The waterpump on my 2011 XF 5.0 NA failed around maybe 55,000miles, maybe 60.

Couple of weeks ago, I had a coolant leak on my morning commute. Had to get towed in. Turns out the crossover pipe failed. It's part No. AJ89664. The dealer handling the crossover pipe said that whenever they do a water pump, they always suggest the customer pay to replace this pipe since they are in there and have seen a substantial number of failures. The water pump was replaced by a different dealer, and I don't recall them suggesting the crossover. It's a plastic pipe that is molded in two parts and then welded or glued together. It's a pretty poor design. I wish I had changed mine with the water pump. I don't recall if it was suggested at the time.

Having seen it, I'm wondering if we shouldn't change this proactively maybe every 50,000 miles. Kind of pricey, though. A fair bit of labor to get it done. Total bill was around $700, most of which was covered by my extended warranty. But I'd say definitely swap this puppy if it is ever exposed for other services.

Attached are pictures of the failed pipe, and of the new one installed which can be seen as the shiny pipe with an upside down Y branch to the right of the air inlet. The skinny Tee hoses above it were also replaced at that service. If you look the crossover up on a parts catalog, it doesn't look much like the big long pipe that it is, because they drew it at an angle which really minimizes the profile.

 

I think all the plastic in the cooling system needs to be on a schedule. That includes all the coolant hoses, thermostat housing, and reservoir since they all have a lot of plastic. The hoses have unions built into them that are a liability.

I just did all this work on my 08 Range Rover Sport because it's the same company and they have tons of plastic under the hood of that car too.

 

I hear they're thinking of plastic engines next.

And I'm not joking.

 

Has anyone done this crossover? I was thinking I'll do it while I have everything torn down and drained for the waterpump.

 

Depends if the failures are design or manufacture. If the failures are manufacturing defects then changing one before it fails is illogical. The probability of fitting a defectively manufactured part is independent of use. If it is a design defect increasing the probability of failure as the part ages then it would make sense to preemptively replace.

Anyone know if it is a defective design bound to fail or uneven manufacturing quality?

The fact that it is made from plastic is absolutely irrelevant to this issue. Radiator tanks have been made from plastic for thirty years or more with very good service life on average. I have replaced only two such radiators since my first such equipped car in 1984.

 

Plastic in an application that heat cycles would appear to be a design decision with longevity consequences. Calling it a design flaw is semantics and simply reflects the point of view of the person describing the part. In other words, The company's cost-savings benefit is the consumer's cost-savings flaw. Labeling it one way or the other doesn't add much to the discussion as to whether and how often it should be addressed in maintenance.

The point is that there may be a finite number of heat cycles before the plastic parts fail, which is likely why people replace their plastic timing gear assemblies on prior generation Jaguar V8 engines before they break rather than after. Sounds like we need to do the same with water pumps and crossovers on the 5.0. The fact that someone may have a radiator that is partly plastic that happened to work ok does not mean that plastic is an ideal material to make into radiator parts. It weighs and costs less so it gets used. If I had my choice I would pay more for the old school all metal parts.

Given the cost of the water pump and crossover pipes and the cost of the consequences if either fails, it makes perfect sense to replace them with a fresh part periodically, even if using the exact same plastic part as original. The real question is how often should we do it to avoid trouble and what should we expect to pay to get it done at a shop.

 

Has anyone done it? I am looking at it and it looks obvious that the intake must come off. Any wisdom?

 

I bought the XF workshop manual. I don't know if it is terrible or if I haven't figured out how to navigate it. It does show a nice picture of the part, but not htf to get it out.

 

Just finished the job. Not that bad. I would do the crossover every time I did a pump on one of these. The manifold did have to come off but that was a far easier job than I expected.

 

is AJ89664 the same part number for the 2010+ 5.0 L supercharged engines?

 

From pictures of the 4.0L I am almost certain that the aluminum crossover
on the supercharged version can be used in place of the plastic piece on
the naturally aspirated version. It has zero problems and is better made
than the aftermarket metal towers. Seen a few on ebay.

Maybe the same situation on the 5.0L?

 

Just did the water pump on my 2011 XF. Ridiculous design with numerous delicate hard plastic parts made of inferior brittle plastics that are prone to fail. They have actually gone out of there way to create as many leak paths as possible. This is poor engineering practice not just poor manufacturing of parts. The engine itself is fantastic but the water pump design is neither cheaper to manufacture nor lighter and certainly not more reliable.
The way to fix this mess is to replace all these connectors and plastic bits with high pressure line and stainless clamps get all that cheap plastic out.

 

I just ordered about $800 in plastic and rubber cooling system parts from parts.com last night. I already have a new water pump ready to go.

For a little over $1K and a day of quality time under the hood, it will give me peace of mind that I won't blow the engine up over the next 50K miles.

I am also going to change the belt and pulleys to keep it running quietly. And I'll do plugs, clean throttle body, and all the fluids like transmission, power steering, coolant (obviously), and rear diff.

That will keep my Jag happy for the next 5 years.

 

combine US style contingency fee based class action
lawsuits with UK style trading standards "not fit for purpose"
claims.

 

..the problem with these is the lawyers win and you have to figure out what to spend your $5 on.

 

It's not the $5 so much as drawing a line in the sand.

The point is to make using cheaper materials and techniques
"not cost effective" for the manufacturer.

In other words, to strip away the incentive to make everything
out of papier mache.

A Senate hearing on after sales parts pricing would be nice too.

 

and now for the icing on the cake. When the water pump and crossover fail under warranty I am now hearing that Jaguar is considering this a "wear item" and is not covering it.

 

Instead of doing what engineers do best and FIX the problem they have resorted to calling one of the most critical parts of an engine a wear item. I am heading to my local deal for their next gen roll out event and will inquire about this asinine decision.

 

My service adviser was out yesterday and the sales guy I talked to knew nothing about the potential change with the water pump, I will say the F Pace I drove had a temp gauge on the main cluster but it had the new technology package I am not sure if you get the temp gauge without the technology package due to the screen changes.

 

I had the water pump replaced under warranty on my 2011 5.0 and a week later, the crossover was leaking. The dealer replaced it under warranty. This was in November 2015.