Radiator has dirt?

**MasonWS6** · 05-13-2015, 04:03 PM

I noticed inside my radiator on the cap and the dipstick for the overflow tank had some crud on it that looks like dirt. i plan on doing a flush soon. Anyone know how or what the could be from? Also my car pissed antifreeze the other day when I got home from a 1hr ride from work from the overflow tank not the radiator, the car never over heated or ran hot. It was probably 85 that day. Anyone know? Thank You

**raynor139** · 05-13-2015, 04:20 PM

Have u ever mixed regular antifreeze/coolant with the GM dexcool? If they mix it will cause this brown crud to form.

**pajeff02** · 05-13-2015, 05:14 PM

^^ This.

Also, if the system has never been serviced it is long past due.

**MasonWS6** · 05-13-2015, 05:15 PM

No I've never heard of it, and also I've never flushed myself. Had it since last june

**pajeff02** · 05-13-2015, 05:18 PM

What color is the coolant - green or orange?

**MasonWS6** · 05-13-2015, 05:22 PM

Orange

**pajeff02** · 05-13-2015, 05:23 PM

Ok - hopefully it has Dexcool in it then. Let me see if I can find my old posts on flushing the system.

**MasonWS6** · 05-13-2015, 05:25 PM

Ok thanks

**pajeff02** · 05-13-2015, 05:33 PM

Here is one of them that I posted a few years back:

On the passenger side of the radiator there is a petcock that you open by turning counterclockwise to allow the coolant to drain. Unfortunately, there is quite a bit of coolant that remains in the block if you simply drain the radiator. The block drains are not all that bad to get to. On the passenger side, the drain is located above the starter. Use a 5/16" allen head on a 9" extension (it may actually be metric, but this had the best fit). On the driver side, the drain is a 17mm allen head located above and behind the alternator. The only thing I had to remove was the alternator splash guard. You can purchase a set of large allen head sockets from Autozone for about $12.00.

There is an air bleed built into the thermostat to allow air to escape as the system is filled. I just did a slow fill over time, adding a bit of coolant every 5-10 minutes, rocking the car and bouncing it on the suspension helps work the air out. On start up, just keep an eye on your gauges. You can also feel your hoses (careful of the belts) to ensure that coolant is flowing. If you are going to the trouble of dropping the coolant, it is best to get all the old stuff out. Flushing it is even better (no chemical flush!) and is easiest with the thermostat removed from the housing.

**pajeff02** · 05-13-2015, 05:33 PM

Here is one of them that I posted a few years back:

On the passenger side of the radiator there is a petcock that you open by turning counterclockwise to allow the coolant to drain. Unfortunately, there is quite a bit of coolant that remains in the block if you simply drain the radiator. The block drains are not all that bad to get to. On the passenger side, the drain is located above the starter. Use a 5/16" allen head on a 9" extension (it may actually be metric, but this had the best fit). On the driver side, the drain is a 17mm allen head located above and behind the alternator. The only thing I had to remove was the alternator splash guard. You can purchase a set of large allen head sockets from Autozone for about $12.00.

There is an air bleed built into the thermostat to allow air to escape as the system is filled. I just did a slow fill over time, adding a bit of coolant every 5-10 minutes, rocking the car and bouncing it on the suspension helps work the air out. On start up, just keep an eye on your gauges. You can also feel your hoses (careful of the belts) to ensure that coolant is flowing. If you are going to the trouble of dropping the coolant, it is best to get all the old stuff out. Flushing it is even better (no chemical flush!) and is easiest with the thermostat removed from the housing.

**MasonWS6** · 05-14-2015, 06:00 PM

What's the best way to get the left over dirt residue out from the radiator?

**pajeff02** · 05-15-2015, 03:00 AM

Pull the hoses off the radiator, stick your garden hose into the inlet and let it run. Give the heater core the same treatment by pulling the hoses on the passenger side of the engine above the AC compressor. I highly recommend removing the block drains and flushing it as well in the same manner. FWIW, the service manual recommends against utilizing a chemical flushing agent.