[K a s h]

The EGR cycle in the Montero is activated at idle and starts reducing with part throttle input and gets completely deactivated at full throttle. It also gets deactivated when the Intake temperature is too cold. So the plan is to cheat the EGR to think that its too cold so that the EGR cycle does not happen.

Why do this?
The Engine Blow-by gases are recirculated into the intake and the EGR also recirculates exhaust gases with soot into the intake. This is a deadly combination and will choke the intake manifold (see my next post for proof), affecting regular engine operation. This needs to be cleaned regularly and I did not want to do this. So i have disabled it in the car.

How to do this?
We add a 4.7 KOhm resistor in one specific (Black + Blue) wire in the MAF sensor wiring loom so that the ECU reads lower temperature than it actually is.

Wont this resistor mod affect regular engine operation?
No, because there are two different sensors for temperature and we will only modify the one specifically used for EGR cycle. See attached image from TorquePro OBD diagnostics app.

Before this mod, the EGR was 69% at idle and was reducing if Accelerator pedal is more than 10%.



With the resistor mod, the InletAirTemp is constant negative 2 deg Celcius. The EGR is also constant at 0. Note the second intake temperature gauge displaying the correct value.



Any side effects of this on the car?
Yes. Its smoking less now. A error popped-up once for low intake temperature. I cleared that error with the Torque App and did not see it again. So i consider this mod to be a success!

[mp417]

Absolutely loved reading through your thread! The Montero is an iconic SUV and a timeless classic.

A few years back, I was seriously considering a pre-owned Pajero Sport, but I had to let go of the idea mainly due to concerns about parts availability and the scarcity of skilled mechanics who can still handle Mitsubishis.

Hats off to you for not just tackling routine maintenance but also delving into every detail to fix and restore it so meticulously. Your dedication is truly inspiring and sets a great example for enthusiasts like me. Wishing you many memorable miles with your Montero!

[K a s h]

Originally Posted by mp417

A few years back, I was seriously considering a pre-owned Pajero Sport, but I had to let go of the idea mainly due to concerns about parts availability and the scarcity of skilled mechanics who can still handle Mitsubishis.

Agree on the spare parts situation. I want to touch upon the skilled/specialist mechanic part you mentioned. As enthusiasts, we also need to know a bit more about our cars. We must be able to tell our mechanic what needs to be done and we must also be able to check if the work was done properly. There are lot of car model specific forums with all the information we need. Once we have that specialist knowledge, its easy to maintain our cars with any mechanic who will listen to us. This is not difficult. There are a lot of nice cars waiting to be rescued.

Originally Posted by mp417

Hats off to you for not just tackling routine maintenance but also delving into every detail to fix and restore it so meticulously. Your dedication is truly inspiring and sets a great example for enthusiasts like me. Wishing you many memorable miles with your Montero!

Thanks a lot for your encouraging words .

[K a s h]

After blocking the EGR, it was time to clean all the crap from the Intake Manifold.

The Battery was removed first.


The fuel filter was removed next. The intake manifold in the 4M41 engine starts after the throttle body assembly (see red line in the image below), has an air temperature sensor, the EGR inlet and then takes a 180 degree bend near the firewall and then connects to the engine.



The fuel rail was then removed to access the intake manifold bolts. The closeup of the EGR inlet port.



The top pipe comes out.





The intake manifold is also removed now.

For accurate measurement of the soot we remove, let's weigh the manifold before and after cleaning.




The manifold was opened up and we had the first glimpse at what we were dealing with - Soot and Oil gunk accumulated over the years!. This had the consistency of a hardened brownie cake.



Let the cleaning begin! We first scrapped off the soot with a flat screw driver and a knife.




Next comes diesel bath. This was not cutting it, so we had to bring in the Paint Thinner.



After many hours of scrubbing, we had some decent results!



Now we weigh the clean manifolds




A quick comparison



So we cleaned around 30 grams from the top pipe and 400 grams from the bottom pipe.

I could not take as many photos as i wanted because my hands were dirty. The EGR pipe and the Throttle body mechanism was also cleaned.



During reassembly, the fuel filter was also changed. It was found that the "water in fuel" sensor wire, was damaged. Another part for my next order.




How does the car perform after this cleaning?
I could not find any difference . But I'm content knowing that my intake will be cleaner for many years to come. With EGR blocked, I expect my engine oil to stay clean for longer duration.

[ringoism]

Originally Posted by K a s h

Any used car comes with its history and its own baggage of issues.
So the Montero had a bunch of issues which were fixed in the past 2 years and a few new ones popped up that are getting addressed.
I have fun fixing these issues myself and getting things to work as it should.

Good to find a capable DIYer here, there are not so many of us and I would say that your bold fearlessness exceeds mine by a fair margin. Most of my bikes have been uncommon ones for which parts / service knowledge could be scarce, and I managed ok; But cars are much more complex, and in the electronic era especially, always was scared of orphaned/unsupported models; I have had enough waiting for spares with something as straightforward as the Getaway.

If it were me looking for a cheap, serviceable luxury SUV I suppose it would have to be a 1st gen Fortuner, but I don't really like the look/image - The Montero seems such a great car and I admire your enthusiasm and grit jumping in, doing the needful, and enjoying it fully. You've put in thr research, know your sources and tools, and just have a can-do attitude that is admirable. It reminds me of some of the Youtuber rebuilders who just get to it and systematically work through whatever the cars throw at them.

-Eric

[K a s h]

Originally Posted by ringoism

Good to find a capable DIYer here, there are not so many of us and I would say that your bold fearlessness exceeds mine by a fair margin.

-Eric

Thank you so much, that means a lot to me . I have fond memories of reading your threads and I'm really happy you find mine worthy of such high praise.

[K a s h]

Next in line was the Intercooler.
This is nestled behind the skid plate protected by the front sway bar.





A little peak inside.



Surprisingly not much oil was found inside the IC.
First step was to use paint thinner to flush out any oil residue.




The thinner was then collected back in the same bottle. Not so dirty.



Next step was to clean the IC with water




After washing the IC we realized that it was almost new and was in black color. None of the fins were deformed. This must have been replaced by the previous owner.

[K a s h]

The final item on my list was the catalytic convertor.

A peek inside


Step - 1 - Blow away soot with air.



Step 2 - Gently wash with water.

https://www.youtube.com/watch?v=-c4YvJK4RDg

All fixed and ready to go home

[K a s h]

The normal service schedule for the montero is to change engine oil every 10k kms. But considering my harsh driving conditions, i change it every 5k kms.



Did a 2 stage flush during the previous oil change because i could not see any metal inside the engine oil cap. There was too much soot accumulation in the oil.

Stage 1 Flush - Added 500ml of STP Flush to existing oil and drained it after idling for 20 mins.



Stage 2 Flush - Changed the oil Filter and added 7 litres of Schaeffler 5w30 oil and 1 liter of STF Flush. Idled the engine for 20 mins and drained it.




Finally filled in 9.5 litres of Addinol Super Light 5w40 and topped up with Liquimoly Ceratec with a new filter.



The Hood release cable had extended a bit due to old age, so replace that too.



After the flush and EGR delete, happy to report that the oil has only become slightly discolored after 300 kms. Usually it blackens within few kms.

[Kkumar]

Vow what a wonderful article. It's not just the passion of owning a wonderful car that matters but the passion to understand that car and being able to diagnose as well as rectify the problems that matters in a successful and happy car ownership. Thank you for penning it down and keep on munching miles.

[maddy42]

Gorgeous looking vehicle. Where did you get the paint correction done in blr as i am looking for a place for a full detailing without getting the usual ceramic coating route.

[K a s h]

Originally Posted by maddy42

Gorgeous looking vehicle. Where did you get the paint correction done in blr as i am looking for a place for a full detailing without getting the usual ceramic coating route.

Thanks. I got the paint correction done at Trend Automobiles (Body Repair & Painting, Glass Repair, Detailing etc. - Trend Automobiles (Bangalore)).

[Lightning2]

Engine flush must be avoided and are Not recommended on high mileage and diesel vehicles !

Points to remember are :

1. Engine flush loosens the gunk partially only, which has got deposited over time. The loosened debris particles remain in oil lubrication lines and come in between engine moving parts thereby increasing wear by coming in between adjacent moving parts.
Remember that much engine oil remains in the system even if you have drained the Engine oil by removing the drain plug.

2. Secondly as you have loosened and softened the gunk, later when you run your vehicle, the loosened gunk gets dislodged more in due time due to heat and vibration of the engine adding to engine parts accelerated wear ( in comparison to had you not flushed your engine )

3. Carbon deposits between moving and Non-moving parts, remain Mated in high mileage vehicles and the deposit Itself provides Lubrication at that particular place. Removing the lubricating deposit again adds to accelerated wear of part concerned.

4. Initially one might experience freer running engine, post flush. But that is initial false feel good experience and does much harm than good, in long run !

5. Engine flush should be exercised Only if one has been flushing the engine regularly from the beginning itself

Thanks

Originally Posted by K a s h

The normal service schedule for the montero is to change engine oil every 10k kms. But considering my harsh driving conditions, i change it every 5k kms.

Attachment 2708076

Did a 2 stage flush during the previous oil change because i could not see any metal inside the engine oil cap. There was too much soot accumulation in the oil.

Stage 1 Flush - Added 500ml of STP Flush to existing oil and drained it after idling for 20 mins.

[K a s h]

Originally Posted by Kkumar

Vow what a wonderful article. It's not just the passion of owning a wonderful car that matters but the passion to understand that car and being able to diagnose as well as rectify the problems that matters in a successful and happy car ownership. Thank you for penning it down and keep on munching miles.

Thanks a lot. Glad you like it.

[Mystic]

In those days, Pajero and Montero were built like tanks to last forever with minimal electronics. In general for non enthusiasts, the culture is use and throw and this is also creeping into automobiles with unnecessary complexity of electronics. Government and car lobby is also encouraging this culture for whatever reasons. One thing we all enthusiasts understand is that resources are limited on this planet and we just cannot afford to scrape such timeless classics and I appreciate your effort in giving another life to this beauty. Wish you many more miles of happy motoring with Montero.

I used Scorpio Diesel VLX for 12 years and had to upgrade to a modern car Crysta Z with 7 airbags ( there is an airbag to protect knees ) only because of end of life of 15 years policy and safety concerns of airbags. It was in perfect condition at the time of disposal. If there is a SOP of converting old cars with 7 airbags and Government making the 15 years extension easy for public, lot of enthusiasts would use their old vehicles with upgrades.