A different kind of EGR delete (ALH)

[486]

Top Post Dawg
Joined
Mar 1, 2014
Location
MN
TDI
02 golf ALH
After a lot of reading on the subject it seems to me that the only good the EGR brings is that it heats your engine, be it through the EGR cooler, or the inert gasses reintroduced to the intake bringing up engine load to make more heat in the jackets. By eliminating the EGR you lose the heat put directly into the coolant, and the extra engine heat brought about by loading the engine down. I live in MN, and it is a little bit cold. I don't like that my engine takes forever to warm up as is, so an EGR delete in the traditional manner is out of the question for me. The other issue here is that the fact that the EGR is run at such a high amount I fear that it is causing some pretty severe coking.

On a tangent, something I learned about the priuses; they get the cabin heat from the engine coolant, and when the coolant is cold it'll run the engine just to heat the coolant, even if it is on battery and there is sufficient charge. This means that they want to scavenge the most heat possible from the engine during the short time it is running. They included an "exhaust heat reclaimer", which is more or less just like our EGR cooler, but on a bigger scale.

With that in mind I get to thinking that if I were to delete the EGR I could keep the EGR cooler to scavenge some heat from the exhaust. So to do that I'd need to get exhaust flow through the EGR cooler element, but without dumping the exhaust into the intake stream. To get flow you need a pressure differential, in the stock system the exhaust backpressure on the engine side of the turbine will always be higher than the impeller's output pressure, meaning some pressure differential and therefore flow when the valve is opened.

My idea of the alternate direction I can dump the exhaust would be back into the exhaust stream, just after the turbine. There should be more pressure differential than the stock setup, so I could probably get more flow and therefore more heat out of the system. The flow wouldn't need to be as precisely regulated to avoid choking the engine with exhaust into its intake either. Could probably even eliminate computer control from it altogether by using a thermostatic vacuum control valve from an old smog-era car. Coolant temperature is low, it allows vacuum to a vacuum operated EGR valve taken off of some other vehicle, allowing flow through the EGR cooler element, once coolant temp comes up the thermostatic valve vents the vacuum which shuts off flow. Simple as that.

The immediately apparent pitfalls of this setup would be that the exhaust gasses would be bypassing the turbine, so the compressor response might be a little different, possibly different enough that the computer would notice a discrepancy in incoming air. Unlikely, but possible. The orifice through any EGR I've seen is at most 1/2", and the iron log going into the turbine housing is 2" or so. Combine that with how much the EGR in its stock form would flow , and the amount this setup would flow and therefore bypass past the turbine is quite minimal.

tl;dr, remove EGR valve, reroute EGR cooler output to a repurposed EGR valve that dumps into the exhaust, post-turbine

What says you guys?
 
Last edited:

Fix_Until_Broke

Top Post Dawg
Joined
Aug 8, 2004
Location
Menomonee Falls, Wisconsin, USA
TDI
03 Jetta, 03 TT TDI
I've got all the parts to do this back in 2008, but never installed it - here's the OEM valve you need...

http://forums.tdiclub.com/showthread.php?t=202876

And a valve just like you were describing for modulating the vacuum from something like an 86 Caprice or similar.

Grab some old EGR cooler pipes and weld one with a flange end into the downpipe and then it's a nice modular install that comes apart like OEM.

I think you'll have very noticeable performance issues if you have this wide open bypassing the turbine - if you don't have a tune you'll for sure get a CEL from the MAF not seeing the EGR Flow and likely an underboost code as well. You'll have to experiment with a flow rate that won't effect performance enough to cause a problem - you'll get lots of heat into the coolant this way in my opinion.

I'm guessing you'd get a relatively quick warmup just by letting it idle for 5min - Here's some more discussion on a similar topic - post 10 brings this idea up again

http://forums.tdiclub.com/showthread.php?t=146040
 

[486]

Top Post Dawg
Joined
Mar 1, 2014
Location
MN
TDI
02 golf ALH
I've got all the parts to do this back in 2008, but never installed it - here's the OEM valve you need...

http://forums.tdiclub.com/showthread.php?t=202876

And a valve just like you were describing for modulating the vacuum from something like an 86 Caprice or similar.

Grab some old EGR cooler pipes and weld one with a flange end into the downpipe and then it's a nice modular install that comes apart like OEM.

I think you'll have very noticeable performance issues if you have this wide open bypassing the turbine - if you don't have a tune you'll for sure get a CEL from the MAF not seeing the EGR Flow and likely an underboost code as well. You'll have to experiment with a flow rate that won't effect performance enough to cause a problem - you'll get lots of heat into the coolant this way in my opinion.

I'm guessing you'd get a relatively quick warmup just by letting it idle for 5min - Here's some more discussion on a similar topic - post 10 brings this idea up again

http://forums.tdiclub.com/showthread.php?t=146040
You're my hero.

I tried to use the search function and there's 100 pages of people doing bolt-ons, thanks for linking me to the good stuff.

Well, yeah it'll definitely show the now EGR flow codes, but people know how to make the computer ignore that. Gotta go research that one next, ain't no fun to pay someone else to do it.
 
Last edited:

[486]

Top Post Dawg
Joined
Mar 1, 2014
Location
MN
TDI
02 golf ALH
I'll be cleaning out the intake and tearing the turbo down to free up the sticky vanes at the same time, so it might not be the most accurate test around, but I'll try and get some "before" logs. (man oh man I'm going to be hateful to everything tomorrow morning, haha)
 

rwthomas1

Veteran Member
Joined
Oct 16, 2002
Location
Wakefield, RI
TDI
'03 Jetta
The system you describe sounds very complex, difficult to fabricate and likely harder to make operate correctly. IIRC, there is a solution offered by one of the tuners that operates the egr but only during warmup to accomplish exactly what you describe. Another solution may be to install a coolant thermos from a Prius. Plumb it into the heater hoses with a cable operated ball valve. Open valve just before shutdown to fill it with hot coolant, then there will be a load of hot coolant stored for the next cold start? That and get or make you own winter front.
 

nicklockard

Torque Dorque
Joined
Aug 15, 2004
Location
Arizona
TDI
2010 Touareg Tdi w/factory Tow PCKG
The system you describe sounds very complex, difficult to fabricate and likely harder to make operate correctly.
+ 1.

The EGR "coking" issue is so dead, as of 2007 when Ultra Low Sulfur Diesel fuel was introduced nationwide . It really doesn't happen to the same degree as it used to unless the drivers are not getting the engine up to temperature by driving very short distances only.

Install a coolant heater, block off the radiator and intercooler in cold winters, and drive.

This is a solution in search of a problem, IMO.
 

Fix_Until_Broke

Top Post Dawg
Joined
Aug 8, 2004
Location
Menomonee Falls, Wisconsin, USA
TDI
03 Jetta, 03 TT TDI
I believe that it's the same level of complexity as the OEM EGR system, just routing the exhaust to the downpipe instead of the intake manifold.

Malone has the "Dynamic EGR" that's only on for warm-up
 

[486]

Top Post Dawg
Joined
Mar 1, 2014
Location
MN
TDI
02 golf ALH
The system you describe sounds very complex, difficult to fabricate and likely harder to make operate correctly. IIRC, there is a solution offered by one of the tuners that operates the egr but only during warmup to accomplish exactly what you describe. Another solution may be to install a coolant thermos from a Prius. Plumb it into the heater hoses with a cable operated ball valve. Open valve just before shutdown to fill it with hot coolant, then there will be a load of hot coolant stored for the next cold start? That and get or make you own winter front.
What's complex about taking the pipe off the EGR valve and dumping it into a bung welded to the downpipe? Ain't even any o2 sensors on the exhaust to disconnect before welding, lest they backfeed into the computer.

Complex would be swapping the turbo's cartridge for a water cooled one I've got. (I should read up on that one, might be able to do some hybridization) Complex would be using old heat crossover parts from a GM V8 to route all the exhaust post-turbine through a heat exchanger without making the cooling system into a boiler once its warm. Complex would be a coolant bottle apparatus to hold an extra gallon of coolant in the system with internal valves to reduce cooling by convection currents.

From what I understand the coolant reservoir in the prius is more to provide a large thermal mass for the heater to draw heat from between the times the engine is running, as in 5-15 minutes at a time. Park the car overnight in -20 degree F weather and the entire system'll be dead cold.

I don't mean to come off as a dick, but by neck sure gets stiff when I take those little blue pills.

It really doesn't happen to the same degree as it used to unless the drivers are not getting the engine up to temperature by driving very short distances only.
My commute is 10 miles. This thing seems to reach operating temperature in about 6 miles when it is warm enough for it to start. My hondurcurr warms up in a mile. It's all relative.
 
Last edited:

rwthomas1

Veteran Member
Joined
Oct 16, 2002
Location
Wakefield, RI
TDI
'03 Jetta
Hey, if you think its easy go for it and post the results. Taking a bunch of stainless pipes, etc and relocating them in the relatively cramped space behind the engine seems like aton of work. The Prius system is specifically for cold startup and the thermos will stay warm for three days. The system is well diagramed on the web and transplanting the thermos and the pump in its entirety while operating the pump, etc. with switches would be relatively simple. Coolant hoses and wiring is easier than cutting, welding and tweaking on stainless pipe. Given the short commute, an engine heater is probably the simplest solution.
 

nicklockard

Torque Dorque
Joined
Aug 15, 2004
Location
Arizona
TDI
2010 Touareg Tdi w/factory Tow PCKG
My commute is 10 miles. This thing seems to reach operating temperature in about 6 miles when it is warm enough for it to start. My hondurcurr warms up in a mile. It's all relative.
Ah, I see. Well, not to be rude, but a diesel power plant is definitely not the first choice for a cold-climate, short commute. Good luck and have fun :)
 

[486]

Top Post Dawg
Joined
Mar 1, 2014
Location
MN
TDI
02 golf ALH
Ah, I see. Well, not to be rude, but a diesel power plant is definitely not the first choice for a cold-climate, short commute. Good luck and have fun :)
Yup, 'sall good. Got the car for cheap, and am slowly working toward fixing what's wrong.

Tried the data logging thing 4 times now and every time it stops communicating as soon as I start moving. I can sit and watch the data displays and log data sitting still but once the thing moves the cable will not connect to the computer. Gonna have to do more troubleshooting, so there might not be any hard data before it warms up.

Might even have a more proper mechanical throttle injection pump on it by the time next winter rolls around.
 

707DieselDean

Well-known member
Joined
Apr 23, 2009
Location
Nor Cal
TDI
98 Beetle
If you have an aftermarket radio installed....turn it off before plugging into the diagnosistic port.
 

[486]

Top Post Dawg
Joined
Mar 1, 2014
Location
MN
TDI
02 golf ALH
I don't even listen to the radio, nothing but commercials, and anyways, just a distraction from the task at hand (driving).

So, 77k miles ago (according to a receipt in the (broken) glovebox) someone cleaned out this thing's intake and drilled the carbon out of the EGR cooler's passages. Previous owner lived in the city. Lawdy lawdy, I couldn't fit a quarter flat-ways through the hole in the poop in the intake.








So much for the EGR coking issue being "so dead as of 2007".
 

rwthomas1

Veteran Member
Joined
Oct 16, 2002
Location
Wakefield, RI
TDI
'03 Jetta
Looks like the Wife's car at @130k. Cleaned the intake, did the RC3 tune and 70k later there was just a black film in the intake. That's with all the egr stuff intact, just tuned out. FWIW...
 

[486]

Top Post Dawg
Joined
Mar 1, 2014
Location
MN
TDI
02 golf ALH
Well, if the EGR is tuned out of the equation then the warmup times will likely increase dramatically. All the tubes in my EGR cooler looks pretty darn plugged up, too, so my baseline might be the same as a dirt simple unplug-and-forget delete. We'll see, first I have to get the thing disconnected from the coolant lines (and I forgot my hose pinching pliers at work, dammit) before I can clean out that part. Might have to get one of those ultrasonic cleaners from HF...

Well, I'm probably not going to post much more ITT until I make some actual progress.
 

nicklockard

Torque Dorque
Joined
Aug 15, 2004
Location
Arizona
TDI
2010 Touareg Tdi w/factory Tow PCKG
Old problem. Doesn't really happen anymore. Don't try to solve problems that are already solved ;)

Edit: and what's that about installing a mechanical fuel injection pump :confused: Your model year of Tdi already has a far superior electronically controlled one. Or are you referring to a lift pump?
 

[486]

Top Post Dawg
Joined
Mar 1, 2014
Location
MN
TDI
02 golf ALH
So I finally gave up and burned the crap out of the elbow bit of the intake. Oh man after all the scrubbing in the world that made it easy. Didn't even get the alu near 700 degrees, so I'm certain it isn't hot-short and gonna crack on me. Then I saw I'd messed up the flange a little while scrubbing it out, steel gaskets don't like that and all. No problem, indicated it in on the knee mill and flycut it flat. Probably could have ignored it, but w/e, 20 minutes work. Thought about gasket matching the runners, but I have no idea where the ports in the head are at. Once I look at those I'll see if I'd get any benefit from doing so, if the ports in the head are smaller than the holes in the gasket as well then I'll just run it.



As usual I forget to take pics until after, and they're crappy cell phone pics...

Old problem. Doesn't really happen anymore. Don't try to solve problems that are already solved ;)

Edit: and what's that about installing a mechanical fuel injection pump :confused: Your model year of Tdi already has a far superior electronically controlled one. Or are you referring to a lift pump?
Well, when the solution involves driving 50 extra miles every time I do a cold start, then that isn't much of a solution for me. Nor is paying someone to do something to the computer that likely won't be controlling anything more than a tachometer and door locks for long.

On the proper IP thing, I'm the sort that doesn't like electromechanical things. Computers are fine, mechanicals are fine, try and mix the two and you're going to have problems. Case in point, automagic transmissions and inkjet printers.
 

nicklockard

Torque Dorque
Joined
Aug 15, 2004
Location
Arizona
TDI
2010 Touareg Tdi w/factory Tow PCKG
On the proper IP thing, I'm the sort that doesn't like electromechanical things. Computers are fine, mechanicals are fine, try and mix the two and you're going to have problems. Case in point, automagic transmissions and inkjet printers.

:confused: ever heard of "Don't fix what ain't broke"?

mTdi is going to cost a bunch of power, smoothness, fuel economy, and clean air. These engines are excellent as is for their intended purpose (economy commuting).

Well, have fun though. It's your ride.
 

Fix_Until_Broke

Top Post Dawg
Joined
Aug 8, 2004
Location
Menomonee Falls, Wisconsin, USA
TDI
03 Jetta, 03 TT TDI
I have to agree with nicklockard here - there is absolutely nothing to be gained by going to a mechanical injection pump - not a single thing.

Electromechanical things make the world go round as we know it. You will never achieve the efficiency, drivability, and power with a mechanical pump that you will with the VE pump that's on the car.
 

margus014

Member
Joined
Feb 22, 2014
Location
Estonia
TDI
Golf 4, 81kw
Hey, little offtopick already.
What about welding a steinless steel tube on a downpipe and directing coolant through it- its a free heat
 

Fix_Until_Broke

Top Post Dawg
Joined
Aug 8, 2004
Location
Menomonee Falls, Wisconsin, USA
TDI
03 Jetta, 03 TT TDI
The issue is turning it off when you don't want it. If you turn off the coolant, then what's in the tube next to the downpipe will boil and turning the exhaust off with this design is not really an option :)
 

bbob203

Veteran Member
Joined
Oct 31, 2012
Location
Louisville, ky
TDI
b5.5v
mTdi is going to cost a bunch of power, fuel economy, and clean air. These engines are excellent as is for their intended purpose (economy commuting).
Have you ever built or driven an mTDi? If you have... you used the wrong pump. The only thing I will give you is loss of smoothness even then the loss in not worth complaining about. My economy on my mTDI is 45 avg as high as 58 flat ground at 55mph for 8 hours. A properly built/tuned pump w/ LDA will be nearly as clean as an Etdi just slightly higher NOX. I'm not sure why an mTDi would cost you any power? Could you explain that? The electronic system isn't bad its just convoluted and only serves the purpose of a homogenous product for the masses.
 
Last edited:

maxmoo

Veteran Member
Joined
Jan 19, 2011
Location
Lakefield, Ontario, Canada
TDI
2000 golf, 2001 golf, 2000 beetle, 2003 wagon, 2004 golf, 2004 jetta, all diesels
I have to agree with nicklockard here - there is absolutely nothing to be gained by going to a mechanical injection pump - not a single thing.

Electromechanical things make the world go round as we know it. You will never achieve the efficiency, drivability, and power with a mechanical pump that you will with the VE pump that's on the car.
Mechanical IP vehicles may be the only ones still running after an "EMP", solar, nuclear or targeted. :cool:
 

bbob203

Veteran Member
Joined
Oct 31, 2012
Location
Louisville, ky
TDI
b5.5v
To convert a vehicle from Electronic to mechanical for the sake of it seems like a waste of time to me personally. On a conversion though esp a non VW conversion I see no reason to go to the trouble when you end up with more to break and figure out for a minimally better if at all better product. After watching my friend probably lose hairs on his Eurovan etdi swap I will pass on that.
 

[486]

Top Post Dawg
Joined
Mar 1, 2014
Location
MN
TDI
02 golf ALH
I have to agree with nicklockard here - there is absolutely nothing to be gained by going to a mechanical injection pump - not a single thing.

Electromechanical things make the world go round as we know it. You will never achieve the efficiency, drivability, and power with a mechanical pump that you will with the VE pump that's on the car.
Eh, we'll see.

Easier for me to dick with the fueling with a mechanical pump. Tried reading up on reflashing the ECU but people are making money doing it, so they don't want to put the info out there. Fine with me.
Besides, plenty of 100hp/liter engines out there with a mechanical pump and fixed injection timing.

ETA: getting the new vnt actuator in the mail today, so I can start reassembling it for now. Oh yeah, old one rusted solid, so I took it apart, knocked it free and freed up the vanes as well as I could. Didn't do too good crimping the can back together but it got me home.
 

[486]

Top Post Dawg
Joined
Mar 1, 2014
Location
MN
TDI
02 golf ALH
I said "future" meaning just that.

Well, anyways, there's a couple nice cores from mercedes' on ebay right now, only 5mm elements in them though, with available ones going on up to 7mm. Probably pass on those. Gonna be in AZ for a week soon, so I'll hit some junkyards and see what's available there. Everything old enough to be interesting's been crushed long ago around here.
 
Top