[sneal4600]

Ok so I have replaced my tstat and want to check for leaks however, Id rather do it while the plenum is off so that I do not have to take it off again... if necessary.

I cannot see why there is a reason not to start the car with the plenum off and bring it to temperature. Has anyone else had experiences with this?

 

[Leezamonkey]

I think it may run in limp mode as no air will pass through the MAF's, but should be fine. Don't take my word for it though, wait til someone else chimes in

 

[russap5]

Mine has been run with plenum off this week with no issues, but I do have Alpha-N MAF-less software installed.

 

[Tj Hunter]

I am still baffled that people take the WHOLE plenum off to replace the thermostat...unless you were replacing other stuff, it is a waste of time.

 

[sneal4600]

I am still baffled that people take the WHOLE plenum off to replace the thermostat...unless you were replacing other stuff, it is a waste of time.

Yes, this was a "get to know my engine" project. I knew the tstat was bad but figured it would not only be easier to replace with the plenum/oil separator hoses off but I could find other things the previous PM's by the PO missed. Sure enough, several wire looms were cracked, lower oil separator hoses were soft and I figured why not replace the fuel tank breather valve while its exposed. Actually, its been a nice experience to explore what is under there. Spent maybe $400 for everything I needed. That included fan clutch and coolant tank.

 

[vantaam5]

I am still baffled that people take the WHOLE plenum off to replace the thermostat...unless you were replacing other stuff, it is a waste of time.

Some feel better that way...

I never removed the plenum on the 10 or so t-stats I changed so far...


The car will run in limp mode with the plenum off and MAFs disconnected.
But possible and save to let it run warm,just clear the errors once everything is assembled.


And make sure the MAF wires do not get caught by the fan blade

 

[sneal4600]

Some feel better that way...

I never removed the plenum on the 10 or so t-stats I changed so far...


The car will run in limp mode with the plenum off and MAFs disconnected.
But possible and save to let it run warm,just clear the errors once everything is assembled.


And make sure the MAF wires do not get caught by the fan blade

Thought about leaving the fan off until I determine that there are no leaks. New clutch ready to go in but sitting on the bench for now.

 

[vantaam5]

Thought about leaving the fan off until I determine that there are no leaks. New clutch ready to go in but sitting on the bench for now.

Good!

Be prepared it makes some nasty intake noise:hihi:

 

[JustinM5]

I am still baffled that people take the WHOLE plenum off to replace the thermostat...unless you were replacing other stuff, it is a waste of time.

It's a lot quicker than waiting for new rings and doing it a second time.
Once you've done one you've an idea of what to watch for etc, first time and learning you're pretty likely to slice a ring.
My attempt the centre tube wasn't even in the recess.

 

[Tj Hunter]

It's a lot quicker than waiting for new rings and doing it a second time.
Once you've done one you've an idea of what to watch for etc, first time and learning you're pretty likely to slice a ring.
My attempt the centre tube wasn't even in the recess.

I should learn to hold my tongue sometimes, haha, I forget how mechanically inclined I am, so things are a no brainer to me are not necessarily to others. The first thing that I did to my M5 was a thermostat, and I did not slice any rings, have any leaks, etc etc, but then again the M5 is my 12th BMW and my 4th M6x that I have worked on.

I hope OP did not take offense, it was a poke fun more then a bash, it is nice to see people actually willing to work on their own cars. I could not IMAGINE how much I would have spent at the BMW dealer or indy if I did not DIY.

 

[JustinM5]

I do all my own work, but sometimes first time is a learner, especially when you can't see what the hell is going on!
Nice to have a poke around under plenum anyway.
As you say save lots of money, and as people on here have found out, bmw don't always get this job right.

 

[sneal4600]

I hope OP did not take offense, it was a poke fun more then a bash, it is nice to see people actually willing to work on their own cars. I could not IMAGINE how much I would have spent at the BMW dealer or indy if I did not DIY.

Yeah I agree... these cars would not be feasible for me to own unless I did most of my own repairs. This project was more about getting it right than cutting time for me. Maybe next time I will give it a whirl...if there is a next time.

 

[Redshift]

I do all my own work, but sometimes first time is a learner, especially when you can't see what the hell is going on!
Nice to have a poke around under plenum anyway.
As you say save lots of money, and as people on here have found out, bmw don't always get this job right.

Agree with that. I'm not new to working on my own cars, nor BMWs, but the S62 is relatively new for me to delve into, so I WANTED to take the plenum off to replace other possibly worn or brittle hoses and other parts. Plus, removal of the plenum only takes 15min and it's interesting to see the jumble of parts under there.

 

[sneal4600]

Agree with that. I'm not new to working on my own cars, nor BMWs, but the S62 is relatively new for me to delve into, so I WANTED to take the plenum off to replace other possibly worn or brittle hoses and other parts. Plus, removal of the plenum only takes 15min and it's interesting to see the jumble of parts under there.

Exactly. Removing the plenum is not that much work. If I were a mechanic and under the gun to get things done on a time schedule then maybe it would be justified to leave it on. For most of us DIY-ers, it is more productive to be thorough.

 

[Redshift]

Exactly. Removing the plenum is not that much work. If I were a mechanic and under the gun to get things done on a time schedule then maybe it would be justified to leave it on. For most of us DIY-ers, it is more productive to be thorough.

Productive and FUN!

 

[JustinM5]

Only 80 odd nuts and bolts to remove it anyway :grinyes:

 

[Redshift]

Only 80 odd nuts and bolts to remove it anyway :grinyes:

Air tools make removal faster. Re-installation is still the time consuming but still easy part.

 

[Neil.D]

I am still baffled that people take the WHOLE plenum off to replace the thermostat...unless you were replacing other stuff, it is a waste of time.

I should learn to hold my tongue sometimes, haha, I forget how mechanically inclined I am, so things are a no brainer to me are not necessarily to others. The first thing that I did to my M5 was a thermostat, and I did not slice any rings, have any leaks, etc etc, but then again the M5 is my 12th BMW and my 4th M6x that I have worked on.

I hope OP did not take offense, it was a poke fun more then a bash, it is nice to see people actually willing to work on their own cars. I could not IMAGINE how much I would have spent at the BMW dealer or indy if I did not DIY.

I removed the plenum. Its much easier and as discussed, gives people a chance to explore the top of the engine and watch for leaks after the install.

I can see how you may have caused offence with what came accross as arrogant and conceited - but hey, you've apologised.

For info, without the plenum my car back fired after about a minute and that was enough time for me to check for leaks after a thermostat leak, and boy was it leaking!

LOL.