Time For Some Maintenance

WolfgangVW

Veteran Member
Joined
Oct 16, 2011
Location
Alberta, Canada
TDI
2003 Jetta TDI - Manual
Hi all. So I have a 2003 ALH TDI Jetta. I have had it for 11 years or so. Obviously done things in the past. It's a bit of a high miler but not crazy about 415,000km (258,00mi or so). Any insight into what maintenance I should look at doing ? As I plan to try and keep the car for a while now. I mean other than routine stuff.

A bit of history I replaced the tranny and clutch around 350k. Timing belt was just done. I am cleaning the intake and replacing MAF this week. Going to have some ball joints suspension stuff done shortly as well, nothing major but I have a friend who's a heavy duty mechanic who will do it for me and there's some minor issues. I guess in short what else should I be looking at as a potential issue for longevity ?? First thing that comes to mind is the turbo. I get a bit of blow by and get some oil pooling the intercooler but drain it at oil changes and it isn't a lot. Last oil change there wasn't even enough to pull out with my suction tube I just sopped it up with a rag. Just let me know your thoughts! Still getting great mileage. Get limp mode here and there but not crazy often I'm hoping cleaning the intake helps that. Should I replace N75 valve ? Did it once before years ago. Scanning I have only one code it's a glow plug fault which I know I have a bad glow plug stripped in the head (for like 8 years now, just run 3 working ones and a coolant heater for cold starts).

Anyway thanks in advance ! Just at that point I want some advice on peoples experience and things to watch out for . Cheers!! :)
 

WolfgangVW

Veteran Member
Joined
Oct 16, 2011
Location
Alberta, Canada
TDI
2003 Jetta TDI - Manual
Hey sorry just to follow up, my comment isn't completely fair about oil in the intercooler at oil changes. I used to drive a lot more and would change the oil 3 times a year at 16,000km and would pull maybe 1/4 cup out each change give or take. Last few years I don't come close to the 16,000km but change oil in the fall when I winterize like once a year hence the residual oil at best. And the turbo is the original.....
 

Diesel Fumes

Veteran Member
Joined
Dec 30, 2008
Location
Creston, bc
TDI
2003 alh tdi 5 speed
Ok is there a DYI around for it??
Probably yea. It's fairly simple. I can't remember the size of socket you need. I want to say 31mm. I used a standard size.

Drain as much oil from the cartridge holder as possible. (drain oil and remove filter basically). Then undo the big nut on the bottom of the oil cooler. There's a gasket on the top and bottom of the cooler. Bottom is flat and top is rounded.

Its much easier to do if you also drain the coolant and remove the cooler but not necessary. It's just such a mess! Be ready for a mess and have rags and wd40 or something on hand to clean stuff off.
 
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Black00Jetta

Veteran Member
Joined
Oct 15, 2003
Location
Relocated to AZ
TDI
2000 Jetta GLS Black 5spd
I replaced the oil cooler orings 2 years ago (original) because of seeping oil due to driving up to a colder climate (MN). Was up there again (2-22} and hit a cold spell ( -10 degrees for 3 days) and again had some oil seepage. I attributed the seeping to oring shrinkage and not getting up to operating temp because of short trips in town (lost about 10 oz during this time period).

Finally got to head back to warmer temperatures and no more seeping and now all is good.
 

WolfgangVW

Veteran Member
Joined
Oct 16, 2011
Location
Alberta, Canada
TDI
2003 Jetta TDI - Manual
I replaced the oil cooler orings 2 years ago (original) because of seeping oil due to driving up to a colder climate (MN). Was up there again (2-22} and hit a cold spell ( -10 degrees for 3 days) and again had some oil seepage. I attributed the seeping to oring shrinkage and not getting up to operating temp because of short trips in town (lost about 10 oz during this time period).

Finally got to head back to warmer temperatures and no more seeping and now all is good.
Thanks ya I've never had an issue but will change them next oil change and keep an eye out in the meantime!
 

WolfgangVW

Veteran Member
Joined
Oct 16, 2011
Location
Alberta, Canada
TDI
2003 Jetta TDI - Manual
Hey so a mini update. The intake is cleaned and MAF replaced. The intake was super filthy and clogged. It's all clean now including EGR etc. Man what a difference! Just power wise and runs smooth and more peppy. I used to get intermittent limp mode I'm excited to see if this solves that or helps......

On a side note think this will effect my mileage?? It's still been good but think it will be better or worse or same?? Just curious...
 

Nero Morg

Top Post Dawg
Joined
Oct 19, 2017
Location
OR
TDI
2014 A6 TDI, 2001 Jetta TDI, 2014 Passat TDI
A clean engine should be more efficient. If say it'll help out a little.
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
Hey so a mini update. The intake is cleaned and MAF replaced. The intake was super filthy and clogged. It's all clean now including EGR etc. Man what a difference! Just power wise and runs smooth and more peppy. I used to get intermittent limp mode I'm excited to see if this solves that or helps......

On a side note think this will effect my mileage?? It's still been good but think it will be better or worse or same?? Just curious...
You cleaned the intake manifold?
I sure hope you did a search first and found the many threads about the hazards of the job. You must clean the intake runners on the head as well. The problem is that the new restored velocity of boosted air will now have something in it's way (the stuff you cleaned) and it will take those chunks off eventually and those chunks will not make it past and will hold open a valve or get into the engine and push against a valve. Bottomed line.... it needs to be cleaned as well. It might not happen right away bit it will and without warning.
It's not a terrible job but when you said you cleaned it I'm assuming you didnt get the head.
Make sure the valves are closed when you do it!
 

WolfgangVW

Veteran Member
Joined
Oct 16, 2011
Location
Alberta, Canada
TDI
2003 Jetta TDI - Manual
You cleaned the intake manifold?
I sure hope you did a search first and found the many threads about the hazards of the job. You must clean the intake runners on the head as well. The problem is that the new restored velocity of boosted air will now have something in it's way (the stuff you cleaned) and it will take those chunks off eventually and those chunks will not make it past and will hold open a valve or get into the engine and push against a valve. Bottomed line.... it needs to be cleaned as well. It might not happen right away bit it will and without warning.
It's not a terrible job but when you said you cleaned it I'm assuming you didnt get the head.
Make sure the valves are closed when you do it!
I had a VW Mechanic do the job
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
I had a VW Mechanic do the job
Most vw mechanics dont know much about older TDIs and unless it was somone on our trusted list... I would ask your mechanic if it was done... hope so.
Many VW mechanics are fairly useless with these older cars... not saying yours is... just saying...
 

WolfgangVW

Veteran Member
Joined
Oct 16, 2011
Location
Alberta, Canada
TDI
2003 Jetta TDI - Manual
Thanks Mongler ya I hope they did too! I did the MAF obviously as it’s easy I just didnt want to take on the intake myself for multiple reasons.
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
The cleaning is easy it's the taking it off and stripping a few bolt heads out that is difficult and without proper tools it's difficult to install and torque down.
 

WolfgangVW

Veteran Member
Joined
Oct 16, 2011
Location
Alberta, Canada
TDI
2003 Jetta TDI - Manual
The cleaning is easy it's the taking it off and stripping a few bolt heads out that is difficult and without proper tools it's difficult to install and torque down.
Yes that’s exactly what happened when they did it there was a stripped bolt they had to deal with. I was apprehensive to do it myself as I don’t know if it’s ever been off, at least since I’ve had it so 10 years and 200,000+ Km. It's quite possible it's never been off so 415,000km so I had no problem letting a proper mechanic with proper tools do the job. I understand these are older cars and they might not see them often but I guess if I'm not going to do it I gotta have faith if I get a certified VW Mechanic to do it they'll have the mechanical inclination and experience to research and complete the job properly. And in my past experience they have done great work for me. So far it seems great and did a highway run today about 200km and ran fantastic. Way more power and zero limp mode issues. That being said thanks Mongler for your input I appreciate it. I've always appreciated all the knowledge shared with me here...... :)
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
Yes that’s exactly what happened when they did it there was a stripped bolt they had to deal with. I was apprehensive to do it myself as I don’t know if it’s ever been off, at least since I’ve had it so 10 years and 200,000+ Km. It's quite possible it's never been off so 415,000km so I had no problem letting a proper mechanic with proper tools do the job. I understand these are older cars and they might not see them often but I guess if I'm not going to do it I gotta have faith if I get a certified VW Mechanic to do it they'll have the mechanical inclination and experience to research and complete the job properly. And in my past experience they have done great work for me. So far it seems great and did a highway run today about 200km and ran fantastic. Way more power and zero limp mode issues. That being said thanks Mongler for your input I appreciate it. I've always appreciated all the knowledge shared with me here...... :)
You should not have this issue any more. With our new ultra low sulfur fuel the problem of coking up an intake is like 80% less mess.
 

Mass. Wine Guy

Top Post Dawg
Joined
May 21, 2001
Location
Ipswich, Massachusetts
TDI
5-speed, 2015 Golf S 6-speed manual; 2015 Golf Sportwagen SEL 6-speed manual
Oil cooler gaskets? I have the same model in a wagon with similar mileage. Is this a big job or a good mechanic (not me)?
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
Oil cooler gaskets? I have the same model in a wagon with similar mileage. Is this a big job or a good mechanic (not me)?
You can do it. It's a bolt you need a deep well socket for. Not difficult but I would say 1 tick above doing an oil change.
 
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