I've got a chatty engine.

[scudderfish]

My engine has started making a new noise. I was doing some gentle driving (dropping my daughter at the cinema) and initially put it down to the bus in front. However, over the course of the next 5-8 miles it got considerably louder. I can best describe it as 'chatchatchatchatchat'. I had a poke around the engine but I can't locate it, I'm partly deaf and have no directional hearing. I suspected a leak between my 4 barrel TB and the carb hat on top, but replacing the o-ring between them made no difference. I've also briefly run the engine without the fan belt to eliminate the alternator and water pump, made no difference. Any ideas to test? 4.3 RV8 running on MS1/EDIS with a 4 barrel throttle body, it had been completely normal for the past few hundred miles. The noise changes speed with engine speed. I had a new exhaust fitted about 50 miles ago, but that didn't involve the headers and it all looks solid. It sounds as if it is coming from the engine rather than under the car.

Regards,
David

[Ian Anderson]

Check if your spark plugs are tight!
I have had one come loose way back and it blew just like you say

Ian

[Eliot]

also head gaskets can fail on the outside which also sounds like a loose exhaust manifold

[DaveEFI]

Also a leak between head and exhaust manifold. Can sound a bit like a noisy tappet. A leak on the inlet side isn't likely make much noise due to the much lower air speed.

[stevieturbo]

video ?

[scudderfish]

video ?

That's my intention this weekend, work has been a bit tough this week

[scudderfish]

I tried to move the phone around suspect areas of the engine. What do you think?

[SimpleSimon]

Sounds valve gear related at that noise frequency almost like tappet bleed down what the oil pressure like ?

[scudderfish]

Oil pressure has been fine, but now the oil pressure light only goes out if I rev the engine. The level was below 'low', but I put some in and it is now mid way between 'low' and 'high' on the dipstick. If I run the oil pump with a drill mounted priming tool, the light goes out but the drill doesn't seem to be straining to pump cold oil.

[DaveEFI]

I'd say something odd there. On my high miles EFI engine where the oil pressure isn't the best when running, the light is never on at idle. And I have the idle as slow as possible.

[scudderfish]

That's how it was, the light used to go out during cranking, now it needs 1500-2000rpm to go out.

[scudderfish]

I suspect my oil pressure relief valve may be cracked open. I've just ordered a new one, any handy hints on fitting (apart from do it over something to catch the oil that will undoubtably wee out)?

[scudderfish]

Well I got the OPRV out (which was a fun task) and it looked like this :-

I think that is not how it's meant to be. Fitted a new one and I now the oil light is out at idle. I need to give the car a bit of a razz but I let the insurance lapse this week as I thought I'd be off the road for longer. Oh well, I've got a couple of jobs to do that need the dashboard out so I'll crack on with those.

[DaveEFI]

Nice cheap and easy fix, then. Just what I like.

[scudderfish]

Turns out my fix was wishful thinking. I've replaced the pump gears but no joy on priming. Twice now I've stripped the pump down, filled it with vaseline and used the priming tool, but after a little strain my drill can spin the pump as fast as it likes and no pressure. I think I'm going to have to drop the sump and check the pick up pipe.