TDI 101: Determining Head Gasket Hole Size

When replacing a head gasket on any motor it is vital to know the thickness of the head gasket on the car. Even though engines are made to exacting measurements, small variations can add up. To deal with the variation in block height, piston and bearing size there are are different thickness head gaskets. It is often impossible to know which head gasket you need based on the model year or VIN since the judgement was often made on the spot during the engine build.

Its easy to find your head gasket thickness. The thickness of the gasket is denoted by “holes”, e.g “1 Hole”, “2 Hole” or “3 Hole” thickness. The holes are physical, circular holes that are stamped into a small tab on the gasket. Follow the break to find the head gasket size on your TDI.

Step one is get to the front of your vehicle.

2002 Jetta TDI Front
Front Of Car…Clearly

Step two, open the hood…

TDI ALH Engine Cover
TDI ALH Engine Cover

Remove the engine cover. On many models this requires a 10mm socket ro remove three 10mm nuts. They are located under the circular plastic caps in a triangle shape, they are visible in the above photo.

TDI Engine
Green Circle is the area we are concerned with…

With the engine cover off we are going to look between the injection pump and the engine, the area indicated by the Green square. Some model TDIs don’t have an injection pump, so there won’t be anything in front of the engine blocking your view.

Head Gasket Size Tab

Thats the straight above view. You can make out the tab, though its a bit dirty.

Head Gasket Size Close Up
Head Gasket Size Close Up – This is a “2-Hole” head gasket…

The important holes are the circular ones, in this case this tab has 2 circular holes, making it a “2-hole” head gasket. The elongated hole all the way to the left does not count.

Importantly, there are only three sizes – 1, 2, or 3 hole. If you find a tab that doesn’t have a hole, or has 4 holes, you aren’t looking at the right thing. Remember, the elongated hole DOES NOT COUNT.

Here are some common TDI head gasket part numbers:

Vehicle Size OEM Part Number
AHU/1Z Head Gaskets – MkIII Jetta TDI & B4 Passat TDI 1 Hole 028103383BP
2 Hole 028103383BQ
3 Hole 028103383BR
ALH Head Gaskets –
MkVI Jetta TDI  ‘99-’03
MkIV Golf TDI ‘99-’03
New Beetle TDI ‘98-’03
1 Hole 038103383H
2 Hole 038103383J
3 Hole 038103383K
BEW Head Gaskets –
MkIV Jetta TDI ’04-’05
MkIV Golf TDI ’04-’06
New Beetle TDI ’04-’06
1 Hole 038103383DE
2 Hole 038103383DF
3 Hole 038103383DG
BRM Head Gaskets –
MkV Jetta TDI ’05-’06
(same as BEW above)
1 Hole 038103383DE
2 Hole 038103383DF
3 Hole 038103383DG

4 thoughts on “TDI 101: Determining Head Gasket Hole Size”

  1. replacing with the same notch gasket is the easy way to go but not the correct way. you need to measure piston protrusion (distance between block and top of piston at TDC) to determine headgasket thickness.

    using the previous size might work but odds are that you’ve replaced pistons, surfaced/decked the head/block, or made other changes that may effect piston protrusion. since diesel engines are interface and rely on high compression a very small error in choosing the wrong gasket can lead to valve/piston impacts or poor operation (especially hard starts)

  2. but, lalo, to answer your question you may need to increase gasket thickness to compensate.

    VW heads generally aren’t made for resurfacing.

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