the dry start rattle

[jvl8433]

hi guys I have the 00 explorer with 4.0 sohc with 180k,well for awhile I would hear the little bit of rattle when 1st start engine so I bought a new rear timing chain tensioner off ebay took it out and put it in and its louder than it was it seemed it would not prime up?? I don't know so I put the old one back in,it seemed still good anyhow,well now I wonder if I should change the front one that maybe that is the bad one because I can hear it rattle a tad louder than what it was b4 I changed it,also I changed oil and filter with 5-30 and thought maybe that had something to do with it so I added lucas oil treatment but didn't help.it does not rattle at higher rpms or at idle just when it has sat for abit for oil to go down,thnx

 

[Flash]

You should replace both the tensioners.
I've heard there's some bad tensioners out there that are worse than the old ones they replace.
Make sure you get a good brand.

I've noticed that if you depress the gas pedal then let it off before you start it, like you did in the old days of the automatic choke, it would start and not rev so hard.

That really bugged me they way it would rev really hard when cold until the oil pressure built up.

 

[jvl8433]

dry start

Hi flash I think I did a buy cheap one that was no good it should have built pressure better than it did and after I took it back out it still felt loose when I squeezed it,the old felt tight so I put it back in,so when you put new good ones in did it solve your rattle?

 

[bluestream1]

Get used to that rattle; they all do it. All the tensioners in China aren't going to fix it...

 

[Flash]

Yes, it did solve the rattle. Take no notice of bluestream.

A replacement tensioner will only work if that's what the problem is though.
The 2000 model has the improved guides afaik so you might be ok with just a tensioner.

I had a '97 XLT that had rattling in the jackshaft chain, a tensioner wasn't going to fix that.
Once again though, I think the 2000s have an improved jackshaft tensioner and guide.

 

[bluestream1]

Yes, it did solve the rattle. Take no notice of bluestream.

A replacement tensioner will only work if that's what the problem is though.
The 2000 model has the improved guides afaik so you might be ok with just a tensioner.

I had a '97 XLT that had rattling in the jackshaft chain, a tensioner wasn't going to fix that.
Once again though, I think the 2000s have an improved jackshaft tensioner and guide.

The info posted by Flash is inaccurate. Primary chain rattle can be easily solved with a new tensioner. The 2000s do NOT have an improved jackshaft tensioner ; that was updated mid year on 2001 models. You can buy the 5 leaf new tensioner for all older models

The SOHC engine has 3 different rattle noises:

1. Start up rattle. The can be alleviated by installing the TM0012 update kit which most engines should have done long ago. The 2 external cam chain tensioners have weak springs that work until the oil pressure is high enough to take over. Installing a new tensioner will do little, as the new ones have weaker springs that the old ones. Its a poor design, and will rattle at start up until oil pressure is built up. The longer the vehicle sits the more it will rattle.

2. Primary Chain rattle. The primary (jackshaft) chain tensioner is a poor design spring based unit that also has been upgraded to a 5 leave spring design. If you have the original tensioner, you will get rattle, but mostly with a cold engine around 2800 RPM.

3. Cam chain Rattle (death rattle) If a guide breaks you will have a constant rattle from the timing chains.

 

[Flash]

3. Cam chain Rattle (death rattle) If a guide breaks you will have a constant rattle from the timing chains.

That's true.

Don't forget I did say, "A replacement tensioner will only work if that's what the problem is though."

And,
"I had a '97 XLT that had rattling in the jackshaft chain, a tensioner wasn't going to fix that."

If the problem is a chain guide then, as you said, all the tensioners in China won't fix it.

I've fixed the rattle in 2 of my Explorers.
One needed the primary chain guide thrown into the weeds so it got the lot, except for the balance shaft.

The second one got by with just the tensioners replaced. It only rattled at start up and obviously the chain guides weren't damaged and the jackshaft guide and tensioner were ok.

Are all of the tensioners available inferior?

I couldn't tell you what brand I got with my chain kit, I bought it off ebay from America.

The single tensioners were bought from Ford in Australia.