remote mount fsd

[buddy]

Even on the intake my PMD never really had heatsoak. The thermistors I had on the IP and PMD heatsink never went high after I shut the truck off, possibly a couple degrees, but nothing noticeable. Even TD's PMD experiment data didnt show heatsoak. gmctd really pushed the heatsoak theory, but gmctd also prescribed to the idea that thermal cycling was the cause of failures. Sure if you run the PMD not on a heatsink it will burn itself up, and thermal cycling requires temps to go high, so how much heat certainly is a component of the failure mechanism. My PMD has run in the 120-140F range every day without issue. But its also always 70-90F every day of the year where I live (maybe 40-60F in the wee hours of the morning), so there is no big swing in temp and no extreme ambient heat to raise the temp shift. Maybe if I towed often and had constant load the PMD would self heat more from more duty cycle and constant higher voltage output.

 

[Turbine Doc]

Plenty of heat soaking going on in there Buddy I never recorded it, over 200F under hood many days here in the deep South, I had one driver that I left on the IP that had exactly 6 miles of operation on it, just the time it took to get home after the 1st warranty IP swap, it was my "get home spare" or so I thought, at 119,997 miles when my last IP went bad, I removed the Heath remote and somehow a bad IP code got set .

I plugged in that new spare and it was actually bad, it had only ever been energized for a single day events test time at the dealer and the return trip home.

So whatever mode you want to call it mechanical thermal failure, or fried on engine component, that driver was 100% new when taken out of service, it's only cyclics were not via energizing of the circuit but from thermal cycles seen while being under hood and on the IP where it was designed to be mounted.

Some drivers last long lives on the SSD cooler over the intake as Walt advertises, many more don't, mine out of engine bay has been there since Oct. 2004.

I hope you have years of continued longevity with yours there, preponderance of evidence collected over the years has shown that under hood mounting just does not last over the long haul, yes some examples such as yours throw a curve into the general population of data collected as do those trucks that run years of the driver mounted on the IP as the General placed it without incident.

 

[JMJNet]

One of variable that is important is Buddy's location where the weather are relatively mild. Only minor fluctuation in the temperature. Hence the heat can be dissipated faster compare to other place such as TX where GMCTD is and MS where TD is.

I did my own crude observation one time in the blasting heat of the summer. The temperature inside the hood where the IP located even when it is open right after a shutdown was about 220F. Then it goes up to around 230F as it has been shut off longer. The PMD itself is also generates heat which cannot be dissipated as fast in the environment. The heatsink will absorb those heat and actually heats up the PMD even hotter.

 

[jmiller]

I had my PMD on the manifold since I had purchased the truck ( on a heat sink similar to SS) for three years. It had started to fishbite, just before the engine broke last christmas. I moved the PMD to the bumper when the reman was installed.

It finally went south a couple weeks ago. New Dtech installed and expect many years of service.

 

[buddy]

TD, your actual PMD experiment testing has temperatures when you opened the hood after shutdown showing temperatures of the PMD going down, never up.

 

[NVW]

5 months, 5000 kms on the manifold, Jan-May. I'll keep mine in the bumper.

 

[Turbine Doc]

TD, your actual PMD experiment testing has temperatures when you opened the hood after shutdown showing temperatures of the PMD going down, never up.

Agreed Buddy but as you say hood opened up, hood closed I had different results, but in error I never recorded that data :mad2: and while those experiments did have gaps in the information I would have liked to/should have posted stuff captured in those days to still be indicating post shutdown heat soak to be a concern.

I still have the equipment & one day possibly in not too distant future before our high heat summer goes away, if I ever get some R&D downtime again vs using the truck to commuter to work I can re-do the test again in a more scientific study routine.

Most of the data was taken off of the DSG under-hood remote located on driver-side fender where the washer fluid bottle would be in a older gasser truck, and some readings for heat soak also taken in the "valley" by the IP that I recorded & posted in post day 2 of the experiments thread that do show the heat soak rise post shutdown.

 

[buddy]

TD I read through you experiment thread a few times to compare to my findinds, which are very similar, and none if it says you had hotter temps post shutdown.

I had commonly read 165F on the side of the IP where the PMD would be located, and about 138F on the surface of the PMD cooler on my intake. You actually put a probe inside the FSD on the transistor so your results for transistor temp I have no comparison. Just that on the intake is cooler than on the IP. And I did have mine always reporting even with truck off, so I did see post shutdown temps on the intake cooler never go up, but maybe a couple degrees and then start going down.