400HP55

When I got my new engine put it, the mechanics said it had a clacking sound when they started it up for the first time. We figured it's because the engine hadn't been started in over 2 years. So we wrote it of because after they let it idle for about 5 minutes it went away.

I wasn't there when they started it for the first time and heard the clacking sound.

So I haven't stared my car in about a month because I've been working on my suspension. I started it tonight and heard the clacking sound. Didn't sound good at all! But it went away after 5 minutes of letting it idle.

It sounded like it was coming from the bottom end.

Any ideas???

bobbyjo9

"Clacking" may be a different sound to you than me. "Clacking" is a higher pitch to me and that is usualy valve train. "Thumping" is a lower pitch to me and usualy a problem in the lower end. A rod knock doesnt just go away after a few minutes of running. Does it still make noise if only let sit for a few days? May just be a "lifter" bleeding down.

400HP55

Its not a thudding sound. It's Weird haha. If I let it sit for a week and then fire it up the sound isn't there. Sounds Only there if its sitting for more than 2 weeks. It just worried me!!!

betrezra

Our ML500 and my clk55 sometimes does this after it sits for a while.....then goes away after warm up.... then not present for days/weeks/months...... I was thinking lifter pump up..... but purely guessing. Reminds me of aftermarket roller rockers that need a shim from my domestic product days

bobbyjo9

Like many others, mine too will make a little valve tick on start up if I let it sit for a few weeks. With the road you've just been down I'd be nervous too! Doesnt sound like you have something to worry bout this time though.

boxeswithknobs

Sounds like it's probably valve train/lifter noise.

After the car sits long enough, residual oil coating drains and thins out at the top of the engine. 1st start gets to ticking/light clackety until oil pump creates enough pressure at the top of the engine to fully restore oil coating.

Not unusual, when I leave a car sitting for a while (+ months), I normally pull the fuel relay and give it a couple start turns to get some pressure built up before plugging the relay back in for a "real" start.

400HP55

I don't know why I didn't think of that

Same thing for priming a new turbo.

400HP55

I know its off this threads topic; however, I'll ask anyhow. Do you guys think the Flex Disc should be added to 100k mile tune up?