[mistryn]

After reading the coolant temperature thread, I had a look at mine on my drive into work this morning approx 15 miles. Outside temperature was 8.5 degrees.

I started off at 19 deg, about 5 miles into the journey the temp was showing 48 deg and about 12 miles it was 74 degress.

The only time it went to 76 deg was when I was stationary in traffic but as i started moving it went fown to 74/75

I parked up in the car park for about 5 minutes, the temp rised to 80/82 degrees

Is it worthwhile me replacing the EGR thermostat?

Also can anyone tell me why my car will only rev to 4k when stationary?
I press the acceerator down fully but the car will only go up to 4k, is this a safety rev limiter?

[mistryn]

Ive gone ahead and ordered a EGR thermostat and will change it for peace of mind

Can anyone confirm this is the correct part number for a 335D?
11717787870

I rang up sytner oldbury and asked for an egr thermostat and the parts guy quoted me £117 plus vat

I went onto realoem and got the part number and rang him back

[shane55]

B11.71.7.787.870 Thermostat €38.75
B11.53.2.248.435 O Ring €0.88

Plus VAT.

[NJ 1161]

This is the trouble with all these threads. You read them and decide to change parts. I'm with you on changing it to be on the safe side. I tested mine today, about 10 degress outside got upto 80 fairly easily and stayed around there. No town driving though, just 20 miles open roads. Will do a further test before changing with some town driving in, but mine didn't seem silly low so not overly concerned.

Be sure to update once you've replaced the egr!

[mistryn]

Thanks Shane

Originally Posted by NJ 1161

This is the trouble with all these threads. You read them and decide to change parts. I'm with you on changing it to be on the safe side. I tested mine today, about 10 degress outside got upto 80 fairly easily and stayed around there. No town driving though, just 20 miles open roads. Will do a further test before changing with some town driving in, but mine didn't seem silly low so not overly concerned.

Be sure to update once you've replaced the egr!

on my way home i took a different route which included a short motorway trip. I monitored the temperature, this time it got up to 65 degrees in a matter of 2/3miles, then gradually climbed to 71 degrees and stayed there. then on a couple of roads where it was the national speed limit I ahem used my right foot ahem and got the temp up to 80 degrees. As soon as I eased off it rapidly dropped down to 71 degrees and rested thereabouts.

On the motorway the temperature never really got above 82 degrees, im pretty sure its the egr stat, if not I will change the other stat as well.

Its worrying that BMW thought not to put a temperature gauge, especially when a dpf regen needs 88+ degree to start and if it never gets to temp then how does it regen? and if there isnt a gauge then we can continously drive on not knowing the engine is not getting up to temp and a knackered dpf becuase it cant regen

I will definatly change the EGR stat and report back here

[NJ 1161]

Your temps sound far from shocking to me but i'm no expert. Don't sound dis similar to mine and i have no reason to think anything wrong with mine ( other than coming on these bl%$£dy forums)

First day i have looked at my temps so going to monitor going forward.

Those temps are pre changing egr stat?

Be intersting to compare when changed.

[mistryn]

Update

I changed the EGR thermostat this morning, it took 35 mins to do, it took 10 minutes trying to figure out how to unclip the black strip so I can get access to the screw to remove engine cover

First thing I noticed when I took off the old EGR, there was no O ring The old EGR I could easily blow throw it so i presumed it was knackered. Refitted the new one and went out for a spin

The outside temperature was 6 degrees and this is what I found -

On the old EGR stat it used to stick around the 73 deg mark

With the new EGR stat, I went on a 10 mile route though the country side which consisted of NSL route. From home to the first 2 miles the car warmed up quicker than before and was showing 68 degrees. Then it slowly creeped up to 78 degrees and stayed there. On one occasion I accelreated quite brisk and it went up to 80 degrees but normal cruising it went down to 78 degrees.

Then I switched the heaters off and temp rose to 80 degrees and stayed there.

I then came back into town and the temp fluctuated between 78-81 degrees. I parked up in the car park and revved the engine (3k) constant for 15 seconds. The temp rose steadily up til 93 degrees and had I continued to rev it would have kept going higher.

Then I moved off for a mile trip back home, the temp came back down to 80 degrees

I do not know if the maim stat is re adjusting becuase it wasnt be used proeprly before but does this sound right? Or should I replace my main stat?
(does anyone have a how to for that?)

I have got a motorway journey tommorow so will monitor it then and report back

[TMP]

So the new stat is giving a lower temp than the old one .

It seems these 3l diesels like running in the mid 80s?

[mistryn]

Originally Posted by TMP

So the new stat is giving a lower temp than the old one .

It seems these 3l diesels like running in the mid 80s?

Sorry, the new one is running slighltly higher than the old one.

No wonder BMW didnt put in a coolant temp into the dash with these wide ranges

I am going to give it a long run tommorow and see what results I get as some say they read 90 deg bang on and others report mid 80's

[b21playa]

In all my diesel Bm's, they run about 90ish.

My 330d only got to 69 max, so I changed egr stat, now it gets to 84 showing goes up and down a fair bit. As I have a spare main thermostat I want to change this and flush the cooling system at the same time. This should get it to sit on 90-92

Anyone changed a main one? I'm having troubles removing the fan

[bazz780]

I changed egr stat to find that temp gets to 70ish quicker but not higher, will change main stat soon and hopefully will be better

[mistryn]

Update part 2

Went on a 100 mile motorway trip yesterday, outside temperature was 11 degrees. Again no problem it getting up to 75 deg within the first few miles, on the motorway with the crusie on the temp stayed a constant 79 degrees. It only rose when going up a slight hill to 81 degrees and then back down to 79 degrees.

When I came off the motrway and driving around town, the temp shot up to 94 degrees and when I was at the lights was hitting 99 degrees but then would fluctuate between 96-98 degrees ( I presume the fan would be kicking in but I did not hear it thought?)


On another note by changing the EGR stat, I have noticed my mpg increase. Normally on a motorway trip I would avg 33-34mpg with a heavy right foot (which I thought wasnt to bad for the engine). todays same journey I avg 37.1 mpg.

I reckon if I was to drive like a granny I would easily see 40mpg+

So I will be getting the main stat changed asap.
does anyone know if its worthwhile replacing the water pump while the main stat is being done? and anything else in that region could do with replacing?

[bazz780]

From what you describe it sounds like your main stat is stuck open or is sticking open.

I have the same issue, I noticed my mpg increase after the egr stat too and only hope once main stat is changed, it will increase higher lol

[mistryn]

Originally Posted by bazz780

From what you describe it sounds like your main stat is stuck open or is sticking open.

I have the same issue, I noticed my mpg increase after the egr stat too and only hope once main stat is changed, it will increase higher lol

If only the main stat was as easy to change as the egr one

How much do you think a garage will charge to change? i plan on buying the part from BMW and getting them to fit it?

Is it best to replace the whole coolant with new coolant or just top it up?

[bazz780]

il be using a specialist as main dealer prices are just too much for me, i bought the part from main dealer, i think will cost approx 60-100 pounds to get it fitted as quite alot of things needs to come out for access.

there is no harm with renewing the coolant completely or you can just top up what you lose, iirc from my 5 series, you will lose quite a bit of coolant.

[mistryn]

Originally Posted by bazz780

il be using a specialist as main dealer prices are just too much for me, i bought the part from main dealer, i think will cost approx 60-100 pounds to get it fitted as quite alot of things needs to come out for access.

there is no harm with renewing the coolant completely or you can just top up what you lose, iirc from my 5 series, you will lose quite a bit of coolant.

Thanks, I normally use my local garage as I took my previous cars to him but just recently I have found a BMW specialist as well so will see what the price differences are

[b21playa]

I'll be doing mine on the weekend. Very hard off the floor, will be using a ramp on Saturday as I need to bleed brakes as well

[makkan00]

Originally Posted by mistryn

Thanks, I normally use my local garage as I took my previous cars to him but just recently I have found a BMW specialist as well so will see what the price differences are

Its old thread but just wondering, did you change the main stat?
Did you change it yourself or get it changed by somebody else?
Thanks.

[mistryn]

Originally Posted by makkan00

Its old thread but just wondering, did you change the main stat?
Did you change it yourself or get it changed by somebody else?
Thanks.

Yes I changed the main stat as well myself, there is a guide on the forum for a 330d which I followed and which pretty much same for my 35d. Took my 3 hours to do but was taking my time but i would guess at a garage probs 1.5/2 hours tops for labour

[johnboy98]

Originally Posted by makkan00

Its old thread but just wondering, did you change the main stat?
Did you change it yourself or get it changed by somebody else?
Thanks.

Gonna be checking the temps on my main stat this week Sam and if low then fitting a new one complete with housing. I know the EGR one is fine (high resistance with the blow through test)

[johnboy98]

Originally Posted by mistryn

Yes I changed the main stat as well myself, there is a guide on the forum for a 330d which I followed and which pretty much same for my 35d. Took my 3 hours to do but was taking my time but i would guess at a garage probs 1.5/2 hours tops for labour

Did you see much if any extra mpg and what were your base line temps when completed mistryn?

[mistryn]

This was done some time ago prior to changing the stat I was hitting no more than 76/78 degrees. My mpg around town I think dropped to 28mpg since changing the main stat within 10 mins into a journey I was hitting 91/92 degrees and mpg was 31/32mpg around town