Is the tdi an interference engine.

concours

Veteran Member
Joined
Jul 4, 2001
Location
Kensington, NH
TDI
2006.6 Jetta GLS 5 speed 125,000 miles, 2001.5 Jetta GLS 5-speed, Tornado Red, Monsoon w/CD changer
Welcome Rolo. YES, things go crash when they break. There are many, many mis-informed "mechanics" and dealerships floating around costing people thousands. You have stumbled upon THE very best forum for repair, maintenance and usage advice for TDI's. Read, read, read... and search, search, search... question EVERYTHING you've been told by the dealer. Collectively sharing ACCURATE technical info here has saved me thousands and many hours of troubleshooting time.
 

redneck_pilot86

Well-known member
Joined
Nov 18, 2007
Location
Durham (The town, NOT the region) Ontario
TDI
2003 Jetta
They are an interference engine, but a timing belt failure does not 100% guarantee a catastrophic engine failure. I had the tensioner let go on me, I guess the spring inside it slipped around about an inch and released the belt, the engine stalled and wouldnt start, but there was no damage to the head. I do beleive I am the exception to the rule though.
 

merkerguitars

Veteran Member
Joined
May 10, 2004
Location
Elmwood, WI
TDI
01 Jetta
Just ask Frank! Just make sure you do your timing belt on time (or early) and make sure you do it properly and you won't have to worry.
 
Joined
Nov 28, 2007
Location
Florida
TDI
1999 GLS Beetle
Can I just say that with 20+ years in the automotive repair business I have never seen so much damage from any other engine when it's timing belt breaks.

Bobby
 

Franko6

Vendor , w/Business number
Joined
May 7, 2005
Location
Sw Missouri
TDI
Jetta, 99, Silver`
About what Redneck says...

The worst exception to the rule on skipped timing belts are the ones that you THOUGHT were non-strikes. Then, about a tankfull of fuel later, you are playing bongos with a valve head on a piston.

But yeah, I've seen a handful or so of crashed heads...
 

GoFaster

Moderator at Large
Joined
Jun 16, 1999
Location
Brampton, Ontario, Canada
TDI
2006 Jetta TDI
Turbo Dsl Beetle said:
Can I just say that with 20+ years in the automotive repair business I have never seen so much damage from any other engine when it's timing belt breaks.

Bobby
Really?

Seen what happens to a VW 1.8T, or practically any Honda engine, when its timing belt breaks?

On a TDI, *usually* it will smash up the lifters. The valves *usually* don't break off - although any valve that has taken a hit should be replaced anyway. The pistons, block, and the rest of the head are *usually* salvageable. I suspect it is because the pistons have a straight-line approach to the valves. YES, sometimes a valve will actually break off and wreak havoc. But on almost any engine with inclined valves, which includes practically every multivalve gasoline engine out there, a broken timing belt almost *always* results in breaking at least some of the valve heads off the stems, then the valve head bounces around in the combustion chamber and smashes up the pistons, the head, and scores the cylinder liners all to crap.

No matter ... the point is that if the timing belt breaks, badness occurs.

You can't build a 4-stroke diesel engine that is *not* an interference design.
 

AndyBees

Top Post Dawg
Joined
May 27, 2003
Location
Southeast Kentucky
TDI
Silver 2003 Jetta TDI, Silver 2000 Jetta TDI (sold), '84 Vanagon with '02 ALH engine
Yeah, my cousin's '99 Beetle sort of survived major destruction when a section of teeth ripped off the TB at about 45 mph. In fact, we installed a new TB and the engine ran fine ... for a few days.

A general visual inspection did not reveal the obvious damage to the lifters (cam followers).

The damage to the head occured when the damaged lifters broke to pieces after we installed the new TB (in less than 1,000 miles).

By the way, the TB had "supposedly" been changed according to the stealership where he purchased the Beetle. We concluded that the original TB had actually made it to 105k miles.

I think the '99 Beetle had a 60k TB from the factory. If that be the case, then there is a considerable amout of "safety" built into the change interval.
 

ArnoldHarris

Well-known member
Joined
Jan 12, 2007
Location
Mount Horeb, Wisconsin
TDI
2006 Jetta manual trans
Assuming all of the above about TDI timing belts...

Assuming all of the above,

1) What is the safe mileage interval with the factory-installed TDI timing belt?

2) What is the safe mileage interval with a replacement TDI timing belt?

3) How can a TDI owner check the condition of his timing belt?

4) How many hours are involved in timing belt replacement?

5) How many hours for timing belt replacement are specified in the VW dealer's shop manual?

6) What special tools are needed for replacement?

7) What other belts should be replaced at the same time?

8) What other replaceable engine parts are there for which the timing belt must be removed to get at them (water pump, oil pump, etc)?

9) What other questions need to be answered about this problem with interference engines in general, and VW TDI interference engines in particular?

Arnold Harris
Mount Horeb WI

(2006 VW Jetta TDI; 5-speed manual transmission; B5 user; 30,500 miles.)
 
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paramedick

TDIClub Enthusiast, Vendor
Joined
Jul 29, 2001
Location
Versailles, Kentucky
TDI
2015 Audi Q5 TDI
ArnoldHarris said:
Assuming all of the above,

1) What is the safe mileage interval with the factory-installed TDI timing belt?

2) What is the safe mileage interval with a replacement TDI timing belt?

3) How can a TDI owner check the condition of his timing belt?

4) How many hours are involved in timing belt replacement?

5) How many hours for timing belt replacement are specified in the VW dealer's shop manual?

6) What special tools are needed for replacement?

7) What other belts should be replaced at the same time?

8) What other replaceable engine parts are there for which the timing belt must be removed to get at them (water pump, oil pump, etc)?

9) What other questions need to be answered about this problem with interference engines in general, and VW TDI interference engines in particular?

Arnold Harris
Mount Horeb WI

(2006 VW Jetta TDI; 5-speed manual transmission; B5 user; 30,500 miles.)
WOW! A bunch of questions in one posting.

Generally, the timing belts are good for the rated duration for the vehicle. There is a possibility of a idler roller or tensioner failure, so you listen for odd noises in the timing belt path indicative of a problem.

Inspection of the TB is mandatory, IMHO. Remove the TB cover when you change the oil. Look for fraying, cracking, missing teeth, or unusual wear on the TB.

I have no clue how many hours VW rates a TB change for. Most of us that do it regularly can change a belt and all components in 3-6 hours.

When the TB is changed, all the idler rollers should be changed, as well as the water pump and tensioner. Camshaft and crankshaft seals need to be changed if there is any sign of leakage of oil. All accessory belts need to be replaced at the same time.

Your last question is interesting. I wasn't aware of any problem with interference engines if properly maintained. My answer is absolutely use the correct oil specified for your car. Absolutely change the TB when required.

Yes, there are special tools needed. Metalnerd sells all the tools you will need in kits. PD engined cars have some additional tools that are needed.
 

tdidieselbobny

Top Post Dawg
Joined
Apr 4, 2005
Location
Stafford,NY (WNY)
TDI
'03 Galactic Blue Jetta TDI, '15 Silk Blue Golf Sportwagen TDI
Water pump every time on A4,every other time on A3/B4 TDI's.I don't know about the TB's on your year(A5 platform)-I believe change same items as the A4.
 

AndyBees

Top Post Dawg
Joined
May 27, 2003
Location
Southeast Kentucky
TDI
Silver 2003 Jetta TDI, Silver 2000 Jetta TDI (sold), '84 Vanagon with '02 ALH engine
At 167,687 miles, I changed my TB for the second time.

At that TB change interval, I also replaced the water pump and all three idlers/rollers for the 1st time. And, of course, the tensioner and other belts were replaced too.

The seals and gaskets have not been changed to date (224k miles)... no oil leaking.

The old WP appeared very okay... not loose, not tight, not leaking!

But, one of the three idlers/rollers was definitely near the end of its life. The other two "felt" okay.

Obviously, there was nothing scientific about the inspections. But, its quite obvious these items can go past 150k miles.

Now, having said all that, when I changed my brothers TB at 86k, the WP was showing signs of leaking. The leaking was apparently very small since he had not had to add any coolant up to that point. Sure, the seal could have failed catastrophically at anytime.

I recall the early model VW Diesel water pumps were notorious to "weep" but never come to catastrophic failure. Or, at least in the 28 years I have driven the VW Diesel, I have not had a WP failure.

For those who cannot do their own TB change, etc., the best advice would be to change all those questionable pieces parts at the TB change.. just for peace of mind!

For those of us with the "know-how" and access to a place (garage) to do the work, we can do the inspections and make replacements as needed.

Sure, its a no brainer when it comes to the WP and idlers/rollers as far as the amount of work required to change them .... do it while you are there attitude must prevail when doing the TB change!
 

ArnoldHarris

Well-known member
Joined
Jan 12, 2007
Location
Mount Horeb, Wisconsin
TDI
2006 Jetta manual trans
1) What does "A4", "A5", etc, refer to in VW model designation? All I know from the information I received from the dealer is that I own a 2006 VW Jetta TDI with 5-speed manual transmission.

2) What significance do the A-series designations play in ordering parts and services?

3) What would be an appropriately detailed, illustrated and model-specific service manual for my use with my own vehicle? I have looked in a large local Barnes and Noble bookstore (west side Madison, Wisconsin) for such a manual, with no success.

4) Yes, I purposely ask numerous and detailed questions. I am trained as an urban and regional planner, which implies seeking information with which to treat probable or possible future problems proactively rather than dealing with their consequences reactively.

Arnold Harris
Mount Horeb WI
 
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TornadoRed

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Joined
Aug 3, 2003
Location
West Des Moines (formerly St Paul)
TDI
2003 Jetta TDI wagon, silver; 2003 Jetta TDI wagon, indigo blue; 2003 Golf GL 5-spd, red (PARTED); 2003 Golf GLS 5-spd, indigo blue (SOLD); 2003 Jetta TDI wagon, Candy White (SOLD)
ArnoldHarris said:
Assuming all of the above,

1) What is the safe mileage interval with the factory-installed TDI timing belt?
For 2006 Jettas I have seen both 100k miles and 90k miles. 90k is a reasonable number, though the TB will not fail at 91k.

2) What is the safe mileage interval with a replacement TDI timing belt?
This depends on what parts you replace. Some dealerships quote a very high price, then ask if you "want" to replace the water pump, etc. Naturally many inexperienced TDI owners are already suffering from sticker shock and are not anxious to pay even more for something the dealer service advisor considers "optional".

What you SHOULD do is replace the timing belt, the tensioner, all three roller/idlers, the water pump, the serpentine belt, and all the single-use torque-to-yield (TTY) bolts. Several vendors here at TDIClub sell deluxe TB kits at attractive prices that have all these parts... and JasonTDI right down the road from you can do the job for a reasonable labor charge.

3) How can a TDI owner check the condition of his timing belt?
You listen to it, trying to discern any unusual swooshing noises, and especially any chirping noises. You can also remove the TB cover and check the tension of the belt, looking especially for any slackness.

4) How many hours are involved in timing belt replacement?
Dealerships will charge 5-6 hours, but an experienced tech can do it in about 3 hours.

6) What special tools are needed for replacement?
A few, mainly to lock the cam in place. These can be rented from www.metalmanparts.com if you plan to do the work yourself.

1) What does "A4", "A5", etc, refer to in VW model designation? All I know from the information I received from the dealer is that I own a 2006 VW Jetta TDI with 5-speed manual transmission.
A5 stands for the 5th generation of the A-platform. Your Jetta may also be referred to as a Mk5 Jetta. The A4 platform included the 1998-2006 New Beetle TDI, the 1999.5-2005 Jetta TDI, and the 1999-2005 Golf TDI.
 

ArnoldHarris

Well-known member
Joined
Jan 12, 2007
Location
Mount Horeb, Wisconsin
TDI
2006 Jetta manual trans
TR, you seem to know your way around TDI engines and tasks such as timing belt replacements. I checked out www.memtalmanparts.com. Their timing belt replacement kits are inexpensively priced.

What suggestions do you have for a detailed shop manual for my car (2006 Jetta TDI, PD, 5-speed manual transmission)? I assume mine is also described as an A-5, in contrast with the earlier Jetta model years.

A useful feature is a printed copy of a shop manual with an online step-by-step counterpart with lots of easy-to-see color photos.

But before I get that far, what is available and useful in shop manuals?

I have been rebuilding computers and 1950s era German 35mm rangefinder cameras for some time, so I am no stranger to exacting and detailed labor.

Thank you for your advice and help.

Arnold Harris
Mount Horeb WI
 

2002-tdi

Veteran Member
Joined
Oct 3, 2006
Location
New Orleans
TDI
2002 tdi jetta
ArnoldHarris said:
TR, you seem to know your way around TDI engines and tasks such as timing belt replacements. I checked out www.memtalmanparts.com. Their timing belt replacement kits are inexpensively priced.

What suggestions do you have for a detailed shop manual for my car (2006 Jetta TDI, PD, 5-speed manual transmission)? I assume mine is also described as an A-5, in contrast with the earlier Jetta model years.

A useful feature is a printed copy of a shop manual with an online step-by-step counterpart with lots of easy-to-see color photos.

But before I get that far, what is available and useful in shop manuals?

I have been rebuilding computers and 1950s era German 35mm rangefinder cameras for some time, so I am no stranger to exacting and detailed labor.

Thank you for your advice and help.

Arnold Harris
Mount Horeb WI
Bentley manuals as found here - http://www.bentleypublishers.com/volkswagen
you would want the following ( you may be able to find this at a lower prices elsewhere)
http://www.bentleypublishers.com/product.htm?code=vj06
 

TJSonOfAnder

Member
Joined
Jan 17, 2013
Location
New Orleans
TDI
2003 Jetta
They are an interference engine, but a timing belt failure does not 100% guarantee a catastrophic engine failure. I had the tensioner let go on me, I guess the spring inside it slipped around about an inch and released the belt, the engine stalled and wouldnt start, but there was no damage to the head. I do beleive I am the exception to the rule though.
I think this is what happened to me, because I literally just checked the both belts a couple weeks ago. The car just died and coasted on my two days ago, and both belts are missing. I'm hoping I have your good fortune of not having any head damage (or to have to replace too many valves). I'm sure I'll be on this forum around the clock this weekend.
 

TornadoRed

Top Post Dawg
Joined
Aug 3, 2003
Location
West Des Moines (formerly St Paul)
TDI
2003 Jetta TDI wagon, silver; 2003 Jetta TDI wagon, indigo blue; 2003 Golf GL 5-spd, red (PARTED); 2003 Golf GLS 5-spd, indigo blue (SOLD); 2003 Jetta TDI wagon, Candy White (SOLD)
I think this is what happened to me, because I literally just checked the both belts a couple weeks ago. The car just died and coasted on my two days ago, and both belts are missing. I'm hoping I have your good fortune of not having any head damage (or to have to replace too many valves). I'm sure I'll be on this forum around the clock this weekend.
It is safest for you to assume the worst, then go ahead and procure a properly rebuilt head with all new valves, etc. A damaged valve does not always appear to be damaged, but it will eventually fail and then you'll have even more damage and another high repair bill. It really is almost impossible for a timing belt to fail without pistons hitting valves.

I recommend that you contact Frank Irving, TDIClub username Franko6, who does great work for reasonable prices. He will either rebuild your cylinder head, or ship you one that he has already rebuilt and you send him your broken head.

You will also need a deluxe timing belt kit -- replace everything in the TB path and you won't have to worry about it for another 100k miles. Frank offers TB kits, but you can also buy a kit from one of the registered vendors.
 
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