3.9 Head Gasket / Liners - with pics - Opinions Please?

[Mike_H]

Firstly... Hi All. I'm new on here!

I'm not a Land Rover owner, but I did used to work there... had an office 20 yards from the old V8 line, back when they still built them on AGV's. Anyway, more on that later... first, the reason why I'm posting on here.

A friend of mine has a Range Rover Classic with a poorly engine. It's not really worth spending thousands on a new motor for it, so I suggested we should pull the heads off and have a look. The symptoms were very much like a blown head gasket or cylinder liner problem - pressurising the hoses, losing water, overheating.

Anyway, we took the heads off over the weekend, and here are some pics... I've wiped the loose oil off the gaskets and heads, and it doesn't look great to me... but I don't have anything to compare them with... opinions please?

At some point in the last couple of years, it's had some 'Wonder Seal' type of chemical in the engine. This fixed the problem for a little while, but it soon went again.

Left Hand Head

Right Hand Head

And the tops of the blocks - Left Hand First

and the Right...

In all the pics you can see there are some varnish marks across the gasket, and the metal faces... I think it's been blowing all over the place, but I'm not sure.

Also, does anyone know much about Cylinder Liner problems? How do you tell if they're leaking? There's a little bit of bore wear, but nothing terminal...

[FridgeFreezer]

Isn't liner slip usually evidenced by one or more cylinders being steam-cleaned? For the money I'd just buy a good running lump for a few hundred quid, Martin Toole (Toolie.V8 on eBlag) should have a selection from 3.5 up to 4.2 guaranteed running.

[Hybrid_From_Hell]

Well

I'll stick my neck out here and make a quick suggestion

You basically can't tell much from the engine in bits without lots of expensive testing, if as you say its had gloop shoved in that just covers up investiagtions even more.

The varnishing isn't odd at all, but you've got tin type gaskets which are frankly horrible, so my advice for a few quid is to clean the block face, head faces etc and refit heads with composite gaskets, new composite valley gasket etc and fire it up as see if it presurizes the system.

You may find it ok, if not then you know you have liner issues etc in which case go shopping maybe ?

For a set of gaskets I would see what happens

Nige

[Mike_H]

Well

I'll stick my neck out here and make a quick suggestion

You basically can't tell much from the engine in bits without lots of expensive testing, if as you say its had gloop shoved in that just covers up investiagtions even more.

The varnishing isn't odd at all, but you've got tin type gaskets which are frankly horrible, so my advice for a few quid is to clean the block face, head faces etc and refit heads with composite gaskets, new composite valley gasket etc and fire it up as see if it presurizes the system.

You may find it ok, if not then you know you have liner issues etc in which case go shopping maybe ?

For a set of gaskets I would see what happens

Nige

Thanks for the input, folks!

So you'd expect a 'cold water decoke' effect if the liners were leaking? There's certainly no evidence of that. The varnish under the gaskets seemed like evidence of big leaks to me though.

Also, I was thinking we should have the heads skimmed anyway. It's been suggested to me that we need to get the inlet manifold skimmed as well, so that the ports line up (although even a very heavy skim is only about 1mm, and I've read that the composite gaskets are thicker, so it should just about cancel out.)

The car's got a pretty hefty history folder, with lots of engine work, including a new cam. Don't think there's any for the head gaskets, so those could well be the originals (car's done 120k).

I'd have to say I'd be nervous about buying a 2nd hand engine, as it could have the same problems, although if it's a known good one, it's certainly an option.

...and I have some annoying newbie questions...

1. Head bolts - are they reusable, or stretch ones (I think they're stretch and we need new ones, but no sense in throwing money away if we don't have to)

2. Tab washers on the exhaust manifold - are they needed? One exhaust manifold had them, the other didn't.

3. Is there a limit of how far we can skim before valve-piston clearance is a problem?

4. What's the opinion on the outer row of head bolts on the Pre '95 MY engines - leave them out, put them in finger tight? Do the composite gaskets have holes for them anyway?

5. The push rods got mixed up - I guess we need to check valve clearances - is that right?

6. What's the best method of cleaning the block face? I've never done an ally one before (lots of ally VW heads on iron blocks, but not ally blocks).

Thanks for any input... I really wish I'd paid more attention - all those times I was at the v8 line and I haven't got a clue!

[steve_d]

Also, I was thinking we should have the heads skimmed anyway. It's been suggested to me that we need to get the inlet manifold skimmed as well, so that the ports line up (although even a very heavy skim is only about 1mm, and I've read that the composite gaskets are thicker, so it should just about cancel out.)

Head skim will be expensive against the value of the engine/car so don’t bother unless the head shows a real burn point. If that was evident then I’m sure you would have pointed to it rather than the generalized photos.

Just clean and fit composite.

I'd have to say I'd be nervous about buying a 2nd hand engine, as it could have the same problems, although if it's a known good one, it's certainly an option.

Depends how much you end up paying.

...and I have some annoying newbie questions...

1. Head bolts - are they reusable, or stretch ones (I think they're stretch and we need new ones, but no sense in throwing money away if we don't have to)

Later 3.9 had stretch bolts which can be identified by them having a flanged head (like the head has a washer built in). Earlier bolts with a separate washer are reusable.

2. Tab washers on the exhaust manifold - are they needed? One exhaust manifold had them, the other didn't.

Would not bother with them.

3. Is there a limit of how far we can skim before valve-piston clearance is a problem?

Don’t skim.

4. What's the opinion on the outer row of head bolts on the Pre '95 MY engines - leave them out, put them in finger tight? Do the composite gaskets have holes for them anyway?

Done up lightly as already said

5. The push rods got mixed up - I guess we need to check valve clearances - is that right?

They will need doing anyway particularly when you fit the composite gaskets.

6. What's the best method of cleaning the block face? I've never done an ally one before (lots of ally VW heads on iron blocks, but not ally blocks).

Just take care using the broadest scraper you can find which will minimise the risk of digging a corner in.

Steve

[Mike_H]

Thanks - good food for thought there. I'll check the head faces for flatness, and see what that yields.

I have some contacts in the cylinder head biz, so I wasn't expecting to pay more than about £30 a head for a skim - also still need to check the liners out. Someone's advised me that there's a clearance figure to check - 3-5 thou proud of the block face. Is that right?

[geoffbeaumont]

I rebuilt my old 3.9 with composite gaskets (heads and valley), no skimming, and had no problems whatsoever, so if you're doing it on a budget I'd just do that. I have to confess I didn't check the tappet preloads - the hydraulic tappets seem to be very tolerant of abuse .

The composite gaskets don't have holes for the outer row bolts, but you can cut notches with tin snips if you want. I did that rather than leave the bolt holes open - didn't fancy them filling with water then freezing. If you buy new bolts don't bother replacing the outer ones - you aren't doing them up tight enough for it to matter.

Cylinder liner issues don't seem to be anywhere near as frequent as people have you believe, going by anecdotal evidence. Very few reports of it on here, at any rate.

While you've got it in bits have a careful look at the condition of the camshaft, and also seriously consider replacing the timing gear (I didn't and seriously regretted it not long afterwards, although that does seem to have been a bit of a freak ).

[Hybrid_From_Hell]

Thanks - good food for thought there. I'll check the head faces for flatness, and see what that yields.

I have some contacts in the cylinder head biz, so I wasn't expecting to pay more than about £30 a head for a skim - also still need to check the liners out. Someone's advised me that there's a clearance figure to check - 3-5 thou proud of the block face. Is that right?

To the best iof my knowledge when the block is made the liners are shoved in and then the tops are decked, thus the liner should be absolutely level, however I have seen a liner moved down this was becuase the liner too short / bore into block on manuafctuer too big so liner dropped, but it stayed put. Therefore they SHOULD really be all level and flush, but if not it doesn't absolutely mean theres a liner issuem, just a maybe

Nige

[Mike_H]

I rebuilt my old 3.9 with composite gaskets (heads and valley), no skimming, and had no problems whatsoever, so if you're doing it on a budget I'd just do that. I have to confess I didn't check the tappet preloads - the hydraulic tappets seem to be very tolerant of abuse .

The composite gaskets don't have holes for the outer row bolts, but you can cut notches with tin snips if you want. I did that rather than leave the bolt holes open - didn't fancy them filling with water then freezing. If you buy new bolts don't bother replacing the outer ones - you aren't doing them up tight enough for it to matter.

Cylinder liner issues don't seem to be anywhere near as frequent as people have you believe, going by anecdotal evidence. Very few reports of it on here, at any rate.

While you've got it in bits have a careful look at the condition of the camshaft, and also seriously consider replacing the timing gear (I didn't and seriously regretted it not long afterwards, although that does seem to have been a bit of a freak ).

Hi Geoff

Thanks for the input - all useful stuff

There's a huge bill in the history file for a cam (and I think timing gear) replacement a couple of years ago. I did have a look down in the valley, and it looked shiny, new, and pointy in the right places.

Overall, there was no sign of steam cleaning in the heads or bores (as you can see from the pics) and plenty of head gasket failure, so I'm inclined to think it's not a liner issue.

We did mark one of the heads slightly when taking it off (those damn wires bolted to the back that we only saw once we started moving it), but I don't think that in itself warrants a skim. What does worry me slightly is that I'm not sure we got the bolts in 100% the right order - got a bit confused between middle and outer row, and the ones hidden at the back. They were still taken off progressively though.

So I'll check heads and block for flatness and take it from there.

Thanks!

[Mike_H]

While I'm on, I see lots of composite gaskets for sale from different sources, and at different prices. Any recommendations?

Also, where's the best place to buy a new set of exhaust manifold bolts?

...and finally, would you put the heads on with or without the rocker shafts? It strikes me as easier to put them on without, and pop the pushrods in afterwards - any thoughts? I think that's how they did it on the assemby line at Solihull too.

[Highway_Star]

Put the heads on without the rockers is fine, way easier.

I half torque the outer row of bolts, I've yet to have one pop it's head gaskets again.

I stick to genuine parts for gaskets, you know it'll fit then.

[Mike_H]

For example, are these any good - they're sold by RPI engineering, via ebay.

http://cgi.ebay.co.uk/Land-Range-Rover-P38...1742.m153.l1262

I try to buy OEM quality parts, but if I can avoid paying OEM prices for them, I prefer that route.

Any idea who makes the composite gaskets - Elring Klinger maybe?

The ones in the ebay link probably aren't OEM, as they're composite gaskets, but with the extra row of bolt holes (unless it was available as a service kit), but RPI seem to be a reputable company - and they should be, having seen the price list!

Thanks

[Bull Bar Cowboy]

I get most of my stuff from Real Steel ......................... they do 3 row composite gaskets for the 3.9..........Part Number AZ900 (46 thou compressed)

http://www.realsteel.co.uk/

Fitting the heads without the rockers is the preferred method ................... make sure the head dowels and holes are really clean before fitting.........also be sure to blow out the head bolt holes in the block with an airline ...............

Ian

[Mike_H]

Cheers, Ian.

As luck would have it, they're about 3 miles from my work! Will pay them a visit!

[Mike_H]

Thanks for all the help so far - with a bit of luck it's going back together this weekend.

I've been shopping for the bits we need, and decided against the special bolts on the manifold (for the heatshield) as they're 8 quid each!

The other one I'm struggling with is the Alternator Bracket countersunk screw (the one that sits behind the PAS Pump body, and bolts the alternator bracket to the end of the head). The man in the LR dealer couldn't find it, although I did give him some misinformation about where it was... just came home and found out I should have said Alternator Bracket, not PAS Bracket.

Anyway... has anyone put an engine back together without that fixing, or will the bracket fall apart if I don't use it?

Any options other than dealers for those bits? I think they're beyond my friendly local fastenings supplier, particularly as they're UNC thread (I think).

[Bull Bar Cowboy]

Yes the countersunk bolt is a slot head 3/8UNC .............. part number ETC8765.

If you omit the bolt the bracket has some movement which causes a slight twist and poor belt alignment.

Ian

[vougese39]

porus block will show as rust on the bores and as mentioned the piston and the head and valves will be steam cleaned as well by the burning on the coolant. on the early 3.5/3.9 engines pre suffix"B" the third row of bolts tip the head whenever i do gaskets on these i ditch the third row of bolts using the original tin gaskets will not be a problem ensure the faces are clean was there any traces of coolant in the rocker covers? if not i would be inclined to rebuild standard the composite gaskets are good but you usualy get oil leaks so it's a bit tit for tat over tin or comp. use the comp valley gasket but smear hylomar around the water ports to ensure a good seal and for the hassel change the stat as well

[Mike_H]

Right... it's finally back together and running. It's been sat at fast-ish idle for 20 minutes and warmed up nicely, sat at an even temp, etc. No sign of any oil or coolant leaks as yet, the cooling system behaved very well, in fact.

BUT:

It's not happy at tickover... I need to reset the timing as I had the dizzy out at one point, and just lined it up by eye (made a note of the position before I took it out) but I think there's more too it than that. It starts fine, but then idles lumpily, and will die if you don't wedge the throttle open. It was idling better before we took it apart - that's for sure.

I'm convinced the plug leads are in the right order - having checked carefully

The injector seals looked pretty bad, so do you think that would cause the issue? I'm sceptical that they'd let enough air in to cause a running problem

I'm even pretty sure we got all the wires and pipes back in the right place.

Do the hydraulic tappets need any more time to pump up?

Next stage is timing light, check the plugs, do a compression test, but any advice would be gladly received. From what's been written above, the valley gasket might be the place to look for air leaks?

The inlet manifold parts were all put together with hylomar, although the inlet manifold to valley gasket / head joint wasn't.

I'd suspect there might be an air leak, but the engine and fan make so much noise it's hard to tell... I'll have to get in there with a can of carb cleaner and spray-check. I'd normally expect an air leak to cause a faster tickover though.

[Hybrid_From_Hell]

er .

When you put the heasds back on you did use a new valley gasket didn't you ?

Theres no need for hylomar except the slightest smig of it where the end seals go ?

Nige

[Escape]

If possible, change the camshaft and tappets. The hydraulic tappets can take and mask a lot of abuse, but they do wear.

My Range Rover had it's short block replaced by the previous owner, but tappets and camshaft were reused. As a consequence, I quickly got backfires and am now doing a proper (but unexpected) rebuild...

[Mike_H]

It had a camshaft and tappets under the previous owner, and I did check for signs of wear - all looked pristine.

It's had new top-end gaskets - all of the composite variety, sourced from Real Steel. It got a smear of sealant on the valley end rubbers, but nothing else (I don't like using sealant normally, as it can block oilways, so I only used it where I thought it was really necessary). I only mentioned the sealant there, as one of the previous posts suggested it.... looks like opinion is divided on the subject.

If you'd had the heads off a v8, would you expect to have to reset the mixture and tickover? I guess with the compo gaskets (it had original steel ones in there) it's got slightly less compression, but I wouldn't expect that to make the difference I'm hearing.

So what are the common 'schoolboy errors' when rebuilding one of these? What will I have connected in the wrong place?

[Mike_H]

Any more ideas? Would leaky injector seals cause it to run rough?

Thanks!

[steve_d]

Have you checked the timing yet?

You may have put the dizzy back in one tooth out which would still run with the dizzy looking like it was in the right place.

Steve

[Mike_H]

Have you checked the timing yet?

You may have put the dizzy back in one tooth out which would still run with the dizzy looking like it was in the right place.

Steve

Not yet... currently working abroad, but will be back up there to check it all this weekend. I was trying to build a list of likely things to check, in advance.

I thought the dizzy was a slot type of drive, so I'm struggling to understand the 'one tooth out' comment.

[DEANO3528]

The slot is for the oil pump drive, it still has a skew gear drive from the cam to run the distributor. This is where it can get difficult as during a rebuild the pump drive can be misaligned to the cam gear which can result in mis-timing if you haven't encountered the problem before.