Cooling issue (old post)

Old post – October 3rd, 2019


So I recently had to redo my head gaskets. 2 exhaust manifold stud broke and it was making a horrible clacking sound and a huge exhaust leak. So that was all resolved with everything being pulled again and having the machine shop drill out the broken studs and put in the Past Power Innovations stainless steel exhaust manifold bolts.

My initial drives after were great. One morning on my way to work, I noticed my engine temperature get high.


I was about to pull over and let my car cool down, then the temperature dropped back into slightly above half (normal range). When I got to my work, I called my mechanic. He said that it was probably an air bubble, but he did bleed my cooling system.

I popped open the hood and see that the bleeder valve was leaking. I see coolant splatter marks everywhere. I called him and he reminded me that the bleeder screw was broken and is only be held on by a couple of threads. (Which he did tell me before). Now as I mentioned, in 2017, I tried to order the upper radiator hose with this T pipe and bleeder screw, only to have it cancelled on me when tracking told me “in transit” to my apartment. My mechanic told me he would take care of this screw once I get the parts. But I never had issues with the cooling or the bleeder valve since then (2017).


Now that I was having some issues that I need to investigate, I didn’t drive my car for a week and tried to do some research online.

I saw that Z1 had the T pipe with screw, but didn’t have the smaller hose outlet by the bleeder valve/screw.


Z1 responded saying they didn’t have anything like that. Additionally, I am unsure if the T pipe and coolant hoses are the same as those other vehicles the part was made for (300zx, 350z, 370z, G35-37, Q60).


I had to drive my car to work again, and again, the temperature went up and then cooled down, but above halfway.

When I popped my hood, I see more coolant splatter on the engine components.

I decided to see look at how much coolant was seeping through the the bleeder screw. I started my car and watched. I noticed a constant drip from the T pipe. At first I thought it was coming from the bleeder screw, but then I noticed it was coming from the upper radiator hose. I took it off and inspected it.


I put the hose back on and tightened the clamps. Refilled the coolant and started up my car. The constant drip was still occurring. So I headed over to O’Reilly’s checked what they had.

They had one in stock and while a bit longer, a small cut down made it perfect!

Upper radiator hose (radiator to T pipe) Gates 21942.


I changed the hose out, let’s just say it was a snug fit, so some energy needed to slide on! But I was happy that the dripping stopped.

I watched the bleeder screw and noticed that it was seeping. I drove it home and noticed it didn’t get high, but it was above half way, which I absolutely hate. So the hose change definitely helped.

When I popped the hood to check everything, I still see splatter. I decided to tighten the bleeder screw and noticed it just kept spinning. I knew it wasn’t perfect, but it held up for 2 years.

I took it off and it was literally “hanging by the threads”, which my mechanic told me before.


I have a complete bleeder screw somewhere, but I couldn’t find it. I decided to hit the auto parts shops and they all didn’t know anything! So with the little piece I had, I went to home dept and picked up anything that would look close to the threads of this screw.

One piece that I hoped would have worked was this brass plug. I felt the threads were the same with what little I could match. But the plug didn’t want to go past a couple threads when I put it on the T pipe.


My next option was a 3/8 x 1 bolt. Threads were different compared to the brass plug. It barely went further than the brass plug, but not significantly. So I put some plumbers tape on it and made it snug. Started up the car and let it run for 15 minutes. Still a leak. But not as bad.

Mark and I talked about it last night. I know this is a common issue, but people just plug it and leave it. Mark said should just bypass it with one whole hose.

Today, I decided to put research into the component.

As I said, I tried to order the the parts as one whole deal (which is what they offered it as).

I did a live chat with and he confirmed the part was not available. I then started to ask about the individual parts. I found out the bleeder screw was still active, but since it hasn’t been requested in awhile, they said it might take a day to verify it in their warehouse.

I did a quick check online and found another that had them in stock as well. I decided to call them and talked to someone. He verified bleeder screws were in stock, but said I needed to purchase 5 since they are in a pack. I had nothing to lose, so I did placed an order.

I then decided to more research because I want definitive replacements and or a solution to these if they are not available.

A big help was finding someone asking the same question on the Infamous Nissan forum! (yes, forums ARE great sources and archive of information!!!)

so let’s give credit!

Infamous Nissan forums

The part identification thread

and ahardb0dy for giving the info.


I set on a mission to replace all these pieces because I wanted everything new.

This entry was posted in parts.