Community Forums

Full-Timers · 04-01-2015, 10:43 PM

I’m getting ready to do a Radiator flush on my 2002 W22 8.1L. What I plan to do is warm up the engine to open the thermostat. Drain the system and refill with a radiator flush and distilled water. Run engine again to open the thermostat. Drain and refill with distilled water, warm up and drain until drained water is clear. Then fill system with the right 50/50 mix. I might possible remove the thermostat and replace it with a 160 at the end of this process.

My question is has anyone used a flush to clean their system? This is why I want to use a flush

Another question is how risky is it to open the petcock. I don’t want to break the cheap plastic thing and end up with a major repair.

Davel · 04-02-2015, 12:05 AM

I have flushed mine two times since 2004 and plan to do it again this summer. I didn't use radiator flush after I read some articles that concerned me. I used the Prestone flush kit and pushed soft water through the entire system till it was clear. I made up a air fitting to push all the water out I could. I never seem to be able to get it all out and therefore can't get the misture quite to 50/50. I would prefer to use distilled, but don't because I can't get all the soft water out. I have the whole coach heating system that makes it hard to fully drain. But I winter in FL. so I'm not worried. I have changed to a 180 thermostat and am very satisfied with it.

I haven't opened the petcock for the same reasons. I pull the bottom radiator hose very carefully. I'm planning on new hoses this summer as the coach is 11 years old.

Good luck,
Dave

onlakegaston · 04-02-2015, 05:40 AM

I flushed my radiator last spring and used Prestone radiator flush and the flush kit. I did open the plastic petcock on the bottom of the radiator and had no issues - but I do like the idea of pulling the bottom hose as the petcock looked and felt a little cheap and I was worried that it may not go back properly but it did. When flushing was complete I let it drain overnight (never got it all out) and refilled with a 50/50 mix of distilled and dexcool. Left the thermostat intact - did not change

M&EM · 04-02-2015, 10:00 AM

The petcock is readily available at Napa. The O ring seems to be the weak point of its' design.

F-T, I don't recall seeing crud at the radiator as you have shown.

This what I do.

I have been on a 3-4 year DEX coolant service doing the following :

I remove the engine block drain plugs and radiator drain cock when flushing with tap water/draining for each of 3 flushes and refilling with distilled water and a flush chemical. Final flush with tap water and drain. close drains and plugs.

With cap off, and one heater hose disconnected(heatercontrol set high heat), I funnel new coolant via heater hose until coolant appears at radiator cap and other heater hose. Re attach hoses.

I refill with 1 gallon pure DEX and 1 gallon of distilled water. Top off remaining amounts with premixed 50/50 DEX and distilled water.

Warm up engine to purge any air and let cool a bit.

Remove cap and top off again.

Fill recovery tank.

I have been using the 180 deg stat for 2 years and am quite happy with it.

vettenuts · 04-02-2015, 03:07 PM

Not sure what is gained with the lower thermostat unless a change in fan control is instituted. Thermostat only controls start of flow, not operating temperature. I would just flush until clear with distilled water then drain and add straight Dexcool to half capacity then top off with distilled water. In other words, after final drain, if capacity is four gallons of 50/50, then add two gallons of straight and top off with water. Final mixture will be correct.

F4Gary · 04-02-2015, 04:26 PM

You could get rid of the Dex-cool too and go with something like Peak Global.

vettenuts · 04-02-2015, 05:02 PM

I am a big fan of Dexcool. Have had several motors apart that use it and have inspected the internal passages with a borescope and they have all been clean as a whistle. Much cleaner than motors that have used the green glycol (Prestone).

F4Gary · 04-02-2015, 05:09 PM

BTW, I'm a vette nut too. I have a 72 LT-1 vert.

Davel · 04-03-2015, 12:02 AM

Switching to the 180 thermostat made a huge difference in fan noise from the clutch fan and a noticable difference in operating temperature. Before switching the actual temperature on the Scanguage II varied from 200 to 206-7 with the clutch fan coming on full blast. Now, with the 180 my temperature varies generally from 192 to 198 and the fan comes on very quietly. No differences in mileage or performance were noted. I wish I had made the switch years ago.

Dave

vettenuts · 04-03-2015, 05:37 AM

Quote:

Originally Posted by Davel

Switching to the 180 thermostat made a huge difference in fan noise from the clutch fan and a noticable difference in operating temperature. Before switching the actual temperature on the Scanguage II varied from 200 to 206-7 with the clutch fan coming on full blast. Now, with the 180 my temperature varies generally from 192 to 198 and the fan comes on very quietly. No differences in mileage or performance were noted. I wish I had made the switch years ago.

Dave

Do you know the operating parameters of the fan? Would be interesting to know.

vettenuts · 04-03-2015, 05:39 AM

Quote:

Originally Posted by F4Gary

BTW, I'm a vette nut too. I have a 72 LT-1 vert.

Very nice

There are actually quite a few people on this forum who have Vettes. Wish it were easier to take with us on the road, although we travel with a Golden Retriever so that might not work out to well.

Davel · 04-03-2015, 11:43 PM

The clutch fan comes on when the air temperature coming thru the radiator reaches 157 degrees. I'm not sure if that's when it first comes on or when it comes on all the way. I have the engineering drawing...somewhere.

Dave

vettenuts · 04-04-2015, 06:07 AM

Quote:

Originally Posted by Davel

The clutch fan comes on when the air temperature coming thru the radiator reaches 157 degrees. I'm not sure if that's when it first comes on or when it comes on all the way. I have the engineering drawing...somewhere.

Dave

Ah, now I understand how the lower thermostat would benefit. On the Vette, with electric fans, you need to re-program. If you don't, when sitting at a light, the fans will still come on at 227 no matter what the thermostat. Have to keep this in mind for later.

Thanks