haxxx

I run dexcool in all my GM vehicles including my corvette. I believe there is a legit reason for it's hate back when it was new. It could turn to sludge and clog up intake runners and stuff. It could ruin engines. It no longer does that and seems to basically last forever.

belairbrian

Same here. Thought for a minute I removed the wrong sensor.

kael

I used the same recently, but added in Prestone Cleaner as well, since mine was really nasty. If you need a heavy clean, you will need to pull the block plugs to get a good drain. Fortunately, the T helps flush those also.


As far as DEXCool, which year matters alot, early C4s should definitely NOT use it.

WW7

If you replace the coolant every 2 years you won't have any crud in your engine.. I just replaced my head gaskets on my 383 recently and when I drained the block there was nothing but coolant in there... I use the Green coolant every 2 years and have no problems with crud in my motor....I do run plain water for a few days just to flush the coolant out , then I drain, fill with 1 3/4 gallon of straight coolant , then top off with water..... No Problems..My C6 Corvette says right in the FSM and owners manual to use clean tap water from the faucet, not distilled or anything special..I would imagine you can do the same with the C4 as long as your using city water and not from a well.. WW
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lectroglide

As some here know Ive had some cooling problems with my 95 so am gonna first try the inexpensive way 1st which is a complete coolant flush,if that doesn't work will go to plan #2

Was just at the shop re a coolant flush and explained the block needs to be drained! but the guy didn't think so and said if the cars heating up thiers something else going on, which in turn I explained C4s just run hot, and if it gets up to a certain temp I turn on the AC, and the other fan comes on and temp drops to around 201-205 depending on outside temp, sometimes I can smell it getting hot but no visable signs.

Heres an uppdate on recent temps Ive had, its been in the 70s 80s and 90s around here so the car has been up to 230, I turn on AC and the temp drops when in traffic, other than that it stays around 205-209
but when moving drops to 201-203.


When I 1st got the car 2 months ago their was some notes re maint. etc
that said "recent coolant service" but just last week when they did a brake flush mentioned the coolant was nasty, so am guessing the maint work note is incorrect, however I just seen a coolant work order for 4/20/16 so am assuming it was done on that date, anyway will see what happens after the flush

Cruisinfanatic

you need to get the radiator out and clean it properly. The fins need to be clean!!!!. Just doing a coolant flush won't change anything
Here's what a dirty radiator looks like

lectroglide

so from your experience are you assuming that's the problem or just a guess?

also is that picture in front or behind the radiator??

lectroglide

just went out and run the temp up to 220 thinking the left fan would come on but didn't, so I cranked up the AC and both fans came on, so now am wondering why the left fan came on only when I started the AC and stopped when the AC was off or wouldn't run at all even at 220

Cruisinfanatic

It's not supposed to. 228 is when it comes on. The debris is always on the front

Cruisinfanatic

You're way too worried about temps. 230 is nothing on a 90 degree day in traffic

A Peter C4

Take out the radiator and clean the fins and flush out core with a hose and reinstall it, you will see a big difference.The picture in post earlier is of the front behind the ac condenser. you will run in the 190's when on hiway.

lectroglide

ok thanx guys, next question is their a link that shows how to remove the rad??? I mean someone actually doing it step X step

A Peter C4

Yes see the sticky section of forum. The 6 little screws at the bottom are a pain to remove but just change the clip nuts over to the oposite holes and it's easier to put back together and remove in the future.

bac22

That's a complete foo recommendation especially if your water is heavy with mineral deposits or at they saying doing this short term to flush?

Cruisinfanatic

did you bother to Google it?
https://www.google.com/search?q=c4+b...diator+removal

don hall

The 'guy' to whom you quote saying the block doesn't need to be drained, may not be familiar with LT1 Corvettes.

The block acts as a sump for coolant sediment, and the sediment will not be removed unless the knock sensors are removed. If it has been a few years since the coolant has been changed, using water under pressure directed into the sensor holes may be required to loosen the sediment. A simple drain will not remove a build up of sediment that has accumulated over the years.

It is suggested that the knock sensors be replaced with new, if they haven't be changed. The sensors come with sealant applied to the threads, so no additional tape is necessary. It is important to torque the sensors to 14 ft# when replacing.

kael

I wish the PO had done that.

jsmcol

I just flushed and replaced coolant in a '93 ruby I just bought in January.
It was the orangish fluid, that's the dexcool right?


I read up on other forum threads and actually flushed using distilled water about 4 times to circulate throughout the engine. Let it cool, flush again. Eventually the water was no longer brown so I refilled with antifreeze. It used to stay about the 195 temp, but have been monitoring and it will go to 204 or 205 if stuck in traffic.


The way I look at it as anything I could have done is only going to help.
I will change it again in another year just to see what it looks like then.
PO must not have changed it in awhile. Had to clean the overflow tank as well, was stained brownish, so can only image what the radiator looks like. I was afraid to use the harsher Prestone Flush stuff in it, I heard it can cause issues if the radiator is thin, and I just didn't know at that point. I think it's good now...


Anyway, instead of water, use distilled water, it's cheap at any drugstore, walmart, etc.

don hall

No matter how cheap, using distilled water for flushing is a complete
waste of money.

Distilled water use in a cooling system is to prevent the build up of minerals which, over many years, may slow the flow of coolant.
The amount of minerals in your water varies from city to city. If you have a faucet filter, many minerals are removed, so using your tap water for the radiator is fine.

Changing coolant regularly (3 years) eliminates the need to use distilled water, even if you don't have a faucet filter.

When you add coolant to distilled water, you no longer have a distilled liquid.

kael

I'd save distilled water for making 50/50 coolant. Tap water doesn't have time to make mineral deposits during flush, even if driving around for a day.