Cooling System

Originally Posted by cmpcpro

So this is after driving freeway, and town, and traffic? 92c? See that's what I don't understand.. either your TSTAT is bad, your DME is opening the tstat way early because of a sensor or something, or your car is running super cool from the small coolant loop and not even using the lower radiator hose.. I don't understand how this could be.. only thing I can think sounds right, is either DME is opening it early, or do you happen to have an 02? I heard somewhere that the early 02's got a 92c tstat.. Or I should say the early N62 engines.

Nope all bmw v8 v12 engines starting from 98 are built to fail with 105C. If your car never goes to 103-105 it means its either half opened or bc DME opens it too early. I personally saw one e65 where DME kept it fully open all the time!!!
It depends on some factors like intake air temp sensor and engine temp. If DME sees that it's super hot outside it would open tstat earlier.
Anyhow I totally understand what's going on:
I bought 160k miles e66 and it worked great but radiator was leaking a little, so replaced it and it worked for a while but recently I got a leak from somewhere else bc of high pressure.
In other words this stupid super hot cooling system sucks and will keep exploding weak areas of this system!!
You fix one leak and you'll get another one over and over, until either you overhaul everything related to cooling system or you replace engine!
What a great car and great ideas
Yes they want more money from us and moreover they don't want luxury vehicles to last over 60k warranty miles and 105C tstat is a brilliant solution!
Coolant pipe and rear cover profile gasket and a heater core are the worst : and all these gaskets only last 3-5 yrs max. I'm not even talking about all oil leaks related to high temp

Originally Posted by SFbay

Nope all bmw v8 v12 engines starting from 98 are built to fail with 105C. If your car never goes to 103-105 it means its either half opened or bc DME opens it too early. I personally saw one e65 where DME kept it fully open all the time!!!
It depends on some factors like intake air temp sensor and engine temp. If DME sees that it's super hot outside it would open tstat earlier.
Anyhow I totally understand what's going on:
I bought 160k miles e66 and it worked great but radiator was leaking a little, so replaced it and it worked for a while but recently I got a leak from somewhere else bc of high pressure.
In other words this stupid super hot cooling system sucks and will keep exploding weak areas of this system!!
You fix one leak and you'll get another one over and over, until either you overhaul everything related to cooling system or you replace engine!
What a great car and great ideas
Yes they want more money from us and moreover they don't want luxury vehicles to last over 60k warranty miles and 105C tstat is a brilliant solution!
Coolant pipe and rear cover profile gasket and a heater core are the worst : and all these gaskets only last 3-5 yrs max. I'm not even talking about all oil leaks related to high temp

Well I have bought the entire cooling system in the last couple days. It's all sitting in my living room.. Was going to install tonight but I didn't make it to the dealer in time to get the last two pipes.. I have new expansion tank, cap, all new hoses, sensors, tstat, the good metal impeller water pump, aux water pump, coolant. The only thing remaining is the radiator, heater hoses/core and engine.

Originally Posted by cmpcpro

Well I have bought the entire cooling system in the last couple days. It's all sitting in my living room.. Was going to install tonight but I didn't make it to the dealer in time to get the last two pipes.. I have new expansion tank, cap, all new hoses, sensors, tstat, the good metal impeller water pump, aux water pump, coolant. The only thing remaining is the radiator, heater hoses/core and engine.

Entire cooling system?? Don't want to upset you, but...
You'll be surprised, but you also need:
-valley pan 99.9% leaking from the rear of the engine (I found small leak on my car)
- rear passage cover (not sure if mine has it, bc valley pan could cause that leak to.
- coolant pipe seals (most likely you can see wheep hole leak but not always)
Replacing a heater core is a real PITA!

Originally Posted by SFbay

Entire cooling system?? Don't want to upset you, but...
You'll be surprised, but you also need:
-valley pan 99.9% leaking from the rear of the engine (I found small leak on my car)
- rear passage cover (not sure if mine has it, bc valley pan could cause that leak to.
- coolant pipe seals (most likely you can see wheep hole leak but not always)
Replacing a heater core is a real PITA!

Yes unfortunately I only have the cooling system that isn't built into the engine/heater core.. what do you mean you aren't sure if your car has a rear passage cover? Don't they all? I am wondering if this issue could be the starts of the coolant pipe/valley pan? I will have my water pump out tomorrow, I will look around and see what I can find.. which reminds me, SFBay, I know TIS said the harmonic balancer has to come off for the water pump but I am reading people are doing it without removing.. what did you do? Thanks!

Been read this for some time and I had the same things happen to mine over heating hacd to replace upper hose and expansion tank and cap the hoses have a poor made were the T or Y connect they just fall apart Im thinking what if we flush cooling systems it could be clug from crap like parts that come from T or Y connectiond from hoses. What do u thing guys?

Originally Posted by cmpcpro

Yes unfortunately I only have the cooling system that isn't built into the engine/heater core.. what do you mean you aren't sure if your car has a rear passage cover? Don't they all? I am wondering if this issue could be the starts of the coolant pipe/valley pan? I will have my water pump out tomorrow, I will look around and see what I can find.. which reminds me, SFBay, I know TIS said the harmonic balancer has to come off for the water pump but I am reading people are doing it without removing.. what did you do? Thanks!

I'm not quite sure if its valley pan or that rear cover since they both leak from rear of the engine.
Idk how to remove waterpump without removing that harmonic balancer, and it's very easy to remove and install.

Originally Posted by B7M4W5

Been read this for some time and I had the same things happen to mine over heating hacd to replace upper hose and expansion tank and cap the hoses have a poor made were the T or Y connect they just fall apart Im thinking what if we flush cooling systems it could be clug from crap like parts that come from T or Y connectiond from hoses. What do u thing guys?

Hey after you replaced that Y pipe did it fix everything?? Mine looks good and cannot see any leaks, so I was wondering if I need to replace anyways 70$ smth!

Originally Posted by SFbay

Hey after you replaced that Y pipe did it fix everything?? Mine looks good and cannot see any leaks, so I was wondering if I need to replace anyways 70$ smth!

Your talking about the one that goes from the expansion tank to the t or y and then into both heads? I have the new one, going in with everything else..

You were saying its very very easy to install, do you mean harmonic balancer or water pump? Thanks!

Originally Posted by cmpcpro

Your talking about the one that goes from the expansion tank to the t or y and then into both heads? I have the new one, going in with everything else..

You were saying its very very easy to install, do you mean harmonic balancer or water pump? Thanks!

My car runs okay now, but still I want to fix that damn invisible leak.
Yes it's easy to remove harmonic balancer. But if I were you I would try to fix that leak first. Your waterpump is okay.

Originally Posted by SFbay

My car runs okay now, but still I want to fix that damn invisible leak.
Yes it's easy to remove harmonic balancer. But if I were you I would try to fix that leak first. Your waterpump is okay.

Waterpump is making a horrible noise everytime car starts cold.. I think bearing is shot.. going to replace it with everything, so it will all be new at once.

Well leaks stop and since I replace cap it stop over heating, but it still goes up to 105c hope all that programming works out, but Like I said we all had a got temp. when first got our 7s so could it be radiators are clug need cleaning from inside

Originally Posted by cmpcpro

Waterpump is making a horrible noise everytime car starts cold.. I think bearing is shot.. going to replace it with everything, so it will all be new at once.

Yes that happend to me made squeeky sound then one morning on way to work it went out fell apart lost power steering control steam all over could not see where I was goin pully fell of lost belt, man I was hating that day.

Originally Posted by B7M4W5

Well leaks stop and since I replace cap it stop over heating, but it still goes up to 105c hope all that programming works out, but Like I said we all had a got temp. when first got our 7s so could it be radiators are clug need cleaning from inside

It's ok you have 105C but what about idling? Can you check When it's 105C will aux fan kick in?? It should be 105C then aux fan lowers it to 103 then it goes to 105 and it's kinda cycle it should have.

That it does in idle, for now nock on wood lol

What I was thinking earlier the OEM tstat could be gutted and put an aftermarket inline tstat.Might be easier than what your doing SFbay.Also my fan dosnt kick in until 105c but it does let the temp get to 107c.Could the fan not be running high enough speed to keep 105c minus?Sorry to keep rehashing but it takes me awhile for it to sink in lol

Originally Posted by dolfan13

What I was thinking earlier the OEM tstat could be gutted and put an aftermarket inline tstat.Might be easier than what your doing SFbay.Also my fan dosnt kick in until 105c but it does let the temp get to 107c.Could the fan not be running high enough speed to keep 105c minus?Sorry to keep rehashing but it takes me awhile for it to sink in lol

Try it, I've already tried it. Diameters are really off. I found some Mazda tstat kinda fits ok, but still had to machine it.

Originally Posted by B7M4W5

That it does in idle, for now nock on wood lol

It means your system works good at tstat opens up when needed. This is how it should be 103 to 105 cycle.
Okay I'll replace that Y hose even though I see no leaks from it.
What's funny that my system was fine a month ago, and I thought it was fine until 3 days ago I got low coolant message!!! In other words you have to check your aux fan every week just to make sure you're not ruining your engine!
So I've been driving my car thinking it was fine for a month and now I can see upper timing chain covers leaking!!! FK

Originally Posted by SFbay

It means your system works good at tstat opens up when needed. This is how it should be 103 to 105 cycle.
Okay I'll replace that Y hose even though I see no leaks from it

Cool

Originally Posted by SFbay

It means your system works good at tstat opens up when needed. This is how it should be 103 to 105 cycle.
Okay I'll replace that Y hose even though I see no leaks from it.
What's funny that my system was fine a month ago, and I thought it was fine until 3 days ago I got low coolant message!!! In other words you have to check your aux fan every week just to make sure you're not ruining your engine!
So I've been driving my car thinking it was fine for a month and now I can see upper timing chain covers leaking!!! FK

I know, isn't it frustrating? Whats worse is BMW did this to us to screw us.. Which y hose are you talking about? The little one that goes to expansion tank? I am doing that one with the overhaul.. gonna have to take the TB off to get to it, so I bought a new TB gasket too.

I replaced the hose behind the intake awhile back.I think SFbay said it when it could be a small leak anywhere.probably shouldn't have done it but I put 1/4 bottle of aluminum seal bars leak.Been holding steady at 105c

Well if it's any of the hoses, or expansion tank, or water pump I should know tonight.. been trying to install this new cooling system for the last few days and have just been too busy.. Sick of looking at all the boxes in my living room everyday.

Originally Posted by cmpcpro

Well if it's any of the hoses, or expansion tank, or water pump I should know tonight.. been trying to install this new cooling system for the last few days and have just been too busy.. Sick of looking at all the boxes in my living room everyday.

Super update:
I removed TB and look what I found:
- previous owner was a btch
- this Y pipe is actually has a bleeding valve inside, so if there is any smallest tiny leak, the system will never get bleeded!!!!
So I guess it was a number one problem, but I need oem clamps to install oem one. FK
This is very very important hose, replace it anyways even if no leaks bc you don't know if that valve is working!!!

I went to 108c anyway.Are you saying the bleed is at the expansion tank connection?

Originally Posted by dolfan13

I replaced the hose behind the intake awhile back.I think SFbay said it when it could be a small leak anywhere.probably shouldn't have done it but I put 1/4 bottle of aluminum seal bars leak.Been holding steady at 105c

That barsleak will clog your heater core, I know from experience and its not a cheap fix. I put a bottle in my car trying to get another month or so out of the crossover pipe leak, my Indy was sooooo pissed.

I suggest a good cleaning of the coolant system. This might be why you are at such a high temp, that stuff sticks to anything and everything