Hey, @goldbug
Any updates on this issue? I'm getting ready to tackle my hoses now that the oppressive weather has eased up. Just wanted to see where you are at on this... 👍

 

No updates as of now, my Z1 hoses are still spotting and I’m going to swap them soon. I just need to go pickup some blue coolant from the local Nissan stealership and find some free time, been traveling lately and busy with work. I have the black CZP silicone radiator and heater hoses boxed up in my garage after hearing good things about their hoses, along with the P2M radiator hose clamps.

My car was scheduled to get dyno tuned w/ UpRev at National Speed this Tuesday and they said not to worry about it for the dyno runs, but honestly I’ve been so busy I might just have them do the hose swap and coolant flush instead of the dyno tune. I’ve also been getting closer to pulling the trigger with a forced induction kit so holding off on the tune for now will save some money in the end vs needing to have it re-tuned. I only have the HKS cat-back and Takeda now so no real need for a tune atm.

Once I get my hoses swapped or have National Speed swap them, I’ll update this thread with how the CZP hoses are holding up.

 

Finally had my radiator and heater hoses swapped. I have been way too busy with work and family lately so I had National Speed install everything (they include a 1yr warranty for their work), and I put off my tune until spring next year when I pull the trigger on my forced induction kit to save a little money for now. They did a great job with everything and did the coolant flush & fill the truly correct way. I had them use P2M radiator hose clamps (1.65”) and they look amazing at least for the 2x I can easily see on the upper radiator hose. I’m going to keep and eye on the CZP hoses but so far so good, fingers crossed I don’t see any spotting again.

 

Take this into consideration, many FI setups utilize the space where you put your cans which means you might end up having to re-do this setup.

 

Yeah I will definitely end up re-doing it. I realized this before I started this project but wanted to try it out for the time being anyways, a little test. Mr. Saikou and I already discussed a few options for the next setup, depending if I end up with a top-mount single turbo or SOHO’s new V2 A2A supercharger. Whenever I pull the trigger I’ll have him draw up a new design with me for whatever kit I end up with and will share that also.

When I do have my next kit made, I’ll be using AN fittings and will have them welded on to the cans for ease of use and to protect from pressure leaks at boosted levels.

 

Small update but so far the CZP hoses are looking great. No signs of spotting on any of the hoses. Definitely recommend their hoses if you are experiencing similar spotting! If these end up spotting down the road I’ll try the Samco hoses next, but I’m very happy with the CZP hoses now.

 

Well I spoke too soon. My black CZP hoses started spotting also. Not as large of spots as the Z1 hoses, but still little spots all over the radiator hoses after a month. This was again using brand new OEM blue Nissan coolant I grabbed from a local dealership.

One thing to consider in this (I’m not sure if it would make a difference) is that my car is not driven daily anymore by any means, and for the past month was only driven twice due to me having to replace a completely corroded over battery- so it sat for extended periods of time without being able to start it and even let the fluids cycle through. Curious if cars driven more frequently don’t suffer the same fate, or at least not to the same extent. I may have the shop that installed the hoses replace just the rad hoses with Samco Sport down the road when I have them replace my radiator, but for now I’m just going to keep an eye on my coolant levels and temps and call it a day. At least the white spots on the black hoses don’t look as bad as the white spotted blue hoses, and I need the silicone hoses regardless for the heat from the upcoming S/C kit going on.

I’ll edit this post and upload a picture of the spotting later.

 

That theory could hold some water (no pun intended). Both my daily and my engine stand are running silicone hoses but cheapo ones and neither of them gave me any.
They did give me problems sealing at the ends (gotta make sure they're extra tight) but my daily sees 40 miles daily and my engine stand sees 20 mins of running time once or twice a week.
I'm running regular green coolant that I blend myself. Usually 1 gallon of concentrate and the rest water to an empty system.

 

I still wonder if the green coolant is key too… my tuning shop also recommended to keep using the blue coolant per my year/FSM. I know for a fact when I purchased my car it (albeit used with 50k miles on it) that it still had the original blue pre-mixed coolant in it. I do know the spotting started after it was sitting for almost 2 weeks without being started and I hadn’t noticed it before then. Honestly I don’t care to do anymore work on the hoses at this point and it’s not actually leaking (other than typical loss through permeation) or losing pressure, so until I replace my radiator it works for now

 

I'll have to take a peak under the hood of my 3000GT. I'm running cheap silicone radiator hoses and a few other coolant lines. I don't recall seeing any spotting last time I was under hood, but I'll look and report. I do run green coolant and it doesn't see much mileage. I've put maybe 2,000 miles on it since October 2019.

 

As promised, here’s a picture of the spotting on my 2 month old CZP radiator hoses, which I had professionally installed by a tuning shop this time around. It’s happening on all of the coolant hoses, but I only grabbed a quick shot of the top radiator hose. I’m going to reach out to CZP and see if they can send me another full hose set since I confirmed with them before buying these that they hadn’t had any issues with their hoses and wouldn’t spot with the blue coolant - I’d really like them to send me another set before I leave a mediocre review for their product, esp. since their service has been top-notch so far and I like to hope they will help make things right.

 

So strange. My car only drove 5k km this whole year, z1 hoses have no issues. I'm wondering if it's something environmental. Makes no sense.

 

Are you running the blue pre-mixed Nissan coolant also?

 

At this point, if it were me, I'd be putting the OEM hoses back on. You seem like the kind of guy who obsesses over stuff, even the little stuff, and rarely gives up until you're content. But maybe it's time to give up.

 

I’ll replace them again sometime next year when I replace my radiator and will run the green coolant. For now they are fine, but you are right in the sense I won’t give up until I’m content! I won’t go back to OEM rubber hoses because of my boost plans/need something stronger with a higher temp rating than the OEM hoses. If I was staying N/A I probably would have gone back to OEM but I like to play it safe and avoid future headaches (even though this turned into one from the spotting). So far it’s only visual so I can deal until I go to replace the radiator.