Intake Manifold Gasket

jimbob · Post by **jimbob** » Fri Dec 04, 2015 8:05 am

Hi,

as the title suggests i've a few issues & questions.

Checked my water level yesterday it needed topping up the first time in about 11months. Which has started me looking for leak.

Looked at the back of the V8 towards the top of the bell housing, piston 7 showed signs of cooling leaking down the block.

I thought bugger head gasket, oil is good, no missing, performance is still on the button, no steam out the exhaust etc.

Then i started to look at where the intake manifold joins the head, as there's a port that allows coolant to flow, so I'm hoping that its weeping out of there and running down the back of the head then down the block.

Ordered a new manifold gasket, this has been on for 45,000miles so wont go a miss, when I changed it last time I used RTV, my question has anybody else seen leaks from this area?

I was going to re-torque it up for interim, until I can take the Disco of the road.

Next question should I use RTV again or Hylomar at least that stays sticky and doesn't set when I place the new gasket on.

Cheers

James

DaveEFI · Post by **DaveEFI** » Fri Dec 04, 2015 9:25 am

My very first Rover factory manual for a P6 V8 recommended Hylomar only round those water ports on the inlet manifold. But that was with the shiny gasket - don't know if it is still needed with the black coated types.

But do make sure it's not something like a heater hose leaking and water finding its way there.

ChrisJC · Post by **ChrisJC** » Fri Dec 04, 2015 7:41 pm

You could just check that the inlet manifold bolts are all torqued up correctly. I have had them come loose in the past!

Chris.

DaveEFI · Post by **DaveEFI** » Sat Dec 05, 2015 12:11 am

ChrisJC wrote:You could just check that the inlet manifold bolts are all torqued up correctly. I have had them come loose in the past!

Chris.

I'll quote something else from that early RV8 manual. The use of Scotch 776 thread sealer. As well as preventing bolts into ally corroding, it seals the threads and locks the bolts. So I use it on every thread that goes into ally.

Without it, I'll bet the 1/4" bolts to the water pump will shear when you come to change one when it fails some years down the line.

jimbob · Post by **jimbob** » Sat Dec 05, 2015 3:16 pm

Gents,

Thanks for the replies.

Ran the Disco around a bit the last few days about 160miles, hasn't lost any water, checked all the hoses & Radiator.

Degreased the whole engine now, going to re torque to the manifold bolts again on Sunday, Lets see where this takes me.

Just a shame I couldn't add some UV dye to the coolant so its easy to see any pinholes where it could be leaking.

James

DaveEFI · Post by **DaveEFI** » Sat Dec 05, 2015 4:52 pm

I have a pressure test kit bought from Ebay - has adaptors for most rads.
As well as the obvious, it allows you to bleed a system cold with the engine stopped. If it has bleed screws.

SimpleSimon · Post by **SimpleSimon** » Sun Dec 06, 2015 2:55 pm

If your using the composite/black/coated gasket you shouldn't need any sealer around the water ports etc IMO unless you have pitting etc on either the heads or intake manifold

unstable load · Post by **unstable load** » Sun Dec 06, 2015 4:56 pm

Give it a coat of Indian Head shellac, IMO.
Can't do any harm.