Engine noise for some seconds after start.

[Imponator]

Hi, just changed both chain-tensioner in my -99 Explorer limited.

After start a cold engine, it come a rattle sound for some seconds, then it sounds normal.

The tensioner in the upper part of the engine, was bad from factory, bought both cheapest at e-bay. Replaced the upper one with an orginal tensioner.
But - still got the noice the first seconds after startup. If I try to just jerk the key to the start engine, so the engine does not start, sometimes, building up an oil pressure, then start - the engine does not make that rattle-noice, those first seconds.

Someone got any clue what it might be?

Should I replace the other lower tensioner as well thought that one come from e-bay as well? Oil pump?

Kind regards Mats from Sweden.

 

[Tech By Trade]

Pull your valve covers and make sure the guides arent shot. If they are you are pulling the engine.

 

[2000StreetRod]

same symptoms

I had the exact same symptoms on my 2000 Sport at 150K miles. The right (rear) cassette guide was broken allowing slack in the chain. The chain was loose enough to strike the guide upper positioning bolt.

As oil collects on the chain and post the rattle sound decreases. I suggest inspecting for damaged cassettes: SOHC V6 Timing Chain Inspection & Repair

 

[Imponator]

Thanks for the quick replies.

Could I make the inspektion of the cassette guide without taking out the engine?
Even change it without take out the engine?

It sounds a bit strange, though I can rev it up without notice, an during the day, when I start it up, it sounds normal, just when I make the cold start. And if it does not start fast during coldstart it make no noise at all?

Kind regards Mats

 

[2000StreetRod]

cassette inspection

. . . Could I make the inspektion of the cassette guide without taking out the engine?

Yes, you only have to remove the valve cover.

Even change it without take out the engine?

In order to replace the right cassette you either have to remove the engine (preferred) or remove the transmission and work in a tight space between the rear of the block and the firewall.

 

[Imponator]

Thanks for the info.
Just one more question, is there any way to see or test if the cam chain-tensioner is good or bad. Though I bought two from the same place at e-bay, and one of them changed by an mechanic at a garage, was not working properly from factory. Bought another but ford-orginal, that worked good, hope and suspekt that even the other is not working well.

Could I take it out and make some kind of test?

Kind regards Mats

 

[2000StreetRod]

improved tensioners

Ford used improved tensioners starting with the 2002 models. Part numbers are:
left: 7U3Z6K254B
right: 7U3Z6K254A
The photo below is of an equivalent Borg Warner set.

One way to test them before installation is to oil them and then compress the piston in the cylinder manually checking for free movement and spring pressure. Some of the aftermarket parts sold on eBay are just junk. The piston may seize in the extended position causing the guide assembly to break. Or the piston may seize in the compressed position resulting is a loose chain which may slip. Unfortunately, the new OEM tensioners available during the last year or so seem to have weak springs.

Another improvement was the incorporation of an oil chamber volume reducer (sometimes referred to as a restrictor) that allows a faster increase in oil pressure to the left tensioner after engine start. It was included in what was referred to as the 00M12 kit (PN: YL2Z9E473AA). The 00M12 kit also includes a new left tensioner, upper and lower intake manifold gaskets, and a new oil gallery plug.