Engine noise briefly after cold cranking
 

Lately my '02 P5 2.0L engine has made a rattling noise briefly after I crank it. By the time I run around to the engine, it has cleared up. It only does it on cold mornings (35 or below is cold in SC), and not every day.

It sounds sickeningly like a rod bearing because it's a fast clatter (like if you beat a big screwdriver back and forth between two pieces of metal). Maybe it's some oil not getting somewhere for the first few seconds. My imagination is killing me.

I hope it's something simple and OUTSIDE of the engine, like maybe the water pump.

This is a meticulously well maintained engine. I warm it up and run it like it was meant to be driven. It sees the redline every couple of weeks and, less often, a little higher. Always extremely smooth, no vibration at all.

Anyone heard noise like this out of your engine?

Has anyone heard of oil supply problems or bearing problems? How about something like a water pump or other simple problem?

I think it's some cold-start emissions crap that you don't have to worry about.

just warm it up, this happens with my 2.0, its just cold start, i keep the revs below 3k until the temp gauge goes to the middle

You're Probably Okay
 

Welcome to among the most common complaints about the (what I consider) primitive FS-DE engine. It sounds like a diesel...

I've long found this an irritating, even embarrassing issue, but it’s at least one that isn’t functionally dangerous. And I've found Mazda warranty service (which I've had to use 5 times) responsive, so even if something's wrong I'm sure they'll repair the problem without incident-- Especially given the great care it appears you render your car. I too have always taken painstaking care of this car, so they've never had any excuses not to fix everything that's gone wrong.

Suffice to say all the problems have pissed me off a lot, however.

My rattle only lasts about ten seconds after cranking, then it's gone before I would even have a chance to throttle up. It's not the inherent noise every one else complains about, mine does that too and it's normal.

This is hard metal slapping somewhere, I suspect until oil gets there. I guess if it's a clogged oil passage hammering a rod bearing, I'll find out after warranty. Any idea what an oil-starved cam lobe would sound like?

I'm glad no one knows of a thrown rod in a basically stock engine.

Thanks for your replies

I hope so.

Relax. It is the VTCS butterfly. It affects the P5 mainly and is part of what makes us a ULEV. It swirls the air/fuel mixture until the cat warms up. (If i have mis-spoke - someone please (gently) correct me!

No 'fix' except to disconnect it.

So just relax.

It could also be a cheap or faulty oil filter. I know of several people with other cars that do this and the problem goes away when they get a quality oil filter. (NOT FRAM). Has to do with the anti drainback valve and/or bypass design.

Worth a try.... I suggest the Wix/Napa Gold/Carquest Premium for this car - which uses a tiny oil filter. The 3 above are the same, and has a nice silicon antidrain back valve, and flows very well. Has eight large inlet holes compared to most others' six smaller ones. And most others use a black nitirile design.

Just my .02, I think its worth a shot to replace and see....

And if it doensn't fix it, you are only out a new oil filter!

Ive been having this problem since I bought my P5 in Dec 2001. Its sounds more like a jet engine starting up then a rattle. It doesnt annoy me, but we just started to get cold weather here in New Orleans. I would love to know if it will do any adverse effect in the future. If it wont, I have no problem with it. :D

I've got a Fram on it now. I think I'll take your advice.
Can the filter be removed without much spillage? I've never taken one off of an engine without draining it first.

FWIW...I have 2003.5 P5, and had some start up rattle problems also. Here's a history with weak conclusions. I apologise in advance for the long prose.
No rattles with the original thimble or teeny Mobil1-110's. Poor flow, but good construction, or maybe they're so darn small that they (re-)fill up instantly. Rattles with two different oversized Wix filters (trying for better filtering and better flow) and a Textron (?) Mazda V-6 filter but one Wix and the Mazda filter were found to have a visible giltch with the AntiDrainBack Valve (ADBV) which would allow leakdown and cause a (larger re-fill volume) dry filter start.
Now using Wix 51356 (V-6 size) and NOT having rattles, or only a very small trace. The new Wix filters have a new semi-synth media and HUGE inlet holes which make for great flow and let you check to see if the silicone ADBV is PERFECTLY centered. (If it's not, check the next one in the rack). One of the ovesized Wix's had the valve pinched and slightly off center, and I didn't catch it.
Bottom line; Give the Wix 51356 a shot, after careful inspection.

mine does the same thing here also my mom's 90 probe also did the same exact thing,(mazdamotor) one thing for sure is that when ever I change the oil in either car, I wouldnt here it for a week or so then it comes back again.

So what are we talking about, a rattle due to the VTCS selanoid or some sort of rattle from the oil filter??

if you are referring to me minky i dont know what it is also when ever iwould change the oil ina licoln towncar or ford ltd in the late 80's they would knock at first start up for a few sec. after each oil change but not so on a5.0 HO on a stang lx/gt or lincoln lsc weird huh?