Tappy/exhaust noise from the engine bay.

I've got a 3.9 V8 disco with 60,000 on the clock. It's an R reg and the bodywork is spot on but the engine bay has had a few mods.

It has twin fans on the inside part of the radiator fitted - I take it that this is a Mod to get rid of the stock fan system. I also have an aftermarket dial to alter the cooling fans to Hot/Normal/Cold environments.

This got me thinking about overheating in it's past life!

I'm now aware of what sounds like an exhaust manifold leak but I can't see a hole in the manifold. It ticks over lumpy and I can definitly hear a blow from manifold/head area. It's very noticable under load.

Can these V8s blow their headgaskets to atmosphere or do they tend to use water? Mine has a visable water leak but it uses very little water at all which I have put down to what I can see leaking (couple of drops a day out of the pipe near the wheelarch).

I don't know whether it's me being paranoid but I think I can see a bit of oil/soot on the headgasket line near cylinder 4.

How can I tell or do I just swap the headgaskets anyway? (hope not!)

It sounds like a tap or a leak out of one cylinder only - ie manifold leak before it mixes with other cylinders (if that makes sense).

I'll try to post up a video if I can work this computer thingy!

Cheers

George

It's a blown Y pipe to manifold gasket if it sounds like a machine gun under load ie going up a hill or accelerating.. mine was.

Cheers for the fast reply..

I really hope you're right

I'll report back on Sunday.

After having a bit of an issue with the Kenlow conversion I have been able to have a look at this.

Kenlow fan stuck on which caused the battery to go flat and lock the immobiliser.
New Kenlow contactless switching unit and uprated fan relay and I now have a nice cool engine bay.

Ran her and grabbed the Cat then rocked the exhaust inboard and outboard and the noise disappeared. I can only assume that I'm pinching the leak and sealing it. I'll get the exhaust off and get the gasket changed. I'll probably do both sides as I'll be in the mood.

Thanks for the reply which is looking spot on at the moment.

Cheers

George

Now changed the gasket and the noise has stopped. Spot on

Still ticking over a bit bubbley but not as bad as I've heard.

I've changed all the Leads and Spark plugs and I've changed the Dizzy Cap for a new Lucas one. I put an after market rotor arm on because they had no Lucas one. No change to the bubbley tick-over. I'm thinking it may be an injector or something.

Getting the rear silencer cut out and a straight through putting on so I can hear that lovely V8 noise

Cheers for the diag' on the ticking

George

Glad to help, it could have been a few things but always go for the easy ones first.