2.0TD into 1987 VW Quantum Syncro Wagon
 

It's been years since I've been on here!

I'm going to start my diesel conversion project this weekend, putting a 1983 2.0TD (I think it was from an Canadian Audi 5000) into my 1987 QSW. I'll log my progress here and will take some pictures this weekend after beginning the work.

I've had the 2.0TD running on a stand (six years ago) but am going to take it apart and inspect everything, installing new rings, bearings and seals as needed. I miraculously found a spare rebuilt head six years ago if there's major problems with the current head and have already gathered gaskets and seals.

A few things I'm still considering and/or still need are:

Finding an alternator bracket that will fit the passenger side so I can move the gasser alternator from the driver's side making more room for an oil cooler, larger radiator and possibly an inter-cooler. I know I can fabricate one but would prefer an original part.

Plumbing a coolant outlet on the back of the head that will constantly flow coolant back to the thermostat thus keeping hot water flowing through the head when the heater is off. V8VOLVO had some good input on this several years ago when I was considering this project.

Finding a spot for the battery, possibly in the space created by moving the alternator or moving it to the rear of the car, opposite the spare tire.

Replacing the rust rotted oil pan with the one from the 2.2 gas engine, if it will fit, or just brazing the pitted pan until a 2.0 pan can be found.

This is going to be a months-long project and I'm beyond anxious to finally be starting it. The car is located 100 miles from my home in a nice concrete floored shop and I plan on working on it every weekend.

Nice find. Is the oil pan from the 2.0TD steel?

It is a steel pan. I will know if it will fit once I get the 2.2 gas engine out of the QSW.

Nice to see you here again!

Sounds like a fun project and engine-car combination. I always heard those Quantum Syncros were really an Audi Coupe Quattro underneath, but in VW station wagon clothing. Supposed to be great to drive. I knew a guy who had one and sold it and missed it afterwards. I imagine the 2.0 TD will be capable of similar performance to the stock nonturbo gasser, and much better mileage, no?

What's the motivation for the swap, just the benefit of turbodiesel power, or does the current gas engine have problems?

I think you will find the 2.0 TD very familiar to the D24T. Even all the same special tools for the crankshaft dampener and bolt, etc. Be fun to see your pictures for comparison to our engines. A lot of the parts are probably the same too, like the IP mounting bracket, cooling system parts, etc, right?

I bet that 2.2 gasser oil pan will bolt right onto the 2.0 TD (though maybe the TD needs a turbo drain return to the pan so that might be a problem to solve?). All accessory component mountings on the front of the engine should be the same too IIRC, with all the same bolt holes and bosses available, AND should also be the same as a 6-cylinder D24 or D24T. So that might be one easy solution to your idea of relocating the alternator to the passenger side, as it's already positioned there on a D24. A D24 or D24T alternator bracket and alternator would likely bolt right on. You might need to trim the bracket a little to remove the bearing housing for the engine driven rad fan (I assume the Audi/QSW don't use those?). Belt alignment might be a question if the Audi engines use a differently designed crankshaft harmonic balancer, I guess.

Look forward to seeing your updates. In case it gives any useful ideas, have you already seen this thread on a similar swap into an Audi 5000? http://vwdiesel.net/forum/index.php/topic,25252.0.html
Slightly different car and he used the long stroke 2.4L nonturbo truck version of the 5cyl IDI for the engine in his and added a turbo to that, but same general idea, gas 5cyl to 5cyl TD. I ran across it accidentally looking for info on something else, but bookmarked it anyway, mainly just since the guy seemed to do an especially nice job with the conversion and put up some great photos. Fun reading and watching at least.

The QSW really does handle well and the 4WD system is excellent, locking rear and center differentials using a two position vacuum switch. The 2.2 gas engine is tired and using oil and just doesn't run right. And I want an AWD diesel station wagon that gets 30mpg. I have another 1985 QSW 2.2 gas vehicle and it gets a little over 20mpg and runs well. It's basically an unregistered backup vehicle and will be used for drivetrain parts if necessary in the future.

The 2.0TD looks exactly the same as the 2.4, minus the one cylinder, which is why I'm on this site, the veterans here know what they're looking at, and yes, all the tools are the same and I have enough experience with the 1.6's and 2.4 to also know what I'm looking at.

The turbo drain is plumbed into the block so if the bolt holes line up I'll be fine.

The harmonic balancer is the same as the 2.4 and the gas engine uses an electric fan on the radiator mounted beside the engine, you'll be able to see it in the photo's soon.

I will need to get either and Audi alternator bracket or the Volvo bracket to bolt on the passenger side and will post a "parts wanted" add in a few days.

I did find that other thread and read the entire thing a few days ago. The one major concern I had is the gear ratios being to low for a diesel but I'm doing it anyway. It drives 70mph at around 3200 rpms so it will be fine for it's intended use, a ski-mobile, mostly winter driving on mountain roads around Reno.

I'll get some photo's tomorrow and post them with a few questions.

Sounds like a cool project!
I met a guy that was trying to do a similar project in yoncalla Oregon, he was hoping to use a d24t, but space didn’t allow so he acquired the 2.0TD to use. He has a HUGE collection of 80’s VW’s and 1.6 diesels.
Anyways, I always have lots of d24/d24t parts of you need anything for the project.

Ive discovered saving sheet steel parts that are badly rusted to be a simple process with the oxy-acetylene powered DHC 2000 welding kit. It could be a valuable tool for your 2.0TD oil pan repair project. It can be used with standard regulators. Of course as always safety first.

I was going to ask what you were planning to do about gearing, but then I didn't because I think you're right, the gasser gearing will probably be fine as is. These old IDI motors like to rev and there are seemingly no downsides to letting them do it. In the example of the Volvos, the diesel models use exactly the same transmission and rear axle gearing from the factory as most of the equivalent gas models. In fact the diesels are actually geared shorter than some of the NA gassers. The engines are suited by design for fairly high engine speeds, small lightweight pistons, direct acting OHC valvetrain, etc, it was clearly part of the plan for them. Especially true for the original design "short stroke" family like the D24/T and your "D20T" (the 1.5/1.6 4cyl, 2.0 5cyl, 2.4 6cyl). The raised deck generation IDI and TDI motors (1.9/2.0 4cyl and 2.4/2.5 5cyl) with longer strokes are maybe a little less optimized for it.

Anyway if the gas engine is turning 3200 at 70 that seems like it would be just fine with the diesel. My '83 760 D24T with stock size tires and stock gearing turns about 3400 rpm in overdrive at 85mph, which is still too slow to keep up with highway traffic here. But it seems happy to do those revs or more all day, in fact it seems to be capable of quite a bit more, although with the 1983-only 85mph speedo I am not too tempted to explore. :p Really the ability to rev smoothly and provide a wide power band is one of the neat features of the old IDI turbo engines, and makes them fun to use for hard driving. The later direct injection engines are much more limited on the top end, although their low end response is better. They seem to pretty much run out of breath even before 4000 rpm.

I'll answer all your replies tomorrow but here's an update from today.

Some before pictures, first the QSW it's going into, engine bay with the 2.2 gas engine, all stock.
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And now the pre-teardown 2.0TD, very, very similar to the D24T
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Cooling system layout.
Existing radiator with current alternator location.
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Dual radiator setup from an Audi turbo 100 or something similar
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A mystery outlet at the bottom of the new radiator, not sure what I'm going to do with it yet.
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New radiators from another view
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Mystery outlet at the bottom of the new radiator.
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Existing alternator alignment to the front pulley. For some reason this picture is not showing.
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Front pulley of 2.4TD with existing bracket which should fit the alternator relocation.
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Turbo's side by side, D24T on the right with the four bolts for the exhaust downpipe flange, no way these will be interchangeable which I was hoping for.
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T-handle wrench for headbolts and this one injector. '85TD Jetta in the background.
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End of day one, head's coming off tomorrow, oil pan and oil pump as well.
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Water flow pictures with questions to follow
Outlet from the block which goes to the heater core, also showing the threaded fitting for the temp sensor which appears to be in/inside a larger threaded fitting in the head.
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Return line from the heater on the left, I just had it looped when I test ran the engine.
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Here's a picture of the thermostat as it sits in position viewed through the water pump hole.
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And here's looking in the thermostat mount hole.
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So here's my question, and this has been discussed here before.

With the thermostat cold, as shown in the first picture, the back of the t-stat is not closing the hole in the block which allows cold coolant to be sucked out of the head (as shown in the second picture), apparently close to where it's being pumped into the block. If the heater is off, the cable operated valve being closed, there's no coolant coming out of the back of the head/block, thus the coolant would seem to pool up and heat up at the back of the head and block while the circulating coolant around cylinders 1, 2 and 3 heats up more slowly.

In the second picture you can see the hole coming down from the head, which is where it's pulling the water from, so there's circulation near the first three cylinders and the corresponding part of the head.

When the coolant is hot the problem appears to be even worse since the back of the thermostat closes that hole and the only flow has to come from the back of the block, which wouldn't happen if the heater is off. I may be too tired and have missed something; is there another passage coming out of the block??

So my question is: how does the coolant circulate to and through the back of the head/block when the heater is off?

I'm considering plumbing in something so there's ALWAYS circulation to/through the back of the block/head even when the heater's off.

Has anyone done something similar?

Good to know you have a lot of that era's engines. I remember ordering some Bosch nozzles from somewhere and giving you a tip on where I got them. I also bought that spare D24T turbo, which is in the picture, from you. I thought it would work on this engine but not to be.

I really like the simplicity of the 1.6, 2.0 and 2.4. No computer. There's value in that for me!

I hope the pan from the 2.2 gas engine fits, but won't know til I take that engine out. I'll have to look up DHC 2000 welding kit, since I've never heard of it. I temporarily welded a small piece on the pan where it was completely rusted through. I got this engine from Canada and everything that's exposed to atmosphere is rusted. I got everything off the block today using a lot of map gas heat, well everything but one glow plug, it wouldn't come out and I twisted off the head. I'll drill and easy out the thing on another day. I had to chisel off a few of the turbo to downpipe nuts as well. All the interior parts, including gaskets appear to be in good condition.

My 1.6 doesn't really generate good power until around 3000rpm's. When I owned the D24T Volvo I recall it had good power below 3000 but didn't mind running at 3500 either. TDI's are better between 2000 and 3000. I think it will be fine which is why, 9 years later, I'm continuing with the project.

I did a compression test before dismantling all the exterior bits today and it was pretty sad, around 280 psi average, but the engine has been sitting a long time. It did hold pressure so I think it will be ok. There was one potentially major problem, the #4 injector was burned up on the tip, I think the crush washer wasn't seated properly by the PO and it wasn't emitting diesel, so that cylinder was running dry for I don't know how long. It only had 50psi dry, but when I put oil in the cylinder it went up to 220.

I'll be taking the head off tomorrow and see what's up. Stay tuned.

Here's a partial answer about your thermostat/coolant flow questions:

In the 7xx series at least, the heater valve is always open, except when running max A/C.

Might want to check that your tstat is the correct one. I would have thought that when fully opened, the block-off disc would completely close up the recirculation port-- isn't that what it's there for?

Greenbook shows the disc should move 8mm min. (fully open) at 216degF (for stock 87degC tstat).

OK I see my misunderstanding of your question about blocking the recirc port.

Interesting question, right. I hope to get some feedback. There's no flow out of the back of the head/block. On the 1.6 in my '85 Jetta the heater core circuit is always open so there's always flow out the back of the block/head.

Day 2 update.
Cylinder walls 1 through five in sequence. #4 is the problem, as stated earlier the injector for that cylinder was burned closed, ie. no fuel injected, so the piston was just going through the motions without any action. That's also the cylinder I snapped the glow plug head off, and still can't get it out. There's some rust on the walls but that's about it. The walls themselves look good and there's very little lip at the top where the rings finish their stroke. I'm just going to do a light hone and install new rings.

https://dp0dfw.ch.files.1drv.com/y4m...&cropmode=none

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Head gasket and head. I'm convinced this engine was recently overhauled, recent in miles or hours not recent in days or years. That's a clean looking gasket. It's hard to see in the photo but there's only one small crack between the valves. I still need to get the frozen glow plug out of cylinder number 4 but the head is very useable.https://dp0cfw.ch.files.1drv.com/y4m...&cropmode=none

Indication of prior rebuild, punch marks on the rods and caps.https://dp0ffw.ch.files.1drv.com/y4m...&cropmode=none

Broken oil squirter in cylinder 1, I have one, I think I got them from Anders several years ago.
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Vinegar soak! I'll leave the vinegar in the block overnight and flush it out tomorrow, will probably do one more soak tomorrow night. The block holds 3 quarts of water/vinegar.
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End of day 2, a little sunset through the shop window highlighting the soon to be awesome engine, car anxiously waiting it.
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Every gasket I've seen: oil pump, rear main, turbo supply and return, etc. looks quite new so although the engine looks ancient on the outside it's in very good shape. I'm quite happy.

Any input on routing coolant from the back of the head/block?

Looks great so far. What size are the pistons stamped? Sounds like they might have been oversized if it was rebuilt before, may want to double check the size for ordering new rings. Pretty clean inside overall!

One time I took the pan off a D24T and saw that it had several squirters broken off. When I got the engine the rest of the way apart, I discovered the reason for the broken squirters was that someone had attempted to use non-turbo oversize pistons during a rebuild, which do not have notched skirts to clear the squirter nozzles. Once the engine "rebuilder" figured out that this would be a problem, they took an angle grinder to the NA pistons and cut notches in the skirts by hand, rather than ordering the correct pistons! Some of their hand cut notches were not deep enough and they chopped the nozzles off. The ones that hadn't been broken had dents from getting kissed.

Anyway, now I think of a broken squirter as a warning sign, might want to confirm you have correct TD pistons in here.

Sharp looking wagon, white is a good color on these. Did the vinegar get the block that clean?? That's a new method to me, sure would be nicer than using solvent. :)

Nice well lit and spacious work space you have there too, sure beats mine.

Regarding your questions about coolant flow:

How is the current engine in the QSW set up? Does it have a method for continuous recirculation? Or does it use a heater control valve? Since the 2.2 gasser is the same fundamental cooling system design, maybe whatever they did to integrate that engine in the car could be done the same way for the diesel?

And what about in an old 5000TD like what this 2.0 presumably came out of? Do they have a heater control valve or does the heater circuit run continuously? And how does the oil cooler circuit work on the 2.0TD? Is it like the D24T where it's fed from the back of the head?

It's an interesting problem to try to solve, but one assumes the original designers must have thought about it too, so maybe their solutions are a starting point at least.

Here are my thoughts: the non-turbo D24 engines look the same as the back of your 2.0TD, with no outlet from the back of the head. There is an outlet from the back of the block for the heater circuit, but that circuit is designed to be able to be closed some of the time (heater output on a Volvo 240 with a D24 is controlled by a heater control valve). So, as produced from the factory, there has to be an accommodation for there being no coolant outlet from anywhere on the backside of the engine, either the head or the block, yet for the engine still to maintain temperature and balanced coolant flow. I think they therefore accomplished balanced coolant flow throughout the engine in the usual way, by using precisely calibrated, and varying, orifice sizes for the "steam holes" (i.e. coolant passages) in the headgasket.

If you examine the headgasket you'll notice that the coolant passage holes towards the front of the engine, closer to the water pump, are very small, practically pinhole size. As you work back towards the rear of the engine, you see the holes get progressively larger. The holes surrounding the rearmost cylinder, and especially behind it at the very rear of the engine, are by far the largest of all. This I think is intended to prevent the problem you describe, of the front two or three cylinders near the WP getting all the coolant flow while the rear ones get nothing. Instead it regulates the flow through the front cylinders and forces much (or presumably an equal) amount of flow to run back to the rear of the engine, through the back of the head, then back around through the head to the upper radiator hose outlet, or the internal return through the block, depending on what the thermostat is doing at that moment. I assume the exact size of these holes in the headgasket is the result of a very careful fluid flow engineering calculation and probably lots of testing. It probably also takes into account the design of the cooling and HVAC systems of the vehicle applications the engines were meant to be used in, and accommodates the possibility that a heater control valve could be closed.

I have an old D24T headgasket floating around that I'll take some pictures of later to show what I'm describing.

So, all that said, I think the question of coolant flow through the rear of the engine probably won't be a problem in this setup, regardless of how you build it. This coolant distribution question is really a challenge that has to be solved in any inline engine, and the longer the engine the greater challenge, since the water pump is way up at the front and there's a long distance to the back of the motor. But obviously there must be good and well proven solutions for it, otherwise long inline engine designs would be considered troublesome, which is the opposite of the real world situation (I-6 is dominant in every heavy duty application, etc). My belief is that the headgasket's careful design is what does it. Bottom line is I think you won't have to do anything for it to work as it should, unless you actually observe a cooling difficulty once it's in the car.

Beyond coolant circulation within the engine, though, there's one other issue that is relevant to reliable cooling performance with this design, and this is the one that has been of greater concern to me. It's the ability of the wax pellet in the thermostat to "read" the engine's temperature. I think that can be problematic due to the way this engine is configured, since the tstat is positioned at the inlet of the water pump, rather than the outlet from the head like in some designs. The WP draws coolant past the tstat from multiple sources, including the heater return. The coolant that flows past it therefore could include some coolant that has passed through a heater core and has been cooled down significantly in the process, thus causing the tstat to "think" the coolant in the engine is colder than it actually is and begin to partially close, even if the real cooling demand is still very high. One of my old goals that I have never really figured out is how to return the heater circuit somewhere else rather than the tstat housing to avoid this. But this is only a real problem in the bitterest cold weather. Not so much if the heater is not in use. Anecdotally, all the headgaskets I have ever blown in D24T engines have been while climbing mountain passes in subzero weather, which is why this issue interests me. It's a bit of a paradox that *cold* weather is a threat to effective engine cooling with this particular design, more than hot weather even. Still want to work more on it, someday.

But that's not really the question you're asking, so maybe it's a separate discussion for another place and time, rather than in your build thread...

Look forward to seeing the next phases of the project, looks like you have it moving along at an efficient pace. :)

Especially considering its Swedish/Germanic roots.

Damn! I need an oil squirter, the ones I have are for a 1.6, a different design. Does anyone have one? I’ll pm Anders since I got one from him before. All the pistons have the notch cast in the skirt so no telling why the tube came out of the base.
I’ll reply to v8volvo’s cooling summary when I’m at a keyboard tonight.
This is a nice shop, cement floor and a forklift!!

Just found two squirters Anders sent me years ago!!!
Thanks again!!!!!

The pistons are stock, I think 76.48 is what was stamped on them. The rings were in pretty good shape so I think they were new, although they weren't lined up correctly, some of the gaps were in the same location. You'll see in the following pictures the cylinders should have been bored but I just don't want to do that right now for lack of time. When the engine is installed and if I like the way it works and drives I'll have no problem taking it out again for some machine work. It's taken so much time removing frozen bolts, cleaning, wire wheeling, etc., that it will be much quicker next time. Plus I'm going to cut the grill metal, the front end of the car, so I can just remove that for a simple engine extraction. I've put rings in a far worse 1.6 and it ran pretty good so I'm not concerned right now.

I don't know why the squirter was broke off, some of them are pretty close to the very top of the piston rod, so maybe that's what happened.

I had to make a turbo piston for my 1.6 and I just hand filed the slot from an NA piston, it ran that way for about 50,000 miles just fine. That's the engine that was completely wore out as well.

[QUOTE=v8volvo;13706]Regarding your questions about coolant flow:

How is the current engine in the QSW set up? Does it have a method for continuous recirculation? Or does it use a heater control valve? Since the 2.2 gasser is the same fundamental cooling system design, maybe whatever they did to integrate that engine in the car could be done the same way for the diesel?

/QUOTE]

The current QSW does have a heater control valve so it's set up to accept this engine as is. It's a cable operated "ball valve" of some sort.

The QSW does have a heater valve, some type of ball valve, cable operated just down-flow from the back of the block/head.

I'm not sure about the AUDI 5000 or 100, whatever this came out of. Since it's a VAG vehicle it may be similar. My 1985 Jetta is just the opposite, there's always flow going through the heater core.