After 15 years of trouble free driving, a short 3 mile round trip rewarded me with a coolant leak. Parked in my garage and a few minutes later I heard a pop and loud hissing. Opened the bonnet to be greated by a geyser of coolant spraying vertically from between the throttle body and the supercharger hard enough to soak the windscreen, engine compartment, wings and bonnet. Quickly opened the expansion tank cap to relieve pressure and stop the fountain. Lost about a gallon of coolant. Removed the intakes and looked carefully and cant find the source of the leak yet. If it's the throttle body hose surely there's no harm in capping it off? It's a track car and never sees cold weather. Searches indicate this's a common mod for those in temperate climes. The super charger has ZERO leaks or issues and I'd prefer to leave it alone until I have to. Of course I've no idea if it's the source of the leak.

 

I've not done it with an X150 but I have bypassed the throttle body coolant circuit on other JLR cars even though they are driven all year round. It's never caused a problem.

Richard

 

My understanding is it's used to heat the throttle body up to ensure the butterfly doesn't get stuck in subzero climates
I can't see an issue at all if blocked off

 

Well, there’s a case of over engineering! Considering on how most of these cars are babied, and then there’s where jahummer lives!
What’s the ocean temp today down there?

 

Sounds like it would matter here (UK) and lots of Europe, not to mention Scandinavia...

Probably Canada, too.

New England?

etc

 

Having said that I'd love to know how many of us garage our xk's I'm guessing it'd be a lot ))

 

Yup, parked in the garage all winter (and usually later into the spring than I would like ).

 

Found the leak, common fail point as I've seen, split throttle body hose right where it bends from the outlet. Trimmed the end off and re-attached and pressure tested, all good. I'll leave it alone for now but if Iever have to pull the super charger, I'll cap off the points where the hoses connect to the manifold.

 

The lifespan of automotive heater pipes made of PA 6.6 (Nylon 6.6) can vary depending on several factors, including:

1. Operating conditions (temperature, pressure, and flow rate).

2. Coolant type and quality.

3. Environmental factors (UV exposure, moisture, and chemicals).

4. Manufacturing quality and design.

5. Vehicle maintenance and usage patterns.

Typically, PA 6.6 heater pipes can last:

5-10 years or 50,000-100,000 miles in ideal conditions (moderate temperatures, proper coolant maintenance).

3-7 years or 30,000-70,000 miles in average conditions (normal temperature fluctuations, occasional coolant changes).

1-3 years or 10,000-30,000 miles in harsh conditions (extreme temperatures, poor coolant maintenance).

Common failure modes for PA 6.6 heater pipes include:

1. Cracking and brittleness due to aging and UV exposure.

2. Chemical degradation from coolant breakdown or contamination.

3. Mechanical damage (kinking, crushing, or abrasion).

4. Thermal degradation (over-temperature or temperature cycling)

Factors that can reduce lifespan:

1. High temperature fluctuations.

2. Poor coolant quality or maintenance.

3. Exposure to oils, fuels, or chemicals.

4. Physical damage or vibration.

5. Design or manufacturing defects.

To extend the lifespan:

1. Regular coolant changes and maintenance.

2. Avoid extreme temperature fluctuations.

3. Protect from UV exposure and chemicals.

4. Inspect and replace worn-out components.
BTW - A short section of 1/4" reinforced rubber hose can be an ideal temporary fix for a pipe that springs a leak. Cut the pipe at the site of the leak. Lubricate the outside and slip the rubber hose over the plastic pipe. The OD of the pipe is about .030" larger than the ID of the 1/4" rubber hose. That's just about the right interference fit for high pressure use. Add two hose clamps and you can likely make it home for more extensive repairs. (I keep a few inches of hose and a couple of clamps along with a pint of coolant in the roadside repair toolbox in the boot.)