Intake Manifold Coolant Leak

[lionvt]

95 Disco I.

What has been an occasional drop of coolant has now become a stream. My Disco I is leaking coolant from somewhere in the intake manifold area. The leak is visible right under the throttle/cruisecontrol assembly right over the left valve cover. I can't tell exactly where. The coolant then runs down the oxygen sensor wire and boils up in a fabulous cloud when it hits the exhaust pipe. All the coolant lines are new and I've double checked all the clamps. I am assuming (but could be wrong I guess) that this is coming from somewhere in the intake manifold/intake jacket area.

My question: is this a call for pulling the entire manifold or is there (keeping fingers crossed) some easier possible fix? I notice that most manifold gasket repairs are due to oil leaks. This is coolant, not oil.

I'm not really sure where the coolant goes when it disappears into (and out of) those lines leading to the intake jacket which makes it hard for me to trouble shoot this.

I'm hoping that somebody here can explain this to me and tell me their best guess about where this leak is coming from.

 

[garrett]

very common leak. very likely can be coming from one of the end seals. but if it really is coming from the intake you will have to pull the plenum and intake. really not a huge job at all. just takes a little time. be patient and take pics if you are unfamiliar with this job.
just make sure you get that new intake gasket and the end seals on properly before seating the intake, etc.

the coolant leaks down the back of the motor and onto the cats. more than likely you will see a white residue on the cats. that is the burnt coolant. that is why you rarely can see it leaking. off the back of the motor, down the trans bellhousing and then the cats.

gaskets are about $35 or so in all.

 

[lionvt]

Where are the "end seals"?

 

[garrett]

they are located at each end of the intake (aka valley pan) gasket. they are held down with a metal bracket and bolt.
you will see them clearly when you take the intake off. they are rubber gaskets.

ps: do you know Mark Hamelin? he lives in Underhill. old co-worker when i was living in Burlington.

 

[Gordo]

oh yeah and

get the composite gaskets and follow the directions in the WSM. not a bad job just take your time. Gordo

 

[Chris-St Louis]

Be advised there are updated bolts with locktight on them from Land Rover.

Rover also wants to repalce intake bolts due to streach. The tend to loosten themselves after time, they say the updated ones wont.

 

[rover4x4]

yeah I am doing this job over thanksgiving. they said I needed the new bolts also I didnt know why now I do. there is some info on the yahoo 215v8 forum starting at post 3707 and also do a search here there are a few conversations. i think my ends seals are what is leaking. seems the hardest part is getting all the stuff out of the way to actually get to the intake.


can you pull the intake without removing the plenum?

 

[Chris-St Louis]

can you pull the intake without removing the plenum?

I take the 6 Bolts out, unplug the electrical connections, throttle heater hoses and fold it to the drivers side with the throttle/kickdown cables connected.

Wait, this is a D1 Right?

 

[rover4x4]

3.9 liter

 

[lionvt]

I bought some time. Maybe.

So I got lazy (all right, it was also freezing rain on the day I was working on it) and tried tightening the manifold bolts. I few of them moved just slightly -- but guess what? No leakage. That was a couple of weeks ago and so far so good.

I have the complete job scheduled (in my mind at least) for a warmer day or when I get my garage finished and heated.

 

[rover4x4]

when i took mine off some of the bolts were just about hand tight. they were easily removed with a open ended wrench. almost like they werent tourqued correctly when the motor was assembled.

 

[d1owner]

Which bolts did you tighten -- the 6 or 8 hex bolts on top of the plenum cover?

 

[rover4x4]

no the regular bolts that secure the intake to the motor, I didnt tighten them but they were very loose when I took the intake off

 

[rover4x4]

the plenum hex bolts were tight real tight. when I put it back together I put a little RTV on the mating surface

 

[tiggerjeep]

Time to dig up an old thread!

Sounds like I have a leak in the same area. It appeared to be coming from teh valve cover but reading I'm not so sure. IT is above the heads and I just had those redone last summer. How do I get to the intake manifold? I haven't been under there in a few days to look around. Any thoughts would be appreciated.

Thanks
Bryan

 

[rover4x4]

when i took mine apart the hardest part was all the ancillary bullshit in the way. I had a tough time with the fuel injector since i didnt wanna take the fuel rail off. its pretty easy to take apart only 8 bolts if my meme serves me right. take the plenum off, its the thing that saus in your case 4.0 i guess. just label everything thats what i did. it was easy and i bet i could do it again in 3 hours. it took me about 6 the first time i did it. an easy operation. good luck

 

[RoverDisco98]

Check the easy thing first and re-seal the thermostat housing. That's where my leak came from.