I was checking things out under the hood last night,, its a 2007 x350 xj8, noticed the bottom hose was collapsed . the engine was cold, the coolant level in the expansion tank was raised slightly,
The expansion tank, thermostat and housing were replaced just under three years ago,
Took car for a run , does not overheat and hose felt ok,
This morning the hose looks ok but when i compress it it feels empty,,
does anyone have any idea what the problem is?
regards Dave
2007 xj8,

 

Hoses are made of a better grade rubber, softer to the touch when squeezed, compared to the regular type of coolant hoses, which are much stiffer. Whats the milage on them?After 100,000 miles you might want to replace them anytime they are removed, as when the water pump, or any other coolant part is replaced.

 

The car has 80,000 miles on it,,, just had a look at it and it feels like both upper and lower hoese are empty, when ipress them there is no movement of the coolant in the overflow tank, wonder if its a thermostat issue,,,,

 

Replace pressure cap

https://www.jaguarforums.com/forum/x...problem-97631/

 

I was going to change the thermostat and the bottom hose but will see if i can get a tank cap tomorrow, I checked the engine temp today, top hose 90c bottom hose 75c so unless i am wrong the thermostat is ok, anyho will try the cap first,
regards
Dave,

 

Dave:

Ditto: Replace pressure cap

Plus, check vent line for blockage

If lower hose is swollen at clamps when engine is hot, replace it too

john

 

Hi John, where is the vent line you mention is it the small pipe that is on the top of the expansion tank?

 

#13, See Meriam XJ8 Parts

[ 13 ] COOLING SYSTEM / COOLING / RADIATOR & COMPONENTS / Vent pipe
Part Number: C2C24574

vent pipe W/O SUPERCHARGER
MSRP Core ? Online Price
$12.15 $0.00 $9.82

 

I had a similar issue on my daughter's BMW X3. I went through all of the above. In the end I bought a new hose and replaced it. Issue resolved.

I would do the same process mentioned by others, but hoses do age and do get soft. From my research a slight negative vacuum is in the system once the engine cools. Heat expands - cool contracts.

 

Just had my upper and lower hoses changed at 102k miles. They had both lost their firmness and the lower always contracted when the engine was off.

 

Replaced the cap yesterday and it seems to have fixed problem, have a good run to Buffalo today so will see if it is fixed, if not i will change the bottom hose, thanks for the help,
regards
Dave,

 

Dave, I have been experiencing the same issue as you. I have had both the upper and lower hose replaced but still notice the lower hose contracting once the engine cools.
Did replacing the radiator cap solve your issue?

 

Hi Mark, I ended up also changing the bottom hose and everything has been ok, i do think the radiator cap is the main problem though, its not that expensive,
regards
Dave
2007 xj8

 

Thanks Dave,
One more question. The new cap that you have....is it marked as 140 kPa or 110 kPa?

 

Hi again, mine is marked 140 kpa I bought it from the local Jaguar dealership,
all the best
Dave
2007 xj8.