An update on the aluminum rear crossover pipe replacement now that I have now had a couple weeks to test.
I bought, received and compared three aftermarket coolant crossover pipes for my 2016 LR4 HSE 3.0 SCV after the OEM model LR122710 unit that I proactively replaced at 62k miles began to fail with coolant leaks. It was not easy to find the leak, but I was starting to lose a couple of ounces of coolant every trip. Since the leak under the car was coming from the rear and I have long arms, when the engine was cool, I removed the plastic engine cover and reached around the rear to the back seam in the plastic crossover pipe and came back with a wet finger. After another drive, I tried this again, but switched to the passenger side where I found far more coolant. I parked the car until its next trip, which was to the shop for repair. When the rear crossover really fails, the damage can be very expensive.
I have included pictures of the failed plastic LR122710 part. One shows the seam while the other shows the mating surface. The manager pointed out that the white discoloration is a result of the heat cycling of the petrol chemical-based plastic. The horizontal seam failure was very visible.
I live in the DFW TX area and contacted several shops, including the Land Rover dealer, a specialty Rover shop and a European repair shop. Repair quotes for labor only - I intended to provide an aftermarket aluminum crossover – ranged from $3,600 at the dealer to $1,100 at the European repair shop with the Rover specialty shop at $1,800, or half the dealer price. The two non-dealer shops noted similar experience with the LR122710 manufacturer upgrade to the original part LR041788 - the new design does NOT hold up.
The European shop seemed clean and organized, and the manager noted that they have made many of these replacements and had a can full of leaking plastic crossovers, but they had no experience with the aluminum replacements. I never choose service based on price alone, but I went with this shop after a couple of calls and a visit. I brought in all three aluminum crossover pipes and shared my thoughts and findings with the manager who agreed with my assessment. I left the car for service. Two days later, I got the car back and a pleasant surprise. The service bill was just over $800 – $800 for labor and $48 for the throttle body coolant hose that runs under the supercharger that I asked to have replaced while they had it off. I asked to examine the old crossover “pipe” we discussed it. See pictures - the leaky seam was very visible. The quote was $1,100 so I asked about the reduced price and the manager noted that the mechanic found a way to replace the coolant crossover “pipe” without removing the supercharger. It’s a tight area to work in, so I can only suspect that the mechanic had done so many of these that he could do it by feel.
It has now been three weeks and two hundred miles since I got the car back, and all is fine. The coolant level when cold is always at the same place. The engine runs at the same temperature level as it did before.
Anyone in the DFW area who is interested in more information about the shop I used can message me and I will provide the name. I did not name it here as I do not want to be perceived as advertising for them. I will be going back to the same shop for all my needs. The shop earned my trust and respect for their competence and honesty. I even asked them to replace the PCV valve while doing the crossover work. While the manager warned me that they have seen the tabs on the plastic valve cover break in the process, requiring a valve cover replacement, I went ahead and took a chance, and they replaced it without issue. A dishonest or incompetent shop could have intentionally or carelessly damaged the valve cover to get more labor. The shop also provided a detailed inspection report without any effort to sell me on more services. Not that I needed any, but all Land Rovers leak a little oil, but they are aware of this and were not pushing me to get the issue fixed.
URO Parts, based in So Cal, was very accessible and answered quickly on my first call and was very helpful. They make a number of aftermarket replacement parts that are intended to outperform the OEM units they replace. With all the plastic in use and poor manufacturer quality, there must be a great market for them and others. The issues I noted with the URO Parts LR122710 include the rough cast seating surface. More importantly, the sealing o-rings did not sit evenly in the molded channel. Also, it appears they used special o-rings with little tabs molded on the sides. I noted green pen marks on the sealing areas, suggesting there was likely a QC issue with the sealing that resulted in the need for inspection of every unit. The box showed lifetime guarantee, which is important as failure of this part can ruin an engine, but the labor is a major concern too.
The crossover ”pipe” is made from two horizontal cast sections of aluminum that together form a tube through which coolant crosses over to another side of the V-6 engine. Since the seam in the plastic molded unit would leak at the seam with age, I was concerned with the sealing of the aluminum “pipe”. I did not worry about the impact of heat cycling, but I examined the torque of all the screws that hold the two and found three that were approximately 3nm or 4nm tight versus the 7nm or 8nm on other units. Loose screws come even looser with vibration, so this concerned me, and I ensured the screws were all tight on each unit.
I used URO Parts before. At 62k miles, I replaced the front plastic coolant pipes and the oil coolant pipe behind the water pump with the URO Parts aluminum products. The quality and fit were very good, and the parts held up well. Frankly, I hoped to use a URO Part LR122710 rear crossover, but what I saw gave me very limited confidence. Amazon $87. No Rating
WMPHE parts are sold on eBay and enjoy a strong reputation. The o-rings looked great and had a very uniform placement in the coolant channel. The screws were uniformly tight at 7nm to 8 nm. The unit even came with a pair of neoprene gloves and the foam packaging surrounding the crossover pipe to protect it. The packaging with molded foam to fully protect the unit was far superior to URO Parts or WMPHE. See pictures. The decision to use WMPHE was very easy, as in all accounts it was the superior product. $46 Amazon rating 5/5 (6) = 5 out of 5 with 6 reviews
MITZONE I was unable to contact the company by phone and the website encourages contact through the Amazon store. For all my measurements and examinations, I found that the Mitzone unit was identical to the WMPHE crossover, except at twice the price. I very closely compared the two, weighing and measuring many areas of the two. In fact, I had to mark the MITZONE unit to be able to distinguish it from the WMPHE part. Amazon $93 Rating 4.4 (13) = 4.4 out of 5.0 with 13 reviews
Note that there are other makes of the aluminum LR122710 crossover “pipe” that I did not order because they had no reviews and my objective was purely to find a good reliable replacement for the OEM plastic unit. While URO Parts had no reviews, I included them as I used their front aluminum parts successfully two years earlier. If the OEM plastic LR122710 had lasted 50k miles, I would likely have used that again, so Land Rover drove me to buy aftermarket parts.
I have now replaced all plastic cooling parts except for the thermostat housing, which will be next, as the current one was replaced at 62k miles. Were I doing this again, I would use thread locking compound on the screws on the LR122710 aluminum part.
Here are the units side by side; WMPHE, Mitzone and URO from left to right
The failed plastic unit
URO Parts with casting issues on flange mount and irregular o-ring
WMPHE flange and o-ring
