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Nervous about doing my first head gasket

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Totally apprehensive about getting this right, but I'm doing my homework, and have my Haynes, RAVE, and this thread: http://www.aulro.com/afvb/projects-tutorials/66259-td5-cylinder-head-removal-how.html

But if I could get a dig out with the answers for these few questions I'd be very grateful

1. Should the gasket be changed A. like for like, B. dependent on how much the head is skimmed, or C. as I've read elsewhere put a three hole gasket on regardless?

2. I read that you need to support the top cam sprocket so the chain doesn't slip off the bottom sprocket, but the guy above doesn't seem to. Do I need to and if so any tips?

3. Should I buy the proper cam lock do-hickey or is a bolt/screwdriver/some other thing fine for the job?

4. Slightly off topic but can a blowing H.G. allow exhaust gases to contact fuel? My fuel pump had a thin layer of black all over it. Will do my injector seals regardless but just interested.

Thanks for any help in advance

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Totally apprehensive about getting this right, but I'm doing my homework, and have my Haynes, RAVE, and this thread: http://www.aulro.com/afvb/projects-tutorials/66259-td5-cylinder-head-removal-how.html

But if I could get a dig out with the answers for these few questions I'd be very grateful

1. Should the gasket be changed A. like for like, B. dependent on how much the head is skimmed, or C. as I've read elsewhere put a three hole gasket on regardless?

A. The head gasket should be changed like for like. Aparently TD5 heads can't be skimmed, but if they where to be skimmed you would have to reccess the valve seats, so you would still need the same head gasket!

2. I read that you need to support the top cam sprocket so the chain doesn't slip off the bottom sprocket, but the guy above doesn't seem to. Do I need to and if so any tips?

A. When I did mine, I think you can let it sit in the two chain guides bunched up, or you can cable tie it out the way. On reassembly you will need to make sure you've pulled the chain up and its sitting around the crank sprocket.

3. Should I buy the proper cam lock do-hickey or is a bolt/screwdriver/some other thing fine for the job?

A. I found the proper timing tools (the cam and flywheel tool) set is only £7 so it hardly seemed worth making something!

4. Slightly off topic but can a blowing H.G. allow exhaust gases to contact fuel? My fuel pump had a thin layer of black all over it. Will do my injector seals regardless but just interested.

A. When I changed my fuel pump it was a black colour, I think it was just the oil in the diesel, so nothing to worry about.

Thanks for any help in advance

You should be fine, just dismantle it methodically taking some pictures along the way, looking at the ozi how to guide which is very good. Although the head bolt sequence sounds horrific, just do it methodically, thats what Land Rover decided!

Good Luck!

Steve

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A fuel pump that is black, is passing injector copper washers & orings

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Thanks lads, any take on the topic is appreciated. I've obviously a bit of homework to do, but plenty of leg work on the strip down first.

There seems to be two distinct schools on whether or not skimming is ok, and I can't find a direct line about whether there are varying H.G.'s to compensate for a skim. Tbh I'm praying the head is straight, but then there are the folk who say it should be skimmed regardless.

About the injector seals, I found that Turner Engineering do a Td5 H.G. kit that includes injector seals and washers, that'll do so.

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I got sall my stuff from Turners, very helpful!

If the head is straight/flat then it doesn't need to be skimmed!

Steve

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When the head is off, you need to take it to an engine machining workshop, they should pressure test first (which will involve checking flatness) and then only skim if necessary. Don't be surprised if it fails the pressure test, i've known a few td5's now that have had a crack between a coolant passageway and no.1 cylinder inlet valve. They're also known for cracks between fuel rail and oil passageway.

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Thanks mate, yeah I'll be sure to have it tested. Presumably it doesn't matter if I have the injectors out before the test? Dreading the results. Captain optimism here.

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That linked thread on aulro is mine. I put about 4 showing the process start to finish and they are all on there somewhere.

I have done quite a few and they have all been skimmed with no issues. In fact the machine shop I use had done quite a few for the local main dealer I believe.

Having said that take off as little as possible if it needs to be done. <7 thou ideally seems to be wise. Never done anything with the valve seats.

The car shown in that thread is mine and is still getting thrashed around relentlessly with no further issues!

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Pete, you're a legend mate. Even just that one post of yours has been extremely helpful. Thank you. Worth saying, the aulro community is amazing in general, for the sheer level of coverage on every topic, Land Rover or not!

I've since spent a hell of a long time online (for someone not looking for porn :D ) and have just posted the following to another H/G thread in the Discovery section here (entitled: "Td5 Head Gasket Check List"), so I thought I'd put it in this thread too in case anyone ever finds it:

Dave, Steve and Mike, thanks to you too guys.

I've stripped everything and have only to actually pull the head. Hesitated because I ordered the timing tool and it hasn;t arrived, but have to just go for it with a bolt or drill bit this morning.

So I have a list of the parts I'll be replacing. This list assumes buying the Turner H.G. kit which comes with inlet, exhaust and rocker cover gaskets, head bolts, H.G., injector seals & washers and head dowels.

ERR6299 - Oil Centrifuge

LPX100590 - Oil filter

LRO47208 - Air Filter

ERR6788 - Exhaust to Turbo Gasket*

ERR3737 - (ESR3674) Exhaust Gasket Turbo to Downpipe - No need to crack both turbo gaskets, the bottom one prob best.

LVJ000010 - Coolant Elbow Gasket - See below. Makes replacing broken head stud easier.

ADU6847L - Copper Washer - Turbo Oil Feed Banjo (x2)

ERR7098 - O Ring - Oil Cooler (x2)

ERR7220 - Oil Cooler Gasket

LDI1000030 - Cam Sprocket Plastic Cover - My cover was loose so needs to be replaced.

PNT1000030 - Turbo Oil Return Gasket

ERR5369 - Rear Camshaft Oil Seal

LXI100000 - Copper washer for timing chain tensioner

PEM500040 - Water Pump (from Turner at Stg£49.50)

LYG101510 - Rocker Shaft Bolt (x6)

?? - P/N for Alternator vacuum pipe to cyl head o ring?

Head Gasket Selection:

Some definitive info on the H.G. thickness. As Ally V8 (thanks for the advice mate) alludes to, the thickness is dictated by how much the tallest piston protrudes from the block at TDC. Haynes quotes these figures for selecting the gasket depending on our results:

Piston Protrusion Gasket Identification

0.351 to 0.500mm 2 Holes

0.501 to 0570mm 1 Hole

0.571 to 0.650mm 3 Holes

Now someone might help me with my decimal places (and math in general) but if I take what I've read as gospel - that is that the head can be safely skimmed up to 8 thousandths of an inch - and if 8 thou = 0.0254mm, then what should be the corrected values *IF* a head was skimmed 8 thou?

I can make a semi educated guess but I wouldn't want to expose my genius :D

Timing:

Another bit of potentially useful info I found is that it takes upwards of 20 turns of the crank for the two darkened timing chain links to realign with the mark on the sprocket when you get to that stage of reassembly. So don't give up early believing it's all wrong. They can and will come round without the sprocket mark.

Other Potential Problems:

I found that the forward most stud for my exhaust manifold was broken off in the head. Seemingly the exhaust manifolds on the Td5 like to warp. (something I was lucky to avoid on my other Td5). When they do warp it's common for them to sheer the head studs, predominantly towards the ends of the manifold. IIRC Turner Engineering do an oversized stud kit that comes with all the bits to - well make your studs bigger. You can also get a ceramic coated manifold, but as you'd imagine it's very expensive.

I also found that the ribbed plastic wiring cover for all the plugs that run across the front of the engine (water temp, MAF, A/C etc) had disintegrated and one of my wires was actually severed. I have a feeling it's for the ambient temp sensor. Do check all wiring.

It's definitely easier to strip off the oil cooler to make getting the inlet manifold off easier.

Having stripped off everything around the rhs of the engine, now's def the time to tackle the oil cooler. I'd be kicking myself if it let go later and I hadn't done it now. Same goes if anyone's considering EGR blacking, although that would only be a little more awkward if the engine wasn't stripped.

I'll be checking my PCV (the crank case breather valve), marked "TOP", as there is a lot of oil on the outside of mine. If anyone has a part number I can't find it. Here's how to check it's working:

"Removing the diaphragm if you suck and blow down the inlet from the crankcase there is no restriction, but place your thumb over the pipe that goes in to the inlet tract then suck whilst slowly removing your thumb and the valve closes off, so it works."

On that subject, there is a contraption called a Provent that you can put in place of that PCV, which will properly vent your crank case but also properly trap and return airborne oil before it gets into your turbo/intercooler/inlet.

Hope that helps. I certainly feel better for the knowledge, although today is make or break (literally) for my D2, cause I'll be F'd if I'm spending €1400 on a new head.

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Flippin hell... latest: the engineering place I was recommended say the head needs to be stripped (save for valves and glow plugs) to be pressure tested. Is this normal or should I be looking for another workshop? Maybe he just doesn't know the Td5 head that well and is covering his bases?

If not then add the following to the parts list - for resealing the cam carrier to the cyl. head.

Sealant - STC4600, STC611, Hylomar 2000 or equivalent.

The Haynes says I should throw away the injector adjustment screws and lock nuts and replace. In the real world is that right?

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I've never been called a legend lol ... Here's all the links for you! and an extra one if you ever fancy doing the full engine!

Also you will definitely need to separate both halves of the head.

You should also replace all the bolts that hold in the injector clamps and the rocker shaft. Turners will have all this stuff. Dont mess about if you are doing it.

removal:

http://www.aulro.com/afvb/projects-tutorials/66259-td5-cylinder-head-removal-how.html

Strip:

http://www.aulro.com/afvb/technical-chatter/66292-td5-head-strip.html

Assembly:

http://www.aulro.com/afvb/technical-chatter/66442-td5-head-assembly-pt-1-a.html

Fitment:

http://www.aulro.com/afvb/technical-chatter/66645-how-fit-td5-head-pt1.html

if you are ever super keen. full td5 rebuild!

http://www.aulro.com/afvb/projects-tutorials/139876-how-rebuild-td5-engine.html

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I've never been called a legend lol ...

You'd enjoy Ireland, we're all legends, least that's what we tell each other.

Thanks for all the links mate, very reassuring to have them.

I dropped the timing top sprocket today, and I think* it's still in the right place, I had the presence of mind to make a mark in the cam carrier before stripping it off, but now that it's gone I'm second guessing the position of the two darker links. I've read conflicting reports about whether the chain can jump a tooth on the bottom sprocket. Do you know?

As a matter of interest, why are your piston crowns patterned in a sort of star shape. Mine are uniform black, but kind of shiny from a certain angle. Save for No.1 that is which by the looks of the discolouration seems to be the offending one.

George

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As long as you put the timing pins in the crankshaft (flywheel) and the camshaft (pin at the front), you just need to make sure the chain is tight from the crankshaft going in an anticlockwise route up to the camshaft sprocket where it has three slotted holes. Then fit the chain tensioner with the three camshaft sprocket slightly bolts loose to get the chain tensioned before torqueing up the camshaft sprocket bolts.

Steve

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Thanks Steve. I've nothing in the flywheel - that's the first I've heard of it. I've ordered the LR pins and when they arrive I'll put the crank one in. Where is that? :D

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