Any advice about the tick, tick, tick sound.....I'm worried!

[Green is good]

My Chim (97 4.0, 41k and very well maintained) has developed a tappety sound that has started since I took it on a nearly 3000 mile trip around France earlier this month. Hell of a trip through the Alps, Menton and Monaco etc (loads of tunnels), anyway I digress. When there it was very hot and the car ran much much hotter than normal (it was 38c some days). It never overheated, in fact it never missed a beat, or used any water and only a small amount of oil but I noticed the tick tick sound. Since I returned home, I have hardly used it but took it out yesterday in the great summer sun.

The noise isn't there at start up, but gets louder as it warms up and is quite noticable when at low revs. It sounds to me like a loose tappet, like a badly adjusted one if you know what I mean. Not what I would call a knock.

Any deas about what I should do, I have seen posts with ideas that thicker engine oil might help?

[mb450]

My money would be on an exhaust system leak - manifold gaskets or at the weld on the headers or the usual suspects.

[Alexdaredevilz]

Is this your tick? About 16 seconds in video

http://www.youtube.com/watch?v=RstjSrv9Iko

[Harrytsg]

Liner?

[TVR Beaver]

More a 'tick' and not a rattle then?

[Timja]

Sounds a bit like mine had which was a hole in the manifold at the point the pipes go 4 to 1. Or may be manifold gasket.

[gruffalo]

Harrytsg said:

Liner?

They normally knock quite heavily when cold from my experience.

[Harrytsg]

gruffalo said:

Harrytsg said:

Liner?

They normally knock quite heavily when cold from my experience.

Good news for the OP, I hope its something easily remedied.

[.Mark]

Manifold Gaskets I'd say.

[BillC99]

It might be worth checking the pads on the rockers.

[TorqueVR]

I'd go with the manifold gasket as well. I had the same problem earlier this year(I called it a tap, tap, tap)and was worried that it was the top end of the engine. The dealer spent ages (well, all of 5 seconds) listening and correctly diagnosing the gasket.

[RichB]

Is it the clock?

[Green is good]

Right, got the interwebs back! Thanks for all the responses folks. No not exhaust sound like in the video clip, not a knocking sound either and only gets louder as it warms up, no noticable sounds when first started up. Sounds like it comes from the middle of the block, in the vee, but hard to tell exactly. Rocker pad did someone say? I mentioned it to a guy i know who used to work at a Rover garage years ago and he said it might be push rod or lifter. Does that sound right? Still goes well and good oil pressure etc. Liner? Wouldn't that be a loud knock. I hate these kind of things.

[cs174]

Check the oil level. It may have burned more than usual running at higher temp.

If the oil level is fine, my money is on the manifold gaskets (or the clock!)

[Green is good]

Well, I checked the oil level and that was fine, the clock was silent and I can't see a problem with the exhaust manifold so I think I will have to get it to a garage for an inspection. I think it is more of a 'tap,tap,tap' rather than 'tick, tick etc. It is so hard to tell where it comes from but I still think it is in the area between the cylinders (the vee). Thanks for the ideas from one and all. I will let you know who was right too, asuming they find what it is!

One final note, the guy in the garage near to me said he had a lady in with a car making a strange noise which she thought was something terminal. He took the car out and heard nothing. She came back and said it was back and it was only then that he realised that she had a dog in the car and it was the dog panting that made the noise! Consider everything!

[Alexdaredevilz]

Cam chain slapping about?

[TorqueVR]

So you've ruled out a dog then?

[v8 racing]

When a knock becomes louder with heat it wont be the exhaust, they tend to be more noisy when cold, and even more so under under load, there are however a few items that cause a tap when warm, yes you could have a moving liner, although extremely rare, the little end on the piston takes a while to warm up and can cause a light knock/tap, and also a slightly worn camshaft, the preload on the lifter is set to around 30thou as standard, when hot this size decreases to around 10-15 thou, if the cam is worn and has taken a lifter with it you only need to loose around 15 thou before you have a floating lifter.

[wilfandrowlf]

I had a similar problem and decided to go with the cam....
On stripping it all down I noticed one of the lobes was almost round! so it was definitely cam related in my case.
While I was at it I did all 8 exhaust gaskets too.
I am nearly at the start up start up stage so I'll keep you posted.
Hopefully it will cure the noise and give me back all 8 cylinders?

Definitely a pretty involved job but if you take your time (take loads of photos too) and get a Range Rover (P38) manual it's basically the same engine.

Hope this post helps?

[Green is good]

Yes, no dogs in my car at the moment. Checked the exhaust, no problems there. The sound seems to be from the engine so sounds like a cam problem then. Thanks for the replies, good to know I'm not alone. Wilfandrowlf, thanks for the advice, I hope you have cured your problem. Let us know how it goes when you start it up.

Cheers