Leaking exhaust manifold stud

[Andrew]

I've recently replaced the exhaust manifold gasket on my 10/4 Saloon.
The manifold took some removing and on replacing the studs one of the old studs snapped and had to be drilled out and re-tapped before putting in a new one.

All is now back in one piece but on filling the radiator there is a water leak which appears to be coming from the
the area around the replaced and re-tapped stud. It's a noticeable drip so it's a problem.

Any ideas?

Many thanks.

Andrew Slater

[Andrew]

I've recently replaced the exhaust manifold gasket on my 10/4 Saloon.
The manifold took some removing and on replacing the studs one of the old studs snapped and had to be drilled out and re-tapped before putting in a new one.

All is now back in one piece but on filling the radiator there is a water leak which appears to be coming from the
the area around the replaced and re-tapped stud. It's a noticeable drip so it's a problem.

Any ideas?

Many thanks.

Andrew Slater

[bob_allison]

There are many different sealants or adhesives which should serve . I would probably use J B Weld , simply because I still have some on the shelf . With a stud with a suitably tapered run out on the thread Hylomar or Hylotite 100 . If you can get a wisp of plumber's hemp a then use this and Hylotite 100 . It works for me on steam engine plumbing . I would send you some hemp in an envelope , but all mine is 60 miles away on the engine .

[Rod]

I've used Loctite 567 many times for this sort of job on other vehicles. If you're feeling lucky, you might be able to double nut the stud, remove it without having disturbing your previous work, apply the sealer to the thread and put the stud back in again.
Non-hardening, if it doesn't work, no harm done. Can be a bit pricey that's all. "Stag" brand sealer I've also used before, that would work too but it can be a pain to clean up/remove later. Have you considered trying some plain old PTFE thread tape?

[Andrew]

Many thanks both for your helpful replies.

Good to hear the comment on PTFE as this was one of my lines of thinking, along with the hylomar products.

With an abundance of time on my hands at the moment, and as both of these are in the garage I'll give it a go
this afternoon and see how things work out!

All best.

Andrew

[peter_winney]

Andrew
Please post idc how it works out. A successful solution is useful for all to know
PW

[ted_prest]

I was going to advise using thread tape,PTFE,as on all the Petro chemical sites i worked on it was used on all pipework threads against high pressure steam etc so it will do i am sure,plus its dead cheap to buy it in fact you might even have some,positive it will work i have used it on many a car over the years.Ted

[Andrew]

Just an update to say that PTFE tape and hylomar blue successfully stopped the leak from the manifold stud on my 10/4.

All back together, no leaks and started up this evening which opened up a number of other issues.
The old girl is certainly not firing on all cylinders but I think that might be plugs and I'll investigate that tomorrow.

Much more worrying was that having run up to temperature (albeit with the engine not running very well) the engine got incredibly hot
and the exhaust pipe literally verging on red hot. Turned everything off, water clearly bubbling in the engine and it looked as if the side core plugs were about to burst out - one started weeping. This doesn't sound right to me. I'm scratching my head and then wondering whether the hylomar might
have blocked a water channel?

Advice would be welcome - I'm loathed to run up to temperature again.

All best.

Andrew

[stephen_voller]

Hi Andrew,

Unless you pumped a lot of sealant in the stud hole I can't see that being the problem.

Firstly we have to ask was the engine running alright before this manifold work occurred.

Secondly if it was running ok before has anything else changed?

Something as silly as the fan belt slipping could be an issue - as although it mustn't be too tight if it's slipping you will get problems.

There other things to cause over heating but we have to start somewhere.

Steve V.