4.0 timming chain

[joelhall1957]

I have a 2002 explorer that when cold runs fine but after it warms up it chatters like the front guides may be bad but replaced both front and back 4-5 months ago does anyone know what i need to do? btw 4.0 engine

thanks joel

 

[Tech By Trade]

I would pull the front cover and have a look. if you didn't use a quality product (oem, Cloyes, Melling) odds are the springs are all sitting in the oil pan.

 

[joelhall1957]

I would pull the front cover and have a look. if you didn't use a quality product (oem, Cloyes, Melling) odds are the springs are all sitting in the oil pan.

is it possible that oil pressure maybe low after it warms up the gauge shows good pressure?

 

[Tech By Trade]

The springs under the timing cover are not hydraulic. They have nothing to do with oil pressure. If you have a constant rattle odds are they were the cheap ones and they have sprung.

 

[joelhall1957]

The springs under the timing cover are not hydraulic. They have nothing to do with oil pressure. If you have a constant rattle odds are they were the cheap ones and they have sprung.

thanks will pull the front to check you are probably right would you change the back guides again don't know were the mechanic got the ones he put in before

 

[Tech By Trade]

Its probably not the cam chain guides. Its probably the jackshaft to crank guides. No need to go after the rear one unless its rattling. You may want to check the front and rear hydraulic cam chain tensioner though. The cheap kits come with crappy tensioners that bind and dont put pressure on the guides properly. You can feel them bind just by pressing them with your fingers. The oem and cloys ones have much stronger springs and are smooth to press from my experience.

 

[Bobbylew]

is it possible that oil pressure maybe low after it warms up the gauge shows good pressure?

Absolutely! The gauge is not a gauge at all. It is operated by a pressure switch that puts a resistor in the circuit to make the gauge read at mid scale. I guess Ford didn't want to use an idiot light.

 

[joelhall1957]

Absolutely! The gauge is not a gauge at all. It is operated by a pressure switch that puts a resistor in the circuit to make the gauge read at mid scale. I guess Ford didn't want to use an idiot light.

would low oil pressure cause it to run quite until the engine gets hot?

 

[2000StreetRod]

Your 2002 probably came with the improved, more robust primary chain tensioner unless it was an early production model. The left one below is the improved one.

If you have 4WD then your engine probably has a balance shaft. The balance shaft chain tensioner is fairly flimsy and your engine symptoms match those for a loose balance shaft chain.

Normally the block cradle is removed to replace the tensioner assembly because of the vertical mounting bolts. However, some forum members have successfully replaced the just the tensioner arm by carefully bending the pivot pin. Other members just cut the balance shaft chain and disable the balance shaft.

 

[joelhall1957]

Your 2002 probably came with the improved, more robust primary chain tensioner unless it was an early production model. The left one below is the improved one.
View attachment 170323
If you have 4WD then your engine probably has a balance shaft. The balance shaft chain tensioner is fairly flimsy and your engine symptoms match those for a loose balance shaft chain.

View attachment 170324
Normally the block cradle is removed to replace the tensioner assembly because of the vertical mounting bolts. However, some forum members have successfully replaced the just the tensioner arm by carefully bending the pivot pin. Other members just cut the balance shaft chain and disable the balance shaft.

Thanks so much for your replys pretty sure the engine that was put in came out of a 2003 2wheel drive but the guy that changed the engine was supposed to have changed the chains and guides front and back before putting it in but could have put cheep ones in been about six months ago,just thinking because the oil when cold the oil pressure on the tensioner may-be greater?? after it warms up is when it makes the death rattle,may-be over thinking it

 

[2000StreetRod]

Most 2WD engines don't have the balance shaft but some do. Apparently it was a factory option to keep the production line moving. Many people try to save a few hundred dollars when replacing the camshaft timing related components. Some of the new parts available on eBay look the same as quality parts but are just junk. The only reliable way to determine the source of the problem is by inspection. Some members pull the oil pan and check for pieces of tensioners or cassette guides. Pulling the oil pan can be a pain on a 4WD vehicle. Other members remove the valve covers to check for broken cassette guides. If you click on "My Helpful Threads" in my signature you'll find links to troubleshooting threads which may be useful to you.