Jump to content
CaddyInfo Cadillac Forum

Flushing or leaving old DexCool?


Recommended Posts

Hi

I just bought a 2003 Cadillac DeVille DHS. I'm in Europe and there are only 3 other DeVilles here in Poland, so let's say that this car is pretty unique and it's hard to find a good, reliable mechanic, so I have to do everything myself as others don't want to touch a car that's so rare :).

So here's my issue. It seems that the car has still got the original Dexcool coolant from the factory. The car's got 95k miles on it, but it's 13 years old, so the coolant doesn't look so good and seems to exhibit the dreaded Dexcool issues: it's not very bad, but the color is a little bit muddy and I can see a lot of residue after opening the coolant tank. The car doesn't overheat or anything, but yeah, the coolant doesn't look nice...

My question is: what would be the best option now? Should I flush it and replace it now and probably use some cleaner to remove all the residue, or should I just leave it be?

Is it OK to use something else than Dexcool? It's not easily available here, but we've got other coolants that are based on the Organic Acid technology without the silicates.

Link to comment
Share on other sites


Welcome; I am glad you are here.

The manual seems excited about it: When adding coolant, it is important that you use only DEX-COOL@(silicate-free) coolant.

If coolant other than DEX-COOL@is added to the system, premature engine, heater core or radiator corrosion may result. In addition, the engine coolant will require change sooner at 30,000 miles (50,000 km) or 24 months, whichever occurs first. Damage caused by the use of coolant other than DEX-COOL@is not covered by your new vehicle warranty.

I would check the product labelling for silicate free coolant to ensure is is compatible

Coolant drain, flush, and refill is due at 150k miles (240km) or every 60 months (5 years)

Bruce

2016 Cadillac ATS-V gray/black

Follow me on: Twitter Instagram Youtube

Link to comment
Share on other sites

Any Organic Acid Type coolant can be used, regardless of manufacturer. You might look for GM approved coolant if you can. Green coolant with silicates should never be used in this engine.

No need to flush anything with this engine. Coolant should be drained from the lower radiator hose. No plain water should be introduced into the engine. You can clean out the reservoir tank while you have the coolant out if you like, just for appearance sake. This year engine also requires the use a block sealant during refill. Use GM sealant or Bar's Leak powder (1 tube). Lacking the Bar's leak powder, the tablets will work, but they need to be crushed up before installation. Put the sealant into the LOWER RADIATOR HOSE, which is the suction to the water pump. This will put the sealant into the block and heads when the engine is first started. NEVER put bar's leak powder or tabs into the reservoir tank, they will never get to where the need to be to work effectively.

Ensure that the coolant mixture is EXACTLY 50/50 concentration before refilling the engine. If you need to mix your own coolant, do it before putting it in the engine, and use only distilled water to dilute it with.

Never underestimate the amount of a persons greed.

Link to comment
Share on other sites

Welcome.

All good news in your post so far....

It is good that the car stillhas the orange coolant as since the car was manufactured, many uninformed switched to the green stuff thinking it was better. Your coolant is supposed to look a little off color and muddy color, as that is the bars stop leak that is recommended by the manufacturer. You just don't know what the change intervals were on your car, but if you are not having overheating issues, that is also good. Many people start messing with coolant only after neglect causes a failure.

Link to comment
Share on other sites

Hi

Thank you everyone for this detailed information.

I found a Valvoline coolant that meets the GM 6277M standard (this is the same as Dexcool standard), it is also orange/amber, so that should be fine.

The car's got less than 100k miles, but it was rarely used and it's already 13 years old... The current fluid doesn't look really bad, but its color is dark amber and it seems that there's some residue left when you open the reservoir tank. I'll replace it this month.

Is this the sealant I'm supposed to use? I haven't bought it yet so I don't know the directions, but should I use all 5 tabs, or only just 1 or something else?

12378255.jpg

Edited by drakerc
Link to comment
Share on other sites

Crush all 5, then disconnect the lower radiator hose on the drivers side, and drop them all down there, then refill the system. You can fill the resouvour bottle pretty high on the first fill as there will be air in the system, and after the first drive cycle, the level will go down. The tank is only filled up 3 inches from the top so just do not over fill it.

Link to comment
Share on other sites

You really don't need to crush them - they will dissolve quickly in the presence of coolant.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

Link to comment
Share on other sites

While you are at it and cleaning things up, please make sure that the air elimination line is open and free flowing with the engine running. This is a small rubber line or tube that originates from the throttle body, (the high point of the engine) and returns a constant small stream of coolant to the reservoir. The hollow bolt that this line is attached to, at the throttle body, can sometimes plug and prevent air pockets from clearing themselves. If it runs a continuous small stream, it is fine. If it does not flow, REMOVE THE BOLT and hose to clean it, do not blow any contaminants back into the engine.

Never underestimate the amount of a persons greed.

Link to comment
Share on other sites

Just one more question.

Does it have a drain plug on the bottom of the radiator? Or can I just disconnect the lower radiator hose and most of the fluid will drain from there? I just bought the coolant and sealing tabs and I'm wondering if I'll have to jack it up in order to drain it from the bottom, or will it be OK just to drain it from the lower hose?

Link to comment
Share on other sites

I believe there is a drain on the drivers side... But if it is like the other years, it is both tough to access, and tough to get any conventional hand tool up to turn it.   I recall a few years ago someone cut a lenght of a broomstick and slotted it so they can stick it up thru the drain access port, and turn the valve open.   

 

Maybe someone with experience specifically on a '03 can chime in.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...