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#1 Furred up waterways/overheating
Posted: Fri Feb 07, 2020 4:14 pm
Having big problems with overheating on my car. It's an ex US vehicle and I've got a feeling it's been standing around for a long time over there as the waterways all seem pretty furred up; it's either sludge or corrosion or a combination of both.
Since owning the car I've only done short trips and the fans cut in very quickly. I've tried flushing the block with a caustic solution twice now. Things have improved slightly............temperature has dropped a bit, to between 80-85 degrees, rather than venturing into the red!
Have checked out all other likely problem areas such as radiator, thermostat and sender unit but all seem fine.
The only other option, that I can see, would be to pickle the engine block for 3-4 weeks in a white vinegar solution but this would involve taking the engine out, which I was trying to avoid!
Any useful idea's would be most welcome.
1970 Series 2, 2+2 (in course of restoration)
1965 Austin Healey 3000
#2 Re: Furred up waterways/overheating
Posted: Fri Feb 07, 2020 5:57 pm
Sorry to hear you are having problems. A bit of a long shot, but perhaps remove the water pump and make sure there isn’t excessive corrosion in the casing behind it or the impellers are clogged up. Either would make the water pump less efficient.
#3 Re: Furred up waterways/overheating
Posted: Fri Feb 07, 2020 6:03 pm
Tim are you relying on the gauge readings or you have checked the effective temperature with a heat gun? Température gauge could really be reading higher than reality.
#4 Re: Furred up waterways/overheating
Posted: Fri Feb 07, 2020 6:08 pm
Hi Tim..as above what Simon suggests...iv seen the inside of XK blocks almost fully blocked up with crud...I would also remove the plate from the rear of the cylinder head and the drain plug ...you could then then jet was out the block...removeing the core plugs if needed.....also worth pulling the thermostat to see if the inlet manifold is blocked...Steve
#5 Re: Furred up waterways/overheating
Posted: Sat Feb 08, 2020 11:06 am
The best agent for defurring cooling systems is citric acid, available from pharmacies in crystalline form. Dissolve perhaps 300 grams / half a pound in hot water, and add to the coolant and then run the engine up to temperature. Then leave for 3 or 4 days, running the engine each day . Then drain , flush radiator and waterways and repeat the process. If this does not work ( a visual sign that it is working is that everything goes green ) then you are onto core plugs out and back plate off
#6 Re: Furred up waterways/overheating
Posted: Sat Feb 08, 2020 12:16 pm
Bigcatfrankie wrote: ↑
Fri Feb 07, 2020 4:14 pm
Having big problems with overheating on my car.
What, exactly, happens for you to say it is overheating rather than simply getting hot? What is the worst that has ever happened?
#7 Re: Furred up waterways/overheating
Posted: Sat Feb 15, 2020 5:17 pm
Have now fitted a set of Revotec radiator cooling fans which definitely helps a bit, as they are much more efficient than the original fans, but I will have to try another good old soak and flush through.
Citric acid sounds a bit severe to pump around the cooling system. Was going to try white vinegar (acetic acid) and leave it in there for about 2 weeks.
Ongoing (and considerably longer than anticipated!) restoration of 1970 Series 2 2+2
1965 Austin Healey 3000
#8 Re: Furred up waterways/overheating
Posted: Sun Feb 16, 2020 12:04 am
Citric acid or acetic acid will do just fine although citric acid is more favoured, especially in things like kettles and coffee makers because vinegar leaves a taste that lingers a while.
Personally, I would use Kilrock, which is citric acid based and is extremely effective and reasonably economical in use. I would use it in a freshly drained hot engine so the Kilrock isn't cooled too much and run it for a few minutes.
Repeat as required.
#9 Re: Furred up waterways/overheating
Posted: Sun Feb 16, 2020 12:05 pm
I think that I have furred up waterways - keep getting up in the night!
Doctor says it’s my age!
#10 Re: Furred up waterways/overheating
Posted: Sun Feb 16, 2020 12:43 pm
I'm not going to recommend citric acid in this case.
Neither would I recommend the umbrella treatment.
#11 Re: Furred up waterways/overheating
Posted: Fri Feb 28, 2020 4:50 pm
Well, as it's Friday, and traditionally "fish" day, I thought I would go for the pickling in vinegar treatment........the car, not me!
A work colleague has given me a 5 litre bottle of white distilled malt vinegar which I will add to the gallon bottle of white distilled vinegar I have already got, to pickle the engine block in. Is anyone aware if the "malt" content matters? (Sensible suggestions only please!)
(Hot and bothered) 1970 Series 2,2+2 (in course of restoration)
1965 Austin Healey 3000
#12 Re: Furred up waterways/overheating
Posted: Fri Apr 24, 2020 4:55 pm
Bringing us back on topic ;)
My '69 S2 runs hot so I thought I'd give the cooling system a flush and re-fill with fresh water/anti-freeze.
First, a little more on the symptoms. Within 10mins of normal driving the gauge gets to the top (right) end of the normal section. If you keep moving along normally it settles there but if you have to stop in traffic the gauge heads in the red. I have an overide switch on the fans so can pre-empt situations where it might overheat but oviously I shouldn't have to. If you leave the car idling for 15mins or so the gauge will go into the red and the car will eject water from the header/expansion tank.
So I've taken off the bottom hose, the coolant that came out looked pretty good, light blue in colour and nice and clear. I've flushed the radiator from the top filler and it flows nicely
Tried flushing from the header tank but that's a no go. The water just spills out the top! Should this happen or do I have a blockage? How should I go about flushing the block or the system from the top/other end?
Any help or advice would be much appriciated.
#13 Re: Furred up waterways/overheating
Posted: Fri Apr 24, 2020 5:10 pm
Hi Mark...Iv been playing about with a few engins lately.....XK,s are notorious for the block filling up with crud.....especially aftet 50 years if there hasnt been regular coolant replacement.......i recently flushed an engine coolant came out looking ok...however on removal of the waterpump and looking into the block there was a huge amount of crud in there...so removed core plugs and rear plate on back of block and drain bolt on block....then jet washed the blockout........about a 1/4 bucket of deposits came out.........thus really is the only way to go .....just filling and letting it drain out dosnt really do the job properly.....Steve
#14 Re: Furred up waterways/overheating
Posted: Fri Apr 24, 2020 7:59 pm
Yes, Definitely remove the water pump and have a look.
I once removed one to find no impeller whatsoever.
Once removed is is much easier to physically remove buckets of crud if need be,
#15 Re: Furred up waterways/overheating
Posted: Mon Apr 27, 2020 7:34 am
Thanks chaps. It's coming off then
False economy putting the old one back on as I have no idea of its age or condition so I'll get a new one ordered. I usually go to SNG Barratt for my spares but are there any makes/brands of water pump to look for or indeed to avoid, either for fittment issues or product quality?
#16 Re: Furred up waterways/overheating
Posted: Wed Apr 29, 2020 4:38 pm
So I've got the water pump off and have to say it looks OK. No eaten up impeller or furry deposits to be seen. Of course I'll replace it anyway now that it's off.
The thermostat and the hoses I can get to at the front of the engine look good as well with more nice clear coolant in there.
Before I install the new pump (next day delivery from SNG Barratts
) where else should I be looking for blockages? I don't really want to take the head off at this stage/
#17 Re: Furred up waterways/overheating
Posted: Wed Apr 29, 2020 4:59 pm
Hi Mark..well at least you now know the block is ok....i would imagin that as it looks good the head and manifold should be ok...next make sure you have a correct thermostat fitted...Just reading back on your initial post... do you have a plain cap on radiator and a 7lb cap on expansion tank...also just check that your fans are turning the correct way it has been known for the connection to be reversed...Steve
#18 Re: Furred up waterways/overheating
Posted: Wed Apr 29, 2020 6:08 pm
Just checked... I have a plain cap on the rad and it looks like a 13lb cap on the expansion tank.
Good tip on the fans
#19 Re: Furred up waterways/overheating
Posted: Wed Apr 29, 2020 6:10 pm
Should be 7lb on the expansion....Steve
#20 Re: Furred up waterways/overheating
Posted: Thu Apr 30, 2020 6:40 am
Did you sort this out in the end?
As long as it's actually over heating and it's not a guage or sender problem you should look again at the radiator
You say you think the radiator is ok but it may well be blocked if it's an old one
It's very hard to tell sometimes if some of the passage ways in the core are blocked up
If everything else seems ok then I would suspect the radiator