Cooling System Questions - a proactive approach 1990 Q45

[gniknave]

I have a couple of questions here. First of all, I'd like to mention that the previous owner of my Q switched the coolant to Dexcool. While I've heard good, and bad about Dexcool, I'd rather be using the green coolant and just flush it regularly.

Anyway getting to the point... I hear about many Q45's that end up overheating due to a lack of maintaining the cooling system. What are some things I can do to make sure this doesn't happen to me? I know the thermostat and waterpump have been replaced within the last 70k, but when SHOULD those items be replaced?

I'm not one that's going to wait until my temperature gauge starts creeping up above normal to take action. What are the things I can do to make sure this doesn't happen to me? Also, what can I do to fully switch my system back to using green coolant and not the Dexcool - without ending up mixing the two in any way shape or form causing sludge?

Second question... I have a front crank seal leak that I want to take care of. However I'm afraid to do so because I'm going to have to remove the radiator, which means I'll have to drain and fill the system with new Dexcool. I've heard hooror stories about even a drain and fill of Dexcool causing sludge buildup. Should I be concerned about doing this? Is there something I can do to avoid this?

As always everybodys input is well appreciated!

[PopPop]

Just make sure that you drain coolant out of engine block along with radiator!

[Q45tech]

Smart people drain and refill every year, regardless of type or brand.

Don't confuse how DexCool [OAT technology] reacts in iron/aluminum vs all aluminum engines.

[Flagship-Q]

You can also buy a flush kit by Prestone that you hook a garden hose to and works very well (have done this in all cars I've owned - just follow the instructions) so you can do a thorough flush every year. Also, I'd replace that T-stat every 40K or so since it's only a $10 part through the Infiniti dealership. Performing both of these things cost less that $20, WAY cheap insurance and keeps things nice and clean in there!

[maxnix]

You can also buy a flush kit by Prestone that you hook a garden hose

But be sure final flush and fill are with distilled water only! Chlorinated and mineralized water is best avoided.

[gniknave]

Don't confuse how DexCool [OAT technology] reacts in iron/aluminum vs all aluminum engines.

So are you saying I shouldn't be concerned about the drain and fill of the radiator when replacing my crank seal? Do you recommend just sticking with Dexcool?

[elwesso]

Heres what I do, this shoudl work great for you.

BUY: A few gallons (4-5) of distilled water from wally world, a new Tstat from Joe, some RTV, and some AF.

1. Remove your Tstat2. plug everything back in (with Tstat out)3. drain the radiator4. Fill the radiator with water5. Start car for a few minutes, or even more ideally you could rig something to the water pump so you didnt have to run the engine... regardless, run the engine for a minute or 26. drain the radiator7. repeat steps 3-6 until you get clear water coming out.8. After the final drain, replace the Tstat, and then fill the radiator up with 100% anti freeze, this will give you about 70/30 mix, which is a good mix...

Or you can do what Dale suggested and use the garden hose method which probably works equally well.....

BTW dont use the radiator drain, just take the lower radiator hose off, makes things go much faster.