For the second time in three months, I've gotten a coolant shower after barely touching the plastic pieces in the cooling system when hot. By barely touch, I mean literally put my finger on the under side to see if there's any weeping at a fitting. This garbage is more fragile than a millennial's feelings, and I am D-U-N done screwing around with it. I spent about two hours cleaning up the garage and the engine bay and boy howdy, am I pissed off.

The short and curly of this is that over the winter, I'm going to begin to build some stainless pipes and fittings to replace this PA6 GF30-50 crap that the cheap bastages at Jag went with. The first piece will be the plastic overflow/burp pipe and its tees and fittings, followed by that plastic manifold in the back of the engine as well as the rubber pipe that runs under the blower. These three items are the three that I see fail the most. I already have a metal supply house, a machinist and a welder all lined up, and my question to you guys is this: should I make jigs to replicate these parts for anyone else? Additionally, can anyone think of any other plastic pieces that commonly fail?

The cost is going to be what the cost is going to be. To me, the piece of mind knowing that plastic has been replaced with stainless steel in a cooling system on an engine as expensive as these is priceless. I haven't crunched the numbers yet because at this point, it's all going to be one off stuff. If you're as frustrated as I am and refuse to replace old with new that's just going to fail again, keep an eye on this thread.

 

Wish you had gotten fed up a few weeks ago, I just replaced the ones under the blower last week, and I've done the others as well. Let me know when they're done.

 

Yes, I did a couple joints on my old '05 Lincoln LS. Once the dang thing gets hot enough to steam the plastic corrodes off the fiberglass and the parts fall apart. **** poor design but I guess it lasted at least through the warranty period.

 

I usually change my broken stuff, when it's to that point, with braided stainless steel teflon A/N stuff. Nothing yet on the XKR, but only those stupid front tubes by the oil filter have broken as of now.
Mandrake, if you have some stuff made up when I need them, I may be interested. If not, I'll just do the A/N again.

 

It outrageous that manufacturers are making all these coolant parts out of plastic just to save a few dollars. The amount of time, frustration and money that people experience down the road replacing this crap..and being stuck at the side of the road too..I wonder if you could sell some of these s.s. pieces on ebay? Theres no copyright infringement if you made these and sold them? Would it be easier/cheaper if you made them from aluminum?

 

Make the jig as I'll be interested in parts for the future.

 

Well, the fact is injection molding is several magnitudes cheaper vs. anything else. I've had offshore aluminum pieces rot from coolant which was pretty crazy. Doing anything is going to be a huge amount of work. Fabbing parts requires each nub to be machined and then assembled as a whole. Casting has it's own issues along with follow up machining.

 

After sleeping on it, yep... jigs will be made.

As for aluminum vs. stainless... well, yesterdays post was fired from the hip shortly after cleaning up the mess, so there wasn't much thought given to the what and the how. I've been wrong before and I'll be wrong again, and I'll admit my mistake of thinking stainless was the best choice. I spoke with a retired engineer friend of mine this morning about this project, and he said to consider galvanic corrosion. He said that stainless could work as long as it was isolated from the aluminum engine by rubber or plastic. He pointed out too that while the plastic doesn't last long, it's a perfect material in the sense that it is inert and won't promote galvanic corrosion at all. He said that the best thing would be to find an aluminum alloy as close to the engine's alloy as possible, and that if the engines alloy couldn't be found, a high grade alloy of aluminum because the engine castings are most likely high grade as well. I told him that the casting on the top of the engine indicates it's a silicon type alloy, and he suggested a 6000 or 7000 series alloy.

He also sent me this link for further reading: Galvanic series

So there you have it. Aluminum it is.

Copyright law is generally used for logos, works of art, performances of the arts, and literary publications. Basically, as long as I don't try to sell them under the guise that they're genuine Jaguar parts (which is protected under trademark law), I'm safe. The law you're thinking of is design patent. If I were a major corporation, I'd look to see if the design of these components was patented, but as some dude subcontracting the work out to a couple local guys and producing infinitesimally small batches in the grand scheme of things, I don't see any issues. But hey, I'm not a lawyer. Maybe a patent attorney or vendor with experience in this regard can chime in and set me straight?

 

Hey! A Teflon liner is also inert!

 

I assume you're referring to the teflon lined braided AN lines? It's not about the liner between the tube and coolant, but the contact between the tube and the engine. If they're dissimilar and are in contact, galvanic corrosion will occur. Interestingly, mild steel is a close second in its compatibility with aluminum and as I wipe the egg of my face, stainless is about the worst material for this application in regards to galvanic corrosion.

 

Stainless hates aluminum.

 

I've had the same crazy thought after reading several threads on here especially about the plastic heater crossover buried under about $1,500 worth of R&R at the back of the 5.0 in the X250. Looking at catalog pictures of the part, I thought of a similar METAL part in my TOYOTA. I was thinking when mine finally went, I'd get the motor attaching plates waterjet cut, bend some tubing to fit, nipples for whatever hoses come off it, tack weld it all up, then take it to a professional to have it tig welded all water tight. But I was thinking it sure would be easier with the engine out on a stand for easy access. Without pulling mine, I considered sort of "borrowing" an engine from a local Jaguar salvage. Hopefully you'll beat me to it (i.e. I won't need one for a few years).

 

Do the earlier XK's have this problem as well? I have not seen these problems with my 2007.

 

Odometer reading?

How many times have you replaced old with new that failed again?

I understand the concept that the plastic parts need periodic replacement, the question is what constitutes a reasonable service life interval.

The 4.2L NA needs to have the coolant outlet tube (which houses the thermostat) periodically replaced because the plastic gets brittle and the thermostat loses its physical alignment within the outlet tube. Some of the coolant hoses seem to be more subject to failure, such as the hose hidden under the intake manifold which connects to the throttle body. I recently changed the outlet tube (which contains the thermostat) and several of the coolant hoses as a preventive maintenance measure, at 78K miles.

 

Patrick, I have about 63k on mine. I'd like to point out that I'm fortunate enough to have both failures happen in my garage with the engine off, so there hasn't been any overheating at all. Both failures were with the burp tubes going from near the throttle body to the reservoir. The first time, the hard plastic line broke when I bumped it with the oil filter wrench. I was able to put it back together with some 1/4" fuel injection line. At that point, I'd decided to replace it with OEM over the winter when I clean the carbon from the intake ports. The second time, the plastic fitting that goes into the cast aluminum pipe going over the throttle body broke when I put my finger underneath it to feel for a leak.

As having owned the car for a hair over three months, this is the first time I'm replacing the part, and according to the date stamp on the part, it's the original part.

What constitutes a reasonable service interval is subjective. To many, this will be an acceptable quirk, but here's where I'm coming from and why I'm doing it. Sure, the part's only about $35 or so and it's already on its way to me as a temporary fix to get me through until the winter and yeah, it'd probably last another seven years and 60k miles, BUT... Had I not been fortunate enough to accidentally facilitate both failures on my terms, how much longer did I have? At what point would the vibration from the engine been enough? What if it happened in traffic where I couldn't have pulled over and shut down immediately? What if it happened in the middle of nowhere where there's no cell service? What if it happened on the track and I'm on the hook for the cleanup bill?

This isn't a spark plug or a belt or a brake pad that will wear out due to the nature of its operation... this is a hard line that can cripple the car, strand the driver, and destroy an engine if not immediately acted upon. To me, that's entirely unacceptable. I work on military aircraft for a living and have been a pilot since I was 16, and this level of unreliability wouldn't fly, pun intended. I look at the maintenance of my vehicles the same way as I do the aircraft I fly and work on for two very different reasons- the XKR because of the financial risk due to failure, and the Land Cruiser because of the risk to life due to the extremely remote places I go with it. If I can spend a grand or two to overengineer some parts to save a $10,000 engine and/or provide piece of mind knowing that I'm not going to be stranded somewhere, then that's money well spent.

 

Thanks for your comments. If in fact you can develop replacement parts that will enjoy a much longer life, that would be great.

Since the supercharged engine can produce 500+ hp, lots of heat is being produced and it seems reasonable the cooling system has become a weak point.

My answer to the general problem of engine overheating is to preemptively replace much of the coolant system in advance of a failure. I bought all of the hoses and have replaced several.

I have a replacement engine coolant pump, serpentine belt, and tensioner pulley sitting in a box, and probably will replace those parts at 100K miles.

 

Please make notes before and after the carbon cleaning.
We would love to know if its one of the easiest means of freeing trapped power.
I care more about the throttle feel and latency, which dyno cant show anyway.

 

I think I came to a similar conclusion the morning after purchase. After parking the car in my garage overnight, I went out the next morning to pull the engine cover off so that I could see what it looks like under there. To my surprise, the top of the plenum was still very warm to the touch, as were the shock towers. Prior to this, the first time I'd seen under the hood of one of these, my initial impression was, "wow... where does the air go after the radiator?" After warming my hands on the top of the plenum, I realized the answer- almost nowhere. Improving airflow management will go a long way towards keeping these things alive long term because the failures we're going to be seeing as they age will be traced back to what I perceive to be excessive underhood temps.

 

One of the only criticisms I have of British design.
They tend not to care too much about the effects of warmer climates on cars.
As many of you know from your dash
Or the XJS where the trans tunnel worked better than the heater core
Or the Production Rover that was fitted with a jet engine with no regard with the heat generated- which proved to be too much even for temperate British climate.

 

Do the side vents actually go through?
I know the hood intake does but flow can easily be increased by 70%.