bflaig79

Happy New Year everyone.

In the mornings when I start the car, the tach needle jumps a tiny bit while idling. This typically happens for the first 5 or 10 minutes or once the engine is up to temp.

The revs only fluctuate about 200-300 rpm, but I notice that the tach does move a little while the car heats up.

Is this a big concern? Or is it okay because the car is trying to heat up.

Also, there is a small ticking noise, I'm not sure if that is regular for the 5.0 L V8 or if thats a sign for something else.
I have hooked it up to an OBD II scanner and no misfire codes come up

Plutoe

If you have a 273.960 engine---what you are reporting is typical ECU idle speed control.

PS: read your manual or google MB idle speed control for your engine!!

Blitz2639

It's completely normal. It's just the engine trying to heat the cats up. Nothing to worry about. As for the ticking that's tough to say the 113 engine is pretty loud and you can hear the valve train easily but without hearing it is hard to say. I would take it somewhere just to check if you feel that it's something out of the ordinary.

bflaig79

Thanks for the replies guys.

One other thing, when i accelerate a little harder than normal, as if merging onto a freeway, once I hit 1,500 to 2,000 + rpms the ticking sound is louder is much more pronounced. It is not the roar of the V8 but a distinct ticking sound.

A while back I had my engine mounts replaced, do you think its possible that the mechanic did not fully tighten the exhaust header to the motor? would this cause the louder (almost truck-like) sound of accelerating?

Could very well be the "normal" valve train sound like Blitz mentioned

I will try to record the sound and post a link to it in the next few days.