Can fresh coolant dissolve old mineral deposits?

Yuk

Yuk

Joined
Jun 16, 2003
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Location
Edmonton, AB Canada
My 2005 Jaguar XJ-8 Vanden Plas seems to have been maintained extremely well by it's former owner, with exception of it's cooling system. It produces great heat on the front passenger's side (80-90˚C), but much less heat on the drivers side (something like 30˚C- 40˚C after I bought it).

I have now flushed the system four times. During one of those flushes, Prestone Total Cooling System Cleaner was used. I have also done an extensive back flush on the isolated heater core. The driver's side floor vent now seems to move heat at the same temperature as the passenger's side, but the extreme left dash vent only reaches about 66-67˚C.

I have now installed Prestone Max All Vehicles coolant. Is there any chance this coolant will clear up any remaining blockages, or is coolant incapable of dissolving such sediments?
 
It will not. I would dump that coolant and fill with fresh water and use citric acid/water mix run for about an hour then flushed out again with water before refilling with coolant. If possible remove the thermostat and put the housing back on sans thermostat to flush and run the cleaner. Use 1lb citric acid dissolved in water for every 5 quarts of capacity. Mercedes specs citric acid and charges a lot more for a small amount. There are a few threads on this search is your friend.

This will work fine.


It is the same as this.

Lemon Acid 000-989-10-25-12 | MB Parts Center

Genuine Mercedes Benz OEM factory Part #000-989-10-25-12Lemon Acid
www.mbpartscenter.com www.mbpartscenter.com

Edit: Personally I wouldn't trust Preston any and all makes in a scooter, you could run Jd CoolGuard 2 or if in doubt use OE coolant.
 
From your description of the issue you are having, I doubt it has anything to do with blockage from mineral buildup in the coolant system.

Unless the heater on your Jag is particularly unique, every car I have ever seen has one heater core, that supplies all heat for the cabin, including defroster, passengers and driver positions. So if you are getting great heat to for the driver position, but little for the passenger, the issue is most likely in the heater box under the dash.
 
BHopkins said:
From your description of the issue you are having, I doubt it has anything to do with blockage from mineral buildup in the coolant system.

Unless the heater on your Jag is particularly unique, every car I have ever seen has one heater core, that supplies all heat for the cabin, including defroster, passengers and driver positions. So if you are getting great heat to for the driver position, but little for the passenger, the issue is most likely in the heater box under the dash.
Click to expand...
What would be wrong with the heater box? My original post actually says that the passenger vents get "great heat".

Since I've done the flushes the drivers floor vent has gone from virtually no heat to tremendous heat.
The extreme left (drivers side) dash vent is the only location that isn't receiving full heat. It has greatly improved though. Since doing the flushes that vent has gained at least 20˚C.

Could it still be a box issue, if heat has improved that much since the the flushes? The volume of air, regardless of it's temperature has always been excellent.
 
FYI, most larger grocery stores carry citric acid powder in the canning supplies section.

To really do a good flush of the heater core (only one part # is available so I'm pretty sure it only has one) disconnect both heater core hoses and route them both into a bucket full of citric acid solution. Use a small electric pump to circulate the solution for 8 or more hours and then flush both directions with water until it runs clean.
 
Last edited:
Trav said:
It will not. I would dump that coolant and fill with fresh water and use citric acid/water mix run for about an hour then flushed out again with water before refilling with coolant. If possible remove the thermostat and put the housing back on sans thermostat to flush and run the cleaner. Use 1lb citric acid dissolved in water for every 5 quarts of capacity. Mercedes specs citric acid and charges a lot more for a small amount. There are a few threads on this search is your friend.

This will work fine.


It is the same as this.

Lemon Acid 000-989-10-25-12 | MB Parts Center

Genuine Mercedes Benz OEM factory Part #000-989-10-25-12Lemon Acid
www.mbpartscenter.com www.mbpartscenter.com

Edit: Personally I wouldn't trust Preston any and all makes in a scooter, you could run Jd CoolGuard 2 or if in doubt use OE coolant.
Click to expand...
I did search, extensively, nothing I found addressed my specific problem.

Why are you so heavily biased against Prestone? When using the properly spec'd coolant, with proper maintenance intervals, I have found Prestone to be perfectly fine. I think in this regard, proper maintenance is far more important than brand.
For example, this car has only ever had OEM Jaguar coolant in it, yet due to poor maintenance, there is an obvious scaling issue.

Also, this car does not require exotic coolant. Jaguar only specs WSS M97B44-D coolant.
 
Can fresh coolant dissolve old mineral deposits? No!
Old mineral deposits are from using tap water in the coolant mix.
The suggested citric acid flush is your best bet.
 
Yuk said:
I did search, extensively, nothing I found addressed my specific problem.

Why are you so heavily biased against Prestone? When using the properly spec'd coolant, with proper maintenance intervals, I have found Prestone to be perfectly fine. I think in this regard, proper maintenance is far more important than brand.
For example, this car has only ever had OEM Jaguar coolant in it, yet due to poor maintenance, there is an obvious scaling issue.

Also, this car does not require exotic coolant. Jaguar only specs WSS M97B44-D coolant.
Click to expand...
I would add-flush in the OPPOSITE direction of normal coolant flow. On the Transit heater cores we had that were plugged by MC Specialty Orange (AKA Dexcool) coolant, the same symptoms as your Jag presented-weak heat out of only one side. Back flushing & switching to Specialty Yellow (AKA Prestone Universal) cured them.
 
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Yuk said:
I did search, extensively, nothing I found addressed my specific problem.

Why are you so heavily biased against Prestone? When using the properly spec'd coolant, with proper maintenance intervals, I have found Prestone to be perfectly fine. I think in this regard, proper maintenance is far more important than brand.
For example, this car has only ever had OEM Jaguar coolant in it, yet due to poor maintenance, there is an obvious scaling issue.

Also, this car does not require exotic coolant. Jaguar only specs WSS M97B44-D coolant.
Click to expand...
Simply because I don't believe anything can be all makes and models. Why are you so heavily biased against OE coolant? Do you know if it contains any 2-Ethyl Hexanoic Acid? Is it a dexcool clone? Does this engine have a wet intake?
Its you car and your money use whatever you want.
 
The most plausible scenario is you had a partial air lock in your heater core that came out after you frigged with the coolant some more. However the dual zone air box is set up, the air for the drivers side likely comes from a higher elevation part of the core. Am I a Jaaag expert? No!
 
Trav said:
Why are you so heavily biased against OE coolant? Do you know if it contains any 2-Ethyl Hexanoic Acid? Is it a dexcool clone? Does this engine have a wet intake?
Its you car and your money use whatever you want.
Click to expand...
Man, why are you being so combative? I'm just asking a question about coolant, I'm not insulting anyone.

I never said I was "against OE coolant". Show me where I said that.

All I asked was why are you biased against Prestone? You said,
"Personally I wouldn't trust Preston any and all makes in a scooter..."

By the way, "biased" is not an insult or negative term. It only denotes an strong, possibly unwavering perspective, which might be based in fact, or opinion.

Is your comment based on a poor result you witnessed, or is that just based on a gut instinct?
Like I said, I've never bad mouthed OEM. I just happen to have firsthand experience where OEM coolants performed no better than Prestone... because of poor maintenance practices.

In over 35 years of vehicle ownership I've never experienced a coolant failure that was due to any Prestone coolant.
Have you? I'm not being obnoxious, I seriously want to know.
 
Last edited:
Yuk said:
What would be wrong with the heater box? My original post actually says that the passenger vents get "great heat".

Since I've done the flushes the drivers floor vent has gone from virtually no heat to tremendous heat.
The extreme left (drivers side) dash vent is the only location that isn't receiving full heat. It has greatly improved though. Since doing the flushes that vent has gained at least 20˚C.

Could it still be a box issue, if heat has improved that much since the the flushes? The volume of air, regardless of it's temperature has always been excellent.
Click to expand...
It is entirely likely that your cooling system needed a flush, so you are able to tell the difference before vs after flush. That would account for why you have noticed a significant improvement in heat. But the engine cooling system has nothing to do with the distribution of heat to the different vents within the interior of the car.

Here is a parts list for the heater components in your car. Air blows through the heater core (find # 4) and that is how heat is transferred from the engine coolant to the interior. I'm limited on my expertise as to what goes on inside the air box, but if I understand correctly, there is a blend door inside the evaporator assembly that directs air flow to, say the windshield defroster or to the footwells, and such.

Heater for 2005 Jaguar XJ8 | OEM Parts Online

jaguar.oempartsonline.com jaguar.oempartsonline.com

If you are getting plenty of heat on one side, and nothing on the other, it seems that something is keeping the air that is passing through the heater core from being directed to the passenger footwell.
 
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Thanks for the information, I really appreciate it!

BHopkins said:
If you are getting plenty of heat on one side, and nothing on the other, it seems that something is keeping the air that is passing through the heater core from being directed to the passenger footwell.
Click to expand...

I totally agree with your quote above, and that's the confusing part. What you said here is not what happening.

For the sake of this discussion, there are 12ish vents in the car. Let's call it 2 vents to defrost the front windshield. Four vents in the dash. One left, one right, two in the middle. Left foot and right foot vents. Two back seat floor vents, two back seat face vents.
All of these vents blow with equal pressure and speed.
All of the vents now produce (after four flushes) essentially the same high heat, except for the left, driver's vent. That one vent produces "good" heat, but not excellent heat. I would say the left vent (based on laser thermometer readings) only produces about 2/3 of the heat of the other vents, but has 100% of the volume of air flow and pressure.

I'm perplexed.
 
It's more likely to be a temperature sensor or temperature blend issue than a cooling system deposit issue.
 
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I did a Google search on driver's side heat on the XJ-8 and saw lots of hits. You might have good luck checking the Jag forums. (Not saying get lost or anything like that).
 
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