Author Topic: How to change left thermostat. ECM is in the way?  (Read 506 times)

Offline Scott & Heather

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How to change left thermostat. ECM is in the way?
« on: November 24, 2017, 09:47:10 AM »
I can’t figure out how to change the left thermostat (drivers side) since the ECM is in the way. Do I actually have to remove the ECM? 8v92 Turbo DDEC II. I can’t even figure out how to remove the ECM plate. It appears to be attached to the engine via a bracket and bolts I can’t get to on the block itself. Can someone guide me here? I’d like to do this when we finally come to a stop for a while over the holidays.


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Offline B_K

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Re: How to change left thermostat. ECM is in the way?
« Reply #1 on: November 24, 2017, 11:57:24 AM »
Scott see if you can get a hold Dave aka "yeold48" and see if he could look his over fer ya. He bought one of my old Setra's with a DDEC 8V92 in it and has the engine at home on a stand. If not when I get a chance I'll try an get to my storage trailer an check the 8V92 I have for Don Fairchild and see what I can tell ya. I know it can be done, just don't remember how I used to do it.
;D  BK  ;D

Offline muldoonman

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Re: How to change left thermostat. ECM is in the way?
« Reply #2 on: November 24, 2017, 06:30:05 PM »
Haven't got a clue but take pics and help the rest of us dummies out. ;D

Offline Iceni John

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Re: How to change left thermostat. ECM is in the way?
« Reply #3 on: November 24, 2017, 06:53:15 PM »
The tray for the ECM is held down by the 3/8" hex-head bolts through the thermostat housings, but there are also two hidden 5/16" bolts on the back side of the tray for the ECM itself that are a PIA to reach.   If my memory is correct from when I replaced both t'stats last year, the DDEC turbo boost sensor's bracket is attached by one of those two 5/16" bolts (I think).   There's no need to completely unbolt the ECM from its tray, just disconnect the two 30-pin connectors and the three others, then move the whole tray out the way.

One potentially very time-saving modification I also did when I rebuilt my Jakes will help a lot whenever removing the driver-side ("left") valve cover.   I have a 1/2" coolant hose between the top of the driver-side t'stat housing and the coolant surge tank, I'm guessing to help bleed air from the cooling system, but it prevents getting that valve cover off without disconnecting it, which required draining several gallons of coolant.   Not convenient.   I put a Parker self-sealing hydraulic quick-connect fitting on the t'stat end of the hose, so it now takes five seconds to do what previously took an hour.   When I readjusted my valves I noticed that the passenger-side were close to perfect adjustment, but the driver-side were way off  -  I assume the previous owner ran into the same issue as I encountered with that coolant hose!

John
1990 Crown 2R-40N-552 (the Super II):  6V92TAC / DDEC II / Jake,  HT740.     Hecho en Chino.
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