Erniep

So what is the best way to flush out the coolant system. It doesn't seem like the regular flush kit would work on a vette.

Nowhere Man

How much do you want to flush. If the hole system remove t-stat housing, both knock sensors, drain raditor, and remove inlet heater hose to the heater core. Let all old coolant drain out. Get garden hose and start run water though until its clear coming out

92ragtop

A lot depends on the current condition of your coolant. If it's all brown, you'd be best to remove knock sensors etc, as previously mentioned. If the coolant is nice and green, you may not want to go to that extent. If so:

Remove the lower rad hose from the rad, drain and then re-attach. Remove the T-stat, and then re-install the T-stat housing to the block. Refill with clean water, and run the engine for a while. Drain and repeat. You can get a lot more water out of the block by removing the T-stat housing and using your (cleaned-out) shop vac to "push" air into the opening. Repeat this process a number of times. Once the water runs nice and clear, drain as much as you can. Install T-stat. Re-fill with distilled water and coolant. Use the air-bleed screws to remove air from the sytem.

Oh, and avoid getting your opti wet.

Erniep

Where are the air bleed screws ?

Erniep

Thanks for the info

Bobby Joe

There are two of them, each about a 10 mm bolt on each side of the thermostat

Bobby Joe

Where are the knock sensors?

Erniep

Thanks, appreciate it.

TorchTarga94

You can also remove the thermostat and reinstall the thermostat housing. Remove the drain plug from the radiator and use a 5hp shop vac on "blow mode" and stick it right in the reservoir snout. This will blow all the coolant out of the block and radiator with clean filtered air. Works like a charm and is fast.

92ragtop

On both sides of the block, above the oil pan. You'll see an electrical connector on them. Do a search here to find out more about how best to remove them.

92ragtop

One is on the T-stat housing. It's the small brass fitting here:



The other one is on the opposite side, underneath the throttle body, and looks the same.

Erniep

I see it, thanks

Erniep

great idea, thanks

Bobby Joe

How are your hoses so dang shiny!!

And did you clean the hell out of your shop vac first?

92ragtop

I keep the engine clean, and then once a year use CD-2 engine detailer.

And yes...make sure the shop-vac is clean so you don't blow crap into your cooling system.

Bobby Joe

I keep mine clean too, but thanks to you and CD2, I can may it shiny too!! LOL. THANKS!

I may try that shop vac idea too

Bobby Joe

When flushing the engine, do you need to use distilled water or can you use hose water? And how much would you expect to go through? I flushed 9 gallons of DI water through last night and there is still some light sediments and greenish color left.

Erniep

Just use regular tap water for the flushing. Use the distilled water to mix with the anti freeze

braveheart3158

Someone else just posted that there is only one on the 94