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Inline thermostat mod to fix the gearbox heat exchanger write up.

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1 hour ago, ZaKaS said:

I think Im next... :) just want to be sure and first check by removing hose from gearbox thermostat on cold engine. 

Best way to check m8

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So did mine few days ago, temps now good and holds on motorway 87-90 :) only one part was hard to put hose on thermostat, that top hose end was pain in ass even I put in boiling water.. Big thanks for GoNz0!!! 

Edited by ZaKaS

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Just now, ZaKaS said:

So did mine few days ago, temps now good and holds on motorway 87-90 :) only one parts was hard to put hose on thermostat, that top hose end was pain in ass even I put in boiling water.. But big thanks for GoNz0!!! 

To be fair I have started to use a smear of red rubber grease to assist it

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What is the 'correct' coolant operating temp?

 

I've done both the stats on mine less than 12 months ago, but I was thinking the other day it hasn't regenerated for a while. 

Checked the temps this morning and it never went above 82 Deg on my 14 mile trip to work this morning. 

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What is the 'correct' coolant operating temp?
 
I've done both the stats on mine less than 12 months ago, but I was thinking the other day it hasn't regenerated for a while. 
Checked the temps this morning and it never went above 82 Deg on my 14 mile trip to work this morning. 
88c

Sent from my SM-G920F using Tapatalk

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Hi guys,

 

I own a 2005 BMW 525D, M57 engine, recently i 've had issues with my coolant temperature, I've had OEM main stat and behr egr stat, the temp was 85 degrees and solid mostly. So i've decided to replace them to improve the temp up to 92. I've bought and replaced VEMO main and egr stat, the temp didn't improved it was sitting on 85 and 88 when idle. I suspected the HE stat also fails, so i've done this mod too, during the implenetation i've checked again the new stats, i guess they are fine because i couldn't blow through the main stat and barely through the egr stat, i've bled the system through the egr stat. The temp is still 85 when ride, 87 when idle, during full acceleration goes down till 79 then raise back to 85 (checked with hidden menu). So now i'm out of ideas, why my car is running on little bit low temp. Anyone has any idea please?

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1 minute ago, posted4 said:

Hi guys,

 

I own a 2005 BMW 525D, M57 engine, recently i 've had issues with my coolant temperature, I've had OEM main stat and behr egr stat, the temp was 85 degrees and solid mostly. So i've decided to replace them to improve the temp up to 92. I've bought and replaced VEMO main and egr stat, the temp didn't improved it was sitting on 85 and 88 when idle. I suspected the HE stat also fails, so i've done this mod too, during the implenetation i've checked again the new stats, i guess they are fine because i couldn't blow through the main stat and barely through the egr stat, i've bled the system through the egr stat. The temp is still 85 when ride, 87 when idle, during full acceleration goes down till 79 then raise back to 85 (checked with hidden menu). So now i'm out of ideas, why my car is running on little bit low temp. Anyone has any idea please?

The thermostat opens at 88 so I have no idea where you came up with 92?

Sounds like you never had a bad heat exchanger and never tested for flow coming through it, the car is 15 years old so I expect the temp sensors reading a few degrees low, booting it will drop the temp as the stat can't react to the sudden influx of cooled water in time, this is why a true temp gauge is dampened like the dual tank readout to prevent this.

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9 minutes ago, GoNz0 said:

The thermostat opens at 88 so I have no idea where you came up with 92?

Sounds like you never had a bad heat exchanger and never tested for flow coming through it, the car is 15 years old so I expect the temp sensors reading a few degrees low, booting it will drop the temp as the stat can't react to the sudden influx of cooled water in time, this is why a true temp gauge is dampened like the dual tank readout to prevent this.

Thanks for the quick reply, i had the idea as well that the temp sensor isn't funtcioning properly, but then i was thinking it wont show anything if it fails. Btw with the previous stats when they were new approx 1 year ago the car was sitting on solid 92. Also i've read everywhere that the temp must be above 88. As ive had put in the extra stat, i feel like the transmission is smoother, but its maybe just placebo. Also :

 

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5 minutes ago, GoNz0 said:

Fitting Vemo parts won't help for quality control either :(

Do you think if i will fit OEM ones, it would improve? Or just leave it like this? Btw I'm from Hungary and the mechanics are shit here but really expensive and also cheating, so i've decided to do it on my own. 

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13 minutes ago, GoNz0 said:

Maybe you could put a cooking thermometer in the expansion tank to check the temp?

I have no better idea, so i will do so, but i expect lower temp there, since its farther from the engine heat, and i guess the temp sensor is in the cylinder head. Anyway thank you so much for the support!

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1 minute ago, posted4 said:

I have no better idea, so i will do so, but i expect lower temp there, since its farther from the engine heat, and i guess the temp sensor is in the cylinder head. Anyway thank you so much for the support!

The return flow into the tank comes where the coolant is about to go into the rad so it is hot and with an engine that is properly warm it won't drop more than a degree by then.

 

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Gonzo great mod, have been running it for a while now. Towed heavy trailers and nothing overheats. Do you have any pictures or instructions for removing the guts of the heat exchanger thermostat from within the housing to aid better flow as I recall you may have said somewhere the original ones break partially open restricting flow??..! Many thanks for your efforts

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9 hours ago, tornado84125 said:

Gonzo great mod, have been running it for a while now. Towed heavy trailers and nothing overheats. Do you have any pictures or instructions for removing the guts of the heat exchanger thermostat from within the housing to aid better flow as I recall you may have said somewhere the original ones break partially open restricting flow??..! Many thanks for your efforts

 

It's quite difficult and pointless to remove those heat exchanged thermostat elements. If they fail they fail open and not causing significant restriction to maximal flow.

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Someone sent me this pic of his car, he was going to do the mod and saw this

 103960939_264915871414846_3465985712673719580_n.jpg?_nc_cat=104&_nc_sid=b96e70&_nc_ohc=TKsi4vYCZ-wAX_PVmOu&_nc_ht=scontent-lhr8-1.xx&oh=b77fb2bd3665cc1cff65d38f8faa1070&oe=5F07BAB4

Edited by GoNz0

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1 hour ago, GoNz0 said:

Someone sent me this pic of his car, he was going to do the mod and saw this

 103960939_264915871414846_3465985712673719580_n.jpg?_nc_cat=104&_nc_sid=b96e70&_nc_ohc=TKsi4vYCZ-wAX_PVmOu&_nc_ht=scontent-lhr8-1.xx&oh=b77fb2bd3665cc1cff65d38f8faa1070&oe=5F07BAB4

cowboys mate,

 

would love to meet the person that did this and slap them.

 

New parts already on order.

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5 hours ago, GoNz0 said:

Someone sent me this pic of his car, he was going to do the mod and saw this

 103960939_264915871414846_3465985712673719580_n.jpg?_nc_cat=104&_nc_sid=b96e70&_nc_ohc=TKsi4vYCZ-wAX_PVmOu&_nc_ht=scontent-lhr8-1.xx&oh=b77fb2bd3665cc1cff65d38f8faa1070&oe=5F07BAB4

 

The world has clearly missed one great thoracic surgeon doing a bypass like this. :lol:

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GonZo thanks for the write up looks straight forward enough.

 

Would anyone happen to know, i have just had the gearbox serviced on my 2005 535d with 107k miles on it.  The car had the ominous revs fluctuating and mechanic reckoned it was due to an oil leak in the box and the level being low.  So oil changed with the proper lifegaurd 6 and zf filter.  Car is back to doing this so cruise at 75mph and its jumping 1800-1550rpm.  Does seem to improve the more miles you do which got me thinking could it be the oil in the box isnt getting to temperature.

 

After reading this my thoughts were before i get the Torque Convertor overhauled by sussex autoparts then i might give this a try.  So wanted to ask if anyone happens to know if this is a possible symptom?

 

Thanks

Mark

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Quick question about this well read topic.

 

My 530d will be getting this inline stat fix shortly before winter.   It was carried out a few years ago using the renault 5 stat route which does not work now.  My question is, should I remove this stat or replace the hose as well?  It is obviously stuck open but I am wary of causing too great a flow restriction in the system when the oil cooler unit is installed.

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