Replacing Headgasket

[Lloydbob1]

I'm changing the headgasket on my 91 Jetta Diesel. I've identified it as having 3 holes and ordered the gasket and new head bolts.
I've changed a lot of headgaskets, but, never a diesel. The only book I can find on Jettas doesn't give any info on changing the HG.
Is there any online info for this job? Do I need special keys to lock the cam and IP? Is there anything else I should know before I start?
I would appreciate any help I can get with this.
Lloyd

[tawney]

Use the Search function at the top of this page; you'll find lots of information, but you may also need the Bentley service manual. They're not cheap, (check ebay,) but if you're going to do your own work on it, the Bentley manual will be some of the best money you'll spend.

Just briefly, though, you'll want to know why the head gasket failed; if the head is warped or it failed because of some cooling problem causing it to overheat, you may go through a lot of trouble and end up right back where you are right now unless you fix the root cause of the gasket failure not just the symptom.

Secondly, the head gasket replacement is pretty simple and straightforward; it's the re-timing of cam and injection pump with timing belt tensioning that is a bit more challenging, but again, the Search function on this forum will bring up loads of good, experienced advice. There are good cheap substitutes for the cam and pump lock tools, but you may want a dial indicator and adapter to re-set the pump timing.

Thirdly, it would be a good idea to replace your timing belt while you're at it, tensioner too, maybe, unless you know how many miles on the belt.

Good luck,

Steve

[82vdub]

Is there any online info for this job?

Yes, search these forums and read. You should also get a Bentley manual before you get too far into this.

Do I need special keys to lock the cam and IP

Yes, search these forums for tools that people have come up with to lock both these if you don't have the special tools on hand.

Is there anything else I should know before I start?

Yes, get a Bentley manual (I know I said this once - it's important). All the answers can be found in this forum. Absolutely make sure you rotate the engine by hand before you turn it with the starter to make sure you don't mash the valves and pistons together. Replace the timing belt and tensioner with new one's. You are essentially replacing a head gasket, timing belt and learning how to time a diesel engine all at the same time.

Just briefly, though, you'll want to know why the head gasket failed; if the head is warped or it failed because of some cooling problem causing it to overheat, you may go through a lot of trouble and end up right back where you are right now unless you fix the root cause of the gasket failure not just the symptom.

If you didn't address the original issue why the head gasket failed, you should now, or do it later, your choice.

[Lloydbob1]

Thanks all. I am going to order the Manual. I thought that if I lock the cam and lock the pump, I won't loose the timing.
Lloyd

[82vdub]

I thought that if I lock the cam and lock the pump, I won't loose the timing.

Well, you're sort of correct. If you lock the IP and remove everything, your IP position to the crank will still be right. However, since your taking one head off and installing another, you need to align the cam to the IP and crank. Installing the cam holder will get you there, and if you didn't move the IP probably close enough for the engine to run pretty good. However, your timing is essentially unknown, since it is not identical to how it was before since you removed the timing belt. As mentioned, it will likely run, but in order to make sure it's timed somewhat correctly, you should time it according to the book - or time it by ear.

[woodrat]

I had to make a special tool to hold the cam pulley while I undid the nut holding it to the cam.



Other than that, it was a pretty straightforward job, except for the fact that 2000 miles later, my supposedly brand new German head dropped a valve head, and destroyed itself.

[duffer]

One other point you may wish to consider...

You say that the existing head gasket is a
three-hole gasket,

As you're probably aware, the thickness of
the head gasket is determined by the height
of the piston protrusion above the block.

Garage mechanics are notorious for simply
tossing in the three-hole gasket rather than
be bothered to take the proper measurements.
( it's cheaper to just stock the three-hole gasket
rather than a complete selection).

You might wish to measure the piston protrusion
above the block and make sure that the
appropriate gasket IS the three-holer.

You'll get better performance if the engine
only requires a one- or two-hole gasket.

[Lloydbob1]

Thank you all. I buttoned it up today. When I cranked it over to bleed the fuel lines I get no fuel even at the fuel fitting on the IP.
. When I sit in it and turn the key I don't here the high speed whine I usually hear. Is there anything I could have done that effected the lift pump? I checked all of the fuses in the area of the pump fuse and they are OK.
Lloyd

[the man 53]

I ruined my first head so I hope that makes me qualified to post . If you took out the injectors for any reason make sure to torque them by pushing toward the head The problem you are having I had as well... I turned it over a little bit to get the oil circulating and knew it wasn't going to start so it got pulled. It took about half a mile to get fuel up there as all of my pressure lines and return lines I took off for the gasket change. I also changed the fuel filter and there was just a ton of air in the lines. I know it would have primed itself eventually, but I liked my new starter so I just pulled on it. It still knocked pretty loud for awhile until the air worked its way out. I don't know how long its been apart, but your battery could have lost a little charge since then.?.
I have done some head gaskets since with no problems. Good luck.

[Vincent Waldon]

. When I sit in it and turn the key I don't here the high speed whine I usually hear. Is there anything I could have done that effected the lift pump? I checked all of the fuses in the area of the pump fuse and they are OK.
Lloyd

Are you sure you have a lift pump ?? They weren't stock on your car.

It will usually take a couple minutes of cranking to prime the lines... I usually do it in 20 second bursts to allow the starter to stay cool.

[82vdub]

You can remove the fuel line and put a brake bleed vacuum pump on it and suck fuel through the lines to get it close to the IP. You should also remove the out bolt and/or fuel solenoid and fill the IP with fuel. I've always done this and ran the car out of a jar of fuel using the fuel line that will be on the car and removed at the filter. After the car runs well, reconnect the fuel line and it should pull fuel from the fuel tank without an issue once you fire it up again.