To flush the cooling system, shops recommend Cascade dishwasher detergent. Supposed to be the best at grease cutting.

 

Do you have any idea how much is put in the system?

 

about what you would put in a dishwasher, I suppose.

 

The engines I've seen it used in are 15 litre diesel engines with a coolant capacity of 32 quarts. I'll find out how much, then you just reduce to match coolant of ours.

 

Ok I've got the pump on, a new radiator in and almost done with the belts. I filled the coolant at the reservoir tank until I had coolant coming out of the bleed screw. Now this may sound silly but I've never turned my heater on and I'm not sure I did it right. I turned the temp **** all the way to the right and turn the ignition key to "on" then I turned the fan to "1". Is that all there is to it? I the. Put a pressure tester on the reservoir and pumped it with a cracked bleed screw and I got a constant stream of coolant. I did not drain the block with the drain on the back bottom of the block so I'm not sure I've done everything right when it comes to refilling the system.

 

Well that is how you turn the heater on, but it will not have any effect without the engine running. The idea of turning on the heater is you do it with the car idling to make sure the coolant cirulates through the whole system, including the heater core.

There is a plastic heater control valve beind the intake manifold that opens to let coolant into the heater core - but it's vacuum controlled so it will only open with the engine running.

Strictly speaking, you should fill the system with the bleed screw fully removed - that will bleed the system a bit more easily. It's not critical though. You may have to go through a few cycles of idling the engine until it's hot, then cracking the bleed screw for a few seconds, then rinse and repeat, until the air coming from the vents is hot. But using the pressure tester the way you did should give you a head start. If you have a lot of trouble bleeding it, use the pressure tester again after letting the car sit overnight.

 

Last Lemming, what car do you have (year, model)? I believe the early cars have, like mine does, a cable operated heater control valve. I do not know when they made the switch-over.

I have also read in some of the forums that some rebuilt or some failing water pumps scraped the impeller to the engine cavity or the pump housing casting which I suppose could also produce some metal "dust" but it is probably radiator stop-leak like the others suggest, I don't know. Good luck.

 

It's an 86' turbo, but I have no idea if it's cable operated or not. The impeller did not scrape the block. I did check for that and the new one does not either.

 

I agree with morghen, the small particles you see is from a sort of radweld. The cheap way to fix a leak. Not uncommon to see, specially on engines that also suffered a blown headgasket of oil cooler leak...

 

that looks like at some point there was a leak in the system and someone added stop leak to it. that stuff is supposed to float around in the system until it trys to get sucked out the leak and blocks it

 

this was the first thing that came to my mind also.

but I figured the metal would be more of a dullish grey color.

 

Well I'm back on the road! I installed a new radiator (to be safe) and a new water pump with all new thermostats. I also installed a new thermo switch.

The car runs fine and I've had no problems with any sort of overheating so far. Heat blows hot as well.

As for the stop leak stuff I don't want to overplay they metal bits I found. I found no more than an 1/8" square of the stuff. I know the previous owner and he only had it worked on at quality shops and only used Porsche parts. He did have a head gasket leak but he had the head removed and milled to have a nice surface and put a "wide fire"
Head gasket back on. The receipts show a radiator flush in that survice so I would have thought that the stop leak would have been removed then. My metal coolant neck (the one that has the bleed screw) that goes into the block did have a fair amount of bad scaling. I administered por-15 to that. My carpets are dry so I guess I need to keep an eye out on it.