the cooling system and overheating problem

Want to chime in here. Coolant, like oil, is a religious thing. I, personally, do not believe in DexCool. It has a significant problem with precipitation in the presence of air and other contaminants. GM has noted this and has had problems with it in some vehicles that has a propensity to leak and let in air. In these old top down radiators without a sealed system, you cannot bleed it completely to remove all air from the system. I use Zerex G05. It is available from NAPA and sometimes at other places. It is the same formulation that MB used for years and very similar to the G48 that Saab and other euros used (Fe/Al engines). It is much better at preventing galvanic corrosion than the green stuff in these engines. As always, you need to mix  distilled or deionized water with coolant to achieve the protection advertised.

This is a bit of background:
http://www.imcool.com/articles/antifreeze-coolant/G05-Glysantin.htm

As for radiators, I want to convert to a horizontal flow with a remote, pressurized, reservoir for better efficiency, but my 3 row old top down does a fine job (no overheating even in Chicago traffic.

Keith

Josh - Sorry. I forgot to post this picture. Here is the probe located under the radiator neck. It is the small, pencil looking thing that is stainless.



I don't know exactly what it is set at. I let the engine go to 195 and adjust the fans to come on at that temp. However, I messed with it the other day and turned them too low. I can tell you driving it around yesterday that the fans make a 8-10 degree difference... It was running a 225 by the time I got home without the fans on (but it is hot right now). Unfortunately when I went out there today to start it up I realized that I had set it too low when I tried to correct it. The fans had ran all night last night and my battery was dead. So it is a pain to get it set up right initially.

Kiethg - I want to change out my coolant next year. They used the green dexcool at the shop I go to. I know that stuff can eat the aluminum blocks, from what I have read. I will switch over to what you are using.

Quick aside here - My dad swears by Purple Ice. He uses it in his motor home to get it down 10 to 15 degrees versus running only antifreeze/water mix. Has anyone heard of it? I am scared to put it in my car because of the corrosion concern.

DexCool is orange. Green is 'traditional' coolant. I do not know what the composition is but it is the stuff that can eat up components in fe/al engines over time. The G05 is amber and is what VW, MB, Chrysler and Ford use (AFAIK) in new(er) cars. Saab used G48 which is blue and similar chemically to G05. If you have Green coolant, it is traditional style coolant and not DexCool.

Just do a search on 'DexCool Problems' or 'DexCool Lawsuit'. As far as I am concerned, it is probably 'fine' as long as there is no air in the system and if it is changed on a 5 year or 100k schedule. I just don't want to chance it in my cars. I know the G05 has proven to work excellently for many years in the Fe/Al and Al engines for many years. I use it in my Saabs and have far less white corrosion on the aluminum parts. When I got the Buick, I used it there as well.

Keith

The mechanic said that it is a generic green dexcool, so not sure what he was talking about. Next year I will switch over to what you have in the Saabs - I would like something designated for aluminum engines specifically.

I went to Zerex G05 in my '08 Z06 because of concerns with Dex-cool and problems GM had experienced. Check this site out it has enough info to make your head explode!
BITOG....http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=cfrm

Thanks for the heads up. I am feeling better about this coolant thing now. I imagine I want to flush everything out first and not mix fluids at all. Josh - how did you add the recovery tank? How did the plumbing work for that?

Ill do my best to try to take some photos of it this weekend. Was a super simple upgrade -- cost less than $20 to do too.

Bill--

I'm seriously slackin' on getting them pix together LOL -- my labor day weekend ended up mostly a blur from one too many daddy soda's and late nights and I haven't been out to the garage since. Ill try to get them tonight.

I used this kit from O'Reilly's http://www.oreillyauto.com/site/c/detail/INT0/MCR3/N0186.oap?ck=Search_coolant+recovery+tank+-+universal_-1_-1&keyword=coolant+recovery+tank+-+universal

-- it had everything one would need to make it work but I opted to use better hose and better hose clamps. I removed the stock windshield washer rezzy and used it's location for the recovery tank. Couple of bends on the supplied bracket and a few selftapping screws in the core support and BAM it was done.

You don't have to worry about the pics- between the explaination you gave and seeing the unit on the website I know what you mean now. I am travelling on business this week but will tackle it when I get back. Thanks!!

Here are some pix anyways Bill -- maybe you'll see something you wouldn't have thought of or would do differently...