NSX Refresh

[Sudesh]

good work sudesh, was the ebay o2 sensor a denso? i had to replace the one in the CAT on my rx8 and it was one.
so i got a bosch o2 sensor, the wiring is really long, so my mate had to cable tie it up a few loops lol.
at least they know to make longer wires.

Im not sure what make the first replacement 02 sensor was? I didnt purchase it or install that one. Denso is a good make and standard fit on the NSX.

[Sudesh]

Just received yet another NSX in for some work over the weekend, so while I had a bit of free time on Sunday I just decided to remove the CCU as it was completely dead. I dont like to jump from one car to another and another, I always like to work on one car the whole way through, but as Andrews car is finished and the other one I have in is awaiting parts, I decided I would remove the CCU as this is simple for me.

I knew the capacitors had gone before I even removed it, due to a strong fishy smell, sounds weird but those that worked on the boards or come across this will know what I mean. Plus the system wouldn't power on at all.

So here are the pics of the many leaked capacitors,

[Sudesh]

[Sudesh]

[Nick Graves]

I'd have said burnt shellac smells more "insecty" than "fishy" but IKWYM!

[Sudesh]

I'd have said burnt shellac smells more "insecty" than "fishy" but IKWYM!

Hi Nick,

Yeah that would be a fairly spot on analysis. I recall exactly what your saying/referring to based on a lamp in my parents house.

Their sealing is quite high and in order to change a bulb or dust out the lamp shaded, requires a really long step ladder which they dont have. Anyway I remember many years ago smelling the same smell in the house and only ever when this light was on the smell increased. So following day I hired out a set of step ladders and myself and my dad removed the lamp shade, well Im sure you can guess what kind of mess had gathered up over the years in there lol.

Cleaned out all the dead insects and the smell disappeared eventually.

[Sudesh]

This was a bit of a long task, took a long time testing and figuring out before rushing into doing something that wasnt the problem.

Last time Andrews car was in, I noticed a coolant smell from the front of the car, but there was no sign of anything, heating was fine, temp needle sat exactly where it always did, and coolant level was spot on. But for some reason I could still smell coolant. When Andrew lifted the car I pointed this out to him and we both had a look at the time but again couldn't see a single drop anywhere. So I sent him on his way but told him to keep a close eye on the levels and always to check the front of the car.

Anyway wasn't too long before he noticed the smell again and this time it was followed by small drips and sometime very small pools of coolant along the top of the radiator. At this stage the car was away from me so we had to converse over the phone, and try and work out what was happening. Very hard to do without seeing the car but Andrew felt coolant may be coming from under the hose, and that the OEM hose clip wasn't tight enough. He didn't want to remove the Honda one as that would required some coolant loss and possible bleeding some air, so he purchased a standard hose clip, slipped that round and tightened it up.

This however didnt work as it seemed that the coolant would still appear, however it was only appearing under certain driving conditions and if the car was left switched off, it was fine! So next we thought it make be a small leek in the radiator that wasnt visible, but I just thought that seemed unlikely and it didnt worsen.

So he continued to drive the car and just be careful because he knew that car was coming back in for this recent work, and at this stage I would do the fault finding on the leek.

It was a tricky one and hard not to jump to blaming the radiator and as mentioned only appeared under certain driving style, but the leek eventually showed itself lol. It was actually weeping out of the lining of the hose itself! Basically along the ridge and through the threads at both the top and the bottom of the hose. The coolant smell was being caused by the bottom leek as it burned off on the pipe.

So this is where it was leaking, It would start weeping out of where the tread can be seen, if you look closely you can see small amounts green coolant color on the threads.



New hose ordered and installed and so far so good!



Strange thing is, the hose that was removed was only a few years old.


I have another NSX in, that has the exact same problem, from the exact same hose and is allot worse. Ill show pics of that as it will better describe in photo form what I was seeing.

[UnhuZ]

Sudesh,

you can't imagine my coolant nightmare... here is the order of events over a period of 2 years:

1 - It all started once in stop and go traffic, saw the temp gauge start to climb slowly past it's middle spot.
I immediatly pulled over and turned the car off. Checked the coolant level and tank was empty. Bought some drinking water
just to bring it to level. Everything was fine.

I ordered Silicon Venair hoses (6 big ones) from Dali and all of the other OEM ones (16 of them).

While i waited for them, i had always to fill the tank after a drive... but once, in a traffic jam, something serious captured my
full attention and after a while, when i looked to the tem gauge, it was slowly climbing but already at the red zone. Don't
really know why, but i blipped the throttle before i turned it off and to my surprise, the gauge came instantly to it's normal
middle position... after like 2 minutes it started to climb and with a throttle blip, it came right down... weird....led me to
believe that on top of a coolant leak, i had gauge/sensor problem (found out later that that was not the case).

2 - Hoses arrived and i replace them all and also replaced the tank to a new OEM....you can't imagine my surprise when i
found that the 2 big ones under the car (both), had a severe coolant leak through the hose lining (in it's thickness) on
both sides of BOTH hoses... Problem solved (so i thought)

3 - Coolant kept vanishing from the system but at a lower volume. Got the car on a lift and found a leak on one of the aluminium
pipes that go from under the car, behind the fuel tank and to the engine bay. Little green lines along that pipe, and a little green
salt at the leak spot showed me where the leak was and why: The square metal plate that is vertical, and between the fuel tank
and those 3 aluminium coolant pipes was touching the pipe and made a tiny hole in the pipe... i had to bent it a little to have some
space. I sourced some used pipe set (Hugabuga), tested them at pressure under water to be sure that had no leaks and replaced
them.... Problem solved (so i thought)

4 - Coolant kept vanishing from the system but the volume increased... i was like WTF ?!?!.... i searched and searched and found
that the front aluminium pipes (over the steering rack) showed dry traces of green coolant... i was in disbelief on how it was
possible that all the aluminium pipes were bad... i sourced new used ones (Hugabuga once again) and replace them..
....Problem solved (so i thought)

5 - Coolant kept vanishing from the system but the volume decreased....i was thinking "when does this stop ?!?"... i searched and
found that some OEM clamps on big hoses were allowing the coolant to exit between the hard pipes and the hoses... i sourced new
clamps (the screw type as you pictured above) but they would become a bit lose over time... i'm using my OEM ones again until
i can find some that keep themselves tight.... Problem not solved, but i was aware of it (so i thought)

6 - Coolant kept vanishing from the system but the volume slowly increased ... and pools of coolant started to appear in the floor
under the radiator.... to figure out where and why, i tried a different method this time: Use toilet paper arround all 4 clamps in the
2 front big hoses and all under the radiator.... let the car idle a bit with the radiator fan working to ensure the coolant would
circulate, always with an eye on the gauge so it doesn't climb.... turned the car off and started removing the toilet paper... the
hose ones were dry... from under the radiator, it came completely soaked in hot coolant...damn... got to find another radiator....
Found a used one on Prime's "Pay-it-forward" until i can afford a new aluminium one (Koyo or PWR)... installed it about 3 weeks ago.
At the same time i replaced the OEM headers with TopSpeed ones and as the headers were off, i replaced the oil pan gasket.
When me and my mechanic friend were cleaning and drying the surface to install the new oil pan gasket, 2 little green drops appeared
from INSIDE the block and hang there on the cleaned edge on the front cylinder head side...
... i immediatly thought "temp gauge on red = trashed HG"...
... and a compression test showed 5 cylinders with 200PSI and 1 with 185 PSI (the middle one in the front head) and harder to reach
185 than the others to reach 200.

7 - Bought a Block Test thing and just tested 3 days ago....the liquid turns almost yellow...so: "blown HG it is"


So... all this adventure with coolant leaks all over granted me with at least a blown HG, let's see if with all this luck i have, my block
or head is not warped or something...

Sorry for all this text...but i think is usefull so you guys know what CAN happen all over the coolant circuit.

Nuno

[Sudesh]

Here are the pics from the other NSX, same problem as was on Andrews

[soddy]

wow that is weird, bad design or type of coolant?
do you find getting hoses pretty handy, as i have trouble getting them for my cars.
coolant levels went down but have been ok since topping up. turns out it was the hose into the engine from the dash, ie the heater and the factory clip similar
to the one in the pic above needing another clip (like the one andrew used) to tighten up and stop the slight drip.

i am wondering though has this ever happened to other car's hoses, ie are they made pretty much the same?