Hey everyone, my mom had made a comment to me a couple weeks ago that the heat on the driver side of her 2005 XJR has stopped working and just blows cold. I searched the issue and found that it is pretty common, particularly with XJRs. I decided to do a flush to see if I could break up the clog. Before I refilled the cooling system with distilled water and the flush agent, I noticed a brown, jelly like substance with what feels like grit in it on the top of the engine where you fill the coolant through the supercharger. This fixed the heat issue, although it still is not as hot as it is on the passenger side...

This car only has 67k miles on it, and has been serviced its whole life per the Jaguar service intervals at the dealership up until about 5 months ago when the warranty expired. Since then its just been going to a reputable Jaguar shop for its service. My point being, its always been serviced with the correct coolant and has never had any additives put in the coolant (up until the flush). How on earth does this happen?

I realize Jaguar says to use their specific coolant which is basically "dexcool". Based on my bad experience with dexcool in the past, I've always swapped it with a different high quality/trusted coolant on my other older vehicles. Particularly with my Land Rovers. My friends have all had issues with head gaskets on their Land Rovers, but I never have... Is that because of dexcool maybe?

Sorry for the long winded post, it is more or less a rant, but I'm not sure what to do about my mother's Jag. It doesn't overheat, and ever since doing a radiator flush/clean the heat is working again (not as well as the other side), but its not good to have that gritty sludge in it. Has anyone on here had any luck with a different type of coolant used in their X350? Part of my wants to replace the heater core, radiator, flush the engine, and use a different coolant. Any advice or insight is appreciated! Thanks in advance .

 

The gritty deposit might be lime scale. Do you get scale in your kettle?

The recommended antifreeze is orange coloured, to a Ford spec. They say you should use none other. The orange is not widely stocked. We do not have Dexcool in UK but I have heard it is made to the basic industry standard.

Good idea to use distilled or deionised water.

 

You are lucky that you have removed some of the gelatinous substance and

have some heat on the driver's side since flushing only works 50% of the time.

I believe the goo comes from the coolant itself but we do not know the

mechanism for the deposition.

I think it is likely to be aluminium hydroxide which is gelatinous and white but it

could be coloured by the dye in the coolant.

There is an oxide of iron which is brown and gelatinous but I think the aluminium

is more likely since AFIK there is little iron in the system.

You could try another flush plus reverse flush but I would not consider using another coolant.

 

If this gritty gel is on the top of the engine, is it coolant that has leaked out? I was thinking of spillage when topping up.

 

Thanks for the replies, and sorry for the late response. From what I've read its a bad idea to switch the coolant. Although, I've flushed and switched our Discovery's coolant to Prestone about 2 years ago (it does say it can be mixed with any coolant), and it does seem to run cooler than before, and no issues to report. I may switch the coolant to prestone in the Jaguar just because of my sucess with the Discovery. In either case the heater does work better now in the Jaguar, but if you are idling it starts to get cold. If you get on the gas, it starts to really warm up. Since we are going into spring, I'll change my attention to other things that need service for the time being. I'll let be sure to post my findings later. Thanks!

 

Don't forget to check the Aux Pump too.