Newbie looking for tips and advice for replacing head gasket on 96 passat

Hey what's up Forum, Let me introduce myself, My name's Josh. I'm a long time lurker, first time poster.
I live in Western New York with my wife and our 4 kids, and I work overnights as a 3rd shift CNC operator. It's not glamorous. I also work part time as a tech at a collision shop for a friend although I haven't had a chance to put many hours in lately due to the birth of my 2nd son.
In March I bought a 96 passat TDI 1.9 with 241k via private seller,
the ad said the car ran fine and nothing was wrong with it except for a blown heater core. The owner was unable to do the work himself, and unwilling to pay a shop the 8 hours of labor for dash & firewall disassy and put it up for sale. I got it for fairly cheap.
I was suspicious of a possible head gasket issue so I checked the coolant after running it for a bit, found no grey grime, also checked the oil and it was pure, albeit black, it had not been contaminated with coolant. I even went as far as to check the exhaust for possible coolant expulsion and found none. I don't have a compression tester compatible for a diesel motor, and felt somewhat confident in my ability to determine the internal health of the motor, so I bought it.
I put it on the road in mid May after a chaotic few months that included my son being born prematurely, buying and moving into a house while going an hour one way to the NICU he was in for nearly 2 months and driving to albany for evaluations for a state job.
I looped the HC lines and put nearly 400 miles on it and after fully filling up the coolant.
I encountered only one minor overheating issue in this time, I attributed it to an air pocket in the system and further burped it a bit. This temporarily solved the problem.
Eventually some how I ran low on coolant a far ways from home, and the engine overheated, after a long series of stop and goes and stops and goes until I could get to some coolant from a gas station and made it home, I topped it off but still had serious problems.
I recognized I was in over my head when the engine temperature remained in operational range but the system would overpressurize and blow coolant out of the overflow bubble bladder resevoir after about ten minutes.
I took it to a garage that deals with imports. They tested it for emissions into the coolant system and detected a small leak due to head gasket.
So here I am.
I wanted to have the car ready to take me to albany by today 6-20, and that obviously isn't going to happen, so I've resigned myself to taking the long and cheap road by doing it myself.
This will be the first time I've done the head on a turbo diesel. I've done chain saws, weed eaters, my liquid cooled snow mobile and air cooled motor cycle before, but never an automotive motor.
I have a haynes that came with the car and it goes fairly in depth in detailing how to do a head, however I know from FIRST HAND EXPERIENCE that the guys who write these usually don't take into account how working on the vehicle 20 years after production adds potential problems or additional steps.
In Essence, what I'm looking for is someone who's on this forum and has done this job to give me a heads up on what to expect.
Any takers?
Any advice?
Any suggestions on what else to look for or do at this mileage while I've got the top of the motor apart?
Like I said, the youtube videos I've seen have looked fairly straightforward, but I don't want to charge in with my uninformed assumptions
Thank you all kindly for patiently reading my post, I appreciate your input. I will be putting together a youtube video detailing my disassembly and the build. As well as the start up,... successful or not.

NOTE: the car still runs perfectly fine. but if it goes for about more than ten minutes the coolant system overpressurizes and it blows coolant out of the reservoir.

Pretty much any time you've overheated a TDI and had a head gasket leak as a result you can guarantee that the head is no longer flat. Simply changing the gasket won't work, you're going to need to get the head skimmed (or at the very least checked for flatness with a machinist straightedge - there's an incredibly small chance that it might not need anything)

Other things to know:

- head bolts are single use, they deform on installation. You'll need new ones
- since you'll have the head off you are going to need to do most of the work of a timing belt job already. Would be crazy not to put a fresh timing set in
- valve guides on these engines are usually worn by the mileage you're at. If you have the head off and are having it resurfaced it would make a lot of sense to do them at the same time since you're already doing most of the labour



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vanbcguy said:

Pretty much any time you've overheated a TDI and had a head gasket leak as a result you can guarantee that the head is no longer flat. Simply changing the gasket won't work, you're going to need to get the head skimmed (or at the very least checked for flatness with a machinist straightedge - there's an incredibly small chance that it might not need anything)

Other things to know:

- head bolts are single use, they deform on installation. You'll need new ones
- since you'll have the head off you are going to need to do most of the work of a timing belt job already. Would be crazy not to put a fresh timing set in
- valve guides on these engines are usually worn by the mileage you're at. If you have the head off and are having it resurfaced it would make a lot of sense to do them at the same time since you're already doing most of the labour


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I was under the impression fromthe Haynes that the heads were not millable?! I can check them for flatness and mill them if need be at work!

I know the bolts are torque to yield, any particular brand I should stick to when buying?

Milling a head is somewhere around $60 usually. I'd believe it if a good source (not Haynes) said it cannot be milled, due to the valve seats being flush with the head surface, unlike on gas engines. A few minutes of searching and I find references to people who've had them milled, but also had to grind down the valve seats and the valve stem tips to match. That's going to be more than $60 but less than a good used head, and with a substantial refresh too.

For something like head bolts, I wouldn't use anything less than genuine OEM, and not made in China even if it is OEM VW-branded (I seem to recall reading about a bad batch of some OEM/Febi bolts that fell prey to Chinese quality control issues). Ditto for the headgasket (or Victor Reinz, who is probably the OEM anyway).

Great time to clean the intake manifold and, since the head is coming off, the intake ports.

You'll be doing a timing belt job at the same time, which calls for a new belt, tensioner, and possibly return roller. To do it right you also need some special tools, some which can be improvised (cam and IP sprocket hold-downs, tensioner spanner wrench) and some can't (VAGCOM to adjust the injection timing).

Some diesels (not sure about TDI) are prone to mushrooming the tips of the glowplugs, which then break off upon attempted removal. While the head's off, I'd take them out, look them over and replace if suspect, and put back in with high-temperature anti-seize.

+1 on Not-milling the head. If warped, it needs to be heated in an oven, then reshaped by bolting down to heavy (and flat) steel plates.

For more info/talk on heads, search the forum here for "Franko6". He's the Head honcho.

And any OE brand is fine on the bolts, Victor Reinz or Elring. Febi are reboxed Elring usually.
-BB

The head can be resurfaced (and should be if you want the new gasket to seal). The reason you aren't supposed to just mill it straight is the cam journals will be out of line if the head is warped. There's no bearings on the cam so it gets a little messy trying to make that right.

There's an awful lot of overhead cam aluminum head engines out there these days so the professes for dealing with this type of head is much better understood by your average shop these days. In the '90s when the Haynes manual was written it was much more rare except on brand new cars at the time, the sort of vehicles that weren't likely to be getting major engine overhauls.

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Another random suggestion: buy or borrow the Factory Service Manual. It has the full head replacement procedure, the proper torquing sequence for the head itself, the proper torquing values for various bolts, and the important table you'll need to buy the correct head gasket (there are 3 different ones available).

turbodieseldyke said:

+1 on Not-milling the head. If warped, it needs to be heated in an oven, then reshaped by bolting down to heavy (and flat) steel plates.

For more info/talk on heads, search the forum here for "Franko6". He's the Head honcho.

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Turbodieseldyke your name and avatar win teh intarnets.

thank you very much for your input. this forum is fantastic.

moroza said:

Milling a head is somewhere around $60 usually. I'd believe it if a good source (not Haynes) said it cannot be milled, due to the valve seats being flush with the head surface, unlike on gas engines. A few minutes of searching and I find references to people who've had them milled, but also had to grind down the valve seats and the valve stem tips to match. That's going to be more than $60 but less than a good used head, and with a substantial refresh too.

For something like head bolts, I wouldn't use anything less than genuine OEM, and not made in China even if it is OEM VW-branded (I seem to recall reading about a bad batch of some OEM/Febi bolts that fell prey to Chinese quality control issues). Ditto for the headgasket (or Victor Reinz, who is probably the OEM anyway).

Great time to clean the intake manifold and, since the head is coming off, the intake ports.

You'll be doing a timing belt job at the same time, which calls for a new belt, tensioner, and possibly return roller. To do it right you also need some special tools, some which can be improvised (cam and IP sprocket hold-downs, tensioner spanner wrench) and some can't (VAGCOM to adjust the injection timing).

Some diesels (not sure about TDI) are prone to mushrooming the tips of the glowplugs, which then break off upon attempted removal. While the head's off, I'd take them out, look them over and replace if suspect, and put back in with high-temperature anti-seize.

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I plan on cleaning the intake, found a cool video of how to do it with MAP gas and compressed air, not sure how advisable it is as it's aluminum casting, but i don't really see too much harm in it if it heats evenly and doesn't get too hot.

as far as buying OEM, if I buy directly from the dealer, would they be able to steer me away from the chinese OEM bolts?

I know i could mill the head if it was able to be done, but if i have to grind out valve seats too I'll probably take it to a pro. the manual machines we have at work are stone age thing the maintenance guys use as glorified drill presses. none of my CNCs have a raw code setup or a basic fixture, it's all hydraulic for specific sized and shape castings.

As far as the sprocket hold downs and tensioner spanner wrench, I'm assuming those are 1.9 year specific tools? buy them from VW or ebay, is there a tool serial number I coudl use ot locate these tools online?

what in the world is a VAGCOM tool haha?

vanbcguy said:

The head can be resurfaced (and should be if you want the new gasket to seal). The reason you aren't supposed to just mill it straight is the cam journals will be out of line if the head is warped. There's no bearings on the cam so it gets a little messy trying to make that right.

There's an awful lot of overhead cam aluminum head engines out there these days so the professes for dealing with this type of head is much better understood by your average shop these days. In the '90s when the Haynes manual was written it was much more rare except on brand new cars at the time, the sort of vehicles that weren't likely to be getting major engine overhauls.

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what is the maximum amount I can remove by resurfacing?

Another question, earlier, moroza mentioned that a hayne wasn't as good to use as a factory service manual.

only thing I can find on Ebay for a factory service manual is for the glow plugs? everything else that I've found so far are haynes or chilton's. anyone have a link?

I really appreciate the immediate help on this guys.

I've been on other unrelated forums before and no one pays attention to the newbie unless he gets to 50 posts or so by commenting in BS threads about non sense. I really appreciate it!

Bentley is the manual of choice. It's the "official" VW book and covers things in much more detail than a Haynes book.

I can't say what the head milling spec is. I believe valve head height comes in to it though.

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seabassisanalien said:

what in the world is a VAGCOM tool haha?

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Vag-Com Diagnostic Software (aka VCDS). It's hard to spend so much money on just a cable, but if you plan on having VWs for any length of time, it's 100% worth the cost. I can't tell you how many times I've used mine. And how many friends have borrowed it.
http://www.ross-tech.com/

vanbcguy said:

mill it straight is the cam journals will be out of line if the head is warped. There's no bearings on the cam so it gets a little messy trying to make that right.

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The camshaft can't tolerate being a fraction of a degree misaligned with respect to the crank, even if its journals follow suit? Or are you saying that a warped head will also warp the cam journals (with respect to each other)?

Can't the cam journals be line-bored to fix this?

I've fixed quite a few headgaskets and had heads machined, and this is the first I hear of camshafts being affected. It makes sense, just wondering why it's never come up before.

seabassisanalien said:

as far as buying OEM, if I buy directly from the dealer, would they be able to steer me away from the chinese OEM bolts?

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Not necessarily.

As far as the sprocket hold downs and tensioner spanner wrench, I'm assuming those are 1.9 year specific tools? buy them from VW or ebay, is there a tool serial number I coudl use ot locate these tools online?

what in the world is a VAGCOM tool haha?

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Volkswagen AktienGesellschaft COMmunications software. It's like a fancy OBD2 reader/programmer that's specific to VW products. In the case of a 96 Passat with its original ECU, it is actually the *only* way to talk to the ECU; regular OBD2 readers won't even connect to it.

As for the tools, again - most can be improvised, and if you've got a CNC, you can make them too. Otherwise, here's a typical toolkit.

moroza said:

The camshaft can't tolerate being a fraction of a degree misaligned with respect to the crank, even if its journals follow suit? Or are you saying that a warped head will also warp the cam journals (with respect to each other)?

Can't the cam journals be line-bored to fix this?

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Once the warped deck is cut, the cam journals will twist out of alignment once the head is torqued down. I've heard of cams snapping. Luckily, I've never had a warped diesel head.

Since there aren't any cam bearings other than the casting, line boring wouldn't help unless you're able to find a non OE bearing to fit. Maybe something like a Redi Sleeve....?

-Todd

Yup, exactly this ^^^^
The cam journals will end up out of line. If you line bore them they'll end up oversized and there's nothing in there to take up that space. The head needs to be straightened properly using heat THEN resurfaced.

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vanbcguy said:

Yup, exactly this ^^^^
The cam journals will end up out of line. If you line bore them they'll end up oversized and there's nothing in there to take up that space. The head needs to be straightened properly using heat THEN resurfaced.

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Forgive my lack of posting. I've been busy with 10 year old baseball and family stuff.the car sitting in the driveway that only is safe to move for 10 minutes at a time is kinda low on the priority list. but my schedule will be freeing up soon now that the boys will be out of school and baseball will be done. I've worked in shops where I've done this type of work (building a fixture to mount the head to and heat it). however I don't have access to a high flow rosebud and for a diy job I don't think this will be applicable.

if I pull the head and check it's surface for flatness and or damage would it simply be adivsable to buy an ebay head?

I wouldn't mind doing valve guides, but if I had to redo valve seats to match up with the new head surface measurement I'd rather just buy a new head I think,

If you have some time to play with the easiest thing to do is to send your head out to Frank (Franko6 on here) and have it rebuilt. Then you'll get it back looking better than new!

Checking it for straightness would be valuable - if it is still within spec you might be ok with just a resurface.

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vanbcguy said:

If you have some time to play with the easiest thing to do is to send your head out to Frank (Franko6 on here) and have it rebuilt. Then you'll get it back looking better than new!

Checking it for straightness would be valuable - if it is still within spec you might be ok with just a resurface.

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I've tried using the search tool to find franko6, however I was unable to find him, any chance you could tag him or link me to his info so I could message him? I have some time, if especially if he's good to do it for a good price.

seabassisanalien said:

I've tried using the search tool to find franko6, however I was unable to find him, any chance you could tag him or link me to his info so I could message him? I have some time, if especially if he's good to do it for a good price.

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Nevermind I did a little extra digging and found the community contacts feature.

does he still frequent the forum often? he joined in 2005!!!

Hi Josh,

Some of the information you have received on this blog is correct. I can distinctly say, we have been told for years what we can't do. For example, we have been told you can't deck the head gasket surface. You can't cut valve seats... you can't regrind valves... BUNK! We have repaired somewhere around 6,000 cylinder heads (seriously, I've lost count...) and continue to perform repairs and as possible, improve our technique.

I have a great deal of trouble marching in lockstep with those who say 'Das ist VERBOTEN!!' We are more likely to tell you what does work. We can rebuild a cylinder head and once we have, we have seen them last well past 250,000 additional miles. Some, have past 500,000 on the rebuild. There are many tricks of the trade we perform that most don't even know about. For example, getting cam cap clearances correct, polishing valve tulips and deburring the finger-cutting head gasket surface edges are some of the things we do that are the norm for our product.

It is correct that if you have overheated the cylinder head, you need to address the warp. The trouble is that the head and the block warp in opposite directions; the head warps down it's length and the block warps from side-to-side. In other words, the low spots in the block are the webs between each cylinder and the high spot in the cylinder head is between #2 and #3 cylinder. Very often, in order to truly get the head flat, both block and head should be decked.

Checking the block is fairly easy and can be done with a machinist's block, laid across the bolts side-to-side that are in line with the web between each cylinder set; 1-2, 2-3 and 3-4. If you set a bright light behind the gauge and see daylight under the gauge, you have a block that has warped into a valley, with the sides of the block being higher than the webs. Alternate method is to strike the top of the block with a flat bastard, single-cut file and see if the block is high at the edges or if it strikes the center webs.

The cylinder head under the conditions you describe is warped. And it is true, if you mill the head gasket surface flat, you build the cam journal warp into the head. That can have disastrous consequences, including destroyed journals and heat-fractured cams. Once the warp has been diminished, we mill the head gasket, then check the cam align bore for straightness. The warp can be checked by the novice by removing the cam, cleaning all the oil off the journal saddles and cam itself. Then reinstall that cam in the saddles and push on the #1` and #5 journals to see if you can teeter the cam in the center journal. If it rocks, it need align bored. We have the specialized tooling to correct the alignment for all 1.6-1.9 engines and another set of tooling that corrects the cam alignment for the PD and Common Rail engines.

If you like, email your contact information: name, address, ph#, email address, year and model of vehicle and we can provide an estimate and shipping label, if you like.

Thank you for those who recommend our service. We appreciate it.

Frank's work is outstanding, much cheaper than new, and a proven quantity, not so with a junkyard or eBay head. For the money it's cheap insurance.

This was a 244K head I sent him to refurbish and replace the original 393K head when my head gasket let go due to a new water pump that was bad.

Thank you, Mark! It is nice to be appreciated. And also to you, Vanbcguy!

By the way, that is a really neat picture, with the record-player shiny valves, but what is the light beam coming from the bottom of the head? A flux generator?

Don't burn yourself on the pulse generator.

Moroza,

I have to disagree with you on a few points.

1. The cam alignment can actually take some 'abuse'. There is an about 1-2 degrees of positive movement on the cam that can improve hp. That has been proven with cams like our Stage II ALH and PD cams.

2. The usual reason that a warped head that is milled does not cause cam issues is that the warp is minimal and the cam caps have not been given proper clearance. We don't often mention this facet of cylinder head reconditioning, but the wear in the caps causes the top cam cap to wear egg-shaped. The cap contact face must be reduced to create proper cam clearance. This is one of the places that can cause insufficient oi pressure in the ALH/ AHU and previous OHC engines. But, adjusting cap clearances will also cause the cam to bind in a warped cylinder head when the correct .001"-.0015" cam cap clearances are maintained. We have seen cam alignment is sometimes warped as much as .006". Correct only the cam caps and you will burn the cam, usually at the #1 journal.

3. We do use the dealership for many items, as they are the only place to get genuine, however any of the vendors for VW, such as Kolbenschmidt, Victor Reinz, Nural and a myriad of others, we can get much better pricing for the exact same item. One of the items we buy aftermarket are head bolts, with thousands purchased; no issues.

4. Last, tooling... We provide tooling for purchase or rent. I suppose you could write a program to CNC a tool, but I think borrowing them works more time-efficiently. That does not mean we do not admire and employ CNC machines. We do and will be adding more machinery with announcement for 'Grand Opening', hopefully very soon.

Todd,

We have seen too many disasters when attempting to install bearings similar to a PD head in an ALH/AHU cylinder head. Although I believe it is possible to repair in that manner, we think by the time you get it right, the cost will dictate to junk the head. However, we have and continually do repair warped align bores with a custom-made align bore bar. Although you could probably get some company to set up with a align boring machine, it's usually around $250 for the setup and cut. Our cost is most typically under $100. The other problem is that the bar needed is smaller than what is generally used, so nobody has one. That is the reason for our custom align bar. We are only one of two I know who have one.

That's informative, thanks; I learned something new about camshafts and warped heads. But I think you switched from talking about cam alignment to cam timing. Custom cam timing - especially with custom cams and/or other engine mods - can make more power, but I don't think that holds true for camshaft slop/misalignment.

Not sure what you're disagreeing with as I made no assertions regarding cams, only questions. Regarding dealership parts - of course the dealer is going to have OEM parts, but that doesn't mean the part isn't made in China, which was the question I answered. Victor Reinz thus far seems to have stayed out of the outsourcing mess, but if I bought OE (Reinz, for the sake of argument) head bolts from the dealer that were made in China (or worse, India), I would return them and source NOS ones made in Germany.

Moroza,

I should have said 'cam timing' rather than 'cam alignment'. Alignment is how straight the journals are. My mistake there...

Thanks for your input, Moroza.

Franko6,

I'll be tearing into the motor within the next month or two, I'm in no rush to get into it, but once I do it'll be a sprint, Im going to buy the timing tools, the bentley manual, and the VAGCOM first and within the next week or so, I want to encounter as few delays as possible as this will be in the spare wash bay at the collision shop I work in. which is OK during the summer when there isn't ice on the road and deer aren't jumping out into traffic begging to be hit.

I want to thank you guys for your input,

Franko6, I feel very confident I'll be shipping a head to you in the next few months

I'll be filming a video that success or fail will be posted here, (if successful i'll try to get it some views for people working on the same process to easily find it) if unsuccessful, I'll simply post it for everyone here's own enjoyment/cringe.

BleachedBora said:

And any OE brand is fine on the bolts, Victor Reinz or Elring. Febi are reboxed Elring usually.
-BB

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moroza made mention that febi bolts fell victim to chinese QC issues?

I want this project to proceed as quickly and with the highest % of success as I possibly can, does this mean I should realistically stick to just the Victor Reinz or Elring products?

I've worked the last week straight of doubles and will start buying materials to prepare for this adventure on friday