remove the radiator. I have never had any problems with core plugs. I source my replacement alloy parts from New Zealand and have found the quality of these to be first class. I follow the above treatment about every two or three years and because the water pump was leaking , then replaced the front cover plate which showed little or no corrosion. Hope this helps. Posted by pdadd 27/06/2012 23:33:06

Philip, Many thanks for your feedback. I will try the 5hr soak.  With my 3 liter I suspect the radiator is fouled more than the head, but I hope this will clean both- otherwise its a radiator re-core. With my 12/70 head, I have already done all the scraping off of loose hard material in the waterways with various tools that I can. I am hoping redlyme will reach the parts other tools can't reach ! It may finish off a leaky radiator- but c'est la vie. Michael Valman Posted by valman 29/06/2012 17:09:06

Just thought I would share my usage of Rydlyme.  The car would overheat after 10 mins idling if the Kenlowe was not used and after a run when you switched her off the temperature would rise in the next few minutes and you could hear the water boiling in the radiator and often came out of the overflow pipe. I was sceptical but I was not keen to be removing the head at this moment so I decided to give it a try.    I flushed the system several times checked the engine drain was running and then drained the radiator and the engine block. I by-passed the heater box with a length of hose as I did not want to be repairing it at this stage.  I followed the recommendation to use a stocking in the top hose and took the opportunity to remove the thermostat housing and thermostat so that I could inspect the housing before and after for any damage. I then refilled with a 50% mixture of Rydlyme and ran the engine at idle speed for 30 mins, waited an hour and ran it again at idle speed for 30 mins. the 30 mins was chosen as it was just about all the car could do, even with the Kenlowe running, without overheating.  I then left it for 10 hours before running it once more at idle speed for 30 mins.  I left it for an hour and then opened the drain cocks on the radiator and engine block, collecting the water into containers so I could inspect it.  The engine drain did not run easily so I bent a length of plastic covered fence wire with a 90 degree bend and gently poked it into the engine drain.  I was frankly surprised at the quantity of what I can only describe as black sand which flowed out. I ran the garden hose into the radiator to flush it through. The drain reblocked several times requiring use of the wire but eventually ran clear. I then removed the thermostat housing to inspect it and remove the stocking.  I found the stocking was solid with a silty debris and was quite difficult to remove, I would use a sock next time I think it would allow a better flow through it and be easier to remove.  The thermostat housing was clean but there was no sign of any corrosion.  The overall effect on the car has been dramatic.  There is now no sign of her wishing to overheat whilst idling and after a run the temperature only rises to 3/4.  I am sure that Rydlyme will not solve everyone's overheating problems but I am very glad that I tried it and perhaps others should consider it. Posted by Davenall 08/11/2012 19:07:06

I tried this earlier this summer, but not with the same success as my TE still overheats in traffic, but I'm thinking about repeating the exercise. Can I just check what Rydlyme is supposed to look like? The stuff I got was brown and quite thick - was that right? It certainly said Rydlyme on the label!  I'd already had the head off and had it thoroughly cleaned (by Guy) along with the thermostat housing and the plate at the back of the head, so I only used one 5l container of Rydlyme. That was probably more dilute than it should have been. The sock caught some flakes but nothing like the amount I expected. I've just taken out the radiator as my waterpump has started leaking (possibly as a result of the Rydlyme, who knows?). I've been able to flush loads of brown sludge out of the radiator, though a layer still sits on the top of the core. I was thinking that I can fill the radiator with neat Rydlyme, though I won't be able to get it hot. Posted by Mikee 11/11/2012 20:24:04

Mike  Rydlyme is certainly dark brown but not particularly thick.  I am not an expert but you do not mention in your post about draining and cleaning from the engine drain plug which was responsible for a large quantity of sand/sludge in my case.  If you did clean out the engine drain I would doubt whether another try of Rydlyme would help.  You have already had the head off and I assume you cleaned out the passages in the block at the time.  I am convinced that in my engine it was the passages at the rear of the block which were blocked as number 6 spark plug also no longer fouls up. Posted by Davenall 12/11/2012 13:30:16

Thanks, Andrew  I had the head off about 3 years ago, and I wish I had cleaned the passages in the block ... but I didn't know about the block scaling up then. I think I'll give the Rydlyme another go as, compared to other remedies, it's relatively cheap. Posted by Mikee 14/11/2012 23:17:20