CLR a cooling system with 20 years of build up

[haryv]

I cannot find my old thread on my cooling system woes but here are the steps I did to clear out most of the crap from the heater core.

Removed heater core hoses and applied static water pressure at both ends. Water streamed out a solid brown color first for 2 minitues. The water flow was slow comming out..it was plugged. Then continued untill it streamed out. Then used calcium lime rust "CLR" remover in the cooling system. That made a BIG difference in the heat output from the heater core. Before I would guess the heater temp at the vent was 70F when the engine was full warmed. After using clr, then flushing with regular engine coolant flush, flush again, then use crystal dish washing agent and flused again after driving it twice the temp at the vent has gone up to 120-125F

A big improvment. The rear heater core which never really had any heat related problems was 135F.

This is all the result of a owner who did not know better and never flushed his coolling system after 20 years then had it flushed by a shop about a year ago because his radiator sprung a leak..I wonder why! So, the last shop did a poor job and I had to complete it. It kinda amazes me that these engines are this tough to not be flushed and will still run.

On the positive side, the engine idles more smoothly, it seems to have a slight amount of pep when excelerating and it warms up alot faster now.

I plan on installing a WVO some day and need all the hot water I can get.

 

[Stone]

Really...CLR is engine friendly?

 

[harveya]

I cannot find my old thread on my cooling system woes but here are the steps I did to clear out most of the crap from the heater core.

Removed heater core hoses and applied static water pressure at both ends. Water streamed out a solid brown color first for 2 minitues. The water flow was slow comming out..it was plugged. Then continued untill it streamed out. Then used calcium lime rust "CLR" remover in the cooling system. That made a BIG difference in the heat output from the heater core. Before I would guess the heater temp at the vent was 70F when the engine was full warmed. After using clr, then flushing with regular engine coolant flush, flush again, then use crystal dish washing agent and flused again after driving it twice the temp at the vent has gone up to 120-125F

A big improvment. The rear heater core which never really had any heat related problems was 135F.

This is all the result of a owner who did not know better and never flushed his coolling system after 20 years then had it flushed by a shop about a year ago because his radiator sprung a leak..I wonder why! So, the last shop did a poor job and I had to complete it. It kinda amazes me that these engines are this tough to not be flushed and will still run.

On the positive side, the engine idles more smoothly, it seems to have a slight amount of pep when excelerating and it warms up alot faster now.

I plan on installing a WVO some day and need all the hot water I can get.

What sort of engine, just that this is very important to do on the 2LT/2LTE engine as the cooling system just loves to build up sludge and they are already on the limit with the cooling system - needs to be 100% for good reliability.

Good service prcatice says you should do this once every couple of years, problem is a lot of cars come with long service intervals now and with standard summer and winter coolant used all the time, no-one ever drains and refills the system like used to be done years ago.

 

[Eric Winkworth]

I do, once a year, coolent is cheap

 

[brownbear]

CLR should be safe. Its a great cleaning product. Only thing tho is I think it is corrosive. So it must be flushed as best as possible.

Glad to hear you got the crap out. Make an adapter and flush the block out too,

might also me a benefit.

 

[haryv]

clr would more etch a surface then be corrosive but..

I may be wrong on this but read CLR it is not to be used on aluminum. My guess is it just etches it. I Probebly would not worry on these tough engines. I may have to do this again as my heater core temp depends on how bluged it gets.

BTW, has anyone heard of air pulse water flush system before? I was watching a shop mechanic in seattle use it on a chrysler minivan and was impressed. You can actually see the heater core hoses jump each time a pulse would go though the system. The head mechanic says it does a excelent job. Are there any shops in the lower mainland that would have this type of equipment off hand? If now one knows then I might start calling around if I do one last flush on this system. Heater core could still get hotter like the rear one.

 

[brownbear]

your heater core is alum isn't it? same as rad. CLR if corrosive will eat right thru it. So flush well. Won't hurt the block tho.

 

[haryv]

Cooling system was flushed.

Brownbear,

So far its okay. Besides if it did reach the walls of the heatercore I would suspect the temp to be 135F like that of the rear heater core.

What should the water temp be comming into/out of the heater core hoses? I will be probebly converting this vehicle to use wvo in the summer.

 

[lshobie]

More important than flushing it - make sure you neutralize it. I suspect thats what you were doing with the detergant.

 

[Eric Winkworth]

I actually wasn't impressed with CLR when using it on my bath tub, doesn't work that great at all, I would rather just put rad flush in my rad.

 

[haryv]

Heater core should be hotter...its cooled down again.

Now, Im begining to wonder if more crap has been breaking off inside the engine and plugging the heater core? It is definatly warmer then before the flush but not as hot now. Grief! anyway, I was wondering what is a really agressive way to flush this cooling system but is still safe? Was seriosly thinking of disconecting the heater core again and this time, ram a pressure washer nozzel in the flow in side of the heater core. That would flush everything out but dont know if it is advisable.

What do you all think?

 

[Mark W]

CLR is a weak dilution of hydracloric acid. Do not use it on AL. It attacks it.

CLR IS more effective than over the counter radiator flushes.

Muruatic acid (a 28%-31% dilution of hydracloric) is MUCH more effective than CLR. This shoulkd notbe used on AL either.


There is really little need to flush your block/waterpump or any thing like that. Build up in this part of your cooling system is minimal and does not cause any problems. Flush your radiator and your heater with muriatic (assuming that neither are AL) and leave the block be.


Mark...

 

[harveya]

CLR is a weak dilution of hydracloric acid. Do not use it on AL. It attacks it.

CLR IS more effective than over the counter radiator flushes.

Muruatic acid (a 28%-31% dilution of hydracloric) is MUCH more effective than CLR. This shoulkd notbe used on AL either.


There is really little need to flush your block/waterpump or any thing like that. Build up in this part of your cooling system is minimal and does not cause any problems. Flush your radiator and your heater with muriatic (assuming that neither are AL) and leave the block be.


Mark...

Mark.

Again depends on the engine. I have seen considerable build up in the waterways of the head and block on a 2LT engine, not so much on other engines.