Flushing the Radiator

[caddy]

I have a 94 and I was wanting to flush my radiator and put in some new fresh go go juice anyone out there have any "procedures" that should be followed for doing this?
thanks

 

[poorboys831]

First and most important is make sure you don't get the OPTI wet.Put towels or something down there to catch and soak up or re-route any drips that might get down there.This is the way I do mine-Make sure the engine is cool,open the petcock and relieve any pressure from your tank.Remove the overflow tank, drain it and clean it out.Remove the upper rad. hose,remove the therm. housing(check therm.)When all the water is gone(done draining),flush the engine from the therm. opening till all runs clear-then the radiator from the top hose.With all this flushing ,this is why you MUST protect the OPTI.when you are satisfied that all is flushed and the water runs clear reconnect the rad. hose ,close the pecock,re-connect the overflow tank,and put the therm. back in .I'm not sure but my '93 has a screw on the therm. housing to let out air so there are no air bubbles when you refill.after all is put back together(keep the OPTI protected)start the baby up and fill her up.I always add water wetter last.good luck I think I got it all-Don't forget to clean the outside of the rad. and a/c. Dennis

 

[caddy]

Thanks Dennis, I'll give it a whril!;worship

 

[rrubel]

If you're going to be complete, remove the knock sensor then when flushing watch until it runs clear from that hole.

When filling it, get it as full as you can, LEAVE THE RADIATOR CAP OFF, then start the car and let it warm to operating temp (so the thermostat will open). Then slowly open the bleed screw that poorboys mentioned; you should get air at first but soon after get coolant. CLose the screw and fill the radiator the rest of the way and then put the cap on. Then make sure the overflow tank is at the right level.

This ensures there are no air bubbles in the system, which can be quite bad...

[RICHR]

 

[jmccloud]

Cleaning cooling system

Do not use cleaning agents (so says the service manual). Use water only. Removing the knock sensors really improves the job. After flush and fill, operate the engine to full warm and allow to cool down once or twice or thrice, keeping the overflow tank up to level. Don't wind it out until all the air is out.

 

[GS/0057]

What happes if your system has air bubbles in it and what does removing the knock sensor do? Can you tell if your colling system has air in it?
Thanks,Michael

 

[rrubel]

If you have air bubbles in the coolant, then you can develop local hot spots and keep coolant from flowing properly (in my personal experience, the temp gauge goes WAY up, even though there's plenty of coolant, or the gauge will go up while stopped but drop down quickly as soon as you move again).

Removing the knock sensor lets you drain out all the coolant that's sitting in the engine. Take it from me - there's a *lot* in there .
[RICHR]

 

[GS/0057]

rrubel, Thanks for the reply. That is exactly what my car has been doing after I changed to a 160 t-stat(computer reprogramed for fan settings at 180/187) and did not use the air release valve on the t-stat housing. It got up to around 95 degrees last Saturday and in traffic with my A/C on my cooling temp was around 220-230 sitting in traffic. As soon as I got moving and on an interstate at 70mph the temp dropped to around 190 after about 5 miles of cursing. How do I fix the cooling system if the air bubbles is the problem? Do I remove the radiator cap let the engine come up to operating temperature and bleed the screw on top of the t-stat housing?
Thanks, Michael

 

[KOPBET]

...dropped to around 190 after about 5 miles of cursing.

I'm glad to hear cursing really does help! You must have been really hoarse by then!

I'm sorry. Carry on.

 

[rrubel]

miles of cursing. How do I fix the cooling system if the air bubbles is the problem? Do I remove the radiator cap let the engine come up to operating temperature and bleed the screw on top of the t-stat housing?

Keep the cap on, but otherwise you're correct - let the car warm up (I was also told to turn the cabin heat to high) and then loosen the bleed screw until coolant flows from it.
[RICHR]

 

[poorboys831]

REMEMBER keep that opti DRY when bleeding-Dennis:W