URGENT - diesel mixing with oil and dpf removal

[datboi]

My mom bought a mazda cx7 2009 with 200k km imported from germany.

 

Only 1 owner and all the services were done at mazda. And everything is documented

 

She drives... Like a mom, never revs the engine, drives often short distances...

 

 

The dpf always gets clogged and needs regen.

 

 

Furthermore, oil was changed 3000km ago and it's alreadu reaches the X meaning its heavily diluted with diesel after only 3000km due to diesel getting past the piston rings during regen.

 

 

Futhermore, the owner changed the timing chain at the mazda dealership in germany and they used RTV for the side engine cover and somehow missed a spot (so much for german quality) so there is a small oil leak)

 

 

First off, is it normal they used RTV for the side engine cover? Is isn't there an OEM gasket like for the valve cover?

 

 

Normally i wouldn't worry about this too much, very small leak, had a mechanic patch it from the outside.

 

 

But probably due to the diesel in the oil, it corroded the silicone he used to patch it and it started leaking again ( it was a temporary fix anyways)

 

 

Now, not only has the oil level reached the X after 3000km, i also have a oil leak, so there is no way of knowing just how heavily diluted the oil is with diesel.

 

 

To fix that issue I'll have to get the engine removed which will cost quite a bit....

 

 

 

First thing i wanna do is get the DPF filter removed, so it will stop getting clogged from all the short low rpm drives

 

I also heard the engine will run and accelerate better and get better fuel economy, the engine will last longer, and generally everything will be better without DPF is this true?

 

 

Once they remove the DPF filter, I won't have the issue of diesel getting in the sump, I'll do an oil change to get rid of the contaminated oil.

 

 

So she'll be able to drive the car for now occasionally checking oil level ( the leak is extremely small)

 

I have to go abroad for sometime, i only have 4 days to find someone who will do this job.

 

 

Then when i comeback I'll go to my trusted mazda mechanic do take the side engine cover off and re-apply RTV.

 

 

I'm a total noob when jt comes to diesel engines and DPF, can someone explain to me all the pros and cons of DPF removal, and give me as much relavent information as possible?

 

(I know it's illegal and what not but no one cares in my country, and it will pass MOT no problem, so that's the last of my worries)

[Frederic]

17 minutes ago, datboi said:

My mom bought a mazda cx7 2009 with 200k km imported from germany.

 

Only 1 owner and all the services were done at mazda. And everything is documented

 

She drives... Like a mom, never revs the engine, drives often short distances...

 

 

The dpf always gets clogged and needs regen.

 

 

Furthermore, oil was changed 3000km ago and it's alreadu reaches the X meaning its heavily diluted with diesel after only 3000km due to diesel getting past the piston rings during regen.

 

 

Futhermore, the owner changed the timing chain at the mazda dealership in germany and they used RTV for the side engine cover and somehow missed a spot (so much for german quality) so there is a small oil leak)

 

 

First off, is it normal they used RTV for the side engine cover? Is isn't there an OEM gasket like for the valve cover?

 

 

Normally i wouldn't worry about this too much, very small leak, had a mechanic patch it from the outside.

 

 

But probably due to the diesel in the oil, it corroded the silicone he used to patch it and it started leaking again ( it was a temporary fix anyways)

 

 

Now, not only has the oil level reached the X after 3000km, i also have a oil leak, so there is no way of knowing just how heavily diluted the oil is with diesel.

 

 

To fix that issue I'll have to get the engine removed which will cost quite a bit....

 

 

 

First thing i wanna do is get the DPF filter removed, so it will stop getting clogged from all the short low rpm drives

 

I also heard the engine will run and accelerate better and get better fuel economy, the engine will last longer, and generally everything will be better without DPF is this true?

 

 

Once they remove the DPF filter, I won't have the issue of diesel getting in the sump, I'll do an oil change to get rid of the contaminated oil.

 

 

So she'll be able to drive the car for now occasionally checking oil level ( the leak is extremely small)

 

I have to go abroad for sometime, i only have 4 days to find someone who will do this job.

 

 

Then when i comeback I'll go to my trusted mazda mechanic do take the side engine cover off and re-apply RTV.

 

 

I'm a total noob when jt comes to diesel engines and DPF, can someone explain to me all the pros and cons of DPF removal, and give me as much relavent information as possible?

 

(I know it's illegal and what not but no one cares in my country, and it will pass MOT no problem, so that's the last of my worries)

I’m afraid you won’t get a lot of technical replies when it comes to diesel issues. This is a platform located and tailored to UAE where diesel is almost non-existant. 
 

I used to drive diesels in Belgium and remember having issues with clogging up if I didn’t take it for longer drives and higher revs once in a while (was a Renault Scenic). 
 

RTV sealant is indeed used in many applications and if applied properly it should hold up fine, in your particular case it would indeed be possible that there is an OEM seal. Perhaps it wasn’t available at the time and hence they used RTV sealant. 
 

[Ishak]

I don’t know how Mazda measure the differential pressure in DPF to measure how much soot collected in DPF. If you remove the DPF without changing the configuration (disable the DPF) in the ECU, the ECU may give an error code.

if you can remove the DPF, it’s better to remove also the EGR system and disable the EGR in the ECU configuration also.

EGR system is to reduce cylinder temperature to reduce Nox, because nox generated when the cylinder temperature is very high. The side effect with EGR is the  particulate matter will increase that is why the DPF is there to filter the exhaust gas.

Edited May 4, 2024 by Ishak