I'm getting ready to have the entire timing group on my 2004 F150 4X4 done. It has the 5.4L 3V motor. My question is regarding the tensioners. The ones that came in the kit (Ford OEM) are the re-designed plastic units, but I've read and heard a lot of talk about using the older, cast iron tensioners as they ratchet and aren't as sensitive to oil pressure (low or high). I've also read and heard some statements concerning the use of the higher pressure M360HV oil pump with the plastic tensioners because it may be too high of a pressure for the seals on the the plastic tensioners. I did purchase the M360HV and intend to have it installed.

So what does the collective here think about that? Should I look into the cast iron tensioners? If so, what brand is recommended? A quick Google search didn't return any Ford OEM cast iron tensioners, but I did see some Melling parts, as well as the usual suspects of cheap, Chinese knock-offs (which I wouldn't use if they were given to me!). Does anyone know if there are Ford OEM parts for this? Anyone have experience using the Melling parts? Is this something I should look into, considering the oil pump I'll be using?

 

Hands down I would use the cast iron ones. Those tensioners are way to critical at preventing valve and piston damage to be fooling around with plastic ones that might fail.

 

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I'm thinking you make a good point about the tensioners, but should I be concerned with the higher pressure affecting other seals?

 

To form an opinion I would need to know how much was the oil PSI with the factory pump and the expected PSI for the one you plan to use?

 

Okay I quickly just read up on the M360HV pump to see if I could answer my own question and the answer is yes you can use it without fear of blowing and GOOD seals. Naturally if there's a bad seal even the original pump could eventually cause it to leak. The M360HV does not increase pressure over the factory design, instead it is a 20% higher VOLUME pump. All that means is that it pumps 20% more oil than the factory pump, it does not mean it pumps at a higher PSI. If the engine is worn and allowing oil to leak past things such as the bearings then that leakage will cause the oil PSI to be lower than it should. The M360HV compensates with the added flow volume to bring the oil PSI back up to, or near factory specs.

 

Thanks alloro. I was afraid that because the 360HV has an 80psi relief spring, it might push more pressure than the engine was designed for. As it is, the engine seems to be in decent shape. Good compression, no visible oil leaks.

 

That's just the safety blow off point in case something clogs, that doesn't mean you're going to normally get 80 PSI out of it. Depending on temperature, oil viscosity, and engine wear clearances, you might only get something like 40-60 PSI.

 

Ahhh... thanks for the info.

 

When starting a cold engine the oil pressure will usually peak fairly high.
At idle on a warm engine oil pressure will be around 18-25 psi.
Oil pressure will peak again at high rpm.
You won't see any of this happen because the dash oil pressure gauges used these days are not really gauges.
The oil pressure gauge will usually display a fixed position when the oil pressure exceeds 7 psi or so.

The plastic timing chain tensioners do not ratchet like the cast iron version.
When slack in the chain develops the cast iron ratchet will eventually catch a new tooth and take up slack.
The plastic tensioner will allow the chain to completely relax and the next time the oil pressure returns it must pump up the tensioner to take up the slack.
I read about an issue with the cast iron tensions sometimes catching a new tooth and tightening the chain too much under extreme conditions such as power shifting with a manual trans.
I would think there would be no issues with any applications using automatic transmissions.

 

Great info, thanks! I just received my Melling cast iron tensioners. Should be going to the shop tomorrow (fingers crossed).