Here's the scoop.
93 940 w/ 267K, bought with 140K in 2002. Over time had a variety of issues relating to large to small coolant loss, eventually resulting in overheating off and on and a diagnosis of head gasket failure.

I have done a head gasket repair on a 740t with help ..had no desire to do it again, at least not right now. The 800+ being quoted to repair did not sound appealing either.

I decided to try Bar's Head Gasket Repair ($10) ...after ..
1) a buddy had tried it on his really dilapidated 740, and it worked ..&
2) I spoke to one of Bar's techs for an assurance that it would not clog my system.

Well, so far - so good. The miss that I had at start up (#2 plug getting wet) is gone, and the pressure and temp are holding very nicely.

I know this is taboo to many, but I just wanted to pass the info on to those who might have interest.

OH ..I followed the instructions really closely. :)
--
' Of all bad men religious bad men are the worst. '' (C S Lewis

Had the same situation on my 78. Miss on startup traced to #2 plug wet.
The Bar's stop leak plugged it. I add more stop leak with every coolant
change. Stop leak is ok to use in The Po' Boys Volvo Club.

It is good that it worked for you. I once tried a similar product, bar's stop leak which had pallets ( My Nissen 3 -row radiator is brand new but there is a small leak somewhere in the system which is not visible) . Those pallets dissolved in to some thing matching horse poo and completely blocked the pipe which comes out of bottom of overflow tank. I found out that in time, before the actual leak brought the coolant level low in rest of system. I will be doubly cautious of trying similar stop leak systems.
Regards
Gopesh
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DD-1990 240 DL SW M47II FI 3.1 220 K miles Turbo Sways,Custom headlight circuit ,Insulated roof,Tinted Glass,

...out that:
New cars have the 'pellets' (made by Bar's) put in the cooling system at the start. Would not be surprised that new Volvo's have it, as I know that Ford does it, and has for quite a while.

There are 2 types of the Head Gasket Repair by Bar's, one that will work not work with anti-freeze, until it cures ($10) - and one that will ($20). Antifreeze can make the $10 version clump up. A-zone or Advance did not have the $20 version.

The one I used was mixed with 3 qts. of warm water, and poured into the radiator ..AFTER a good flushing to get rid of antifreeze. As I said, I followed the ritual laid out in the instructions pretty closely.

Just glad it worked.
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' Of all bad men religious bad men are the worst. '' (C S Lewis

I have read that Jaguar (in the pre-Blue Oval days) used to prescribe a dose of a fibrous additive put into the cooling system as part of regular maintenance. On the Jaguar forums one of the first prescriptions for cooling system woes is to blast out or replace the radiator due the masses of gunk that collect in there. I suppose the upside would be the comfort one would feel knowing that your Jag was well-maintained...

-Will
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850 / Mini

It will buy you some time. But the next time you replace the antifreeze, it, most likely will break loose and you will get the leak back.

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'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me http://home.no.net/ebrox/Tony's%20cars.htm

I will post back and let you know if the antifreeze does break it loose. Apparently Bar's does not think it will, as part of the instructions was to let it all set for 12+ hours, empty ...& then put the antifreeze back in.

I guess i will find out soon.
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' Of all bad men religious bad men are the worst. '' (C S Lewis ; on Evil Men) 89 764 (170K), '94 940T (265K), 92 245 (150K)