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GoNz0

The old thermostat questions (again)

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I did both stats with genuine parts on my 2009 built 535d, it's freezing outside, zero degrees to be precise.

The car warms up reasonably fast, as fast as my other car but using the hidden menu temps were between 62 and 70, the only time it shot up to 75 was when I got to a 60 zone and put the throttle down. The rest of the time I was taking it steady due to the bad weather and a small stint down the M1 resulted in it staying at the low end of 60.

 

Is this due to it sacrificing heat to warm the car up or do I need to get the stats out and test them?

 

Just wondering what other peoples results are in this freezing weather?

 

Thanks.

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How did you bleed the system?

 

Filling and venting instructions with auxiliary heater.

  • Switch off engine, coolant temperature ≤ 40°
  • Open cap on expansion tank (AGB)
  • Open vent screws.
    • On EGR cooler thermostat
    • On coolant return pipe
  • Switch ignition on
  • Seat heating to maximum temperature and fan to low speed (heater valves are opened and auxiliary water pump starts up)
  • Add coolant slowly
  • Close vent screws after coolant emerges or after filling up to max. cold fill level
  • Fill expansion tank to maximum cold fill level
  • Start engine and run at idle for 5 minutes (top up coolant to maximum cold fill level if required)
  • Close cap on expansion tank, press accelerator pedal several times to approx. 2500 rpm
  • Open cap on expansion tank, run engine at idle for a further 5 minutes (bubble-free coolant emerges at vent line in expansion tank)
  • Fill to maximum cold fill level
  • Top up expansion tank with an additional 250 ml
  • Close expansion tank cap

 

https://www.newtis.info/tisv2/a/en/e61-535d-tou/repair-manuals/11-engine/11-51-coolant-pump-with-drive/FuDHHLp

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Apart from the bit about the aux pump as I didn't read about that,  I did have the heater on max temp, fan on low vents open so it should have fired the aux pump

I suspect it is going to be the transmission heat exchanger as that has the mysterious 3rd thermostat I had heard rumor of!

 

The 250ml top up bit doesn't apply when you go out the next morning and check it when cool :)

 

I will do it again but I did expect a badly bled system would cause it to overheat not overcool?

Edited by GoNz0

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Sounds like your main stat is 'cattle trucked' 

The only time mine dropped below 85 in winter was going down hill with no throttle and i''m assuming the wind chill cooled the engine block

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6 minutes ago, Blobby said:

Sounds like your main stat is 'cattle trucked' 

The only time mine dropped below 85 in winter was going down hill with no throttle and i''m assuming the wind chill cooled the engine block

I could understand if it wasn't a brand new genuine one, I guess I will have to take them both out and do the pan of water test on them....

 

*edit, might be better testing the ones I removed, if they both still work I doubt the new ones are faulty either.

Edited by GoNz0

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So, both the old stats check out ok, main one starts to show signs of opening around 86 and is fully open at 95 using a pan of water, cooking thermometer and IR thermometer to check against. When it is closed it is sealed tight. The EGR stat also shows signs of life mid 80's and as that is not sealed when shut it always allows some flow through it, when it opens the shaft narrows to allow more flow but the blowing down it trick wouldn't work on that type of stat.

Based on this I doubt I need to remove the new stats to test as the old ones check out so I assume it is the gearbox heat exchanger to blame. Some good news, whilst it isn't beyond a job I am capable of I have opted to let a local well recommended indy do a gearbox oil change and mechatronic seal so I sent him a message to see what he wants on top of that to do the heat exchanger as he will be refilling the gearbox oil up on a ramp after doing the service work so I may as well let him do it right 1st time.

The old process of elimination at play again.

Edited by GoNz0

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100% gearbox heat exchanger mate.

 

Just pop an inline one in the top hose .... standard mod that I and many others on here have done with no detriment. Only costs a £5er as well.

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I remember doing that on an old car that was a pain in the arse to do as it needed the engine mount and cam belt removing to get the thermostat housing off. Appreciate the link and I had read that but it's not the sort of mod I want to do on a car like this, gearbox stat has a higher opening temp for a start and I guess it's down to personal choice, just not mine :)

 

IIRC it was a cheap ass Corsa and a Renault 5 thermostat rammed in the top hose, happy days but you were only replacing one thermostat for another instead of 3 for 1

Edited by GoNz0

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Confirmed it is the heat exchanger as @Wabby said, I got the Irwin quick grip out and clamped off the hose, tie wrapped it up to stop it moving and went out for a drive, it was up to 88 in about 15 minutes of mixed steady driving (no lead foot) and stayed between 86-92, 88 on the M1 doing 70 when I got back in the car. I let her breath up a hill and got to 94 so all is good!

Apart from the £135 for a Hella-Behr unit that I should be able to fit later this week and then get the gearbox serviced.

20171211_134911.jpg

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That was a very flat stretch of the M1, it was at 36 by the time I got home after driving through town. I had reset it just b4 the pic to see what it was capable of running at the correct temp as it was 40 doing 65mph back from Manchester a few weeks back.

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On auto boxes it is located under the alternator to keep the gearbox oil under 94c (I think if what I read yesterday was true) but if the thermostat built in is failing it will dump engine heat into the gearbox until the gearbox is up to the same level as the engine meaning the engine can take a hell of a long time to warm up instead of 10-15 minutes.

 

Easy way to check it to look at the left side of the rad from the front of the car, you will have an additional pipe located about 1/3rd of the way down about an inch wide that drops down the rad, under the fan to the cooler, it comes back up to a T piece on the pipe the runs into the right side of the engine block to complete the loop, if you have a manual you wont have it :)

 

http://www.realoem.com/bmw/enUS/showparts?id=PX92-EUR-12-2009-E61N-BMW-535d&diagId=17_0244#17217803830

Edited by GoNz0

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mine is auto as well and after reading your thread i check the temperature on mine. and didnt go over 75.  both thermostats changed like 2 months ago. Probably the distance wasn't long enough. only 3.5 miles mainly dual carriage way and ambient temperature 1C

Edited by Paris 530d

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In this weather I would do the 50mph test, give it 15 minutes to get hot (including the cabin obviously) then find a dual carriageway/motorway and set cruise to 50-70mph constant for another 10 minutes. After I had the same as you I clamped the pipe I spoke about (have to take the undertray off to get to it and make sure the clamp cannot move as it may take out drive belts or the fan, I used tie wraps and a 12" Irwin quick grip clamp that I had in my tool bag) and within 15 minutes I was up to temp (88)

 

At least you can find out if it is that without throwing any more money at the car!

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Typically, my stat has decided to pack up - Ave temp was 70c peaking at 75c in traffic.  Gonna replace both the water pump and stat though, as I appear to be on the original water pump at just under 200K miles!

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1 minute ago, Dotcom1970 said:

Typically, my stat has decided to pack up - Ave temp was 70c peaking at 75c in traffic.  Gonna replace both the water pump and stat though, as I appear to be on the original water pump at just under 200K miles!

Don't forget to test (clamp off) the heat exchanger if it doesn't come up fast enough when you do the main stat.

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Just now, GoNz0 said:

Don't forget to test (clamp off) the heat exchanger if it doesn't come up fast enough when you do the main stat.

 

I'll mention this to my chap! :)

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Well the exchanger arrived, I committed to this horrible job as it isn't designed for blokes with mars bar fingers. Eventually got the old one out and as predicted I could blow through it, the stat had locked open. New one cannot be blown through. Temps now 88-94 on the little run I did taking it steady as the gearbox is down probably a pint of oil and I am waiting to get the box serviced.

 

£230 on parts to do all 3 stats, genuine BMW engine ones and Hella Behr heat exchanger that for all intents is identical to the original, I think they may be BMW ones as the sticker has been cut in half (at a bit of an angle) probably to remove the BMW part of it.

 

FYI Comma G48 extreme is on the BMW approved list of coolants as I think it's a load of poop about using genuine coolant :)

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11 hours ago, GoNz0 said:

£230 on parts to do all 3 stats, genuine BMW engine ones and Hella Behr heat exchanger that for all intents is identical to the original, I think they may be BMW ones as the sticker has been cut in half (at a bit of an angle) probably to remove the BMW part of it.

 

 

Can i ask where you bought the heat exchanger from? i think on my car needs replacing 

 

Thanks

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5 minutes ago, Paris 530d said:

 

Can i ask where you bought the heat exchanger from? i think on my car needs replacing 

 

Thanks

https://www.carparts4less.co.uk/search/215110135

They have discount codes, ignore the 10% one you get via email, I used weekend14 at the checkout to bring the price down. You can get it a bit less on eBay but I would rather not take the gamble.

 

If you want to test it you can clamp off the pipe that is clipped under the fan housing frame or pull the same pipe off the rad and blow down it with the coolant cap off, if it bubbles coolant it's bust.

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My recent E61 2007 purchase has the DPf flashing a lot now and I've just done cluster reading. That will probably explain why it will not regen..? Took the car for a 30 mile round trip and the temp peaked at 70 and fluctuated between 65-68.........should I buy the engine coolant sensor first or do the clamp thing first. As it happens I'm looking to get the autobox serviced too and there is some leakage to been seen from below on the pan.

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Clamping is free m8. Chance is it's all of them but hard to tell without taking them out.

 

If your in the Midlands we have a great Indy in Nottingham, RGA services who is a BMW specialist who does a lot of ZF services.

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