ALH warm-up time: EGR cooler vs. Deleted EGR...

I have searched, have read several different opinions, looking for more before spring!

Currently fixing up an 01 tdi Golf auto, hopefully someday in the near future will be used to daily drive to work, etc. I picked up the car in very neglected/poor shape and I need to decide if I'm keeping the EGR system or dumping it. Currently the existing EGR system is a non-functioning mess, intake looks clogged.

I live in central MN, -20*F is not unusual during winter. Quick trips in the winter will probably involve one of my quick to warm up v8 gassers but I would like to keep the TDI "winter-ready" regardless. Fuel economy on the cold days is not important to me, defrosting the windshield is...

For simplicity's sake, I would like to delete the EGR and focus on getting the car cleaned up and running properly. If deleting the EGR cooler, I will install a Frostheater, however, will not always have a plug in. Tell me: Fix up the EGR system, you need the cooler! Or delete EGR and use other means to warm up? Cold climate facts and options greatly appreciated!

^^^ MY car. Folks' response is always: "I've got to get rid of this so it doesn't happen again!"

Cleaned everything up and reinstalled. I was so horrified of the prospect of this happening -NOT- that I did the same thing on the wife's car (with the added bonus of hours of work cleaning up the intake ports on the head of that car).

I expect to have my cars for a long time to come. Never again will I be needing to do this work on these cars, I am CERTAIN of it. ULSD, better oils AND proper driving will all but eliminate the need to ever clean again (to pretty much eliminate it completely my tunes include Dynamic EGR programming). And to be honest, I may only get 200k more miles out of each car, not because they cannot go more, but because I'm getting old. BUT, in 200k miles I'll wager that there won't be any performance issues related to clogging: at that point my initial cleanings will have gone over 250k miles.

If I encounter a bad EGR cooler I'll likely yank it and not install a replacement. I live in a temperate climate, so benefits of faster heating are minimal. Cost will be the concern here, not functionality.

Yes, having the EGR stuff removed make a big difference in freeing up space to work in the engine bay (mostly only of benefit for turbo/head work), but, I don't really find that I'm having to do much work on my car's engines, so, in reality/practice, not a big gain to be had.

Having had both, I would say keep the cooler intact and working if it is all there, and get a tune done that takes advantage of it.

ULSD has made the intake clogging pretty much a non issue. What used to happen in 75k miles would not take 250k miles, maybe even more.

I would say this is especially important if you have to do much low speed city driving during warmup periods. If you jump on the highway right away, and drive 50+ miles, the longer warmup time may not bother you so much. My wife does not like to drive my Golf in the winter due to how much longer it takes to make heat versus "her" Passat.

Oh! Forgot to add that the biggest help in cold weather is HEATED SEATS! Even in my mild climate I'm finding heated seats to be a huge plus: given the amount of work to retrofit heated seats I sure expected them to deliver!

On the ALH engines I see no reason to remove a functional EGR cooler and the associated bits. I would not pay to replace a leaking one, however, unless I absolutely HAD TO (e.g. lived in an emissions-testing area where the vehicle was not exempt due to age, etc) simply because they're damned expensive.

But the ALH has no history of eating these things on a routine basis, so.... yeah. Odds are it'll be just fine for longer than the rest of the car's drivetrain is.

Keep the EGR and get a dynamic EGR tune. I've been running the dynamic tune for a few years now and I only have the slightest coating of soot/oil in my intake and EGR valve with about 60k miles since install.

Maybe it's just me, but I feel like I've seen these same EGR delete type threads over and over again. It's very helpful in our cold MN temps and can be dynamically tuned so it doesn't operate once the car is warmed up. Like was already mentioned, ULSD has really helped to slow down the rate at which intakes clog up.

Other things that can help you warm-up faster:

• Block the grill. I used coroplast to cover the whole radiator as well as the factory grill block. I keep this in until the high temps are above 50F.
• On days where the high temp is 0 or below, I put in the '2.0 lower grill' that blocks 90% of the air to the intercooler.
• Check your thermostat. A lazy one will hinder warm-ups with the potential that the car will never get to 190F.
• Install a FrostHeater and run on ~2 hour timer before you leave.

As you know, this past winter in MN has been brutal for cold. I have some pretty short commute trips here in the city and I've found the above really helps with warmup.

I have dynamic egr and a frost heater on my tdi and I still have to deal with a cold car sometimes. I would keep it in MN because when you run the heat you lose a lot of engine heat in the process when it is 0f outside. You have the benefit of the auto increasing the amount of heat produced compared to my 5sp. I would clean the intake and use a dynamic egr tune. If you are looking for mpg and performance look at other mods nozzles, tune, exhaust etc.

I removed my EGR cooler a long time ago after cleaning the intake. My car does not have a space in the garage, so out in the cold is where she sets. I recently installed a Frostheater (which was a really simple job) and have the timer on it set for a 4 hour run time prior to my needing to leave for work. I can honestly say, "I wish I would have installed a Frostheater years ago; by the time I get to the highway from my driveway I already have noticeable heat available." The distance from my house to the highway is less than 2 miles.

oilhammer said:

Having had both, I would say keep the cooler intact and working if it is all there, and get a tune done that takes advantage of it.
ULSD has made the intake clogging pretty much a non issue. What used to happen in 75k miles would not take 250k miles, maybe even more.
I would say this is especially important if you have to do much low speed city driving during warmup periods. If you jump on the highway right away, and drive 50+ miles, the longer warmup time may not bother you so much. My wife does not like to drive my Golf in the winter due to how much longer it takes to make heat versus "her" Passat.

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If you are not experienced clogging anymore, it's not because of ULSD. I cleaned my intake completely when I got my ALH at 60k miles - it was about 50% clogged. I recently replaced my weeping EGR, and inspected the intake, and at 180k, the intake is nearly completely clogged again. And this is with an EGR delete installed for about 100k miles now. ULSD has been at the pumps the whole time since I cleaned my intake.

I have an EGR delete, and there is a noticeable difference in warm up time. When the outside temperature is in the 20s (F), my car never comes fully up to temperature -- it only reaches about 160F. With the EGR operating, it will reach the thermostat temperature.

Oh, and I recently removed my Frostheater. Last few times I used it, it caused coolant to leak under my dash and fogged the inside of the windshield. Instant heat was nice, but not seeing is not great.

Interesting how people have different experiences with warm up times and intake clogging. Between my sons and I we have five rotary pump TDIs, three of them with the EGR duty cycle tuned out. One of the tuned cars still has the EGR cooler in place, the others don't. We've never experienced any issues with intake clogging on any of the cars, deleted or not. And warm-up times vary pretty widely. I notice my Wagon with significant fueling upgrades warms up pretty fast. I usually get heat within a couple miles of leaving my house. My '99.5 Golf with no EGR cooler and a tune only is slower to warm up. Both cars are garaged. My sons' cars are similar in warm up times, despite one being tuned and the other being stock. Go figure. I will add that a good thermostat is an important help in warm up times.

My thoughts are: if your intake is still clogging with ULSD you're driving the car too gently. And if the car never reaches full operating temperature, the thermostat isn't working correctly. To my knowledge my son's '02 Golf has never had the intake cleaned and shows no clogging at 352K miles. Bone stock, EGR cooler in place and working.

My converted auto warms up very well after insulating the engine bay (see the soundproofing thread in the upgrades section), and of course I always use a radiator blocker of some sort (I usually use cardboard cut in an L and slipped in from the top on both sides).

My EGR/intake was at least 50% clogged after 200k miles. First few years she slept outdoors, last ten or so in a garage, mostly.

Note that my car lived in Virginia, and now Wyoming, not Massachusetts and other similar humid/cold climates. The humidity is a huge factor in warmup times, as windchill in dry air is absolutely nothing compared to a windchill factor in the northeast!

But windchill factor only applies to mammals, not cars or engines.

IndigoBlueWagon said:

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My thoughts are: if your intake is still clogging with ULSD you're driving the car too gently. And if the car never reaches full operating temperature, the thermostat isn't working correctly. To my knowledge my son's '02 Golf has never had the intake cleaned and shows no clogging at 352K miles. Bone stock, EGR cooler in place and working.

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You make points, and I have not replaced my thermostat in quite a while. Before I replaced it, the engine would not get up to temperature under any conditions less than 90F outside. Once replaced, it does warm up to 190F eventually in temperatures above freezing, so it doesn't seem like my thermostat is bad, but it could be failing.

The way I disable the EGR can be reversed quickly, and I have re-enabled it quite a few times; sometimes because of winter temperatures, or when I take it in for emissions testing. The difference in warmup time with and without EGR enabled is quite obvious.

Nevada_TDI - I disagree. Evaporation of the thin coat of water that ends up on all engine bay components definitely has an effect, and a humid atmosphere is more dense, making evaporation slower to boot.

Judson said:

Nevada_TDI - I disagree. Evaporation of the thin coat of water that ends up on all engine bay components definitely has an effect, and a humid atmosphere is more dense, making evaporation slower to boot.

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Judson, you are way overthinking this. While the relative humidity may have a
minor effect on how efficiently a radiator works, before the thermostat is open
warm-up time involves internal heat production and starting temperature.

Thanks for all the great replies. My main concern/reason for post was strictly on warm-up time, not EGR clogging. I do plan on pulling the intake to clean it and the head ports. Car will likely "sleep" outside most of the time. (Currently sleeping on jackstands in the garage)

I will plan on keeping/fixing up the EGR system intact mainly for faster winter warm-up. Cooler doesn't leak to my knowledge. I will start by modifying EGR parameters with vag-com or simply disconnecting vac hose (summer), perhaps get a tune down the road (dynamic tune before next winter perhaps). Feel free to carry on with related facts and opinions!

I am well aware of how vital a good working thermostat is, on any car really. I plan to stick a new one in said car also. I just finished the Timing belt/WP job so I suppose now would be a good time...

I'd forgo looking to tweak the EGR functions via VCDS as doing so won't really achieve the desired results: yes, back in the day when people were freaking out about clogging there was a bit rush toward this change, but without comprehensive programming, "tuning," it's just not real effective.

Most of the concerns can be dealt with by sufficient warm-ups and hitting some good boost from time to time. The tune stuff helps increase the overall effectiveness; but, the former things alone are more effective than say only the tune (by itself, w/o heeding the need to properly warm up and hit boost).

I agree with UhOh. Don't change the duty cycle parameters or remove the hose in the summer. The ECU compensates in other ways when you do this, which could also affect warm-up time / overall economy / performance. I've been incredibly happy with my dynamic EGR feature in addition to my Stage 4 Malone tune.

I still highly recommend completely blocking off your radiator for the winter as well. Without it, I've seen my coolant temp drop in traffic and even on the highway going into a stiff wind. The ALH is crazy efficient.

Thanks UhOh and djrhetoric. I'm an ALH newb, will take your advise!

Judson said:

Nevada_TDI - I disagree. Evaporation of the thin coat of water that ends up on all engine bay components definitely has an effect, and a humid atmosphere is more dense, making evaporation slower to boot.

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Humid air is less dense.

May feel thick to perspiring humans but it isn't.

Air can contain a finite proportion of water vapor. As that proportion is approached (100 percent humidity) evaporation slows. Nothing to do with density.

Hot air is less dense yet can hold more moisture.

Radiation and conduction. There's more than one way to transfer heat! (and thus some possible reasons for confusion)

Guys - relative experience here. Grew up on east coast, moved to Colorado, moved back to east coast, now in Wyoming.

East coast cold humid air is more dense than low humidity cold air at five to six thousand feet.

It makes a difference in warmup times. Please don’t overthink this. Makes a huge difference in the decision to remove an EGR/cooler or not.

I second the thought on heated seats by UhOh: i finally wired mine up and damn do I love them!

Obviously air on the coast is more dense than Wyoming air. has nothing to do with humidity.

Water vapor is less dense than oxygen and nitrogen, the main components of air so 10% humidity air in WY is denser than 20% humidity air in WY.

We have egr coolers deleted in both our alh’s. Tunes to both. Donna’s lives outside and starts easily. We never block air and both have new stats. Climate here is milder than yours, we are even with Minnesota’s south border. Neither car has an issue warming up or starting. Donna’s did have the IP start leaking in sub zero temps once and I had to reseal, other than that car is great in cold temps and warms fine. Mine had issues before changing stat, which to my recollection stayed cracked open VERY slightly way too long. That is my experience, not opinion. As always, my opinion is, suit one’s self if that is the main purpose. You can’t go wrong.

jmodge said:

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Appreciate your experience post!

I've mainly found the egr helps warm up the car if I'm either unable to have the room to get up to speed due to traffic etc or if the car is stationary.

Other than that as above, a good t stat makes a huge difference. The best one I've had so far cost me £5 UK! Worst one I've had for warm up is a genuine from the dealer! Go figure lol

I'd buy the cheap one again but I can't find one made by the particular company, other cheap ones have just been pure crap.

I live in Scotland UK, it's always cold

KLXD said:

Obviously air on the coast is more dense than Wyoming air. has nothing to do with humidity.

Water vapor is less dense than oxygen and nitrogen, the main components of air so 10% humidity air in WY is denser than 20% humidity air in WY.

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Looked that up, and it is surprising! I guess the effect is that it is harder to breathe humid air than dry, giving the illusion of being more dense.

But again, if you have a wet engine bay, it'll take longer to get up to operating temperature than a dry engine bay, all other things being equal, yes?

On topic: I only just deleted my EGR and EGR cooler, and I did notice slightly longer warmup times. But then soon after, I soundproofed my engine bay, and now it warms up better again, and more importantly, something I noticed, is that it stays warm longer.

Here is one to throw at you guys on humidity, it takes less btu's to heat water than air as far as btu output goes. How would that relate to humidity/heat under the hood. People make a good living in Florida on remanned heads. How about in dry states like Arizona? This could be a new thread probably.

Wouldn't hurt to check the new stat with a digital thermometer and boiling water. They generally close at a much different rate than they open. open rather abrupt, close very slow, especially as they age.

Nevada_TDI said:

But windchill factor only applies to mammals, not cars or engines.

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knob