98 TDI Build

vwishndaetr

Veteran Member
Joined
Aug 1, 2010
Location
WNC
TDI
98 Jetta
Sweet thanks. 🙏

Another question, and I'll post a more formalized update soon, but I brought home two mk4 parts cars on the cheap.

One is a ALH tdi, auto.

I read that the injection pumps on the MK4 autos are larger and can bringeth' more power to the AHU I'm working on. Now I am not doing some absurd power build here, but since things are out and I have parts available to me, why not?

Thoughts on whether it's justified. I can never make up my mind.

The car already had larger injectors because previous owner was all about rolling coal (smh 🤦‍♂️) - curious what bump in power I can expect from the injection pump change... Trying to justify my time or move on with my life.

Edit: Even went as far as considering swapping in the mk4 platform into the mk3. Only hesitation is that the AHU ran really well before I got into it, and the ALH is definitely lacking power... It needs to be sorted.

Edit 2: Always mix the AHU/ALH platforms up. Fixed now.
 
Last edited:

garciapiano

Veteran Member
Joined
Feb 12, 2018
Location
Southern California
TDI
1997 Jetta TDI (1Z)
The mk4 to mk3 swap isn't exactly straightforward and I wouldn't recommend it unless you're well versed in rewiring harnesses and custom fabricating certain hoses and brackets that will be needed to house the ALH parts. However, lots of people swap the ALH pump into the AHU by modifying the pump bracket and repinning the harness connector.

That said, the 11mm pump that came on auto mk4s is not a very useful mod unless you have an upgraded turbo. The stock 10mm pump on the AHU can flow more fuel than the stock turbo can accommodate, with the right injectors. I think the stock AHU block is good for about 150 HP after which you'll probably want to look into upgrading the engine internals to deal with the power. ALH has a sturdier bottom end all around compared to the AHU and purportedly a better-flowing head, but the difference is not so large that entirely swapping the ALH in is worth the headache.
 

vwishndaetr

Veteran Member
Joined
Aug 1, 2010
Location
WNC
TDI
98 Jetta
The mk4 to mk3 swap isn't exactly straightforward and I wouldn't recommend it unless you're well versed in rewiring harnesses and custom fabricating certain hoses and brackets that will be needed to house the ALH parts. However, lots of people swap the ALH pump into the AHU by modifying the pump bracket and repinning the harness connector.

That said, the 11mm pump that came on auto mk4s is not a very useful mod unless you have an upgraded turbo. The stock 10mm pump on the AHU can flow more fuel than the stock turbo can accommodate, with the right injectors. I think the stock AHU block is good for about 150 HP after which you'll probably want to look into upgrading the engine internals to deal with the power. ALH has a sturdier bottom end all around compared to the AHU and purportedly a better-flowing head, but the difference is not so large that entirely swapping the ALH in is worth the headache.
Nice - I did a little more digging since my post too and the swap certainly isn't worth the time. So I'm going to stick with the platform that I have and do things as I go.

With that being said, I have almost everything off the block at this point. The only thing that is really giving me a hard time is the 19mm crank bolt - I'm replacing all seals (even though I've read that folks said not to touch the front crank seal if it isn't leaking). I'll just need to get the counter hold tool... Pretty sure I'll need it to put it back together anyways.
 

vwishndaetr

Veteran Member
Joined
Aug 1, 2010
Location
WNC
TDI
98 Jetta
TLDR;
  • I've been adulting, finally got some time to make some progress.
  • Got some tools.
  • If there is some other trick I can try to remove the front crank bolt before I buy the tool, I'm all ears.
  • Does anyone know if I can just replace the top "cover" that contains the "nipple" instead of replacing the entire vacuum pump unit?
Has been a while since I touched the TDI, but as the previous posts have it, I got some time to crack into the build again.

As time goes on, I constantly fight the "I'll just..." and "while I'm in here I'll just..." battles that keep progressing me deeper and deeper into the build. This all started as fixing the exhaust and replacing the waterpump and now I'm, well, see for yourself.

Anyways, I have always wanted to have a mint engine bay and subconsciously I think that's where this thread is going. I want the bay to look like the day it rolled off the factory floor. The other "subconscious itch" I have is to get a little more power out of the powertrain. I have 175hp in my head, and I think that will become my goal once I pull the head off and confirm I have a good head/block to get to that number. I'm also human, so all of that can change. I've had plenty of projects I've worked on in the past, but this is my first time getting this deep into an engine build. I want to get down to an empty block and go from there. I also don't know why I chose an AHU as the guinea pig, but I am here and that's that.

Aside from getting married, doing some house renos, and other adulting, I spent some time getting my compressor hooked up.

I have a media blasting cabinet I wanted to have available for this build so it helped to have it hooked up and good to go - the 80gal capacity and flow rate from the 3 heads will be ample for my hobby usage without running at a 100% duty cycle. Since I needed to wire a 240v outlet for the compressor, I can also use my mig welder (which also needed a 240V supply). So win win from the compressor hook up. Sooo, while I haven't touched the TDI, I've been adding some resources to my disposal to aid my wildest desires.

All hooked up and good to go. Need some hoses for the blaster, but at least 99% of the setup is complete.



First thing I tackled was pulling off the valve cover to clean up some of the pitting. I went through and degreased it, sanded it, then did a pressure wash and quick wipe down with acetone to make sure no oil was remaining before laying down some primer.





Coated it with primer. Now I will say, I intended on applying my gloss black coat too, and then realized I should be using something that has a higher temp rating. The paint and primer I had both had a max temp rating of 200F - eek. I already had the valve cover primed. With that being said, I did well sanding and prepping, but will likely be stripping the primer off again to apply one that has a higher temp rating.

Regardless... Looks good for what it is.





My next obstacle, as I touched on earlier, is to remove the front crank bolt. I couldn't counter hold it with the tools I had. I did a quick search last night for the counter hold tool for $50 ish? I might just pick one up, if I had to guess it should be the same tool for all mk3 VW 4cyl platforms, so it will come in handy. If there is some other trick I can try to remove the front crank bolt before I buy the tool, I'm all ears.



Pretty clean for the mileage as I keep saying.





Other thing I mentioned earlier, during disassembly I broke the "nipple" on the vacuum pump that connects to the hose (honestly it was so aged and brittle, maybe it's a good thing it gave out now?). I found some of the vacuum pumps online, but at $300+. Does anyone know if I can just replace the top "cover" that contains the "nipple" instead of replacing the entire vacuum pump unit? Don't really see the need to replace the whole assembly.



This is where the block stands now, just have to remove the oil cooler and a few other bits, but very close to being a bare block.



 
Joined
Apr 27, 2003
Location
Stafford Virginia 22556
TDI
96 glx variant tdi
Copy the bolt pattern for the 4 sprocket to crank bolts, 3 in" piece of flat stock about 18" long and make your own holding device. Those bolts are tight suckers. No impact guns, I've seen pictures of the crank breaking from that.
 

vwishndaetr

Veteran Member
Joined
Aug 1, 2010
Location
WNC
TDI
98 Jetta
Copy the bolt pattern for the 4 sprocket to crank bolts, 3 in" piece of flat stock about 18" long and make your own holding device. Those bolts are tight suckers. No impact guns, I've seen pictures of the crank breaking from that.
I like your thinking. I wonder how a 2x4 will hold up. I don't have the metal stock to do it otherwise.
 
Joined
Apr 27, 2003
Location
Stafford Virginia 22556
TDI
96 glx variant tdi
I don't think a 2x4 will hold up to that twisty action. You will probably have to wedge the holding bar against the floor or something sturdy and watch you don't tip the engine stand over.
 

vwishndaetr

Veteran Member
Joined
Aug 1, 2010
Location
WNC
TDI
98 Jetta
I don't think a 2x4 will hold up to that twisty action. You will probably have to wedge the holding bar against the floor or something sturdy and watch you don't tip the engine stand over.
Ya it broke. I don't have the material to make what I need, just going to buy the tool and call it a day. It would be nice if it was the same pattern for modern EA888 2.0Ts since I'll need it for timing chain service anyways - that's coming up.

Once again, for science, I kept tearing into the block yesterday.



The condition of the head gasket was good. The block and head also looked good. Don't see any cracks or pitting or anything like that with the naked eye, so glad to know I have a solid base. This all jives with numbers I got when I did the compression test a few months back. Probably wasting my time/money pulling the head off all things considered but oh well.

Cylinder 1



Cylinder 2



Cylinder 3



Cylinder 4



The head.



Cylinders 1, 2



Cylinder 3, 4



Gasket (cylinder head side)



Cyilinder 1, 2 close-up



Cylinder 3, 4 close-up



Initially I thought I had a leak in the head gasket between the oil and coolant ports considering the "wetness" present, but the oil didn't really show any signs of coolant present, and vice versa (before the teardown the car ran fine too). So if anything I think it some "spilled" out of the oil port in the head when I was lifting it off the block. Not sure what everyone else thinks. I would expect some discoloration between the two ports if there was in fact a more long-term leak. Or maybe I'm wrong.

There was a substantial coolant leak from the front rad hose, along with some paste (hack repair) and it would not surprise me if the previous owner overheated the engine at some point, but I would expect much worse if that was the case. Moot point at this point I guess.





No questions at this point... I'm going to keep cracking into this. Maybe today I'll pull the pan off and take a look at the bottom end.
 

vwishndaetr

Veteran Member
Joined
Aug 1, 2010
Location
WNC
TDI
98 Jetta
Forgot I pulled out the injectors to inspect them too. The previous owner said they're upgraded nozzles and "she rolls coal" so it would help to know what I have.

I pulled them out and made a note of the markings. I'm just getting what appears to be standard VW part numbers, so I am guessing they're OE injectors with upgraded nozzles if they're upgraded? But I am guessing I cannot see the nozzles unless I take them out... and even then, would there be any markings left? I don't want to bust these guys up.







Markings on injectors.

 
Last edited:

Abacus

That helpful B4 guy
Joined
Nov 10, 2007
Location
Relocated from Maine to Dewey, AZ
TDI
Only the B4V left
You have to disassemble them to find out what the nozzles are. The markings are on the end that’s underneath the injector body itself.

If you want to find out what they are my recommendation is to put the injector in a vise facing up, unscrew the top of it and lift it straight up, then remove the injector nozzle itself. If the injector comes apart and you get the orientation wrong they won’t work.
 

vwishndaetr

Veteran Member
Joined
Aug 1, 2010
Location
WNC
TDI
98 Jetta
You have to disassemble them to find out what the nozzles are. The markings are on the end that’s underneath the injector body itself.

If you want to find out what they are my recommendation is to put the injector in a vise facing up, unscrew the top of it and lift it straight up, then remove the injector nozzle itself. If the injector comes apart and you get the orientation wrong they won’t work.
I'm assuming I hold it by the flat on the injector body and then remove the nozzle by undoing the nut closest to the nozzle? Any harm in using PB blaster on the injectors/nozzles? I'll likely have them sent out/cleaned before the re-install so I assume that's fine.
 

ToddA1

Top Post Dawg
Joined
Aug 3, 2011
Location
NJ 08002
TDI
'96 B4V, '97 B4 (sold), '97 Jetta (scrapped)
I’ve made a crank holder that chocks itself against the block. I’ve also just pulled the pan and put a chunk of 2x4 between the first counterweight and block. Both worked fine.

-Todd
 

vwishndaetr

Veteran Member
Joined
Aug 1, 2010
Location
WNC
TDI
98 Jetta
I’ve made a crank holder that chocks itself against the block. I’ve also just pulled the pan and put a chunk of 2x4 between the first counterweight and block. Both worked fine.

-Todd
I ended up just getting the tool from idparts. Was $60ish shipped so not too bad. I took the lazy route this time. 😬
 

vwishndaetr

Veteran Member
Joined
Aug 1, 2010
Location
WNC
TDI
98 Jetta
Firstly, huge thanks to @G60ING for organizing all the threads into the initial post of THIS THREAD.

I literally went through every thread in the initial post and ready everything (well, like 90%). A lot of unknowns were answered, and I can confidently say I have a pretty good understanding of my direction.

I came into my build thread not really knowing what I wanted and arbitrarily set on some vague hp number. Truth be told I've learned that there are more important things that could affect the experience that go beyond hp numbers.

I have maybe one or two things to verify on my current AHU (need to verify nozzles) to know exactly what direction I'm going. This paired with all the info captured in the threads I've skimmed, I have the following takeaways:
  • 11mm injection pump is completely unnecessary unless my setup requires fuel in excess of what the 10mm pump can deliver
  • k03/k04 hybrid has marginal gains over the stock turbo, and is really only justified if the stock turbo needs to be replaced (ie. not worth the $$$ if the stock turbo has plenty of life left)
  • VNT setups seem to be most ideal considering the boost it provides across a broader rev range (ie. less lag at lower rpm ranges and still plentiful boost at upper rpm ranges)
  • Unless doing "heavier tuning" bottom end is pretty robust and there is no need to upgrade crank/pistons/rods, etc.
  • Flow of head and intake are a bottleneck (BUT, modifying these usually isn't justified considering other hp gains that can be done for less $$)
Taking all this (and then some) in, I'm going to do a wee bit more digging to see how I want to approach this. I always liked the idea of really going all out on the TDI, but in the end, it's a dog of a platform compared to modern engines so money might be better spent on the EA888 when it comes down to getting silly.

I can say that for me, I am still chasing 50mpg, I will be doing an 80mi/day round trip commute once on the road, and I want decent drivability (OEM clutches). I think I will look more into the VNT setups since they appeal most to me in terms of power delivery and fuel economy, but I haven't decided yet.

My questions: I have decided on stock internals for the bottom end and head- what can I do while everything is apart to comfortably say I have a fresh "0 mile" unit. I understand 225k will never be 0k, but I am about 8 nuts away from replacing main bearings and maybe another 8 from doing valve guides/seals.

What supplemental machining and/or inspections are associated with the following so it's done right?
  • re-ringing pistons
    • is honing of the block required?
  • replacing valve stem seals/guides
    • Valve stem inspection?
    • Any attention to valve seat when rebuilding to OEM spec?
    • Any inspection to lifters?
  • replacing main/rod bearings
    • any re-work of crank required?
 

Phi1osopher

Veteran Member
Joined
Jul 31, 2019
Location
Austin, TX
TDI
'96 B4V TDI Passat Wagon
I just want to chime it, having just replaced my timing belt, that you really really really will want to have the alignment tools for reassembly. In the very least a correct pin for the injection pump, a cam locking tool, and something to hold the pulleys in place to torque all the things. I have done many, many timing belts over the years as a professional mechanic, and am don't think the head can be reassembled with correct timing without the special tools. Also, add a cheap $180 camshaft and tappets to your list for when you reassemble, as yours are almost certainly worn enough to benefit from fresh ones.
 

vwishndaetr

Veteran Member
Joined
Aug 1, 2010
Location
WNC
TDI
98 Jetta
I just want to chime it, having just replaced my timing belt, that you really really really will want to have the alignment tools for reassembly. In the very least a correct pin for the injection pump, a cam locking tool, and something to hold the pulleys in place to torque all the things. I have done many, many timing belts over the years as a professional mechanic, and am don't think the head can be reassembled with correct timing without the special tools. Also, add a cheap $180 camshaft and tappets to your list for when you reassemble, as yours are almost certainly worn enough to benefit from fresh ones.
Yes I will source those. I've been been looking at some of the kits online that include all the locking tools needed.

What are tappets? We talking about the lifters?
 

ToddA1

Top Post Dawg
Joined
Aug 3, 2011
Location
NJ 08002
TDI
'96 B4V, '97 B4 (sold), '97 Jetta (scrapped)
I own the tools, but you can get by without them. A deep socket works as the pin and a door hinge will suffice as the cam lock. Vince Waldon, did a great write up that helped me with my first IDI, maybe 15 years ago,

-Todd
 

vwishndaetr

Veteran Member
Joined
Aug 1, 2010
Location
WNC
TDI
98 Jetta
My counter-hold tool came in, and let me say I don't regret the $67 it cost me... Bought it from idparts.

I had the front crank bolt loosened in about 30 seconds. Always appreciate when "the right tool for the job" does what's intended.



Got the timing gear off, and inspected the front crank seal - no sign of leaks. Not that it matters, but I like to look for these things. All the crud came from further up the block.



With those out, I finally got all the moving parts out of the block.







And a couple pics of the shaft that drives the vacuum and oil pump because science.




I didn't spend too much time inspecting parts yesterday since it was late. I have some measuring tools that came in as well - picked up a bore gage and some micrometers so I can start checking my parts to see what is in spec and good versus what needs to be addressed. Also picked up a valve spring compressor which should be in this week so I can start disassembling the head for inspection. Stay tuned.
 

vwishndaetr

Veteran Member
Joined
Aug 1, 2010
Location
WNC
TDI
98 Jetta
I could probably make you one for a few hundred dollars. lol
I'm good actually. I had some ideas around one but have since moved on. Not really necessary anymore. Thanks though.

Damn TDI club used to be populated by intelligent members...seems like there has been a collective loss of IQ....Covid Brain?
Got some feedback for me? I'm all ears.
 

vwishndaetr

Veteran Member
Joined
Aug 1, 2010
Location
WNC
TDI
98 Jetta
Any updates?
Not at this moment, at least not on the car, but I will soon! Once again, house renos have been a priority over the car unfortunately. Additionally, I've been trying to get some of the other items all organized and situated in the garage to make room for a MaxJax lift! :)

I should have a break from house stuff soon and I made a promise to myself not to give up on this so update coming soon hopefully!
 
Top