[Vish8895]

Hi all,

I have recently purchased a 325D with 67K miles. I am conscious of carbon build up (CBU) and was wondering if anyone had any input to my query.

I wondered if you guys are aware of tell tale signs to look out for on a diesel car suffering from CBU? I have Carly for BMW and regularly scan for codes (of which there have been none since clearing it before the test drive last week). I also have looked a the DPF section in Carly but it doesn't mean a lot to me at the minute as I don't know what healthy readings would be...

I have and will continue to only run on V-Power and often use the rev range when warm to try and agitate carbon build up and give the car a good clear out.

Any advice appreciated.

Thanks

[Aragorn30d]

Clean the manifold out and Delete the EGR if your worried about it.

My engines on 147k and i was actually quite surprised when i had the manifold off. Yes, there are some deposits, but nothing spectacular.

[Vish8895]

I think I'll be leaving the EGR for the time being. How long did it take you to remove and clean the intake manifold? Might make this a mini-project for the new year.

[abeardo83]

You're worrying over nothing at 65k. My good lady's 325d is on 154k miles. DPF light has juct come on. Did a forced regen and it removed 50g of soot. Drives like new again.

[Aragorn30d]

It took maybe an hour or so to get the manifold off. Its not particularly hard, just lots of dismantling.

I did mine as i wanted to replace the glowplugs and blank the swirl flaps.

I didnt clean my manifold. ideally you'd want some thin pipe cleaners and some sort of solvent that was going to dissolve the gunk but not harm the plastic manifold. I didnt have either, and it was such a thin layer on the sides that it wasnt worth messing with.


abeardo: if the DPF isnt regenerating automatically you need to make sure the engines warming up properly (thermostats) and make sure it gets a decent run every couple hundred miles.

[Vish8895]

Thanks for the input fellas. I'm just trying to make sure I don't run into problems. The engine probably only gets warm a few times a week so on the weekends I try to do a good 20 miles+ on the motorway to allow it to regen and to allow me to boot it a bit.

[Aragorn30d]

I guess the critical thing is ensuring that it IS warming up. Faulty thermostat might mean even on your 20mile drive its not getting to temp!

[Vish8895]

Yes that is something I have thought about. There are no codes being thrown at all currently, would the stat throw a code?

Also, the coolant temp was a stable 87 Degrees-C after a nice drive the other day, is that the avg coolant temp for the car when warmed up? I noticed the diesels don't have a temp gauge like my 335i did :/.

[Aragorn30d]

yeh 87c is about right

[Digitalize]

Thermostats won't produce an error code.

87c sounds like they're both working fine.

[Pumper]

+1 on 87C being a good temp for normal driving conditions. Would get to 90-91 when pushed a bit harder.

[abeardo83]

Originally Posted by Aragorn30d

It took maybe an hour or so to get the manifold off. Its not particularly hard, just lots of dismantling.

I did mine as i wanted to replace the glowplugs and blank the swirl flaps.

I didnt clean my manifold. ideally you'd want some thin pipe cleaners and some sort of solvent that was going to dissolve the gunk but not harm the plastic manifold. I didnt have either, and it was such a thin layer on the sides that it wasnt worth messing with.


abeardo: if the DPF isnt regenerating automatically you need to make sure the engines warming up properly (thermostats) and make sure it gets a decent run every couple hundred miles.

I think it was just at the point where the DPF was nearly full with the sooty remains from the regens tbh. The garage did a forced regen and a Terraclean and *touch wood*, it seems to have sorted it.
That Terraclean is good stuff, it seems. Car really pulls again now. Am thinking of giving it a go on my 335i at some point.

[Aragorn30d]

From what i've seen, terraclean doesnt do much at all.

They claim it cleans carbon buildup and other random claims, but its injected into the cylinders just like the fuel, so its no more likely to clean carbon than the petrol/diesel does on any normal day.

Some additives can help clean the DPF, i think essentially by burning hotter and getting the EGT's higher.

[abeardo83]

Originally Posted by Aragorn30d

From what i've seen, terraclean doesnt do much at all.

They claim it cleans carbon buildup and other random claims, but its injected into the cylinders just like the fuel, so its no more likely to clean carbon than the petrol/diesel does on any normal day.

Some additives can help clean the DPF, i think essentially by burning hotter and getting the EGT's higher.

Dunno what did what then, but all I know is that there was an awful amount of cr@p coming out of the back of the car during the session. Could have been the Terraclean, could have been the forced regen, who knows.

All I know is that the amber DPF light is gone and the car is far more eager now.

[Vish8895]

Glad to hear 87DC sounds spot on! Always like to make sure the cars running sweet .

Does anyone use carly for BMW? Just wondering what the normal DPF readings look like as I have nothing to compare mine to!

[Pumper]

Originally Posted by Vish8895

Glad to hear 87DC sounds spot on! Always like to make sure the cars running sweet .

Does anyone use carly for BMW? Just wondering what the normal DPF readings look like as I have nothing to compare mine to!

Was monitoring my DPF and temp a couple of weeks ago on a highway trip.

Soot mass was over 31g at the begining with ~420km since last regen.

When the engine temp reached ~80C, the exhaust strarted to heat up from ~360C to ~550C. That's when the soot started to being burt away - took maybe 15 or 20 km to get to almost 0g.
After the regen finished, engine temp dropped from ~91C to ~89C, exhaust back to 360~380C and by the time I stopped the car (after ~90 km) soot mass got up to ~4.5g.

Did not see higher revs or lower MPG (might be because I get crap mpg to begin with) during the regen. Was driving at ~70-75mph.

[mob17]

Meth will help

[Vish8895]

Originally Posted by Pumper

Was monitoring my DPF and temp a couple of weeks ago on a highway trip.

Soot mass was over 31g at the begining with ~420km since last regen.

When the engine temp reached ~80C, the exhaust strarted to heat up from ~360C to ~550C. That's when the soot started to being burt away - took maybe 15 or 20 km to get to almost 0g.
After the regen finished, engine temp dropped from ~91C to ~89C, exhaust back to 360~380C and by the time I stopped the car (after ~90 km) soot mass got up to ~4.5g.

Did not see higher revs or lower MPG (might be because I get crap mpg to begin with) during the regen. Was driving at ~70-75mph.

Ah ok thanks for the readings! Mine was at 2g when I arrived home after work the other day.

I've been taking it for a good motorway blast every weekend so hopefully that gives it time to regen if it needs it.

Originally Posted by mob17

Meth will help

Yes I understand meth will indeed help the CBU, maybe if i tell the insurance its a preventative maintenance modification rather than performance they might not probe me to death for it