Manifold nuts

[DWW]

I got a question regarding the nuts both holding the manifold to the block and to the exhaust downpipes. I noticed an exhaust leak in the engine bay area so decided to check whether all those nuts are properly secured. I found quit a few of the nuts on the block studs loose some even finger tight. On the downpipes side they were all loose and three were missing, luckily I had some spares from my original manifold so replaced and tightened all so no more leaks now.

My question is in people's experience and opinion, do those work them selves loose in time or that the last to have the engine out were slack on properly tightening the manifold and especially the exhaust downpipes.

[christopher storey]

I assume that these are all brass nuts . If so, I have never experienced them coming loose of their own accord

[DWW]

Yes the are all brass nuts, if this is the case it must be that the last outfit who worked on my car (engine out) didn't do them up as they should.

[DWW]

Thanks Chris, in this case I am only to assume the last outfit that worked on my car (engine out) didn't do them up tight enough.

[christopher storey]

That sounds the most likely explanation : in fairness, it is rather difficult with brass to know when you have got them tight enough - there is a rather fine line between correct torque and stripping them - generally speaking ( although others may disagree with me ) I think the best technique is to tighten them with a shortish open ender or ring spanner to a reasonable feel of tightness, and then keep retightening at regular intervals once the engine has been run several times until they will not tighten further without considerable extra torque

[DWW]

Chris, that is exactly what I have done, used my set of small spanners for the most part

[dlgis]

I am frequently having to tighten the manifold nuts, more so the manifold to downpipe. And I’m using the brass nuts. I’ve fitted some Nordlock washers but won’t know if they resolve the issue until the car comes out from the trimmers next month. 🫤

[DWW]

So it is not that uncommon after all....

[mgcjag]

Hi Danny....there has been a lot of reports of manifold to downpipes comming loose...I never had a problem ...I have read about other that have used nordlocks....Steve
viewtopic.php?f=6&t=4774&p=33101&hilit= ... uts#p33101

[DWW]

Thanks Steve, will leave it as I tightened them and check it again from time to time, if I see a change I will take additional steps as mentioned to remedy.