[serious] '14 M5, no coolant on hot day - how far could it go?

[d.b]

I am hoping one of you know definitively one way or the other on this - I've asked a few people who should know but still need more evidence.

2014 M5 in Atlanta, GA in September - If the engine coolant was completely empty, under normal driving conditions on a hot day - how far do you think it would get?

1 mile? 5 miles? 10 miles? 20?

again, very serious question with alot riding on the answer. I will explain at a later date.

Thanks

[M5Rick]

Originally Posted by d.b

I am hoping one of you know definitively one way or the other on this - I've asked a few people who should know but still need more evidence.

2014 M5 in Atlanta, GA in September - If the engine coolant was completely empty, under normal driving conditions on a hot day - how far do you think it would get?

1 mile? 5 miles? 10 miles? 20?

again, very serious question with alot riding on the answer. I will explain at a later date.

Thanks

Just one and a half miles

[HeyKC]

You could probably make it 20 miles although they would not be healthy miles.

I do wish I had more than an oil temp gauge. Its not uncommon for the oil temp to take 20 min to be at operating temp in my car.

[Dwaynos]

I would say no more than 5 miles at the most. This engine gets very hot very quick and relies heavily on its cooling system.

[Sophisticated Redneck]

Assuming you are just ticking along at 2000 or less rpm You could get away with about 1 mile at freeway speeds without much worry of any damage, right around 3-5 min (or roughly 3-5 miles) you will be in danger of cracking your heads and warping the block. By about 10-15 miles or 8-10 minutes the engine should be about ready to seize if it has not already. Damage to cylinder bores, rings, heads, etc. The turbos will also most likely be damaged too.

[d.b]

Originally Posted by Sophisticated Redneck

Assuming you are just ticking along at 2000 or less rpm You could get away with about 1 mile at freeway speeds without much worry of any damage, right around 3-5 min (or roughly 3-5 miles) you will be in danger of cracking your heads and warping the block. By about 10-15 miles or 8-10 minutes the engine should be about ready to seize if it has not already. Damage to cylinder bores, rings, heads, etc. The turbos will also most likely be damaged too.

Thanks very much. any clue or guess as to what kind of oil temp would be visible on the gauge cluster at the 20-25 minute mark assuming the car was still running? (normal driving conditions, car is driving - not idling)

edit - actually, the above question doesn't really matter much at this point. I was just checking myself to confirm that I am correct in assuming that when I drove my car to the shop 11 miles away and made it there without being near overheating temps that I _did indeed have coolant in my car_ (and it has never been driven without coolant to my knowledge)...

[wallyman424]

You car would be dead if you drove 11 miles without coolant.

Was the coolant low light on your dash? Why do you think you had no coolant?

[arucano]

what was the oil temperature. The coolant loss will affect the cylinder walls and the oil temperature will affect the bearings, cams and pistons.

[d.b]

there were no signs of low coolant, messages/lights or otherwise. In september (the last time I drove the car), I drove it 11 miles to a tire shop and had fronts put on and then had it towed to a local indy shop where I was told that one of the turbo coolant lines was busted and the car had zero coolant.

It had been getting progressively harder to start over a couple of weeks prior to this and I couldn't get it started back up at the tire shop. It was closing time, so we left it in the install bay for the night and i had it towed from there to a local indy shop the next day. It was a few days later that they (indy shop) could get to it and that is when they told me.

The guys at the tire shop managed to get it started to move it out of the install bay the next day before the tow came and that was the only other time it was driven.

odd right? welcome to the beginning of a very complicated story full of twists and turns, mystery, with my dream car unlikely to survive it :*|.

Honestly if it weren't for the info on this forum and an expert that I was lucky enough to get ahold of, Im not sure if it would have standed a chance.


to ease the suspense - lol - the indy shop called me up after running a compression test and told me that the car had warped heads and quoted me 10k because of overheating...

the only thing about that is - its never been overheated.

to be continued in another thread, I have one more question, and the answer will likely determine her fate.

note - I paid their diag fee, and had the car towed to BMW service where (thank you forum) the injectors were found faulty and had flooded the engine with fuel, and replaced under the extended warranty. - its still there.

[d.b]

Originally Posted by arucano

what was the oil temperature. The coolant loss will affect the cylinder walls and the oil temperature will affect the bearings, cams and pistons.

oil temp was usually a bit shy of the half mark on the dial, with coolant temps (I monitored them religiously through obd app / kiwi3) in the 195-215F range on avg.

[Craze]

Do u mean no coolant or non in resovoir?

[d.b]

Originally Posted by Craze

Do u mean no coolant or non in resovoir?

I mean running bone dry.

[Dwaynos]

Originally Posted by d.b

I mean running bone dry.

If the turbo lines had leaked you wouldn't loose engine coolant. The systems are separate. The small reservoir is for turbos, ecus and charge coolers to my knowledge.

[wallyman424]

Originally Posted by Dwaynos

If the turbo lines had leaked you wouldn't loose engine coolant. The systems are separate. The small reservoir is for turbos, ecus and charge coolers to my knowledge.

Yes, a leak in the turbo coolant lines will not affect engine coolant at all. Also when it's too low your car will be throwing error messages

[d.b]

Going back over text messages and emails - upon receipt engine coolant empty, turbo coolant full.

In the diagnosis write up it states that the turbo coolant line bank 1 was broken.... incompetence or lies?

[wallyman424]

Originally Posted by d.b

Going back over text messages and emails - upon receipt engine coolant empty, turbo coolant full.

In the diagnosis write up it states that the turbo coolant line bank 1 was broken.... incompetence or lies?

Leaking turbo coolant line would in no circumstance have any affect on engine coolant.

If your engine coolant was empty you could have blown head gaskets as your other thread suggests, or you could have ruptured a hose. There are multiple ways to diagnose it. First thing to do is a compression and leakdown test.

[d.b]

Originally Posted by d.b

Going back over text messages and emails - upon receipt engine coolant empty, turbo coolant full.

In the diagnosis write up it states that the turbo coolant line bank 1 was broken.... incompetence or lies?

turbo coolant circuit - does it interact with the head gasket?

[d.b]

Originally Posted by wallyman424

Leaking turbo coolant line would in no circumstance have any affect on engine coolant.

If your engine coolant was empty you could have blown head gaskets as your other thread suggests, or you could have ruptured a hose. There are multiple ways to diagnose it. First thing to do is a compression and leakdown test.

if anything was empty it would have been the turbo circuit, but like I said I never drove it with low coolant. I think the hose is just a coincidence and does not factor into the big picture.

edit: general FYI: I've never questioned whether or not my car was low or empty on coolant - I know for a fact that it wasn't (I was watching the coolant temperature in app). this thread was to prove that it would have been literally impossible for me to have done so, which is just another point of support for the warranty case I will make if the rest of the line can be drawn.

[wallyman424]

Originally Posted by d.b

turbo coolant circuit - does it interact with the head gasket?

Nope, only provides coolant to intercoolers, turbo and ecus.

[d.b]

Originally Posted by wallyman424

Nope, only provides coolant to intercoolers, turbo and ecus.

this is getting very interesting. thank you so much for the info.

[technician117]

Originally Posted by d.b

this is getting very interesting. thank you so much for the info.

Originally Posted by wallyman424

Nope, only provides coolant to intercoolers, turbo and ecus.

This is incorrect. The DME's and intercoolers are on their own separate system that runs at a lower temperature than the engine and turbos. It's true that the turbos have a cooling circuit, but it's run from the same system and reservoir as the main engine. The confusion comes because the turbo coolant system is run by an electric pump after the engine shuts down. People think this is a separate system but it's actually drawing engine coolant to run it. I just reviewed the technical data so please don't argue.

The S63TU technical data document is posted on this website, I don't have the link handy (I have the document on my computer now). They actually do a good job with pictures and diagrams separating out the different systems.

Summary:
DME's and intercoolers have their own (2) electric waterpumps and a reservoir in the middle/top of the engine. This system does not utilize a low coolant sensor in the reservoir, but the pumps will shut down and store a code and display a message if they sense they are pumping air.

The engine and turbos run from a separate system utilizing a mechanical pump AND electric pump (to continue cooling the turbos after shutdown). They run off of the reservoir located near the firewall. This tank does have a coolant level sensor.

[d.b]

Originally Posted by technician117

This is incorrect. The DME's and intercoolers are on their own separate system that runs at a lower temperature than the engine and turbos. It's true that the turbos have a cooling circuit, but it's run from the same system and reservoir as the main engine. The confusion comes because the turbo coolant system is run by an electric pump after the engine shuts down. People think this is a separate system but it's actually drawing engine coolant to run it. I just reviewed the technical data so please don't argue.

The S63TU technical data document is posted on this website, I don't have the link handy (I have the document on my computer now). They actually do a good job with pictures and diagrams separating out the different systems.

Summary:
DME's and intercoolers have their own (2) electric waterpumps and a reservoir in the middle/top of the engine. This system does not utilize a low coolant sensor in the reservoir, but the pumps will shut down and store a code and display a message if they sense they are pumping air.

The engine and turbos run from a separate system utilizing a mechanical pump AND electric pump (to continue cooling the turbos after shutdown). They run off of the reservoir located near the firewall. This tank does have a coolant level sensor.

Thank you very much this is very informative.

What a mess.