slottler
Member
- Joined
- Jul 27, 2012
- Messages
- 16
- Reaction score
- 0
- Location
- South Africa, um all over
- Your Mercedes
- 2002 C270 CDi
Hi All
Although I've been reading these forums for about 2 years, this is my first post. (I have another in mind: to put together ALL the info I've gathered on using the 5g gearbox. Because I wish I could have found all the info in one place). I've learned so much!!! Thanks, guys. eg: I experienced a battery drain and was able to diagnose a faulty outside temp sensor, thanks to the forums.
I have been wanting to do the EGR shunt (a-la Dieselman and Alex Crow's postings) on my 2001 C270 CDi for a while now. Wanting to make a start, I identified the EGR vacuum relay and disconnected it. I knew that the MAF would cause errors and cause limp mode, but I took the car for a spin "just to see" how it felt. Actually, I quite liked the sound and feel, but let me explain...
1) On starting, I immediately noticed a change in the sound of the engine. Then I realised that the turbo wasn't working.... what was missing was the turbo whine. Actually, I don't like the whine of the turbo during low rpm town-driving... so the engine actually sounded better!
2) I had plenty of torque at pullaway... but the engine would not rev beyond 2000rpm. And was gutless when I put my foot down. But perfectly adequate for driving around my local village... my CDi felt like my dad's old W202 250D (non turbo)... not a fast car, but adequate. My gearbox seemed to work fine... I counted changes up to 4th gear at approx 70km/h.
3) My fuel economy appeared unaffected... or perhaps even better! The computer said that I used approx 8l/100km for this short (1.5km) journey to the shops and back. The engine didn't even have a chance to warm up.
So I started to think: this could be great!! I could fit a switch to disable my turbo just by disconnecting the EGR. Why? Well I could think of a few reasons:
a) For short journeys in my village, I hate to think of excess wear on my turbo as a result of running while still cold... or clogging with soot and deposits. So... wouldn't it be nice to be able to preserve my turbo by not using it when I don't need it?
b) A C270 is quite a quick car; quicker than most people realise. So I hate loaning my car out... because once people realise she's quick, they want to find out how quick. I would love to be able to "tame" the performance when I take the car to eg a valet or loan it to a friend. It really goes fine without a turbo... just not fast!
c) I would imagine that a non-turbo car might be more economical than a same turbo-car (at low engine loads and speeds). Anybody care to comment? I haven't noticed increased consumption as mentioned by some others.
BTW... this "limp mode" (no Turbo) is different to the "gearbox limp mode" (symptom: stuck in 2nd gear) which I have also experienced. My gearbox works OK.
I thought that all this was quite cool, but decided to reconnect my EGR until I get the parts to make my shunt. I did so, but my turbo did not return. Anybody have any ideas why? The obvious thought would be that I damaged a hose or wire while disconnecting the EGR wire... but I was careful.
So here are a couple of questions. I'd welcome comments and answers!
i) Is it possible that a code has been stored which needs to be reset.... before my turbo will work again?
ii) Can any harm be caused by driving the car like this? I wouldn't think so!
iii) Does anybody else think that this might be desireable sometimes? To disable the turbo!!!?
Cheers!
Although I've been reading these forums for about 2 years, this is my first post. (I have another in mind: to put together ALL the info I've gathered on using the 5g gearbox. Because I wish I could have found all the info in one place). I've learned so much!!! Thanks, guys. eg: I experienced a battery drain and was able to diagnose a faulty outside temp sensor, thanks to the forums.
I have been wanting to do the EGR shunt (a-la Dieselman and Alex Crow's postings) on my 2001 C270 CDi for a while now. Wanting to make a start, I identified the EGR vacuum relay and disconnected it. I knew that the MAF would cause errors and cause limp mode, but I took the car for a spin "just to see" how it felt. Actually, I quite liked the sound and feel, but let me explain...
1) On starting, I immediately noticed a change in the sound of the engine. Then I realised that the turbo wasn't working.... what was missing was the turbo whine. Actually, I don't like the whine of the turbo during low rpm town-driving... so the engine actually sounded better!
2) I had plenty of torque at pullaway... but the engine would not rev beyond 2000rpm. And was gutless when I put my foot down. But perfectly adequate for driving around my local village... my CDi felt like my dad's old W202 250D (non turbo)... not a fast car, but adequate. My gearbox seemed to work fine... I counted changes up to 4th gear at approx 70km/h.
3) My fuel economy appeared unaffected... or perhaps even better! The computer said that I used approx 8l/100km for this short (1.5km) journey to the shops and back. The engine didn't even have a chance to warm up.
So I started to think: this could be great!! I could fit a switch to disable my turbo just by disconnecting the EGR. Why? Well I could think of a few reasons:
a) For short journeys in my village, I hate to think of excess wear on my turbo as a result of running while still cold... or clogging with soot and deposits. So... wouldn't it be nice to be able to preserve my turbo by not using it when I don't need it?
b) A C270 is quite a quick car; quicker than most people realise. So I hate loaning my car out... because once people realise she's quick, they want to find out how quick. I would love to be able to "tame" the performance when I take the car to eg a valet or loan it to a friend. It really goes fine without a turbo... just not fast!
c) I would imagine that a non-turbo car might be more economical than a same turbo-car (at low engine loads and speeds). Anybody care to comment? I haven't noticed increased consumption as mentioned by some others.
BTW... this "limp mode" (no Turbo) is different to the "gearbox limp mode" (symptom: stuck in 2nd gear) which I have also experienced. My gearbox works OK.
I thought that all this was quite cool, but decided to reconnect my EGR until I get the parts to make my shunt. I did so, but my turbo did not return. Anybody have any ideas why? The obvious thought would be that I damaged a hose or wire while disconnecting the EGR wire... but I was careful.
So here are a couple of questions. I'd welcome comments and answers!
i) Is it possible that a code has been stored which needs to be reset.... before my turbo will work again?
ii) Can any harm be caused by driving the car like this? I wouldn't think so!
iii) Does anybody else think that this might be desireable sometimes? To disable the turbo!!!?
Cheers!