Thermostat Malfunction?

[JAXX5]

Originally Posted by wpoll

And thanks to photobucket for rendering my writeup near-useless.... I'll re-host the images and fix the links one day soon...

So JAXX5, bit late now but did your new thermostat sort your temp issues?

Yes it did. However, unfortunately I to part ways with my E53 recently. It started showing symptoms of a pending tranny failure. I replaced it with a CPO E70... so far so good.

[andrewwynn]

Tip on the t-stat: to remove the fan use a 1-1/4 open end wrench and smack it with a hammer. Look for YouTube video. The radiator hose stops the wrench.

[Lamby]

Originally Posted by andrewwynn

Tip on the t-stat: to remove the fan use a 1-1/4 open end wrench and smack it with a hammer. Look for YouTube video. The radiator hose stops the wrench.

There are some out there that tell me that I don't need to remove the fan on teh M57TU - which is the one I have? Is this bogus? Should I do it anyway?

[andrewwynn]

Originally Posted by Lamby

There are some out there that tell me that I don't need to remove the fan on teh M57TU - which is the one I have? Is this bogus? Should I do it anyway?

Search YouTube you'll find answer. I'm M54 and it's a must. It's not difficult to do if you need to do it. I thought it was pretty bogus as well until I did it and removing made the job 10x easier.

[yes_its_neil]

Originally Posted by Lamby

There are some out there that tell me that I don't need to remove the fan on teh M57TU - which is the one I have? Is this bogus? Should I do it anyway?

No need to remove the fan or the fan shroud. Space is tight and the hex head bolts on the MAF are awkward, I found that the right length allen key tool made it possible.

[upallnight]

If you had the proper scanner, you could have scanned the X and it might have logged a trouble code with the thermostat. My X drove normal in the summer, but in the winter it took quite awhile for it to reach operating temp. Scanned the X with Carsoft 6.5 as well as BMW Scanner 1.4 and got a trouble code for the thermostat being stuck open.

[andrewwynn]

That's great feedback. I was going to do the same and take pics to share but once I figured out the trick to remove the fan it's actually easier.

[wpoll]

Originally Posted by andrewwynn

That's great feedback. I was going to do the same and take pics to share but once I figured out the trick to remove the fan it's actually easier.

There's a lot more room to work at the front of the M57TUD30 diesel - not sure why this is so but access is pretty decent.

[wpoll]

My $0.02 on this...

Use the BC to watch the engine temp. If you can't get above about 75DegC. - the thermostat is shot. A good thermostat will take the engine to 88DegC. and keep it between 88-92DegC.

Yes, you can replace thermostat on an M57TUD30 in a E53 without removing the fan - but NOT on the M57D30 (i.e. you CAN on a facelift/LCI but CAN'T on a pre-facelift).

I drained some of the coolant before pulling the thermostat - it's less messy that way. Drain is on lower left end of radiator. Use a 10mm socket to open it - or is it a 12mm?

UAN - there's no codes in the diesel regarding the thermostat - it's not controlled by the DDE.

And yeah - always use a genuine BMW part for this - unless you enjoy replacing it often.

[upallnight]

Originally Posted by wpoll

My $0.02 on this...

Use the BC to watch the engine temp. If you can't get above about 75DegC. - the thermostat is shot. A good thermostat will take the engine to 88DegC. and keep it between 88-92DegC.

Yes, you can replace thermostat on an M57TUD30 in a E53 without removing the fan - but NOT on the M57D30 (i.e. you CAN on a facelift/LCI but CAN'T on a pre-facelift).

I drained some of the coolant before pulling the thermostat - it's less messy that way. Drain is on lower left end of radiator. Use a 10mm socket to open it - or is it a 12mm?

UAN - there's no codes in the diesel regarding the thermostat - it's not controlled by the DDE.

And yeah - always use a genuine BMW part for this - unless you enjoy replacing it often.

That may be true, but I was posting to the original poster that has a 4.4 petrol V8 and my personal experience with my 3.0 petrol engine X5.