Hi all.

I have a 2007 Grand Voyager 2.8CRD and the diesel water heater won't turn off when the engine water gets up to temperature.
It's 10 degrees centigrade outside and it will run for a good hour or more!
I have the fan on low and set to a normal temperature.

Crystler tech have said they can't find a fault but agree that it is running excessively long. I think they are just unwilling to think outside the box!!

Can anyone suggest something I could check or a known fault that would remedy my infuriating problem

Thanks.

Pabs.

 

I have no idea how those things work, but if I were to design one, I'd include a temperature measuring device that would operate to shut it off once a certain temperature was reached. This would require some sort of probe that could somehow ascertain the temperature and some sort of logic circuit that could tell the heater to stop heating. Since most things in cars nowadays are computer controlled, I would assume that the system might likely utilize the engine coolant temperature sensor to measure the temperature and the PCM or the body computer to control the heater. So if a problem developed, I'd think about checking those things and the wiring connecting all of them. There's probably some sort of solenoid to control the flow of fuel to the heater so I'd want to be sure that's not sticking. Try a logical approach and you might be able to noodle this thing out.

 

Hi Pabs1977:

What is your engine temp gauge telling you? If it is indicating about 9 0'clock it is about right, but any less than that would be a problem becuase the engine would not be considered warm enough to turn of aux heat. If it is at 9 O'clock then I guess you have a water thermostat stuck open. But first things first what temperature is your engine running at?

Mike

 

Hi guys.
That's all great information. Thanks.
My issue is that I have had it back to the garage a couple of times and the mechanics say that they can't fault any part of the heating system!
Personally I think they're not checking the bits that they are supposed to be.
For example, the thing is running when the radiator valve has opened. That's not normal is it, having that cooling the water that the heater is heating?!
The temperature gauge never gets to half way. It sits on the line below the half way line.

Does that information help with further diagnosis?

Kindest Regards.

Pabs.

 

OK Pabs, I would say your thermostat is definately stuck partially open. Mine is too! Mine is actually running at around 60 - 65C which is about 1/4 way up the gauge. You will find there are several threads on this an other forums regarding this and I would say it was a common problem. I have just ordered a new thermostat for £77.78 +VAT delivered from Shane at JNL Engineering in Camberley, including the gasket. It is about 50% less than buying from Chrysler and JNL are the engine manufacturers representative in the UK. They will ask for your VIN number to be sure they send you the right one of the 8 or so thermostats they carry in stock If your VIN has a 7Y in it, it is the same as mine - apparently 7 = 2007 and Y = 2.8 (automatic).

I have not changed one, and I will take my car to my favorite garage in Solihull - I dont know where you are based but you can email me at mike@aeroventures.co.uk if you want the chapter from the engine manual regarding cooling/heating.

I would not be surprised if your mechanics didn't find anything because they didnt want to replace the thermostat! It is likely a 2 hour job, but I hear Chrysler allows only 1.2 hours - or something like that.

vrm8883

 

Hi vrm8883.
That is exactly what I had in mind. Didn't want to lead the thread though!
You're exactly right about Chrysler, the car is just coming out if its free warranty with the Dealer I bought it off!! I've had it in 3 times over the last year and its always the same answer "It's just one of those things" they'll say and tell me that I'll have to live with it.
They're lazy and cheap.
Out of interest, is there any way to check the position of the valve either visually or electronically? And you mention other threads about this problem. Would you be able to put a limit to it on here for me to browse.
Thanks again for the great info.
Pabs.

 

OK Pabs, the threads I mentioned are from last year the titles are "2.5 crd Running Cool" and "Voyager Thermostat" I suppose you could enter the thread name in the search box at the top of the page. It seems, although I am not certain, that a 2.5 is an engine with a manual gearbox and a 2.8 an automatic... However, remember there are several different thermostats and they come complete in the thermostat housing - so be sure to get the right one! As far as I know there is no way to observe the thermostat operation, however:

If your aux heater is almost continuously on these days and;
If your engine temp. gauge is somewhere around the 1/4 mark (1/2 is normal)

I think you can be reasonably confident that the thermostat is stuck at least partially open.

I see you have a 2007 2.8CRD so I would suspect it is similar to mine, but not necessarily, so do use the VIN Number.

Most dealers are struggling to stay in business these days and simply cannot afford to do things that don't have a high return. Some mechanics get a cut on the parts they sell you, which I suppose explains why it is so expensive to buy parts from dealers? Changing the thermostat is not that difficult (I'm told) but does involve draining coolant and removing the windshield wiper section below the windshield and then it is quite fiddly as hose clips have to be released and bolts undone at odd angles - not to mention cleaning off old gaskets, so I would not be at all surprised that they would opt for a simpler job with more in it for them with less actual work. Just a guess...

What else do you have to "live with"?

Mike

 

Hi Mike.
Thanks for all the help with that.
I have found an intermittent fix for the problem. If you wait for the temp gauge to get to 'its' operating I can turn down the temperature control by 3 or 4 degrees on both sides to force the logic of the water heater to turn it off then I can slowly turn the temps back up to about 21 degrees. Any hotter and the water heater will come back on.
Much to the dismay of my wife who likes it tropical in there, but not if I'm paying for the diesel she's not!!
Sorry for the delay in my reply.
Pabs.

 

Well,Pabs -

If it works for you! I bought a new thermostat assembly from JNL Engineering and had it installed - not an easy job, I admit, but my car is a lot warmer and the aux heater turns off as it should, after a while.

Funnily enough the temp gauge only registers about two needle widths higher, just below half-way - but it does make all the difference.

It is amazing how complicated the thermostat assembly is and I guess one thing to note is never put leak repir products, in the system...

Right now I am struggling with leaking injectors! I will be at a loss when everything is fixed! Funny how it all happens at once.

 

The best way to run the Automatic Temperature control is to set it to a temperature that will be comfortable, push the "auto" button and leave it alone. Cranking the temperature setting through wildly varying settings will only confuse the system and make you uncomfortable to the point that you will want to open a window which will only aggravate the situation further. There's never a situation where turnng up the temperature 21 degrees will accomplish anything good. The system is designed to get a cold car warm as quickly as reasonably possible when set on "automatic". Cranking up the temperature setting will not make that happen any quicker, it'll just make it too hot and that's when the window opening starts. Does your wife set the oven to 500 degrees to make it heat up faster to the 350 setting where she wants to do her baking? I didn't think so.