Can a Mocal Thermostatic plate fail ? For my oil cooler?
 

Lately my oil temps have been sky high despite having my 24 row oil cooler... Cruising with a buddy who also has a cooler, My temps were 20-40 degrees warmer than his at all times... I never was hardly ever getting over 220 after the cooler, regardless of the weather, and now I'm hitting 230-250 if I am driving aggressively and 220 on a hot day like today just cruising around :confused:...

I have this 20mm thread Mocal 180 degree sandwich plate...
(MOC-SP1FT Mocal Sandwich Plate- 20mm Thread $86.95)

Can this fail ? I can think of no other reason why my oil temps are sky high.. Its basically like I have no cooler... I cant see anything else in the system that would cause it to not work... the cooler is just a housing for oil so I can not see how that could be malfunctioning.

http://www.racerpartswholesale.com/i.../MOC-SP1FT.jpg

I am also going to flip my cooler and have the fittings up top after reading about the possibility of it messing with my oil level readings.. With the lines down, I cant find the thread I read a few weeks back, it is possible that my oil reading on the dip stick could be wrong as my cooler empties than re-fills when engine starts.. I am not sure if that is the case, but regardless flipping it to fittings up top would make me more comfortable, so I need to get the bumper off and re do the lines and fittings...

Should I order another Thermostatic plate? Could this be my issue... I had asked someone and they told me they "can't fail" but I don't see how that is possible...

I purchased my cooler off of modshack himself, so he installed it around May 2009 so it is a few years old.

Thanks for any help!

I think you definitely have an issue. Even though ambient temps are really high, you still shouldn't be that much over 200 just cruising. Who did you get the oil cooler from? Maybe you can get a new thermostatic plate under warranty.

I was in stop and go traffic in 100 degree temperatures the other day and it barely passed 200 with my 25 row cooler and a thermostatic plate.

I def have an issue. Two other 370s I cruised with on two different occasions and both were WAY cooler than mine.

I have a custom kit with stainless lines local thermo plate and a tru cool core.

I am going to get a new thermo plate and pick up a 34 row setrab for summer and use my 24 row tru cool for winter with a plate on it.

But I'm curios if anyone knows if the thermoplate can actually fail.

I'm guessing the thermostat is stuck in the closed position and won't open at 180 or 190? sometimes just pushing it open un jams it, but also in some cases it just fails and needs to be replaced.

I did a quick search around google and there are a number of cases where the Mocal plates have failed by remaining closed. I think that definitely narrows down your suspect.

The problem wouldn't be remaining closed, it would be remaining open. The temp-sensitive valve in the Mocal plate doesn't ever restrict the flow to the cooler.

Basically the Mocal has two paths for your oil to flow through, one through the cooler, and the other a direct bypass that doesn't go through the cooler. The passageway to the cooler is permanently open and doesn't have a valve. When the oil's cold, both passageways are open, and some oil flows through the cooler, but most of it bypasses (path of least resistance).

The thermostatic valve begins closing off the bypass route at around 170-175-ish, eventually closing completely and forcing all oil through the cooler somewhere around 185-190-ish.

You could probably test all of this by taking the Mocal plate off the car, placing it in an pot of water, and heating it up while watching with a thermometer. See if the valve operates and blocks off the bypass at roughly the correct temperature or not.

Ah great point. I will test that but I bet the plate is bad.

Thanks to all. I will post my findings.

darn i just installed this today

You will be fine, the majority have never had a problem but some of them may fail sometimes. I along with many others have been running these thermostatic plates and have had no issues.

do people not see that most of the failures or ineffectiveness comes from the tru cool?

What does the cooler have to do with the sandwich plate?

Its a mocal sandwich plate. And what other tru cools have failed ?

The cooler worked great before this. Hardly ever went over 220 despite any conditions.

Mocal adapters have a failsafe in that they would be stuck open, not closed. I guess you can have really bad luck and lose it, but that is definitely freaky. THere was just a guy complaining about how his tru-cool can't get him away from limp mode a week or two ago.

First off I would do what wstar recommended and test the plate in hot water. ALSO check for crimped lines and use an air compressor and to blow through your lines to insure your cooler and lines are all clear. Good luck....

Anyone else have this happen? I know I'm reviving like crazy, but figured it was worth a shot. I'm stuck in the worst of both worlds because I think it's stuck in the "cold" position. I get overcooling when it's cold out while driving on the highway, but my temps still go up with really hard driving even when it's cold or just with a few hard pulls and then driving on surface streets. Any troubleshooting tips or am I just gonna have to buy a new one? Mocal plate is < 1 year old.

First thing first check for codes, i am guessing you might have the engine build from 2009 to 2012 witch all have a weak galley gasket problem causing low oil flow and ultimately ENGINE FAILURE, most of the time there is no code, nissan ECU throws it after it drops below 2psi or near that, watch this vid to give you an idea.

https://www.youtube.com/watch?v=P1UnTHKkP3Q