Where to stop?

andy2

Veteran Member
Joined
Sep 24, 2004
Location
Bowmanville,Ontario,Canada
TDI
13 Jetta,94 Golf drag car 585bhp,Samurai buggy BHW 300bhp,97 Ram cummins
My mistake.I was meaning to suggest using a gtb2260vk as the LP turbo when combined with the current HP turbo. Sorry for the confusion :)
 

andy2

Veteran Member
Joined
Sep 24, 2004
Location
Bowmanville,Ontario,Canada
TDI
13 Jetta,94 Golf drag car 585bhp,Samurai buggy BHW 300bhp,97 Ram cummins
Also in terms of transient response I was meaning to refer to between stages.

I'll have to make a video of both boost readings on my daily driver.Once the oil is up to operating temperature both turbo's should follow each other if looking for a responsive daily driver compound setup.

Between stage boost should be ideally half of what intake manifold pressure is at all times.
 

FRtdilover

Well-known member
Joined
Nov 4, 2015
Location
europe
TDI
2001 4motion ARL 150
Andy2, you made me meditate since you wrote this as I never seen a double vnt compound.
Do you have an example to help me to figure out how it could work ?
Two vnt vanes to regulate in parallel isn't too hard to drive for the N75 ?
Something like gtc1549 with 2260vk could have an awesome trancience response for the power it could make

Edit: sorry I didn't see your last reply
 
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Fix_Until_Broke

Top Post Dawg
Joined
Aug 8, 2004
Location
Menomonee Falls, Wisconsin, USA
TDI
03 Jetta, 03 TT TDI
I put a compound gauge on the LP Compressor and moved the LP Exhaust to the green needle on the 50 psi dual gauge and drove it around today.

The short summary is that the 0-50 psi Hewitt Industries gauge that I'm running is damaged on the Red needle (positive offset and I think there's a slope issue as well) and there may be a slight negative offset on the green needle - so any conclusions/comments that I've made regarding the sizing of the two turbos should be promptly ignored.

There is not a vacuum on the HP inlet, but when you're into the boost and let off the throttle the LP boost will rise 2-3 psi as the vanes open and you really need to get into it to get the LP boost up over a couple psi.

I'm going to pull all the gauges out, connect them together and correlate them to a known reference at a few different pressures before making any "big" decisions on the setup.
 

GOFAST

Well-known member
Joined
Oct 1, 2014
Location
nederland
TDI
vento afn
I put a compound gauge on the LP Compressor and moved the LP Exhaust to the green needle on the 50 psi dual gauge and drove it around today.

The short summary is that the 0-50 psi Hewitt Industries gauge that I'm running is damaged on the Red needle (positive offset and I think there's a slope issue as well) and there may be a slight negative offset on the green needle .
how come it's damaged ?(EGT?)
and do you use motor oil in the tube from exhaust to gauge ?
 

Fix_Until_Broke

Top Post Dawg
Joined
Aug 8, 2004
Location
Menomonee Falls, Wisconsin, USA
TDI
03 Jetta, 03 TT TDI
Well, I've got ~20k miles on the compound turbo setup and have run into my first issue with it. Anytime you start doing things non-factory, you run the risk of something failing that you build/did/asembled, etc.

I had an instance about a month ago where the engine wouldn't crank over when you turned the key. The first attempt it would just barely engage the starter then nothing. No click of the starter, just the little relays that engage/disengage when you turn the key from run to crank. I did notice a bit of a burning plastic smell, but couldn't find anything amiss

I opened the hood, rummaged my hand down by the starter a couple times and it finally started when I hit the key. I knew I should have looked into it a bit more (at all...) and knew it would come back and bite me because I didn't fix anything :). Today it happened twice while out running errands - same thing. One thing I noticed was that the -6 braided stainless hose from the oil filter housing to the turbos was warm when I grabbed it. I didn't think much of it since the oil was warm, but this was a clue. The hose ran in a big arc from the front of the engine to the back and I didn't take enough care to look at where it contacted.

So I dug into it today and found that the braided oil hose was arcing/shorting out on the trans mount bolt and one of the brake lines off the master cylinder/abs module. Luckly I didn't drive a long way because at the brake line, the hose was leaking a decent stream of oil when the engine was running.

I'll end up replacing the hose, but have temporarily put a tube splice in and have isolated the hose so it doesn't touch any more, but I still have not figured out why this hose was looking for ground when the starter is engaged? The main engine ground from the upper transmission/block bolt to the battery is solid, looks good, etc. I looked around for other chafed wires - specifically the starter solenoid wire, but didn't see any.

We're not done with this yet - Any thoughts/ideas are welcomed.










There was also a significant groove worn in the brake booster diaphragm cover from the hose. No significant wear on the hose - that stuff is tough!

 

[486]

Top Post Dawg
Joined
Mar 1, 2014
Location
MN
TDI
02 golf ALH
Give the ground cable from the engine to the body (and on to the battery negative) a good hard yank, bet it comes apart.
 

Fix_Until_Broke

Top Post Dawg
Joined
Aug 8, 2004
Location
Menomonee Falls, Wisconsin, USA
TDI
03 Jetta, 03 TT TDI
Good idea - Did that on both ends and it didn't come apart.

I'm going to look a bit closer at the starter solenoid wiring, maybe pull the battery/tray out . The more I think about it, the more sense it makes that it has to be something in that circuit. It started at -10F just a few weeks ago and cranked over nice and strong. It wouldn't do that grounding through incidental contact on a braided hose.
 

Fix_Until_Broke

Top Post Dawg
Joined
Aug 8, 2004
Location
Menomonee Falls, Wisconsin, USA
TDI
03 Jetta, 03 TT TDI
Not a lot - maybe 175 or so? Have not had it on the dyno since the twins went on, nor have I done anything with the tuning/fuel delivery. Just keeping it running for the last few years while I finish my Roadmaster/Duramax project.
 

Fix_Until_Broke

Top Post Dawg
Joined
Aug 8, 2004
Location
Menomonee Falls, Wisconsin, USA
TDI
03 Jetta, 03 TT TDI
I pulled the battery out

Removed the ground wire from the block - still good
Followed the braided hose from one end to the other looking at anything even close to touching it - didn't see anything
Inspected the starter solenoid wire from the starter until it goes into the bundle behind the battery - no signs of damage

Still have not found/fixed what's causing it to occasionally not start :(
 

[486]

Top Post Dawg
Joined
Mar 1, 2014
Location
MN
TDI
02 golf ALH
Good idea - Did that on both ends and it didn't come apart.

I'm going to look a bit closer at the starter solenoid wiring, maybe pull the battery/tray out . The more I think about it, the more sense it makes that it has to be something in that circuit. It started at -10F just a few weeks ago and cranked over nice and strong. It wouldn't do that grounding through incidental contact on a braided hose.
Only time the engine sees a lot of potential above the chassis is when cranking, for the oil feed to arc to the chassis it needs to be ground side troubles, even if it isn't the cause of the no-crank (though there's a good chance that it is)

Same as engines burning off throttle cables. The starter ground side current's finding an easier path than through the wire.

ETA: best bet is under the battery tray, it goes bare where they crimped a flag terminal on to ground the chassis, this is where it flexes when the engine moves.
 

hugho

Active member
Joined
Feb 17, 2018
Location
NW wyoming
TDI
red 2002 vw Jetta wagon 250K miles, MT
when to stop?

My 03 Jetta has ~170k miles on it and has served me very well over the last 8 years, but it's starting to show it's age and need some work

Shocks/Struts/Mounts - Original and tired
Ball Joints - Loose
Tie-Rod Ends - Loose
Motor Mounts - vibrates and moves a lot
Headlights - really hazy
Antenna base - radio all fuzzy most of the time
Cabin Fan motor - makes noise when below ~10F

I figured I'd probably put springs in it while the suspension was apart.

By the time I'm done with all of the above I'll have ~$1500 and 2-3 full days in it.

I spent this last weekend doing my research and putting my parts lists together at various vendors, but have not ordered anything yet.

So, on my way home tonight from work, crusing along at ~50 MPH in 5th and go from 25% throttle to ~35% throttle and it accelerates normally for about a second and then stops accelerating....wierd....back off the throttle and get back into it and it accelerates but definately has a different "note" to the engine.

Pull into a parking lot under a light, white-ish smoke coming out the exhaust, engine running on 3 cylinders shaking like hell, remove the oil fill cap while the engine is running and a geyser of smokey mist shoots all the way to the hood and pushes my hand out of the way. Put the cap back on, close the hood and get back in the car. I'm 8 miles from home at this point - may as well go for it.

It was a calm night with minimal wind so the car looked like it was on fire at stoplights it was smoking so much - sounded like a WRX when taking off from the lights on 3 cylinders :).

Get it home, pull in the garage, rip it apart and find this in hole #3...


The bore looks spectacular in #3


There were some wierd marks on the cylinder walls of the other pistons as well - This is #2 - both sides of the bore. You can't feel anything in these areas, but it sure looks like the wristpin was sliding along the cylinder wall.



This is #4 - The rusty looking radial marks about halfway down the cylinder are in both #4 and #1.


They don't wipe off and you can't really feel them with your fingers at all - do the bores ever crack and seap water?

So, I need a piston at the minimum - most likely a set.
Stock ALH pistons? Coated? Deeper valve reliefs? Lower Compression?
May as well do rings and rod bearings as long as it's apart...
Do I put main bearings in?
Do I put aftermarket rods in?
There's really no cylinder wall damage - a few passes with a hone will clean it up (assuming there's no cracks or anything in it).
Should I pull the whole engine or try and do this "in car"?
Anything else I should do while it's apart?
Is it worth repairing?

Any thoughts as to why it cracked a piston? It's been a couple thousand miles since I pulled a trailer with it - it didn't run any differently before/after this, but it was definately a workout - sustained high loads and temps.

I would like to significantly improve the power in the 1000-2000 RPM range

Maybe I continue to look at new cars like I did a couple weeks ago...though I could do a lot to the Jetta with only a years worth of car payments....

So, back to the original question....Where do I stop?




I'll tell you when to stop. Stop towing with a little car. That's why God created Cummins pickups. Absolutely overheated it no doubt. Melted the piston. I personally believe in gauges on any powered up diesel unless you're just driving Miss Daisy. We have gauges on all our trucks and our TDI. I wouldn't rebuild. You have thermal damage in the whole motor. Find a good salvage yard TDI and pull the head. If it is pristine you're back on the road.
 

Exenos

Veteran Member
Joined
Apr 29, 2014
Location
Ontario
TDI
02 Golf
I'll tell you when to stop. Stop towing with a little car. That's why God created Cummins pickups. Absolutely overheated it no doubt. Melted the piston. I personally believe in gauges on any powered up diesel unless you're just driving Miss Daisy. We have gauges on all our trucks and our TDI. I wouldn't rebuild. You have thermal damage in the whole motor. Find a good salvage yard TDI and pull the head. If it is pristine you're back on the road.
Might wanna read the thread first, just sayin...
 

[486]

Top Post Dawg
Joined
Mar 1, 2014
Location
MN
TDI
02 golf ALH
I'll tell you when to stop. Stop towing with a little car. That's why God created Cummins pickups. Absolutely overheated it no doubt. Melted the piston. I personally believe in gauges on any powered up diesel unless you're just driving Miss Daisy. We have gauges on all our trucks and our TDI. I wouldn't rebuild. You have thermal damage in the whole motor. Find a good salvage yard TDI and pull the head. If it is pristine you're back on the road.
you joking? that ain't the least bit melted
crack also isn't even lined up with the injector nozzle holes (the hottest points on the bowl rim)
 

Fix_Until_Broke

Top Post Dawg
Joined
Aug 8, 2004
Location
Menomonee Falls, Wisconsin, USA
TDI
03 Jetta, 03 TT TDI
If you remember back up in post 503, I found this bolt on my skidplate - broken off my LP turbo mount.



Well, that was the start of a downhill slide...That broken bolt I think caused the other side of the bracket to fatigue and crack, which then caused the between turbo's exhaust pipe to fatigue and crack, which then also caused the downpipe to fatigue and crack. I had been getting a whiff of exhaust in the cabin on startup, but it kept getting worse, and then there was this hissing noise on boost. Figured I should check it out - poppet the hood, put my hand on the LP turbo and was a bit surprised that it moved - a lot!. The only thing holding it in place was the oil drain tube and the compressor connections (silicone). I pulled a few pieces out of the way, stuck the wire welder in there and goobered some weld on the exhaust pipe just for mechanical strength so I could get to the shop and exact a more permanent fix.

I don't have many pictures of the actual failures as I was too busy fixing it and forgot (sorry), but the below should illustrate well enough.





To repair the original bolt that failed required both turbos to come out so I could slide the intake manifold straight back off of what was left of the broken bolt to then remove it so not much extra work due to my procrastination, but extra things to weld up/fix.

Once I got it all welded up and put back together, take it for a test drive and it's better, but still sounds like someone is filling a tire with air when on boost. Do a bit more digging and find that the hose coming off the HP turbo had split.



This seemed like a good excuse to finally install the Darkside FMIC kit I've had for a year or so, but ran into issues with fitment so had to come up with plan C (maybe D?). Scrounged around and found the right size silicone elbow in my stash of stuff to fit the HP turbo outlet, then had to fab up a reducer/expander out of some scrap pieces of exhaust pipe to connect these two together.



Finally, no more hissing on boost, no more exhaust smell on startup and it's a lot more responsive than it used to be (imagine that!).
 
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Fix_Until_Broke

Top Post Dawg
Joined
Aug 8, 2004
Location
Menomonee Falls, Wisconsin, USA
TDI
03 Jetta, 03 TT TDI
Ok - I need some opinions from the masses (and probably some mental help :))...

It's been almost exactly 100,000 miles since this thread was started, car has 270k miles on it. It has been starting hard for the last month or so - Kind of like when it's cold, cranks for a revolution or two, then catches on 1-2 then finally all 4 cylinders and kind of stumbles to life. Before it would fire within 1/2 a rev and jump to life. I first noticed it when hot, then it started to happen when cold, it's not every single time, but most of the time.

Once it's running, it runs well, maybe a bit more smoke, lower AFR's and higher EGT's, but nothing dramatic. Wouldn't notice if you weren't paying attention.

- Injection timing is right where it should be, slightly advanced at idle
- Cam/Crank timing is where it should be, slightly advanced
- No signs of a head gasket leaking

Hmmm, how about a compression test...Hot engine, injection pump unplugged, all glow plugs out, All 4 cylinders level off at ~340 PSI. Well, crap. I have not specifically verified the gauge on the compression tester (it's in process), but have no reason to believe it's off by that much. Prior compression tests were in the upper 400's PSI.




I didn't pull the valve cover, but assume that the cam is likely fine
Blowby does not seem excessive at idle - not enough to be loosing that much in cranking compression.
Hard to believe that I would have kinked the Rosten rods
Doubt that I would have worn the rod bearings enough to drop compression ratio that much - no knocking
Could be the cylinder head/valve seats - strange that it would effect all 4 cylinders the same though and roughly at the same time.
One thought is the rings have worn? Once it's running the rings seal well enough, but at cranking speeds/pressures they just don't seal well enough?

I won't know anything for sure until I get it apart, but at this point I'm wondering if I should even start in again with this car? It's got some rust on the rear rocker panels, trunk lid, hood (rock chips), right rear door, and has a lot of little things that need fixing (headliner, door panels, door lock switches, etc).

I really like the MkiV platform - it fits me very well, it's comfortable, capable, etc. What other vehicle - at any price point - does what this one does?

I need a reliable daily driver (35 miles/day) that holds 4 passengers and can tow a 2000+lb trailer 250 miles, and I can't hate it like I did my 2013 Passat

BMW 335D is the only thing that comes to mind. I really want a Tesla, but the only one that can make the 250 mile drive without stopping is the 100kWh battery which the cheapest I've seen those at are ~$100k which is way out of my price range.

I can probably fix the Jetta for less than $1k and 2 weekends of work so my answer is probably right there. I'll have way more money and time in both buying a different car as well as selling/parting the Jetta out.

I'm interested in your thoughts. I'm an open book here so if there's questions, comments, criticisms, etc - let me have it and I'll do my best to answer and/or give them some thought.
 
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[486]

Top Post Dawg
Joined
Mar 1, 2014
Location
MN
TDI
02 golf ALH
That even loss of compression across all four makes me think that it is more likely the gauge than wear or broken parts. Even if you've boiled the coolant out and the rings lost tension, you'll still usually show a good amount of variance across the cylinders when there are problems.

I'd bet more on nozzles getting tired. Aftermarket nozzles are never as good as bosch, and they do certainly have a finite lifespan.
 

[486]

Top Post Dawg
Joined
Mar 1, 2014
Location
MN
TDI
02 golf ALH
Yes, I agree that the consistency is surprising. How would worn nozzles contribute to low compression?
No, hard starting because of worn nozzles.

'low' compression because the gauge got dropped or someone maxed it out, or you're using a longer hose on it than last time, or...
 

3L3M3NT

Veteran Member
Joined
Jun 16, 2008
Location
Sturgeon Bay, WI
TDI
04 Jetta GLS TDI, 04 RTDI
I had a hard starting issue in my Jetta and it ended up being the engine speed sensor. If it's not that it could possibly be the cam position sensor.

Either way hopefully you get it figured out and can keep your Jetta on the road, since it would be tough to see you part it out after you spent so much time on the hitch and everything else over the years on your car.
 

TDIMeister

Phd of TDIClub Enthusiast, Moderator at Large
Joined
May 1, 1999
Location
Canada
TDI
TDI
This is what happens when you have a have a PD engine and give advice on an ALH. :D
:)

@F_U_B. When cranking your engine, after it catches and fires, do the revs momentarily rise beyond what was usual before settling back down? How does the exhaust smoke look like at start-up and cold idle - anything out of the ordinary?
 

Fix_Until_Broke

Top Post Dawg
Joined
Aug 8, 2004
Location
Menomonee Falls, Wisconsin, USA
TDI
03 Jetta, 03 TT TDI
:)
@F_U_B. When cranking your engine, after it catches and fires, do the revs momentarily rise beyond what was usual before settling back down? How does the exhaust smoke look like at start-up and cold idle - anything out of the ordinary?
Before this issue it would fire up to maybe 1500 rpm and then settle in at 950 or so. Now it doesn’t overshoot at all and just works it’s way up to 950.

Haven’t noticed any smoke changes at startup hot or cold - it has always had a puff of startup smoke (grey) with the lower compression.

Will hopefully run a compression test again tonight with a calibrated gauge as well as verifying the function of the lift pump.
 

Fix_Until_Broke

Top Post Dawg
Joined
Aug 8, 2004
Location
Menomonee Falls, Wisconsin, USA
TDI
03 Jetta, 03 TT TDI
Ok - back to reality here - I bought another $30 Harbor Freight compression tester (couldn't find the adapter from the other one I bought...), checked the gauge itself on the deadweight tester and it's within 0.5 bar below 35 bar and is linear.

Re-did a compression test tonight
1 = 380 psi
2 = 400 psi
3 = 410 psi
4 = 400 psi
1 = 380 psi (repeat)

Looking at the above cranking compression chart (also with calibrated equipment), I was in the 460 psi range so not as bad as I originally thought (nothing ever is :)). Still not great numbers, but it does have 100k hard miles on it so not sure if this is "normal" wear or not. I don't have fears of significant internal damage/wear like I had a couple days ago.

I checked the lift pump and it's getting power and has a ground. With the cover off and cycling the key you can hear a click at the pump, but it used to have a submerged gurgling sound when the tank was low. That is what I didn't hear this morning before I filled up.

I had a gauge setup a year or so ago that tee'd in to the line between the filter and injection pump, but I can't find the tee. I have the gauge and the hose, but will need to find the tee to see if I'm getting the ~7 psi charge pressure I was getting before.

The nozzles R520's do have about 95k miles on them and the 11mm injection pump has ~170k miles on it so those could be getting tired as well.

Other than this hard starting issue, it runs fine, good power, etc.

Next steps:
-Get a pressure between the filter and lift pump

-Order timing belt kit and front wheel bearing - Repeat compression test with verified cam timing to see if compression numbers recover. Timing belt wear/stretch could reduce those numbers quite a bit, though 10+ degrees seems like a lot...

-Maybe pop-test the injectors to see if they've taken a set or are leaking from when I originally set them up (see picture below)

-Consider sending in a spare injection pump before winter

-Consider going back to a stock ALH cam (see cranking compression chart a few posts up).



Thanks to everyone for the help, advice, suggestions, etc - I really appreciate it. It's easy to get "lost" in the thick of things so the alternate viewpoints are really great.
 
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