Car overheating / any diagnosis tips?

wersal gummage

Hi,

Have spent over an hour googling this.

Car (bmw e60 523i with 160k kms) gave an 'engine has overheated' warning tonight. Car is known to have cooling system issues (the model in general I mean).

Car gave the warning after about 5kms driving from cold start. No obvious overheating symptoms from engine bay, coolant reservoir didn't feel exceptionally hot. After a few minutes to allow it cool, checked coolant level and it's fine. No apparent leaks either. Gave the car an hour and started again with a cheap obd tool hooked up, coolant temp rose steadily from 80 to 120 in about three minutes, at which point the engine warning light came on and I switched the engine off again. No fault codes. At this point, coolant reservoir was not hot, was just luke warm to touch.

Obvious thing is to have car towed to a garage but I'm out of the country and due to make the return journey tomorrow. Leaving it into a garage is beyond an inconvenience!

I know driving an overheated engine will destroy it. But would coolant really heat up that quickly in just two or three minutes? If coolant was really 120 degrees, would the reservoir be very hot? I'm thinking (hoping) it could be a failed sensor..... Coolant was flushed about two years ago so would be due again around now, but equally isn't years beyond its lifespan either.

Google says it's the water pump and /or thermostat.... Is there any symptoms or signs of water pump failure I can look for myself?

Thanks!

testicles

This post has been deleted.

wersal gummage

wersal gummage wrote: »

Hi,

Have spent over an hour googling this.

Car (bmw e60 523i with 160k kms) gave an 'engine has overheated' warning tonight. Car is known to have cooling system issues (the model in general I mean).

Car gave the warning after about 5kms driving from cold start. No obvious overheating symptoms from engine bay, coolant reservoir didn't feel exceptionally hot. After a few minutes to allow it cool, checked coolant level and it's fine. No apparent leaks either. Gave the car an hour and started again with a cheap obd tool hooked up, coolant temp rose steadily from 80 to 120 in about three minutes, at which point the engine warning light came on and I switched the engine off again. No fault codes. At this point, coolant reservoir was not hot, was just luke warm to touch.

Obvious thing is to have car towed to a garage but I'm out of the country and due to make the return journey tomorrow. Leaving it into a garage is beyond an inconvenience!

I know driving an overheated engine will destroy it. But would coolant really heat up that quickly in just two or three minutes? If coolant was really 120 degrees, would the reservoir be very hot? I'm thinking (hoping) it could be a failed sensor..... Coolant was flushed about two years ago so would be due again around now, but equally isn't years beyond its lifespan either.

Google says it's the water pump and /or thermostat.... Is there any symptoms or signs of water pump failure I can look for myself?

Thanks!

wersal gummage wrote: »

Hi,

Have spent over an hour googling this..........Google says it's the water pump and /or thermostat.... Is there any symptoms or signs of water pump failure I can look for myself?

testicles wrote: »

This post has been deleted.

Eh, thanks!

Alanstrainor

The BMW 6 cylinders will overheat very quickly if coolant isn't flowing around. I would not for a minute even consider it being a faulty temp sensor without having a code that says that.

The e60 has an electric water pump, which is prone to failure. This would be my first thought on this too, but I would expect there to be codes relating to this when you read with your OBD reader.

This link should help:

http://www.pelicanparts.com/techarticles/BMW-E60/15-WATER-Electric_Water_Pump_Testing/15-WATER-Electric_Water_Pump_Testing.htm

I would not drive it at all tomorrow. It is seriously inconvenient, but even if you do drive it I would not expect you to get far and you'll just end up with a very dead e60 if you do!

wersal gummage

Alanstrainor wrote: »

The BMW 6 cylinders will overheat very quickly if coolant isn't flowing around. I would not for a minute even consider it being a faulty temp sensor without having a code that says that.

The e60 has an electric water pump, which is prone to failure. This would be my first thought on this too, but I would expect there to be codes relating to this when you read with your OBD reader.

This link should help:

http://www.pelicanparts.com/techarticles/BMW-E60/15-WATER-Electric_Water_Pump_Testing/15-WATER-Electric_Water_Pump_Testing.htm

I would not drive it at all tomorrow. It is seriously inconvenient, but even if you do drive it I would not expect you to get far and you'll just end up with a very dead e60 if you do!

Thanks. Obd reader not picking up any codes but it's a cheap eBay job. God knows what it'll cost to get a BMW dealer come and tow the car and fix this for me. Probably more than the car is worth!

pippip

wersal gummage wrote: »

Thanks. Obd reader not picking up any codes but it's a cheap eBay job. God knows what it'll cost to get a BMW dealer come and tow the car and fix this for me. Probably more than the car is worth!

why, get a good indy.

where are u based?

wersal gummage

pippip wrote: »

wersal gummage wrote: »

Thanks. Obd reader not picking up any codes but it's a cheap eBay job. God knows what it'll cost to get a BMW dealer come and tow the car and fix this for me. Probably more than the car is worth!

why, get a good indy.

I'm in a non English speaking country and due to be on a ferry in the morning, staying here is not am option so I need the car collected asap tomorrow morning. No time to research and check what possible local (speaking a language I don't understand) might do the job cheaper.

alias no.9

Thermostat would be the cheapest trial and error fix to start with. Sounds like it could be stuck shut. The stat on my Volvo S60 failed shut and it was a little module that dropped into a seat in the coolant circuit when you removed a cover, this type can be quickly tested by dropping them in a pot of boiling water and just watch them open or maybe not. Some are combined with the housing (an Alfa 156 twin spark I had about 10 years ago had one like this but it failed open) and I'm not sure there's a quick diagnostic for these except swapping out.

alias no.9

Thermostat would be the cheapest trial and error fix to start with. Sounds like it could be stuck shut. The stat on my Volvo S60 failed shut and it was a little module that dropped into a seat in the coolant circuit when you removed a cover, this type can be quickly tested by dropping them in a pot of boiling water and just watch them open or maybe not. Some are combined with the housing (an Alfa 156 twin spark I had about 10 years ago had one like this but it failed open) and I'm not sure there's a quick diagnostic for these except swapping out.