Ticking noise

[jon haines]

I have a loudish ticking noise that sounds like an exhaust blow when accelerating but not cruising. It is also there on start up when cold but i cannot find an exhaust leak. Anyone any ideas?

[v8s4me]

Manifold gasket? Pin-hole in in the manifold?

[jon haines]

Thanks for the speedy reply i will have a look at those points.

[mrzigazaga]

Hi Jon.


Im sure someone I know had the same thing and that was a manifold gasket....

[adam quantrill]

Jam some card under the throttle stop then start it so it's on fast idle, from cold, you have about 60 seconds to get your hand down there and feel for the blow before it gets too hot to touch!

Nine times out of 10 you can just nip up the bolt heads a bit and it's usually obvious which one is loose as it will take a turn with not much torque.

[rev-erend]

Get someone to hold a large rag over the exhaust(s) outlet.. the leak will be a lot more obvious.

[jon haines]

Found it. Its coming from the nearside manifold at the front but bolt is tight. Could i get away with loosening it up and squeezing some exhaust sealant in then tightening up? i know it sounds like a botch job but its only 3 years since i replaced the gaskets and it wasnt a fun job.

[rev-erend]

The bolts at the bottom are difficult sons of b1tch3s to get at ..

Tighten all top bolts on that side first and then all bottom bolts too

Doing the tops first takes the stress off the bottoms.. allowing you to tighten them a bit more.

Personally I have changed over to ARP exhaust bolts as they are a smaller head and allow better access.

[adam quantrill]

I have previously loosened all the bolts and taken out the two for the offending gasket, then put some white sealant on the gasket faces, wait for it to mostly dry, and then slip it back in. You can lever the manifold away from the block with a jack handle to get more clearance.

[TVRleigh_BBWR]

I use ARP small head bolts also, make things a lot easier.
Biggest problem is if you remove the complete exhaust your may find the mating surfaces are extremely poor, and may even have gaps. Just tightening bolts can lead to them stripping the threads. the only real way to solve the problem is to get the holes filled on the surfaces and then re-ground flat.

Every service my car had, there was new gaskets fitted, but not since I done the above.

[adam quantrill]

Actually I have also been using copper gaskets now for a couple of years - they have the advantage that they are reusable. Mind you I had to make them by hand - not too hard with some tinsnips, but I'd rather do it on a CNC machine.

[jon haines]

When I did the gaskets originally I had to have the surfaces of the manifolds ground flat as there were as you said gaps/corrosion on the faces of both sides so I was hoping that I would not have to touch them again but hey ho.

[TVRleigh_BBWR]

jon haines said:

When I did the gaskets originally I had to have the surfaces of the manifolds ground flat as there were as you said gaps/corrosion on the faces of both sides so I was hoping that I would not have to touch them again but hey ho.

you could have a bad thread that's causing one of the bolts to come loose, this can happen if previously you have bad manifolds and they was done up too tight to try and fix the problem. I had to helicoil a few of mine.

[Tasmintvr]

TVRleigh_BBWR said:

jon haines said:

When I did the gaskets originally I had to have the surfaces of the manifolds ground flat as there were as you said gaps/corrosion on the faces of both sides so I was hoping that I would not have to touch them again but hey ho.

you could have a bad thread that's causing one of the bolts to come loose, this can happen if previously you have bad manifolds and they was done up too tight to try and fix the problem. I had to helicoil a few of mine.

[adam quantrill]

I have some soft alloy at the front of my RHS cylinder head and the two threads have stripped, so I tapped out to M10 and inserted some removeable studs, and then clamp that port down with M10 nuts. This has been in place for 8 years or so after tracing a similar noise to the top bolt being loose.

[jon haines]

Well i have sorted but for how long nobody knows! Loosened the two front bolts of the manifold squeezed some exhaust paiste in then tightened back up and hey presto. Fingers crossed thats that for a while. Can move onto the next job now.