Normal to hit 21mpg for an 03 alh tdi golf?

ecala001

Active member
Joined
Aug 17, 2020
Location
California
TDI
03 golf
I noticed when I put gas today, I was averaging 21mpg is this normal? I drive to work which is a 10 minute drive local streets and sometimes the engine doesnt go to full operating temp. Wonder if that's the main culprit.
I recently did the timing and vagcom shows a tad bit over the green line too.

Stock
01m auto
Drive casually
 
Last edited:

Mozambiquer

Veteran Member
Joined
Mar 21, 2015
Location
Versailles Missouri
TDI
1998 VW Jetta TDI. 1982 VW Rabbit pickup, 2001 VW Jetta TDI
I noticed when I put gas today, I was averaging 21mpg is this normal? I drive to work which is a 10 minute drive local streets and sometimes the engine doesnt go to full operating temp. Wonder if that's the main culprit.
I recently did the timing and vagcom shows a tad bit over the green line too.
Manual or automatic? What's your driving habits like? Is the car stock or tuned?
That seems quite low. Do you have any codes?
 

ecala001

Active member
Joined
Aug 17, 2020
Location
California
TDI
03 golf
Will being over the green line in vagcom affect gas mileage?
I also have a cargo rack I just put just yesterday but I was already at 40 something miles. About 15 to 20 miles are with the cargo rack.

Even then I was hauling 2 kayaks and full car and was averaging 33mpg.
 

ecala001

Active member
Joined
Aug 17, 2020
Location
California
TDI
03 golf
Ok, that is not so far off for an auto, especially in town. I'd set the timing, then plan to manual swap it. ?
Lol yeah I was planning to do a swap in the future. Was thinking of getting the transmission from the junkyard of just a damaged body alh TDI here and grab all the parts for it
 

jettawreck

Top Post Dawg
Joined
Aug 2, 2004
Location
Northern Minnesota-55744
TDI
2001 Jetta and 2003 Jetta
Timing is fine marginal over the line (advanced?) and better than being below (retarded). I've never had the auto versions but even towing a snowmobile or ATV I've been in the mid/upper 30's.
I can get 20 with the Dodge Caravan 3.8 driving back and forth and around town.
Brakes dragging, wheel bearing(s), fuel leak(s), etc. Something isn't right.
 

Tdijarhead

Top Post Dawg
Joined
Nov 10, 2013
Location
Lawrenceville PA
TDI
2003 TDI Jetta Daughters Car, 2001 TDI Beetle, Daughters car, 2005 Golf TDI Mine, all 5 spds
The worst I ever got with my 01m was 32mph in the dead of winter, but I don’t drive around town and rarely do short drives.
 

mannytranny

Top Post Dawg
Joined
Oct 14, 2003
Location
CA
TDI
02 Jetta
Your thermostat is stuck open, change it. This should be done on every car at 100k or less, usually less.
 

Franko6

Vendor , w/Business number
Joined
May 7, 2005
Location
Sw Missouri
TDI
Jetta, 99, Silver`
There are several good examples in the posts why your vehicle is getting poor economy. Other examples are: slipping flywheel lockup in top gear. At around 65mph, the transmissions final drive, the valve body is supposed to lock the torque converter 1:1. If you have VCDS and measure the top gear slippage at 65 mph, and there is more than 30 rpm, your going to toast the tranny and it will stop working altogether.

The Thermostat is a sensitive issue. We always check thermostats prior to install and most important, we make sure it's a good make. Recently, we rebuilt an overheated BRM. The #1 culprit was a Chinese thermostat that didn't open completely until the temp was 212 degrees. All thermostats should be checked prior to install to make sure that on closing, it is cracked open just a smidge at 185 degrees.

The single most likely contributing factor are injector nozzles that are properly set. As we have been accustomed to saying about gasser engines, "No matter how well you build an engine, it won't run without spark plugs." A diesel engine will not run well unless injectors are properly flow rated.

If you don't have injectors that are set well, overfueling will ruin economy and also ruin pistons. Unlike the gassers, too much fuel means pistons that can get melting hot or in performance engines, crack.

We check injectors against VCDS. First, we like the injection timing in the middle of the graph. All fans, A/C, radio and lights should be off for all settings.

We take timed runs; 3rd gear, starting at 35 mph, going to WOT (wide open throttle). When the speedometer hits 40mph, count 3 seconds (stop watch is on almost every cell phone) and make note of speedometer reading. If you start with the I.Q (injection quantity) on a low enough number that the injectors smoke, then raise the I.Q. by doing a 'Hammer Mod', raising the I.Q. point by point until you lose performance. I.E., if raising the IQ too much creates a reduction in speed at 3 second count, revert to the previous I.Q. setting. That will optimize your fueling.

Then, with timing set and IQ set, you can examine the VCDS/ engine module/ Block 13 Idle balance, and Block 15 liter per hour fuel economy (FE).

At idle, the Idle balance numbers should be within .5 mg/ str, or better, .2mg/ str. A good FE number would be between .2 lph to .4 lph(Liter Per Hour). Record your VCDS results. Then, raise the throttle position to 1575 rpm. In order to maintain engine speed, place a proper length stick between the fuel pedal and front of the seat to precisely set rpm. Please lock e-brake.

Now, record the block 13 and block 15 readings. Most commonly, the idle balance will vary substantially from idle, if injectors have not been set for flow rate. FE in block 15 should be on average, 1.8-2.4. Since the second stage on the injectors is now required in order to make the engine run at that speed, (At 1600rpm, the idle balance program is shut down in the ECU. The idle balance numbers will freeze), You can get the flow rating between injectors at this higher engine speed. Since this is where the engine spends almost all its time, getting the block 13 and 15 numbers optimized at 1575rpm, creates best driving results.

At 1575rpm, a negative number for any cylinder in idle balance means less fuel in entering the combustion chamber. Conversely, a positive number means that cylinder is receiving more fuel. The objective it to get each cylinder to get the same fueling by altering the shimming for the top stage. Performing the proper flow per cylinder not only creates overall power improvements, but also FE improvements.

This method of vehicle-tested nozzles is how we set flow rate for our injectors. Instead of emulations, we get actual operation parameters. To give you some idea, for my own nozzles in a 2002 ALH, our most recent tank of fuel, running P764 nozzles(.230um), with Stage II cam, ported head and Stage 4 Rocketchip tune, and driven an average 75-80 mph, we achieved 46 mpg. Yes, we could get better FE if we could just slow down...oh well.
 
Last edited:

ecala001

Active member
Joined
Aug 17, 2020
Location
California
TDI
03 golf
There are several good examples in the posts why your vehicle is getting poor economy. Other examples are: slipping flywheel lockup in top gear. At around 65mph, the transmissions final drive, the valve body is supposed to lock the torque converter 1:1. If you have VCDS and measure the top gear slippage at 65 mph, and there is more than 30 rpm, your going to toast the tranny and it will stop working altogether.

The Thermostat is a sensitive issue. We always check thermostats prior to install and most important, we make sure it's a good make. Recently, we rebuilt an overheated BRM. The #1 culprit was a Chinese thermostat that didn't open completely until the temp was 212 degrees. All thermostats should be checked prior to install to make sure that on closing, it is cracked open just a smidge at 185 degrees.

The single most likely contributing factor are injector nozzles that are properly set. As we have been accustomed to saying about gasser engines, "No matter how well you build an engine, it won't run without spark plugs." A diesel engine will not run well unless injectors are properly flow rated.

If you don't have injectors that are set well, overfueling will ruin economy and also ruin pistons. Unlike the gassers, too much fuel means pistons that can get melting hot or in performance engines, crack.

We check injectors against VCDS. First, we like the injection timing in the middle of the graph. All fans, A/C, radio and lights should be off for all settings.

We take timed runs; 3rd gear, starting at 35 mph, going to WOT (wide open throttle). When the speedometer hits 40mph, count 3 seconds (stop watch is on almost every cell phone) and make note of speedometer reading. If you start with the I.Q (injection quantity) on a low enough number that the injectors smoke, then raise the I.Q. by doing a 'Hammer Mod', raising the I.Q. point by point until you lose performance. I.E., if raising the IQ too much creates a reduction in speed at 3 second count, revert to the previous I.Q. setting. That will optimize your fueling.

Then, with timing set and IQ set, you can examine the VCDS/ engine module/ Block 13 Idle balance, and Block 15 liter per hour fuel economy (FE).

At idle, the Idle balance numbers should be within .5 mg/ str, or better, .2mg/ str. A good FE number would be between .2 lph to .4 lph(Liter Per Hour). Record your VCDS results. Then, raise the throttle position to 1575 rpm. In order to maintain engine speed, place a proper length stick between the fuel pedal and front of the seat to precisely set rpm. Please lock e-brake.

Now, record the block 13 and block 15 readings. Most commonly, the idle balance will vary substantially from idle, if injectors have not been set for flow rate. FE in block 15 should be on average, 1.8-2.4. Since the second stage on the injectors is now required in order to make the engine run at that speed, (At 1600rpm, the idle balance program is shut down in the ECU. The idle balance numbers will freeze), You can get the flow rating between injectors at this higher engine speed. Since this is where the engine spends almost all its time, getting the block 13 and 15 numbers optimized at 1575rpm, creates best driving results.

At 1575rpm, a negative number for any cylinder in idle balance means less fuel in entering the combustion chamber. Conversely, a positive number means that cylinder is receiving more fuel. The objective it to get each cylinder to get the same fueling by altering the shimming for the top stage. Performing the proper flow per cylinder not only creates overall power improvements, but also FE improvements.

This method of vehicle-tested nozzles is how we set flow rate for our injectors. Instead of emulations, we get actual operation parameters. To give you some idea, for my own nozzles in a 2002 ALH, our most recent tank of fuel, running P764 nozzles(.230um), with Stage II cam, ported head and Stage 4 Rocketchip tune, and driven an average 75-80 mph, we achieved 46 mpg. Yes, we could get better FE if we could just slow down...oh well.
thank you for the awesome write-up!

a few things I had I mind regarding your post.
post.
- I had already changed thermostat about 5k ago. engine is cold till I almost reach work. 10 min drive local.
-at 65mph I'm around 2200 to 2500rpm. only hits 3k around 80mph

I'm planning to upgrade my nozzles to .205 first then I will do a tune once I have the funds.

there a local diesel injection service in town that specializes in diesels especially tdi which I may go to to get the nozzles properly calibrated and tested.

will I still need to run the vcds method if I take the new nozzles to my local diesel injection shop to have them tested and such?
 

Franko6

Vendor , w/Business number
Joined
May 7, 2005
Location
Sw Missouri
TDI
Jetta, 99, Silver`
To give you an idea about thermostats, we just rebuilt a warped cylinder head and resurfaced the block to correct from the overheat caused by a recently installed, cheap Chinese thermostat. The reason the owner did not see the problem; the temperature gauge is a liar. From 175 degrees to 210 degrees, the gauge of the dash does not work correctly (assuming everything except a few vehicles that have idiot lights). So, the constant overheat made about $3800 worth of work on the engine. Quality parts pay their own way.

The moral of the story: 1. Always check a thermostat's accuracy by boiling in a water bath before you install it. You need to see when it opens and when it reaches wide open temp. 2. Purchase a quality brand.

In your case, it appears you have a thermostat that opens way too soon or is stuck open. That will make an engine very cold-blooded.

If you want .205 nozzles and want them installed the way we install, we have the nozzles and will install, calibrate and flow test the nozzles. Send them. I'd rather represent our own product and methods than let someone charge you more for our great ideas.

Here's the thing. First off, most shops aren't going to have a 'test car' to install your injectors, or are they going to want to spend the time doing any swapping of injectors in and out of a car. As for me, I don't think you will find anyone who can swap out injectors more efficiently than me. Then, by testing for fuel balance the way I do, the advantages are obvious, especially after you've had a chance to drive them.

As for a tune, the .205's are a small improvement in fueling, but a tune can get more economy and performance. We do have tunes that are perfect for your ALH car. We provide a Stage 1 or Stage 2 tune that should meet with your needs. We need to know what the last 2 Alpha characters on your ECU, so we can match the version of ECU. Then, we offer a 'test drive'. You pay a core fee for the ECU and install the tune. Drive it... You like it? Return your old ECU for the core refund.

If you don't like it, return the tuned ECU for a refund. We refund all money except the shipping charges. OK? The advantages of working this way, is no down time on your car.
 

ecala001

Active member
Joined
Aug 17, 2020
Location
California
TDI
03 golf
To give you an idea about thermostats, we just rebuilt a warped cylinder head and resurfaced the block to correct from the overheat caused by a recently installed, cheap Chinese thermostat. The reason the owner did not see the problem; the temperature gauge is a liar. From 175 degrees to 210 degrees, the gauge of the dash does not work correctly (assuming everything except a few vehicles that have idiot lights). So, the constant overheat made about $3800 worth of work on the engine. Quality parts pay their own way.

The moral of the story: 1. Always check a thermostat's accuracy by boiling in a water bath before you install it. You need to see when it opens and when it reaches wide open temp. 2. Purchase a quality brand.

In your case, it appears you have a thermostat that opens way too soon or is stuck open. That will make an engine very cold-blooded.

If you want .205 nozzles and want them installed the way we install, we have the nozzles and will install, calibrate and flow test the nozzles. Send them. I'd rather represent our own product and methods than let someone charge you more for our great ideas.

Here's the thing. First off, most shops aren't going to have a 'test car' to install your injectors, or are they going to want to spend the time doing any swapping of injectors in and out of a car. As for me, I don't think you will find anyone who can swap out injectors more efficiently than me. Then, by testing for fuel balance the way I do, the advantages are obvious, especially after you've had a chance to drive them.

As for a tune, the .205's are a small improvement in fueling, but a tune can get more economy and performance. We do have tunes that are perfect for your ALH car. We provide a Stage 1 or Stage 2 tune that should meet with your needs. We need to know what the last 2 Alpha characters on your ECU, so we can match the version of ECU. Then, we offer a 'test drive'. You pay a core fee for the ECU and install the tune. Drive it... You like it? Return your old ECU for the core refund.

If you don't like it, return the tuned ECU for a refund. We refund all money except the shipping charges. OK? The advantages of working this way, is no down time on your car.
also the thermostat I got was from oreily the murray brand. not sure if I should replace it with a better one. also work is about 10 minutes away and I go to work at 6am when it's about 50degrees. Gets to operating temp when I'm around 8 minutes driving. this means its stuck open right?


PM'd you regarding tune and nozzles
 

Franko6

Vendor , w/Business number
Joined
May 7, 2005
Location
Sw Missouri
TDI
Jetta, 99, Silver`
Not unlikely... We prefer two brands. Wahler or Borg Warner. Even then, we check each before selling one. I know... it's just something we do. Last set of Borgs, every one was perfect. We always carry them on the shelf, and because the housing can be a bit tricky, we sell that with the oring.

What you get from O'Reilly's is Chinesium, almost all the time.
 

Franko6

Vendor , w/Business number
Joined
May 7, 2005
Location
Sw Missouri
TDI
Jetta, 99, Silver`
Seriously, even the worst of thermostats wouldn't cause 21 mpg, in my opinion. Maybe you should check for wet spots.

One of the more common issues is the fuel filter. Once again, the CRAP filters will cost you in the long run. The thermostatic Tee on a good filter (Mann, Bosch, Mahle) the Tee opening has a radius going down into the hole. The CRAP will be square going into the hole, tearing the double seals on the Thermostatic Tee.

Btw: What is a giveaway for a good filter if they bother to put in good thermostatic Tee seals. They will have one blue and one black seal Why? Why? I dunno for sure... that's the way I find them. Put the black seal in the lower groove and then the blue one rolls over the lower seal into the higher position. I think the reason is the upper seal is NBR Nitrile butiedine rubber, is because it's impervious to diesel or oil, also to WVO. The lower seal is the cheaper Butyl rubber, which just keeps the unit from tilting in the hole. Blue ring on top.

But do I really know? Just guessing, but everybody knows... blue on top. If the top of your filter is wet, maybe you need to get a good one. We just happen to have goodun's.
 

ecala001

Active member
Joined
Aug 17, 2020
Location
California
TDI
03 golf
Seriously, even the worst of thermostats wouldn't cause 21 mpg, in my opinion. Maybe you should check for wet spots.

One of the more common issues is the fuel filter. Once again, the CRAP filters will cost you in the long run. The thermostatic Tee on a good filter (Mann, Bosch, Mahle) the Tee opening has a radius going down into the hole. The CRAP will be square going into the hole, tearing the double seals on the Thermostatic Tee.

Btw: What is a giveaway for a good filter if they bother to put in good thermostatic Tee seals. They will have one blue and one black seal Why? Why? I dunno for sure... that's the way I find them. Put the black seal in the lower groove and then the blue one rolls over the lower seal into the higher position. I think the reason is the upper seal is NBR Nitrile butiedine rubber, is because it's impervious to diesel or oil, also to WVO. The lower seal is the cheaper Butyl rubber, which just keeps the unit from tilting in the hole. Blue ring on top.

But do I really know? Just guessing, but everybody knows... blue on top. If the top of your filter is wet, maybe you need to get a good one. We just happen to have goodun's.
I have a Mahler fuel filter I replaced about 5k ago. did the timing and showed between blue and green line on vcds.

I also forgot to mention I have oem arristos 17s and have a yakima space cadet cargo box. i think that may be a big factor. on highway I get 33mpg though
 

ecala001

Active member
Joined
Aug 17, 2020
Location
California
TDI
03 golf
I also may have a bad wheel bearing on left side as it makes a weird noise when driving. like a growling noise and goes away when I turn to the right. no sure if this affects mpg too
 

Franko6

Vendor , w/Business number
Joined
May 7, 2005
Location
Sw Missouri
TDI
Jetta, 99, Silver`
The bearing sure doesn't help mileage, but it's not going to drag fuel economy down that much. It's fairly easy to determine which bearing is bad. Most often, if you turn right and it's louder, the left wheel bearing is bad and vice versa. The best way is to raise the front wheels off the ground and grab the top and bottom of the wheel and rock the wheel. If it moves on the hub, the bearings are shot. Also, you can hear the rough noise of the bearing as you turn the wheel.

We have tooling to replace the bearing without removing the steering knuckle from the vehicle. Ebay has a wheel bearing press set for about $50. There are several 'How To's' on YouTube. Otherwise, you remove the knuckle and the bearings are pressed out and in on a 20t press. There is a bearing race that stays on the rotor hub. We cut them off with an acetylene torch (not for the faint of heart or unpracticed). Or you can use a cutoff wheel and hammer the cut with a cold chisel to crack the race. You may find the job to be about a 7/ 10 skill level and require several tools you may not feel are reasonable to buy. Some you can rent. Also, there are always some bolts, screws and fasteners that will be rusted into place. Maybe in sunny Commiefornia that won't be a problem

Here's a good 'How To' on YouTube...https://www.youtube.com/watch?v=aCK1k8RVrn0

That video shows the tools I'm talking about. Instead of the rented slide hammer to remove the rotor hub, we made a standoff plate(shaped like a big 'U' with a hole through the middle) and use parts and pieces of the wheel bearing press. It's quicker and can apply more pulling force.
 

IndigoBlueWagon

TDIClub Enthusiast, Principal IDParts, Vendor , w/
Joined
Aug 16, 2004
Location
South of Boston
TDI
'97 Passat, '99.5 Golf, '02 Jetta Wagon, '15 GSW
This thread is either amusing or frustrating, not sure which. I'm hard pressed to see any normal circumstances where an ALH, even an auto, would get 21 MPG. I had a 5 mile commute for several years and my ALH (admittedly a manual) would get mid-40s on the trip, summer and winter. Worst case with an auto, especially in CA, would be mid-30s.

There's something wrong with your car that goes beyond wheel bearings and thermostats. Where are you in CA? I think you need to find a guru to diagnose what ails your TDI.
 

ecala001

Active member
Joined
Aug 17, 2020
Location
California
TDI
03 golf
This thread is either amusing or frustrating, not sure which. I'm hard pressed to see any normal circumstances where an ALH, even an auto, would get 21 MPG. I had a 5 mile commute for several years and my ALH (admittedly a manual) would get mid-40s on the trip, summer and winter. Worst case with an auto, especially in CA, would be mid-30s.

There's something wrong with your car that goes beyond wheel bearings and thermostats. Where are you in CA? I think you need to find a guru to diagnose what ails your TDI.
I'm near Santa barbara, California.

yeah it is frustrating. was thinking maf and thermostat

unless my current nozzles are shot. they are currently stock.
 

Franko6

Vendor , w/Business number
Joined
May 7, 2005
Location
Sw Missouri
TDI
Jetta, 99, Silver`
There are lots of ways to reduce economy. I haven't heard if any under car checks have been done. Leaks from fuel lines, filter, injection pump, Hole in tank... Something that every auto trans vehicle and every vehicle '04 and later has is a fuel cooler under the car about at the passenger's seat. There are o-rings on plastic push-on connectors that clip into an aluminum radiator. The cooler is positioned to be susceptible to a lot of rock strikes. It is possile a fuel line to get cut or the connector to be damaged.

I haven't heard whether there is much smoke. I think I mentioned that earlier. And I have already said it's more than a wheel bearing or a thermostat. Not like you don't have to fix both of those issues anyway. I know some good TDI mechanics further North, but none that far South.
 

ecala001

Active member
Joined
Aug 17, 2020
Location
California
TDI
03 golf
I'll check under the car for possible leaks. also there is no smoke. It also idles around 9
**edit**
 
Last edited:

TornadoRed

Top Post Dawg
Joined
Aug 3, 2003
Location
Saint Paul (ex-San Diego)
TDI
2003 Golf GL 5-spd, red; 2003 Golf GLS 5-spd, indigo blue; 2003 Jetta TDI wagon, Candy White
I also forgot to mention I have OEM Aristos 17s and have a Yakima space cadet cargo box. I think that may be a big factor. on the highway I get 33mpg though
17" wheels or bigger will hurt fuel economy. And anything mounted on top of the car will hurt as well.
 
Top