Flushing Coolant Out Of A 1998 Chevy Monte Carlo

[c3po]

This is how I flush coolant out of a small block chevy:
1) Drain radiator
2) Take Thermostat Out
3) Disconnect upper radiator hose
4) Run car while pouring water in radiator and continuing until the water coming out the upper radiator hose is clear.
Will this same procedure work on this Monte Carlo that has the V-6 engine in it.

 

[Donald]

Are you using distilled or tap water. You do not want the system filled with tap water after the flush.

 

[Drew99GT]

Originally Posted By: c3po
This is how I flush coolant out of a small block chevy:
1) Drain radiator
2) Take Thermostat Out
3) Disconnect upper radiator hose
4) Run car while pouring water in radiator and continuing until the water coming out the upper radiator hose is clear.
Will this same procedure work on this Monte Carlo that has the V-6 engine in it.



Yup, sure will. Is this a 3800, or a 3100? If it's a 3100, getting at the thermostat is a beetch though.

 

[c3po]

I forgot to mention when I flush I use distilled water, and yes it is the 3100. How hard is it to get the thermostat out.

 

[Drew99GT]

Originally Posted By: c3po
I forgot to mention when I flush I use distilled water, and yes it is the 3100. How hard is it to get the thermostat out.


Well, take a look at the engine - thermostat is on the driver side under the exhaust crossover pipe. It's kinda like changing the plugs on the rear cylinder bank! (you may need to have some adult beverages on stand by

).

You'll likely need some longer socket extensions and u-joints for your sockets.

 

[Donald]

How about flushing tee you install in heater hose. Wouldn't that be easier if you can find a stretch of rubber heater hose?

Maybe you could put a funnel in it or in a short length of garden hose and pour in distilled water?

 

[mechtech2]

I flush when needed. Only when something needs to be purged and scoured.
Normally, I just drain and refill.

 

[c3po]

Well, since it is my Mom's car and my Dad is old school we might just drain the radiator and refill. I am not doing the tee thing in the heater hose because they eventually leak.

 

[Donald]

Well you can buy a 1' piece of heater hose, add the tee in between the new and old heater hose and remove it when done, no cutting needed and nothing left in.

 

[c3po]

Donald, you love this heater hose tee thing, the problem I see with the tee thing is that it will not get all of the coolant out. Please correct me if I am wrong.

 

[Drew99GT]

Originally Posted By: c3po
Donald, you love this heater hose tee thing, the problem I see with the tee thing is that it will not get all of the coolant out. Please correct me if I am wrong.


Yes it will, it reverse flushes the system and leaves 100% water left.

 

[c3po]

As far as the tools I do have some extensions and universal joint things for the sockets.

 

[mstrjon32]

You might as well buy a new petcock for the radiator now, because the old one IS going to break when you take it out.

Be sure to open the bleeder valves after the flush to let air out of the system. You'll likely have to do this 3 or 4 times until it's all out.

Coolant service on those cars is a pain.

 

[c3po]

If I took the upper radiator hose off as well as the thermostat I guess I would still need to drain the radiator, a new PETCOCK.

There are bleeder valves on this car, this is not sounding like something as simple as flushing a small block chevy. Why did the engineers do this, do they not want the average SHADETREE MECHANIC to work on there cars anymore.

If this is going to be a complicated procedure I might just bring the car into Chevrolet and say do a coolant flush without the chemicals, my Dad had the water pump replaced a week ago and he thinks the coolant was changed at 60,000 miles as the car always goes in for checkup's and maintenance according to the schedule, the car now has 101,000 miles.

If anyone has flushed coolant on a small block chevy and then did it on this 3.1 V-6 Engine let me know if I should tackle this myself or take it to the dealer.

 

[mstrjon32]

I have done both, but the SBC was a pain too for other reasons (1977 Corvette, use your imagination).

I say do it. It's certainly not hard, but it is a pain. If you don't need to replace the thermostat, I'd avoid it--the tstat is much more of a pain to replace than just a coolant drain + refill. If you think it's bad (but not like, intake gasket failure bad), just do it twice.

 

[Rock_Hudstone]

Originally Posted By: c3po
I forgot to mention when I flush I use distilled water, and yes it is the 3100. How hard is it to get the thermostat out.

You're asking for trouble removing the thermostat on a 10 year old 3.1L for no good reason, its a lot of work and totally unnecessary.

We have two GM cars in the family with the 3.1L engine: A 95' Olds Cutlass and a 99' Monte Carlo, that were bought new or almost new. I've flushed the coolant on both cars many times and the easiest and best method I find is as follows:

Remove the radiator cap, open the petcock, drain the coolant, disconnect one end of the short coolant bypass hose near the water pump. Then using a garden hose with a pistol grip nozzle, alternate the water stream between the radiator filler neck and the open bypass hose until the water runs clear out of the filler neck and hose. Close the drain cock, fill the system will plain water, start the engine, put the heater on high and repeat flushing.

Yes, there will be some tap water in left the system. If you're really anal you could remove the block plugs and drain.

However, I never have and the Olds is pushing 170,000 miles.

 

[mstrjon32]

I'd avoid removing the block drain plugs. While I've never had a problem, many others have had issues with getting these bolts out and then back in smoothly. You'll be between a rock and a hard place if you strip the threads on that plug. You can easily replace a radiator, not so for an engine block.

 

[c3po]

I do not need to have any problems with the block drain plug, so that is probably out unless they are easy to get too. My Dad has a lift, I don't know if this would make the job any easier.

 

[Drew99GT]

At this point I'd just take it to a good shop and have them use a flushing machine!

 

[eljefino]

You can also drain the radiator and refill with pure water and drive around for a day, burping the bleeder valves etc. (They're only sticky the first time, you'll get good at it.)

Repeat a couple times until the junk all comes out. Benefit here is warm water is flushing the rust and sludge out of all the nooks and crannies.

When you're done, flush once with pricey water if you live where there's lots of minerals in the tap, then drain and fill with 100% antifreeze to half the rated capacity.

This will be better than a drain & fill. If you don't watch the dealer they will do a real half-fast job b/c they assume you won't know the difference.