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I track F Type S sales on BaT and just had an interesting discussion about the aluminum pipes experiencing galvanic corrosion. Here are quotes from that.
"michael211: You don’t want the aluminum coolant pipes. You want the updated factory pipes made without seams. The problem with the original polymer “plastic” pipes wasn’t the material. It was that they were made in sectioned halves and then bonded with seams. These seams is where they will eventually leak. The updated factory replacement is made from the same material but without seams. The aluminum replacements degrade on the ends (galvanic corrosion) because the coolant in these engines acts as a conductive electrolyte. I.e., these pipes were made from polymers in the first place for a reason, not just to save some money."
And this when I asked the poster for his source.
"michael211: My source is a Jaguar Master Tech with 35 years experience. I recently had the job done on my car, and he advised me not to go with the aluminum pipes for the reasons I mentioned. A friend who is a metallurgical engineer verified the science behind my tech’s explanation. My tech also said they’re already seeing corrosion problems with the aluminum pipes. I’ll see if I can get a copy of a JLR Tech Bulletin from him to verify. If I can, I’ll send it to you."
First of all, the statement JLR solved the crossover pipe failure by removing seams is false, there's tons of empirical data which proves even the new revised updated redesigned plastic genuine pipes fail by disintegrating due to heat. I have personal experience with this, I've even seen older seamed pipes NOT leak from the seams but fail at their bases just as the latest new versions do. Another example regarding seams, the rear plastic seamed crossover on mine did 100K miles and was NOT leaking when I removed it.
The statement about galvanic corrosion's also false as the points where the pipes join are both aluminum alloy. Additionally if the correct engine coolant's used (DexCool) it's actually engineered to prevent corrosion.
Yup, agreed. OAT has long proven performance and I would literally only believe the statement about the aluminum pipes corroding and dissolving when I see it. Aftermarket pipes may have dubious origins and nonmatching or forged materials certs, this is for certain. I have not heard of any JLR dealer dealing with issues with the latest and greatest OEM castings.
I would very much like to see the TSB on this issue.
Jaguar made OEM aluminum pipes for for the XKs. They now once again make aluminum pipes (for the new LRs that fit our cars). Another case of an internet expert quoting another "expert's" opinion. You can quote me on that.
P.S. Many of the failures are at the flange, not the seams of the old pipes, and there are documented cases of the same with the newer seamless pipes. Other manufacturers also have had problems with plastic coolant pipes/caps cracking. Not a new thing, not just a Jaguar thing. I'd chalk it up to environmental conditions, bad luck, and maybe how hard you flog your car (pperhaps repeated stress from engine torque and movement? not sure).
Last edited by bfrank1972; Mar 21, 2025 at 01:41 PM.
Jaguar made OEM aluminum pipes for for the XKs. They now once again make aluminum pipes (for the new LRs that fit our cars). Another case of an internet expert quoting another "expert's" opinion. You can quote me on that.
P.S. Many of the failures are at the flange, not the seams of the old pipes, and there are documented cases of the same with the newer seamless pipes. Other manufacturers also have had problems with plastic coolant pipes/caps cracking. Not a new thing, not just a Jaguar thing. I'd chalk it up to environmental conditions, bad luck, and maybe how hard you flog your car (pperhaps repeated stress from engine torque and movement? not sure).
Correct. I have OEM original aluminum front pipes in my 2011 XJ 5.0 SC. BaT poster is BS
And here is another post from BaT
"Posting just because people blow these threads up all the time and try to negotiate value on the pipes. Unless they are aluminum, they will have a service life. JLR has now made LR Defender and certain SVR pipes in cast aluminum. I just had my 2019 F Pace SVR engine replaced under CPO warranty and the dealer went ahead and updated both the Y pipe and front crossover to the new castings. The rear coolant crossover is a longevity risk but just check your coolant. It is one of those things that all 3.0 and 5.0 will experience, regardless what someone thinks will happen."
Seems to me that the comments above confirm my choice to go aluminum before anything leaked.
And here is another post from BaT
"Posting just because people blow these threads up all the time and try to negotiate value on the pipes. Unless they are aluminum, they will have a service life. JLR has now made LR Defender and certain SVR pipes in cast aluminum. I just had my 2019 F Pace SVR engine replaced under CPO warranty and the dealer went ahead and updated both the Y pipe and front crossover to the new castings. The rear coolant crossover is a longevity risk but just check your coolant. It is one of those things that all 3.0 and 5.0 will experience, regardless what someone thinks will happen."
Seems to me that the comments above confirm my choice to go aluminum before anything leaked.
Thank God someone is correcting on that BaT thread.
Also I wouldn't assume aluminum pipes go without a service life, they still use rubber o-rings which can fail eventually. Just not as often and catastrophically as the plastic pipes.
Just had a huge preventative maintenance service done on the Jaaaaag. Among other things we did the new OEM Aluminum coolant pieces and the Euro Amp Aluminum Rear Coolant pipe & Thermostat. Being tested over the weekend and I'll get her back Monday. Will report back of any issues.
And here is another post from BaT
"Posting just because people blow these threads up all the time and try to negotiate value on the pipes. Unless they are aluminum, they will have a service life. JLR has now made LR Defender and certain SVR pipes in cast aluminum. I just had my 2019 F Pace SVR engine replaced under CPO warranty and the dealer went ahead and updated both the Y pipe and front crossover to the new castings. The rear coolant crossover is a longevity risk but just check your coolant. It is one of those things that all 3.0 and 5.0 will experience, regardless what someone thinks will happen."
Seems to me that the comments above confirm my choice to go aluminum before anything leaked.
I really don't think that coolant would do this consistent effect on the whole block/supercharger. The oxidation is everywhere, there is no way coolant would be that high and that consistent I think. Also F*** the person who thought having no drainage in the block is a good idea.
What in the hell? That must be from coolant eating the aluminum. There's no way that's just corrosion.
Anything is possible but highly unlikely. That portion of the supercharger is the intercooler manifold, so it would happen from the inside out.
5.0s from Ford are also Aluminum construction and experience no corrosion internally a significant level.
Anything is possible but highly unlikely. That portion of the supercharger is the intercooler manifold, so it would happen from the inside out.
5.0s from Ford are also Aluminum construction and experience no corrosion internally a significant level.
I also don't think there is any coolant running from the other internal side. This could be rain or somebody washing the engine and trapped moisture under the foam - I think. You can see the classic 2 rusted bolts on the right side of the valve cover too.
Agree, the foam traps a lot of moisture. Aluminum doesn't really corrode, alloy has a risk of having real corrosion, but this doesn't look meaningful in any way either. Best wishes on the cooling upgrades!
Coolant runs on both LH and RH sides of the charger cover - those front plastic bits are coolant connections. I think MAHLE makes these for OEMs and is the parts supplier to Eaton/JLR.
I also don't think there is any coolant running from the other internal side. This could be rain or somebody washing the engine and trapped moisture under the foam - I think. You can see the classic 2 rusted bolts on the right side of the valve cover too.
The bolts rust because they aren't aluminum. Aluminum doesn't corrode unless subjected of high ph. Isn't the picture above showing rusted through aluminum or am I looking at it wrong?
The black portion with bits on, is the plastic foam pad removed from the underside of the Eaton charger. I'll try to find a picture of a factory charger underside, but if you look at your vehicle you can see a black sheet poking out between the intake manifold and the valve covers.
EDIT: Here's a V6 charger underside. It probably looks similar under the foam. The listing shows 32k miles on it, so it looks newer.
The bolts rust because they aren't aluminum. Aluminum doesn't corrode unless subjected of high ph. Isn't the picture above showing rusted through aluminum or am I looking at it wrong?
What, where? Under the supercharger? There is a residual glue and foil from the foam and there are 4 symmetrical "pockets" in the form by design here but all is surface oxidation. Btw, rain is acidic.
Also, as any engineer would say, everything oxidize
The bolts rust because they aren't aluminum. Aluminum doesn't corrode unless subjected of high ph. Isn't the picture above showing rusted through aluminum or am I looking at it wrong?
Looks like black plastic and glue or foam. At first glance, I also thought it was a hole in the bottom of the super charger.
@J444G Bravissimo on exposing the "sous vide" effect of the foam - the black envelope traps moisture in the foam and allows for basting of the surrounding metal. I used to think a hot engine would evaporate all moisture over several hours but not with the foam there.
Use a steel polishing wheel on a drill and clean it all up?
Last edited by JagCode3; Mar 31, 2025 at 02:16 PM.
