Exhaust Manifold Replacement

[rickv100]

My S109 has developed a leak around the exhaust manifold. It looks like some type of silicone sealant was applied to it before. The mating flange to the exhaust pipe also has one of the corners cracked off so I am replacing the manifold.

I have purchased the manifold, fixing kit and gasket to replace the manifold. Is there anything else I should pickup prior to starting work?

I will review the manual but would it help to remove the drivers side fender to get easier access to the manifold?

Rick

[east high]

I just did this job two weekends ago. I decided not to remove the wing as mine is a LHD and all the steering bs would still be in the way. I recommend soaking the bolts with some PB Blaster or the like a day or two before tearing into it. There's a chance you'll need to replace some of the hardware too.

Reassembly is much easier if you loosely install the exhaust manifold first before sliding the intake down on top. Those little spreader nut/bolt things are a pain to get started with both manifolds in place. Remember to keep it as loose as you can as there are two locating dowels on the head you need to sneak the intake by.

[rickv100]

Thanks for the tip. Does anyone know if I can use Permatex Copper Anti-Seize instead of the Foliac J166 called for in the manual?

Rick

[SafeAirOne]

Not sure of the 2.25 manifold setup (whether bolts or studs are used), but I've taken my cue from the aviation maintenance community and used brass nuts to secure the manifolds on my 2.5. That way, I'll never have to worry about breaking off a stud when I have to mess with the manifolds 10 years from now.

[Broadstone]

Reassembly is much easier if you loosely install the exhaust manifold first before sliding the intake down on top. Those little spreader nut/bolt things are a pain to get started with both manifolds in place. Remember to keep it as loose as you can as there are two locating dowels on the head you need to sneak the intake by.

Check that your intake manifold fits on the new exhaust manifold before you even try to put anything back together. I had to grind a bit of the cast material of the exhaust manifold to get my intake to fit on. I took both off attached together and also assembled the two before installing. Enjoy the smell of the new manifold.

[parrie]

Rick, I've used the copper anti-seize on numerous exhaust projects as well as hi-temp industrial applications, it should be fine. Make sure the threads are clean and free of dirt/rust.

[siii8873]

I also did this job recently except it was both the intake and exhaust which I did not seperate. Be sure to put everything in loose and make sure the dowel pins engage in the manifold befor tieghtening everything up. Mine was a real tight fit on the outer holes and had to be aligned very well to engage on the pins.
I like the brass nuts idea, think I will change mine over.

[SafeAirOne]

I like the brass nuts idea, think I will change mine over.

It's time well-spent.

[jac04]

Does anyone know if I can use Permatex Copper Anti-Seize instead of the Foliac J166 called for in the manual?
I don't think your question is fully understood, that's why people are talking about using anti-seize on the threads.

According to the manual, they want you to use the J166 anti-seize on the mating surfaces between the head and exhaust manifold only. This is called out because originally there was no gasket between the exhaust manifold and head, only between the intake manifold and head. Now it is typical to use a single gasket that seals both the intake & exhaust manifolds to the head, so no anti-seize is required on the manifolds or head.

[gudjeon]

There is better luck had in using the one piece gasket that seals the intake and exhaust ports. The later two gaskets to seal just the intake was a "later" rover idea. I say it in quotes as I have no idea when the change was made

[rickv100]

Jac thanks for the response, that was the question I was asking.

How long should it take to do this job? I am allotting an entire day assuming worst case scenario(Rusted bolts, etc)

Rick

[jac04]

I am allotting an entire day...

Yeah, that should cover it. Seriously though, it shouldn't take more than an hour or so as long as you don't break off any fasteners in the head. I've removed many manifolds and never had a problem with a manifold to head fastener. Now, the 3 studs to the front exhaust pipe are a different story. You don't need to worry about those since you have a new exhaust manifold. The biggest PITA will be cleaning off the mating surface on the head.

[tmckeon88]

There used to be a stainless steel/brass fitting kit for the exhaust manifold available from British Northwest Land Rover. You might also be able to source stainless fittings at your local hardware store. That plus the anti-seize stuff makes later disassembly much easier.

Tom

[rickv100]

Many thanks for all the tips. I have ordered some surface conditioning discs from McMaster so I can clean up the mounting surfaces prior to installation.

Looks like I am all set.

Rick

[rickv100]

The manifold replacment went pretty easily it took a bit longer then expected as I did not order new studs for the intake/exhaust manifold connection and the old ones were pretty much welded into the old exhaust manifold.

After installing the manifold the truck now sounds like crap. seems like alot of valve noise. I torqued everything down as per the instructions and installed all bolts in there previous locations.

I have to adjust the valves and timing to see if that resolves the issue.

Rick

[SafeAirOne]

After installing the manifold the truck now sounds like crap. seems like alot of valve noise. I torqued everything down as per the instructions and installed all bolts in there previous locations.

Valve noise? Like a ticking? Not sure how manifold work would affect the valves. However, an exhaust leak at the manifold = loud ticking sound.

I'd get a length of vacuum hose, stick one end in my ear and probe around the manifold area with the other end till I found the leak, were it me.

[gudjeon]

Any exhaust leak will make it sound like its ticking. Usually a culprit is the joint to the exhaust pipe. The ball and socket of this must be cleaned and I use some exhaust cement to make sure on these. Rust and old hardened crap will make it impossible to seal properly once removed.

Note to self: must tighten up mine as it has left black spots on the down pipe.