I wouldn't be concered with the 617, that's for sure. I'm quite sure it could handle almost any temperature, provided the coolant does not boil.

But, the 603, with the aluminum head, is another story.

I don't think I want the 603 above 110°C. (230°F.) whether it boils or not.
I just don't have confidence in the growth of the aluminum up there.

That sounds like a valid concern. Aluminum heads are not reliable much over 200F -- I ran my 280Z on the track last fall with a failing alternator (and electric cooling fan). Head temperature never went over 200-210F, but I developed a rasp in the exhaust, sounds like a warped exhaust manifold.

The 617 on the other hand, doesn't seem to even notice what the head temperature is, once it's over 40C...

__________________
'83 240D with 617.952 and 2.88
'01 VW Beetle TDI
'05 Jeep Liberty CRD
'89 Toyota 4x4, needs 2L-T
'78 280Z with L28ET - 12.86@110
Oil Burner Kartel #35

http://i16.photobucket.com/albums/b1...oD/bioclip.jpg

A good article for those who haven't seen it yet.

While we're on the subject of fluid replacement/flush, has anybody ever used liquid dishwasher detergent to clean their radiator before refilling with coolant?

Good article. Thanks. I hadn't seen it.

Cheers,

Bill

An appreciative bump for a very nice article...

and a vote to 'sticky' this document!

Chris
'85 300SD

I've used Liquid Tide a few times.

Len

For some reason I don't get anything when I click on the link. Just a blank window.

__________________
Ralph

1985 300D Turbo, CA model
248,650 miles and counting...

Here's another article worth reading:

http://www.aftermarketbusiness.com/aftermarketbusiness/data/articlestandard/aftermarketbusiness/332005/174357/article.pdf