dreadlocks

Link: Audi Q7 (4L) TDI Webasto Retrofit

This thread is a supplement to that document above, extra photos and more details may be found here.. if you have any questions or need any help this is the best place to ask.

I've ordered the main unit from a wrecker in Netherlands, the key research I did on this was determining the correct parts for the Q7 as they are not same as T-Reg.. and how to identify variations that exist, like single evap vs dual evap.. and if it had the valves to be used as a parking heater vs a block heater.

Since the full emissions delete on my TDI dramatically increases the time it takes to get heat/defrost, I decided this retrofit was a must-have for me.. When I did this on my Golf TDI I installed a 120VAC Parking Heater, but the Gen2 3.0L TDI made a thermosiphon heater impossible to install. The OEM Solution can still run while vehicle is driving, running cycles are configurable for 15-60mins.. I hear it can warm up the cabin in 5-10mins.. so I figure if I start it up 15mins before I leave it'll warm up the cabin, then continue to pump out hot air for another 15-20mins of driving while the diesel engine slowly warms up.. which should be faster w/out the heating loop in the mix.. It will also fire up the parking heater automatically to help warm the engine up without intervention below either 41F or 32F depending on how its configured.

Credit where Credit is due, most of this was made possible by chewblekka @ clubtouraeg he figured it out first for our sister vehicle, and made it dramatically easier for me to pick it up for the Q7 with confidence.. although very little is the same the paths we traveled looked much alike.

cuatrokoop

That is fantastic, Dread. Looking forward to your install, as once the emissions warranty is out I think I'll be in the same boat..

drjonez

I look forward to reading more on this, especially on warm up times after you do all the deletes. The warm up time may be a driving factor in whether or not I delete....it's dang cold here in the winter.

dreadlocks

Yeah one of only nice things about the fix was how dramatically faster it warms up the engine, but OTOH I hate knowing its hurting the engine in the process.. When I did this to my golf it increased warm up time by ~5mins, but that thing was never fixed in my possession so cant really say how different the time vs a fixed Golf.. After seeing what the fix did to my Q7 I think its safe to assume it'll be substantially longer without the EGR forcing the engine to dutch oven itself.. If I hadda guess I'd say 15-20mins of driving to get it to operating temp w/everything deleted in the middle of the coldest parts of winter.. vs ~7-10mins post-fix.

I wont be getting much data on operation tho until next winter.. by the time the heater makes it to me from the netherlands and I get it installed its going to be ~June I suspect.

dreadlocks

Here are the photos from the unit I purchased, with language barriers and stuff try to keep communications simple.. It took me 3 tries before I found a wrecker willing to ship it to USA, for €120.

Remember they made Q7 for a very long time, more so in Europe.. things changed there between revisions before here because they got engines we didnt, and other things.. so keep that in mind if your hunting for one of these for your model year.. I was finding some very cheap units that upon further inspection had build dates from 2005, we didnt even get Q7 in NA until 2007 IIRC.. I wanted something appropriate for my model year, not that old, with less mileage than I got.

I'm dealing with covid issues, many european auto parts sites are not shipping internationally right now because of that.. so I may get stuck on this project waiting for one final piece, it feels like the fuel system is gonna give me trouble, may have to aftermarket tap the fuel tank and save some money.

Here you can see its got full exhaust, mounts, and recirculation pump




Build Date: 2014



Here you can ID its a 4-Zone, and that it has the N279 Valve

Built4Sin

Awesome!

dreadlocks

Sigh, well at least I have all summer to get this project done.. thats about the 6th time I've gotten this response thus far on this project.. ah well, back to the hunt.. have decided to forgo all the OEM fuel lines, ordered a generic standpipe from china w/fuel tubing for dirt cheap, its just a metal tube and plastic tubing so it was starting to look less and less attractive to spend hundreds on just the fuel lines, that I cant even source right now thanks to covid.

Need to source a fuel pump, I dont needa go OEM here.. can just get a normal diesel heater pump for a Thermotop C Webasto and get one new.. that again raises costs, but at least its a new in box mechanical part and not a used plastic tube.

Timtheguru

This the right one? Maybe someone in the UK can send it?

https://www.ebay.co.uk/c/2112655266

dreadlocks

First determine if you need a 2-Zone or 4-Zone, if you dont have a multizone rear climatronic unit in the back seats with a 2nd air conditioner and heater core in the rear fender then you can use either 2-Zone or 4-Zone (cut and plug extra pipes).. if you have a 4-Zone you'll likely wanna get one for a 4-Zone or you'll be needing 2 extra pipes and maybe some hoses.

Secondly you determine if it comes with a N279 valve so it can isolate the engine from the heater cores, you need this to obtain quick heat/defrost.. without it, it has to heat up the engine block first, in arctic temps this could take hours.. This was more common on premium vehicles and less common on base model vehicles, its what provided parking heater ability vs auxiliary heat w/cold engine.

That one has a 2007 build date, does not have a N279 valve, looks like the pipes are for a 2-zone climatronic, and is missing a bunch of piping, a couple brackets, and all of the exhaust.. by the time you pieced all the stuff together, assuming you can get anyone to ship those missing bits too you right now, you'll likely end up paying more than you would for a more complete unit.. shipping from EU is gonna be the killer, so getting as much as you can in one shipment is gonna pay dividends even if the purchase price is a little higher.. Returning an item that is faulty is gonna kill your budget, likely cost more in shipping than the item itself.. these Diesel burners are known to foul out and become finicky as they age, if your trying to do this super cheap with an older unit I'd definitely plan on disassembling the Webasto, cleaning the carbon out of it and possibly putting fresh injectors/ignitors in it before going through the hassle of installing it.

The Parking Heater CAN module is actually attached to the top of the Webasto unit, the revision letters at end of model number often indicate what firmware is running on the module.. getting module from 2007, and trying to make it talk to a 2013 vehicle has potential to create some headaches if the 2013 is expecting functionality to exist that does not.. so keep that in the back of your mind as you browse all the old, worn and cheap Webasto units that are out there.. also I know for a fact in NA the cooling system for Gen2 TDI was changed significantly from Gen1 TDI, so thats another potential headache point if the hoses/pipes have any variations in em.. I think EU switched to Gen2 a year or two before NA did.. Older cheaper units might fit fine w/no trouble at all and could have very little usage if nobody used em, or they might throw codes and give you headaches.. Only one way to find out, and i'm not trying.

These are all unknown factors, I dont have the time and budget to figure out.. the onus is on you to ensure compatibility, good luck to everyone following me down this path.. It took me quite a bit of effort to find an acceptable unit that was able to be shipped to NA, after several dead ends I only found 1, it was the last option and most expensive.. and now its mine, so you might needa setup search alerts on Ebay and patiently wait for the right deal to popup.

dreadlocks

Parking Heater is here, Fuel Pump is Here, waiting on wiring harness and standpipe to arrive.