Slight top end rattle?

[Jcerb]

Evening all, my 2.5 has been sat for about 6 weeks in the garage and started up for the first time tonight and noticed under very light throttle at idle; right next to the throttle there is a rattling? Once the revs pick up you can't really hear it. But it's like a quick mini wood pecker! Is it oil not getting around to the top end? I never noticed it before...Cars on 28k and just had remap (about 3 months ago). Many Thanks

[andygtt]

I had a little top end rattle on my car immediately after I first had it remapped years back... sounded just like tappets and was only in certain low rev, after much messing around changing tappets, chains etc etc I took the engine out and it was main bearings

its almost impossible to assist diagnosis of this over a forum, from your message it could simply be a loose nut or bolt or it could be something more serious. Best take it to someone like jet stream

[Jcerb]

Oh dear, well I hope it's not that! You can only hear it when you're down close with your ear, it doesn't do it a idle at all. Never noticed it after the mapping just after being sat for a while... It was only at Jetstream a couple of months back just before it was mapped!

[andygtt]

So you can only hear it when you have the rear clam open and lean in close to the engine?

[Jcerb]

That's right, and strangly after letting it cool down for a couple of hours it had stopped for the first 30 odd seconds, then it started up again?? It's like a little rattle snake it probably a better way to describe it ha ha. But it is coming straight from the throttle body, no where near the rocker covers. I checked the butterfly and no play there also checked the TPS all fine mmmmmmmm

[Midlifecrisis71]

I know it sounds daft but have you checked the throttle cable nuts that hold the cable above the intake. Mine rattled free and loose on the cable, rattled at certain revs.

[Jcerb]

I will have a look, I didn't notice any nuts around there only the tensioner spring. Do you think a stethoscope would narrow this down? I hope I can get a garage to just have a listen to get an opinion.

[v8yes]

Hiya you may have had a hydrolic cam chain tensioner ratchet fail heard of it before on dura tec motors Could mean a timing chain has jumped a tooth not a major fix A compression test would soon tell you as valve clearances would be to pot with top dead Quite common on ford forum . A quick check for main bearings is drop the oil n see if it has a silvery metallic look to it 2 easy tests wouldn't recommend keeping starting it though

[andygtt]

Midlifecrisis71 said:

I know it sounds daft but have you checked the throttle cable nuts that hold the cable above the intake. Mine rattled free and loose on the cable, rattled at certain revs.

From your description it does sound like a nut on the intake somewhere its also possible one of the inlet manifold bolts has come a little loose, there are 8 in total, 4 for the upper manifold and 4 for the lower.... the fuel rail is also bolted down and would rattle is a nut had come loose.... my noise was heard from inside the cabin driving so i think its not that

Jumped chain would make the engine loose power and not be sooth running due to mismatch timing across the banks.

[Hairsy16]

I'd place a small bet on fuel pump. Mine sounded like a woodpecker until it had a cleaner fuel filter on it.

[Jcerb]

Thanks guys for all your help so far, I have a mechanic looking at it later today. Fuel filter is new and pump should be fine as not long had wiring mod done by Jetstream. The sound is very localised to throttle body, nowhere else!

[Jcerb]

It turned out to be the electronic boost control valve!!! It is perfectly fine. Thanks very much to all of you for your help here.