Intake manifold gasket

[pavel]

Capt Ron: before you decide to pull the heads, consider the fact that it involves a fair amount of work and money. Also, you need an 'angle attachment' for you 1/2" socket drive. I broke 2 sockets removing the head bolts last time.

1 Do you have other transport if your Disco is sidelined for a week or more? (It took me over 2 weeks to do the last head job on our Disco.)
2 Do you know when the heads were last off?
3 Is there any evidence of coolant in the oil?
4 Have you done a compression check lately?
5 Has she ever overheated in your experience?
6 Are you planning on keeping the truck for more than a few years?
7 Is the truck worth it?

If there is good even compression, no evidence of 'antifreeze' in the oil, then it's a tossup whether or not it's wise to remove the heads. Personally, if all is OK now, I'd leave the heads alone and pray nightly to one of the Automotive Goddesses as well as "Lucas - Lord of Darkness"

[Capt. Ron]

Long story short: I feel like there is something wrong with the motor, power wise. The P.O. did some work on it and I inherited the problems. I've got a decent set of tools I've acquired and when I run into something I need, I got get it. So, to answer your questions Pavel:

1) yes, god I hope it doesn't rain (see avitar)
2) three years ago? maybe more?
3) no coolant in da oil
4) compression is between 120 ish and 130. Could have been my fault for readings though, had never done it before and wasn't sure of the correct proceedure.
5) yes, but it doesn't seem to have effected anything
6) ? I love my Disco, but I'd like an '04...
7) what are we talkin' $500 U.S.D.? There's a place close by that will level the heads. But if I include a valve job, it will go UP! Maybe $1000 total? Sure beats $400 car payment for 3/4 yrs.

[p76rangie]

Originally Posted by Capt. Ron

Long story short: I feel like there is something wrong with the motor, power wise. The P.O. did some work on it and I inherited the problems. I've got a decent set of tools I've acquired and when I run into something I need, I got get it. So, to answer your questions Pavel:

1) yes, god I hope it doesn't rain (see avitar)
2) three years ago? maybe more?
3) no coolant in da oil
4) compression is between 120 ish and 130. Could have been my fault for readings though, had never done it before and wasn't sure of the correct proceedure.
5) yes, but it doesn't seem to have effected anything
6) ? I love my Disco, but I'd like an '04...
7) what are we talkin' $500 U.S.D.? There's a place close by that will level the heads. But if I include a valve job, it will go UP! Maybe $1000 total? Sure beats $400 car payment for 3/4 yrs.

The big thing with heads is not taking them off, it is putting them back properly. The place they usually leak is simply from the front and rear water galleries. If you use coolant, you will tell if they are leaking by a white power left on the block after the water evaporates.

The problem with putting them back together is that with changes in the head bolt threads in the block over the years, it is difficult to get the correct tension. This means that even if you use a torque wrench, it will not tighten down properly. Within a relayively short time it will start leaking again.

So if you are going to do it, go and buy a set of ARP head studs to replace the head bolts. This will get the head tension correct as you are tensioning with steal thread to steel thread, rather than steel thread to alloy. ARP may not have anything listed under Rover V8, but they have them listed under the old Buick V8 on which the Rover motor was based.

[p76rangie]

PS. If you motor has done over 70,000 mile, the most likely reason for lack of power is a worn cam. So have a look at it, and check the lifters, while you have the valley cover gasket off.

[Rovin4life]

never reuse head bolts. In fact its included in any kit from ab or the dealer.

[pavel]

Yes, new headbolts are a must but be careful. I sent back a set of the headbolts because they were so poorly made - the threads were very rough and did not fully match from one bolt to another. Also, the heads were shallow. Ended up buying a set from the dealer (expensive but good). The parts guy wouldn't tell me where they crap ones came from (or he didn't know).
If you go the ARP stud route, please report back on the part numbers and how it went. Cheers.

[p76rangie]

Originally Posted by Rovin4life

never reuse head bolts. In fact its included in any kit from ab or the dealer.

I was not referring to the thread on the bolt, but the thread in the block that the thread screws into. After 2 leaking head haskets, I will NEVER use bolts again.

[Rovin4life]

if they leaked quick I would assume that the installer didnt follow directions or did something wrong at time of install.

other then warping a head or damaging the head they should last a long time.

besides studs are no guarantee of staying in place as well.

when you go to take off leaking head gaskets and find the head bolts tight then its a fair bet the issue is bad gaskets and not head bolts.

[p76rangie]

Originally Posted by Rovin4life

if they leaked quick I would assume that the installer didnt follow directions or did something wrong at time of install.

other then warping a head or damaging the head they should last a long time.

besides studs are no guarantee of staying in place as well.

when you go to take off leaking head gaskets and find the head bolts tight then its a fair bet the issue is bad gaskets and not head bolts.

They were installed correctly. Took a few years to start to leak again. Studs allow for correct tension to be obtained without the inconsistancies of steel to alloy and condition of threads. Steel and alloy have a reaction with each other. Just because that the bolts were tight to undo, does not mean that they were at the correct tension. The heat and expansion during engine operation changes the tension as well.
Nearly all leaking head gaskets on Rover V8s are from the front or rear water galleries. Even though there is no definitive reason for this, incorrect tension is a likely factor. The studs are about the same price as new bolts, so why not go for the better option and eliminate one risk.

[apbtpetey]

If it were me personally I would do the head gaskets. When I did the head gaskets on my 97 Disco I got a top end kit from AB along with the bolt set they sell. Give them a call if you haven't gotten the parts as they will make sure you get everything and make sure you have all the correct parts.

The bolts can be a real bitch to break loose, but all in all doing the head gaskets on the rover 4.0L was one of the easiest head gasket jobs I have done on a v-8 engine. Just take your time, make sure you clean everything good, I didn't use any of the rtv sealant or gasket compound stuff and didn't have a single problem by not using the stuff, and make sure you torque everything correctly in the right order. Follow the repair manual and you'll be set.

ps- The rear head bolts can be a royal PITA, but just relax and everything will come apart and go together just fine.

I had the heads and everything apart in one afternoon and it took one afternoon to put all back together as well. Longest part of the job is waiting for machine work if you need it done.

[Capt. Ron]

Doing the heads is an "idea" right now, they're not leaking. Anyway, this motor has over 191k and the earliest I could do this would be mid December. But it sounds like fun. I might also replace the cam with one of those Crower jobs. Thanks for all the input. Now, who will supervise?

[apbtpetey]

Originally Posted by Capt. Ron

Doing the heads is an "idea" right now, they're not leaking. Anyway, this motor has over 191k and the earliest I could do this would be mid December. But it sounds like fun. I might also replace the cam with one of those Crower jobs. Thanks for all the input. Now, who will supervise?

With that many miles I would without a doubt do the head gaskets and have the heads looked at. Trust me there is more than likely alot of crap built up in there. If you are taking stuff off to get to the intake gasket whats a few hours more worth of work Again it all depends on how comfortable you are with doing the work and how much time you have.

If you were close to NY I would come give you a hand with the work.

[flunkster]

do it all at once....

head gaskets, 3 angle valve job, rebuild oil pump and new camshaft (the crower kit includes chain, gears and lifters). in doing all this you will have new seals/gaskets galore and freshly torqued bolts abound. everything else that breaks is easy breezy.

enjoy!

[Capt. Ron]

OK, several more years of life for what...$1200-1500?

Cam options have been mentioned, Crower 258 or 260, w/kit

Three angle valve job

New ARP head studs, as opposed to new head bolts

New valve cover bolts

Torque wrench-to what N-m/ lb-ft should I get?

Head gaskets

anything else?

[apbtpetey]

Originally Posted by Capt. Ron

OK, several more years of life for what...$1200-1500?

Cam options have been mentioned, Crower 258 or 260, w/kit

Three angle valve job

New ARP head studs, as opposed to new head bolts

New valve cover bolts

Torque wrench-to what N-m/ lb-ft should I get?

Head gaskets

anything else?

Not sure on the price difference between the ARP head studs and the head bolts, but I didn't have a single problem using the head bolts I got from AB

I would recommend the following kit from AB includes just about everything you need for the head gasket job(I am sure you can the same from any parts place as well) it has all the gaskets you'll need, plus valve seals. I would also change out the thermostat while in there and of course new plugs/wires. I forgot the exact torque specs, but if you have the shop manual they are listed in there.

http://www.roverparts.com/Parts/STC4082.cfm