egr blocked?

[ricardo62]

hi im asking this question to you learned people , could my egr be coked up , my car a e320 il 6 diesel has spent the last year of its life , mainly being used around town , and spends a lot of time just idling .
I dont live anywhere were i can give it a long run and the nature of my job which i use the car for is all low speed stop start driving , i have noticed that on some occasions i have poor throttle responce and no kickdown , and when i do floor it i get clouds of black smoke from the exhaust.
the other symptom i have is when im stationery and have it in park it wont rev over 3000 rpm .
If i turn the ign off and back on again to statr it then the problem cures itself and wil rev to the limit .
i gave it a good 5 mins today in the supermarket car park holding the revs at near the red ,lots of black smoke and upset shoppers!! i explained to 1 angry woman who asked why i was doing this that i was trying to clean my egr valve , she looked confused !! im thinking of buying a tin of wynns egr cleaner , ive read good reviews of this product and hope that will cure it ? just wanted to know if a coked up egr would cause these symptoms

 

[bob6600]

This could be a number of things, MAF is a likely culprit. Best advice is to get the fault codes logged, MAF can be tested on STAR. Some people will take the gamble and just change the MAF.....if you do decide to do this, buy a OEM one (Pierburg I think).

Cleaning the EGR will do no harm, then do the EGR mod to preent it coking up again

 

[ricardo62]

thank you bob
I have read about the mod , but I don't think im competent enough to do it , it involves wiring and diodes and resisters if that's the mod your describing , ive had a look at the egr valve and it seems quite an involved process to remove , ie unbolting inlet manifold ?
just a thought I think the maf is the small item bolted with 2 nuts to the air intake with a electrical connector , can I just disconnect it and if so what will that do ?

 

[bob6600]

Yes the mod is the one you describe, it's not difficult but if you have not done that kind of stuff it can seem a bit much

You can change the EGR without unbolting the intake manifold, you do need to remove the cooler and it can be a bit fiddly.

Yes the MAF is what you describe, If you disconnect and the car is exactly the same, it should point to a faulty MAF.

 

[Dieselman]

A sticky EGR valve could well be causing the limp home mode.

 

[mbenz1]

Out of interest, I would like to know what mpg you are getting for purely town driving and idling

 

[ricardo62]

well according to the computer average 17mpg ,, but a lot of the time the car is not turned off because if owing to the nature of my job if i switched it off every time i was staionary it would be around 100 starts a day and i figure over the course of a year that would be thousands of times the starter moter is being used and i think it would wear it out , i figure its prob best fot the 2 mins im out of the car to just keep the engine running hence why it never gets a proper run and spends 5 hrs a day basically ticking over , if i disconect the maf to check will it harm the engine and if it does go better with it disconnected will it hurt to drive with it like that

 

[mbenz1]

well according to the computer average 17mpg

Surely you would be better off with a petrol. Like a kompressor or a V6? By doing this you will avoid all the problems in diesel engines such as inkectors, turbo, egr, clogging, swirl manifolds etc... But saying that, the engine you have is bullet proof.

 

[ricardo62]

yes i would but it is my late fathers car and i know the car , and it has sentimental value , if i sold it now i would get next to nothing 4 it and better the devil you know , just not really the ideal job i have 4 this car i admit , but as i said will disconnecting the maf hurt the engine or put a limp mode on the computer that needs resetting with a solus reader , or if i connect back up will it be ok no limp mode , im just worried in case i do any damage disconnecting it

 

[Dieselman]

It won't do any harm, but will select limp home mode.

 

[ricardo62]

thank you dieselman

 

[mbenz1]

yes i would but it is my late fathers car and i know the car , and it has sentimental value , if i sold it now i would get next to nothing 4 it

Ahh,if it holds sentimental value then keep it for as long possible. No money can buy sentimental value . By the way, isn't 17 mpg low for your engine. My dad's 08 S320 cdi gets 20-22 mpg in.town... Bigger car as well...

 

[Giantvanman]

Don't know if it's the same for MB's but on our diesel Saab, the EGR could be cleared by giving it a run at 70mph for at least 20mins as per handbook. Worth a try?

 

[ricardo62]

Ahh,if it holds sentimental value then keep it for as long possible. No money can buy sentimental value . By the way, isn't 17 mpg low for your engine. My dad's 08 S320 cdi gets 20-22 mpg in.town... Bigger car as well...

yes not good mpg , but I guess that's prob down to the car engine running all the time so giving low mpg , its ok on a run , I did a journey last yr and at a constant 65 mph on cruise I got 46 mpg according to the computer , and yes it was my fathers car and gives me a nice feeling knowing he drove it

 

[mbenz1]

yes not good mpg , but I guess that's prob down to the car engine running all the time so giving low mpg , its ok on a run , I did a journey last yr and at a constant 65 mph on cruise I got 46 mpg according to the computer , and yes it was my fathers car and gives me a nice feeling knowing he drove it

Yes probably due to the use, its doing low mpg. Give it some shell V -Power if possible, maybe it'll ease the engine a little. Its nice to hear that you enjoy driving the car your dad had.

 

[Dieselman]

Don't know if it's the same for MB's but on our diesel Saab, the EGR could be cleared by giving it a run at 70mph for at least 20mins as per handbook. Worth a try?

Do you mean the DPF?

 

[mbenz1]

Don't know if it's the same for MB's but on our diesel Saab, the EGR could be cleared by giving it a run at 70mph for at least 20mins as per handbook. Worth a try?

If this is the case for MB, then.it should be written in the owner's manual. Saying that, I will also check the owners manual for my dad's 320CDI and see if it mentions any criteria for cleaning the EGR... If it does then will have to follow it unfortunately

 

[Giantvanman]

Do you mean the DPF?

When the warning light came on, time to clean the EGR, according to the handbook, and the process cleared it.