the cat is out of the bag . . .

[lesapandre]

When the new Jaguar X350 XJ8 was launched in 2003 it did not sell in the numbers predicted - and Jaguar facelifted the design twice to improve sales.

The X358 2007 second facelift acquired dummy wing vents - something not seen on a Jaguar saloon before.

After

Rummaging around in their box of styling cues - maybe it was this original XK arrangement they used for an idea.

🐣 🐰  Happy Easter.

[Surface Rust]

You might find dynamat (or similar, there are lots of cheaper alternatives) effective on the wheel arches to cut road noise. It's also thin so won't affect the fit of existing carpet / trim.

I couldn't believe the difference it made in my Acadiane (starting from a low benchmark though!).

[Bfg]

On 02/04/2026 at 22:09, lesapandre said:

When the new Jaguar X350 XJ8 was launched in 2003 it did not sell in the numbers predicted - and Jaguar facelifted the design twice to improve sales.

The X358 2007 second facelift acquired dummy wing vents - something not seen on a Jaguar saloon before.

Rummaging around in their box of styling cues - maybe it was this original XK arrangement they used for an idea.

🐣 🐰  Happy Easter.

odd that they were dummy trim panels.  Sir William would never had condoned such a thing ! 

I cannot imagine sitting in the golf club bar bragging about my new car's dummy wing vents    .. mind you that may be because I don't play golf, nor do I frequent Golf club bars.  

[Bfg]

3rd April - Carmen's Work In Progress - Thermostat bypass

Following on from my swapping out the radiator's overflow pipe, there were a few other jobs I wanted to attend to.  In the first place the heater still doesn't work, secondly the antifreeze was pink rather than blue, and thirdly when I came back from Hadleigh Castle last weekend, after a 30 mile jaunt up the A12 at 70mph, the traffic was for no sensible reason at a standstill before the Copdock roundabout junction.  As I sat there, stopped or barely creeping along - Carmen's temperature gauge stepped up from its usual 83 degrees to over 95 degrees.   Worrying, not least considering the ambient temperature wasn't exactly that of balmy summertime.  

Thankfully the traffic moved on ..as there was nothing there to cause the stop start delay anyway, and the water temperature resumed its 83 degrees. It was however a useful prewarning that something might be amiss. . . 

My first test was to see if the heater pipes were getting hot ?  so I ran the engine until the gauge read its usual hot at 83 degrees hot which is when the thermostat opens.  The pipes to n' fro the car's heater valve were not hot. The one running across the bulkhead was quite warm but not exactly hot. Those into and out of the heater matrix were not even as warm as my hands. 

The thermostat housing, the top of the radiator and its top hose were hot, but the bottom of the radiator was still cool, as of course was the bottom hose.   Clearly water was circulating but not very much through the radiator.  In retrospect, I was lucky, when driving the car almost 400 miles, to not get stuck in heavier traffic congestion ! 

 

    

^ First job was to drain and flushing the radiator.  I didn't want to remove it, to shake it out ..that'll come soon enough but on another occasion. 

   

^ after the initial draining of the pink antifreeze coolant, I emptied the stainless steel tray, under the car, and just used the hope pipe in through the top hose to flush the radiator a bit.  This is what came out, pink and blue and black bits.  I'd guess the darkest particles are rust from the engine but the more colourful bits are unfamiliar to me.  There's also pink encrustations around the thermostat cover.  I don't know what's happening there.    

 

    

Can't find it now, but I seem to recall reading about / discussing the original sleeve type thermostats here on the TR Register forum, and how ; as the thermostat opens, its sleeve advances to restrict the slot in the housing, which leads to the radiator's by-pass hose.  In doing so, the hot engine coolant is directed through the radiator to be cooled.  I'd pulled Carmen's thermostat ..and it was not of the sleeve type  . . .and there was no restriction to prevent the coolant following the bypass route rather than going through the radiator.  

Earlier in the morning, as I was trying to find out the spec's for the XK150 thermostat and radiator cap pressures, I spent a while reading through various posts on the Jag-Lovers forum, particularly those regarding XK heaters and avoiding engine overheating.  Pertinent to what I was looking for .. I noted the following extracts (which I paraphrase) . . .

" you MUST always run with the correct thermostat, and not the more common flat / modern type, and definitely not with no thermostat at all. The thermostats primary function is to direct the water flow as appropriate for engine's temperature.  The original type thermostat when HOT, blocks off the by-pass to the water-pump, to ensure the majority of the hot water is directed through the radiator to be cooled.

If there is no thermostat ; that hot coolant follows path of least resistance, directly to water pump and not through the radiator.  If you have correct (original sleeve-type) thermostat ; when HOT, the water is blocked (by its sleeve) from the direct path down the by-pass hose to the water-pump, and is thus directed through the radiator.  If you have a modern type thermostat (with no sleeve to restrict the radiator's by-pass route) ; when HOT, both the by-pass route to the water-pump ..and the route to the radiator are equally open, but the majority of the hot coolant will follow the path of least resistance - via the by-pass to the water pump, and not through the radiator.

XK engines do not overheat as a rule, unless something has been modified from original design (inc., the thermostat) or the cooling system has not been maintained sufficiently.

Roger Payne (Australia) "  Mr Payne was co-author of the excellent book XK-140 Explored

" Jaguar intended for the by-pass to be restricted when the thermostat opened, which is why the original thermostat had a sleeve to block the flow through the by-pass.  If you use a regular (modern) thermostat, without that sleeve, you need to otherwise restrict the by-pass hose.  I have a 1’’ brass disc with a 1/8’’ hole in the centre that fits over the by-pass intake of the water pump.  The disc is placed in the bottom of the by-pass hose. Its purpose is to restrict the flow of coolant through the by-pass. 

The purpose for putting a hole in the disc is to have some coolant flowing while the thermostat is still closed to prevent hot spots in the cylinder head. 
There are three ways to do this ; 1. Hole in the disc. 2. Holes in the thermostat. 3. Leave you heater valve open at the heater core. 

The reason I use a disc is that I’ve had failures with sleeve type thermostats.  And even when working - the area of the thermostat housing, where the sleeve is supposed to seal against, was too corroded for it to sufficiently block the coolant flow, into the by-pass.  But with the disc installed you can run without a thermostat, or with a standard (modern) flat type stat.

Joel - Denison, TX, United States "  I understand Joel has restored and owns several XK's.

- - -

Following Joel's suggestion I did much the same . . .

   

^ a 6mm hole through a stainless steel 30mm outside diameter penny washer was very suitable to be "placed in the bottom of the by-pass hose"  ^^ it's just loosely resting on the water-pump's spigot, and when the rubber hose is refitted, that washer cannot go anywhere ..so it doesn't need any fastening or adhesive.   Joel used similar but with a 1/8" hole, but I thought I'd give this a try. 

I'd be glad to hear your thoughts re. this 'mod' ?  

 But for the time being it's all back together again now, with blue antifreeze,

With the restrictive washer in the bypass hose, the cold start was normal, and I think the warm up was quicker (to when the thermostat opens). 

Before restarting the car I've tried to bleed air out of the car heater's matrix by lifting up its top hose ..and I've easily pumped water through the matrix.  But in trying the car around the block - the heater still doesn't work. !

I've expressed my concern before, that this car is mechanically noisy.  I couldn't hear clearly when I bought the car because the engine was running too fast, the carburettors / the engine was unbalanced (rear carb was far too rich), the axillary cold start was hissing, and there were no air filters to stifle the sound of the intake roar. Furthermore the fan belt wasn't running true, the coil was bouncing all over the place on its home made bracket, and the cooling fan was catching on the radiator shroud, and the bonnet trim was loose.  One by one I've been working through those, and finally the cacophony of extraneous sounds are lesser and more distinct.  And working in those confines I noted excessive slack, of the wrong kind, in the water pump's bearing. 

A good amount of the engine noise is I believe excessive tappet clearances (a larger than standard spec gap is liked by racing types).  I'll need a shim set before I open up the rocker covers, but I'd like to reset the tappet clearances sooner rather than later.  And it now seems that a noticeable amount of noise must have been the water pump's bearing (it sounded as if the cooling fan was still catching / loose / out of balance and reverberating / a blade was perhaps cracked ?).  But this is very encouraging .. because (having eliminated the cooling fan from the list of suspects) I feared the timing chain & its hydraulic tensioner must be the issue.  Hopefully though, it's just that the water pump's bearings. All being well, that'll be sorted soon. 

As it is, the water pump now sounds quieter and the sound of a rattly bearing race is more clearly defined. I might only reason ; the lesser noise is because the restrictive washer I fitted - prevents the coolant from flushing around n' around ..and the pump now has some resistance to work against (drawing the engine's coolant through the radiator core).

When refilling the radiator, the filling was very slow. I fear the core may be blocked.  And I wonder if those pink and blue bits were radiator sealant ? 

It's ongoing work-in-progress.  Little steps (tasks) each in the right direction. 

Wishing you and yours a very Happy Easter Weekend. 

Pete