Engine Rattle at start-up

[tomhilmes]

I have read posts about engine noise all morning and I can't find anyone that seems to have same problem although I'm starting to form a diagnosis from the various stories. Here's mine:

In the morning or after sitting for a few hours, at start up the engine rattles (sounds like valve train with no lubrication). Lasts for 2-4 seconds. You can watch the OP gauge climb up to normal and about 1/2 way to normal pressure, the sound goes away.

It does not happen if the engine is warm. It does not happen at any other time than a relatively cold start up. Running factory specified oil and filter - always have. No leaks, oil level is dead on. First thought was oil pump issue - but nobody is talking about that.

Everybody is talking about chains and tensioners but absolutely no issues except at start up.

Has 90,000 easy miles. I grew up working on engines but have never gone too deep into this thing. It's my daily driver. Everything in my gut says oil pressure problem.

Where do I start guys?

Tom

[slickster]

I'm leaning more torward chain but ether or could be a vary big prob if not taken care of soon and soon like don't even start it until you fix it. Try rock auto.com or tasca ford for oem parts

[RF Overlord]

This may seem simplistic, but what brand of oil filter are you using? More specifically, you need to use a filter with a silicone ADBV, like the factory-recommended Motorcraft FL820S. The anti-drainback valve stops oil from draining out of the filter, which then requires re-filling every time you start. Many filters have a nitrile rubber ADBV which doesn't last. This is a common cause of start-up noise.

[tomhilmes]

The drainback valve was my first thought. Have always used the 820 motorcraft filter as well as the motorcraft oil that's specified by the owners
manual/dealership.

I appreciate the feedback as I'm really looking for the simple things first before I take the front of the engine off.

My biggest concern with the whole process is getting it sealed back up so it doesn't leak. It's pristine now.

Does anybody think it could be the pick-up tube? Does the pan have to come off to replace oil pump?

I should mention that the gasket that attaches the oil filter mount to the block was leaking a couple of years ago and I replaced it with no problems. Haven't had a leak since (~20K miles).

Where is the oil pressure control valve located? Is it inside the oil pump?

Thanks everybody,

Tom

[TFB]

Noise for a few seconds at startup is usually the timing chain tensioners letting the chains slap, till oil pressure fills them and tightens the chains... Is it fatal??? Well I dunno, the guides may be worn out or possibly just the hydraulic cylinder in the tensioners are a little worn, which would likely run for another 50K mi...

Forget about the pickup, not your issue...

[tomhilmes]

Thanks for your response. The idea that the tensioners are collaspsing then refilling at start up makes sense as it very much feels/sounds like a start-up with a fresh oil change on any car - that moment that you wait for the oil pressure gauge to jump as the new filter fills.

Can the tensioners be accessed or replaced without removing the front housing? If not, seems like I may as well change everything since I'm already going to be that deep in.

Looks like I'm going to be pulling valve covers, front housing, radiator, etc. Looks like a full weekend.

Tom

[RF Overlord]

Tom, since you brought it up, you do know the the oil pressure gauge is a fake, right?

[tomhilmes]

Nope. Made the assumption that it was a real gauge with an electric sensor on the block. That's crazy. Guess that's why it reads just like it always has.

[RF Overlord]

Exactly. It's a glorified idiot light.

AutoMeter DOES make a real working gauge that looks almost identical to the OEM fake one. P/N 4327... Includes new sender (needed).

[Blackened300a]

I hope its not that stupid starter problem makes people think its the engine making noise.
This noise also only happens on cold starts and is quiet on warm engines like you are describing.

This sound familiar?

[stangracr]

just my .02cents My Marauder has rattled at startup since I got the car with 24,000 miles. Car has over 60,000 on it now with no problems. I think lots of the 4.6 dohc cars have this concern. I wouldnt worry too much about it if it were me. I am sure others will chime in. Im sure it is tensioner and chain related but I have never heard of anything catastrophic happening.




ed

[RacerX]

There is a one way ratchet in the tensioner that keeps constant tension on everything as parts wear. The oil pressure pushes the tensioners against the tensioner arms which in turn tighten up against the chains. Get a cheap auto stethoscope and try and pinpoint it everytime the car starts cold. Have someone else turn it over.

[tomhilmes]

Thanks for the video. Would have never guessed a starter could sound like that! That's not my sound but I will get out the mechanic's stethoscope and poke around and find the actual source.

I'd feel pretty stupid taking the front of the engine off to fix a starter!

Thanks,

Tom

[tomhilmes]

Almost forgot: I'd leave it alone if I could. It has gotten worse than say 3 months ago. But now I think about the issue every morning. I'd rather fix it than deal with my mental state.

Tom

[Blackened300a]

Any way of taking a video of the sound? It may just be something stupid. Recently I would rev my engine and when the RPMs came down it would make this rattle knock sound which had me concerned. Turned out to be the belt tensioner spring creaking when the belt would come back to idle.