Anyone know how to thermostat on 2.1L?

Gabe Athouse

New member
Need to swap it out, and I’d like to have an overview before diving in. I can’t find any info on it. Strange, seems like a standard part to be replaced. It’s right on front but under a bunch of delicate wiring and it has like 8 hoses connecTed to it so it’s a bit crazy
 

sailquik

Well-known member
Gabe
Why do you need to change it?
With the variable vane impeller (vacuum controlled I believe) there’s a lot more to the USA spec OM-651 than
a simple change of the thermostat.
I suspect some of the hoses going to/from the thermostat are actually vacuum controls for the water pump.
Roger
 

Gabe Athouse

New member
It was sticking in various positions. Nope, all 5 ports are wet, and there’s a sensor too. Whoever designed it should be shot. It’s a very stupid design in that you have to force it in two directions at a right angle, unless there’s more more removal of parts that I don’t see. In any case its pretty tough to swap out despite being on the front top of engine. I was able to do it but it took a lot of swearing and some blind fastening and high dexterity moves.
Variable vane pump? Is that really true? Wow. I hadn’t considered that. Why would they design that in?

I wonder if a coolant filter would be a worthwhile install.
 

Gabe Athouse

New member
Test run now coolant PID reads 175°-199° And heater is stabilized. Hopefully my engine didn’t overheat. I haven’t been able to source a lot of tech info on this engine. And any I find is usually from other vehicles they used them in.

I will say it’s quite a little power package and paired with that trans it makes for a very versatile drivetrain I can see a lot of smaller cars benefitting from.
 

mikeme

2015 LTV IB: 2015 3500 V6
...Why would they design that in?

....
You have a very well-engineered fuel-stingy powerplant pushing a pretty large and heavy vehicle.

there is a lot of engineering optimization involved, and management of heat flow directly impacts the operating condition of the engine.

The design is complicated because the design goals are challenging.
 
D

Deleted member 50714

Guest
It was sticking in various positions. Nope, all 5 ports are wet, and there’s a sensor too. Whoever designed it should be shot. It’s a very stupid design in that you have to force it in two directions at a right angle, unless there’s more more removal of parts that I don’t see. In any case its pretty tough to swap out despite being on the front top of engine. I was able to do it but it took a lot of swearing and some blind fastening and high dexterity moves.
Variable vane pump? Is that really true? Wow. I hadn’t considered that. Why would they design that in?

I wonder if a coolant filter would be a worthwhile install.
Water pump made from plastic too.
 

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asimba2

ourkaravan.com
I'd love to have a car with this powertrain. A buddy gets over 50 MPG in his E-class with the OM651.
 

Kajtek1

2015 3500 X long limo RV
I'd love to have a car with this powertrain. A buddy gets over 50 MPG in his E-class with the OM651.
I have black one for sale.
Takes grandma driving to get 50 mpg, but even with me averaging >80 mph between CA left lane huggers, I am still getting 40.
Sorry for sidetracking the main thread, but this is very exiting powertrain and comparing to OM642 engine in sedan, I am getting 30% better mpg on the same trips.

 
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