jas_r_1

What a dilemma!!!

I have had the same issues:

- temp not hitting 90 degrees, unless stuck in traffic
- temp decreasing once car moves off
- temp being as low as 79 degrees when driving on a motorway

I raised this with my dealer a year ago and was fobbed off by the service advisor, who said no error messages no problems.

As the temp generally made 87 degrees I didn't pursue the issue. However recently it has taken 50 mins to get to 85 degrees so I have raised this again with my dealer. The same service advisor repeated the same thing. This time I printed this thread and eventually spoke to a tech. He pretty much said he had monitored my temp and said it seemed fine. I was persistent in that the optimum temp is not being reached and the temp decreases once the car hits a constant speed. He explained that the temp would go down as once the car moves, the air will cool it down. As my car does not have flaps it seems fine that the temp goes down, where as the flaps would help maintain a constant temp.

In essence the tech didn't think there was a problem but is going to try and see another car tomorrow and then monitor the temp. I think it's pretty much a no go from what I have been told so far. The tech said he could replace the stats but if there is no fault, I have to pay.

So I am stuck. I can try another dealer but will probably get the same responses. Even if another dealer agrees to carry out the stat changes under warranty, I still have a £250 excess which is more than what it would cost to get the main stat changed from an independent. The EGR stat seems straight forward enough to change so I can give that a go myself.

If anyone has any suggestions on what more I can do to convince the tech there is a problem
Please let me know.

Otherwise, I'll change the EGR. Does the bleed screw on the EGR need to be used everytime the EGR is changed? If so, when do I stop the bleed?

phelix

Great thread - checked my 04 535d - car ran at 75-80 deg on the move. Have replaced the EGR thermostat and it's generally running around 85. Now to replace the main thermostat in the hopes of getting a car that runs at 90+.

neil.d

Great thread.

I dont suppose any 535d chaps have the EGR thermostat part number?


Mine runs around the 82C mark yet returns around 40 mpg on the motorway on a steady run.

For info, the DMS 535d currently runs at 86C, Ive asked them, as does my work E61 LCI 530d that is thrashed every day.

The DPF needs coolant temps above 75C so as long as its above that I wont be worrying too much.

Thanks,

Neil.D

neil.d

Ah,

Im guessing part 8.

http://www.realoem.com/bmw/showparts...97&hg=11&fg=50

phelix

It is indeed #8; consider replacing #10 at the same time for 60p.

tsaros

I just went for a hour long drive and the temp according to the cluster was 88c, it would not go any higher even if left idle for 5 min, ambient temp at the time was around 8c.
Looks like my car will go in for a checkup as well.

mmitev

I am a bit perplexed:
My car (2004 530d E61) ran around at 65-75 degrees on B-roads in cold weather. I also recorded several times how quickly it warms up in the morning, along the same city route.

I changed my EGR thermostat, but there is almost no improvement. The car ran at 75 degrees in city night traffic yesterday (ambient around 8-9 C, and the warm-up after start was only a little bit better.

My old EGR thermostat could also not be blown through, so I suspect it might not have been broken at all!

Is it possible that only the main thermostat is responsible for such a low operating temp of 75 degrees?

I just hope that a main therm replacement will cure it as I will have problems regenerating my DPF outside city driving, which is pretty cr**py.. :thumbsdown:

neil.d

Got them both, thanks a lot.

When I took off the EGR thermostat it loses a fair bit of coolant be warned! Probably about 1/3 litre.

Messy really.

jas_r_1

Managed to change the EGR stat over the weekend - the back bolt was a nightmare but got there in the end. There was also quite a bit of coolant that poured out when I removed the EGR so if you do it, best to put a couple of rags under the EGR before taking it off. Took about an hour to do.

I could definitely blow air through the old EGR stat and a quick drive and the car seemed to warm up quicker but the real test was the morning commute to work. I have listed the before and after results below

BEFORE (Ambient temp was 2 degrees and starting temp of car was 22 degrees)

6.1 miles - 71 degrees
6.9 miles - 76 degrees
9.3 miles - 81 degrees
13.1 miles - 83 degrees
18.7 miles - 85 degrees

AFTER (Ambient temp was 3 degrees and car temp was 13 degrees)

2 miles - 71 degrees
2.6 miles - 76 degrees
3.9 miles - 81 degrees
5.2 miles - 83 degrees
6.9 miles - 84 degrees
9.3 miles - 85 degrees


The ambient temp was only 1 degree warmer on the morning after the EGR had been changed but the car temperature was 9 degrees colder. It's clear the car warms up a lot quicker as it only took two miles to get to 71 degrees but before it took 6.1 miles.

I have also noticed that once the car hit 85 degrees the temp stayed pretty solid - only changing 1 degree up or down. Before the temp could fluctuate a lot depending on if I was stuck in traffic (temp would go up) or moving at a constant speed (temp would go down).

I wish I done this when I first saw this thread but it's done now and for £25 and an hours work, it was definitely worth it.

I have been back to my dealer with the results and the old EGR to support there being an issue. The dealer check fault codes (no errors) and done a coolant pressure test (no problems). They then checked the main thermostat and I have been told it remains open so they have ordered the part and all should be sorted by tomorrow. I'll post up results of the temperature change (if there is any).

I have asked to see the old main thermostat and wanted to know if I could do any test whilst I am at the dealer to see it is staying open (I doubt I'll be able to pour hot water over it so was hoping for a similar test to blowing air through the EGR stat).

mmitev

Thats a great test of the results, glad it helped in your case.
This is what I also tried after changing mine but there was no improvement (I've done a third run now and averaged the results over three runs - they are almost identical to the three-run-average before the change).
As I also said, I am not able to blow through it, so I suspect its still ok. Main therm on the line now..