They have slightly different markings. The unit on the right is my old unit and seems to have a date stamp from January 2015. Also It isn’t sealed the same as the new unit.
This PTU was causing my car to have the strange revving behaviour I had previously reported, and towards the end of its life, quite a nasty misfire at speed.
Strange one this.
It hardly seems worth the while to fake.
Never heard of a fake one before, although the J723T PTU itself is used on many Mitsubishi V6 engines. (Only the bracket is unique to the platform.)
There are pattern parts about obviously.
Having said that, I have never seen a ‘genuine’ one date stamped before.
They are a fragile thing…(unfortunately)
Did the old one come with the heat transfer paste to put between the PTU and the bracket? I assume the new one did. ( The bracket acts as a heatsink)
Failure to put the paste in place can lead to early failure, as the PTU overheats
This is one reason why so many supposed ‘good’ second hand ones seem to fail quickly. The are swapped in place without the paste.
I know this, I found this out the hard way!
If you ever remove your PTU, be sure to renew the paste. Heat Transfer Paste
Marty
I didn’t a long time ago either!
Like I mentioned above, I found out the hard way.
I had one fail on me(the original) and had a used one so swapped it in(tested it first)
Failed really quickly( few weeks)
Been tight, I bought a second hand one, tested it, and swapped it in. Cured the fault, but also failed in a few weeks. Same thing with another…
In the end I reluctantly bought a new one(non genuine) but still expensive.
Came with the paste, which I used. That one is still on the car many years later.
Doesn’t mention it at all in the manual, but I expect that is because the genuine ones come pre-assembled.
Marty
My new one didn’t come with paste, it was an assembly. However I have paste to apply, i didnt split it to check before I fitted it. To access it now would be easy enough however. The old one didn’t have paste. The Whole setup to me does looks like there is no consideration of a thermal nature for the ptu. I didn’t test it but pretty sure the bracket is made from steel, and bolted to the side of the engine conducting all that lovely heat, and sits right next to the turbo water pipes. All of this looks like a specially made oven for the ptu. I’m goin to keep an eye on it after a few runs and test how hot its getting with my heat probe.
An aftermarket ally bracket with cooling fins would be quite nice if somebody had fabricating connections.
Right, where do I get this paste Marty, what is it as when I changed mine over, which incidentally cured the fault, I haven’t used paste. Have only done two short journeys in it so have to get it done asap.
Cheers again Marty,
You won’t believe this, just told 'er indoors about this paste and she says, “Oh! you want thermal grease, here is a half a syringe from my computer rebuild”
I think the Bracket is steel too.
The standard set up is far from ideal, although I suspect the reason it works is the PTU must get hotter than the bracket does.
Still, I imagine a better solution can be accomplished.
The earth path isn’t through the bracket, so it could be isolated. Ie Ceramic washers, that sort of thing. Earth is through pin 4
An aluminium bracket with fins should be a much better solution, or remote mount the PTU in a cooler area. I was also wondering about adding an aluminium heatsink to the bottom of the bracket.
I have found references to other marques having similar issues, and custom brackets made, but no pics yet. The almost exclusively seem to use Mitsubishi PTU’s, even though some are rebranded. Skyline, 300zx etc all use Mitsubishi PTU’s
The 300ZX PTU seems to be a favorite for relocation to a cooler area of the engine bay.
Might well be worth investigation. I wonder how far our PTU can be moved if the loom is unwrapped.
I have also found some aluminium heatsink that may well be either suitable to secure under the existing bracket, (after modification), or suitable to make a new bracket from for remote mounting. Aluminium Heatsink
I was thinking of something along these lines…
You could pretty much make these from the off the shelf aluminium heatsink from ebay.
Marty
I have started a new thread for the relocation.
Will take me some time, as I have a lot to do to the car, but I have already ordered the heatsink material.
Marty
get a proper PTU.
