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Duratec rattle


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Hey guys. It seems quite early in terms of mileage but I've got a rattle in the duratec 2.0. Cold start you can barely hear it - as the engine warms up it becomes more evident. Poking around with a stethoscope it's on the front end but that's about all you can ascertain.

 

Pulled the valve cover and all looks well. There is some play in the chain between the cam gears - say you can move the chain up and down about 1/4 to 3/8 of an inch. I think that's loose but my buddy thinks that's fine. How much play should the chain have between the gears?

 

Also, regarding the chain tensioner - do we know if Caterham uses the Ford part or something better? I know there's a modded tensioner available, and Cosworth makes one - though I don't know if it's different.

 

Thanks for any input!

 

- Tim

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Everything on the serpentine belt sounds ok with the scope. Noise only comes up when the motor is warm. Injectors sound fine. Checked the tolerances between cam and buckets, all at 10 thou. Scoped the cylinders and all look fine albeit a bit of oil and more carbon that I'd expect at 200 miles.

 

Ugggghhhhhhh

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Sound is more prominent on the timing cover, toward the bottom. If we probe the cover we can hear it more so than probing the block directly behind the timing cover.

 

The timing cover will work to collect the sound because it is not solid. Unfortunately the rattle may not be in the same place as the sound - its just easiest to hear it on the timing cover.

 

My logic tells me that the rattle is internal from an oiled part given the noise increases as engine warms (and oil thins with heat). However, to rule everything else out - are all ancillaries (alt, water pump) tightly mounted and not rattling as loose? Engine mounts all good? Dry sump mechanism (if applicable)?

 

Any sense of it being higher or lower in the engine - head or block?

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I checked my notes regarding tensioning the chain with the Raceco manual chain tensioner. Ammo said to push down hard with the heel of your hand to ensure all the slack is between the cam pulleys, and then adjust to 10mm of movement, which should result in the optimal 3mm of movement when hot. He indicated that verifying the critical hot measurement is a good idea, so it might be worth doing that if you can't find another culprit for the rattle.

 

-John

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Tim

What oil viscosity grade are you using? Going to a more viscous oil will not fix a mechanical problem, but if the only problem is noise, a thicker oil is likely to make it quieter.

If your engine was in a Focus, under the insulated hood, is the rattle loud enough that you would hear it?

Blaine

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Very true that the timing cover will transmit sound more readily. All the ancillary stuff is pretty solid as best we can tell. I haven't physically checked the motor mounts but I will.

 

Noise definitely seems louder down low. I'm wondering about the oil pump drive, as it's down there and has its own tensioner. The car has a dry sump.

 

The oil is still whatever V's performance put in when they installed the engine. I'm still waiting for oil filters to come in. I got the car at 39 miles, it's now at 200. Hasn't been over 5k on my watch, and the noise is new.

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I'm wondering if, at 200 miles; human error couldn't be the most probable cause. I know the motor was put in by V's performance in CA, but I don't know who preps these Ford engines with the Caterham bits. Does that happen at Caterham?

 

Either way, I'm supposed to have the modified timing chain tensioner, but I suppose that it's possible I don't. I've got a dry sump too so I assume that components of the oil pump drive have been changed as well. Either way, there's plenty that's been hand done so maybe there was an oversight.

 

I'm going to try and get a few more people over this weekend to listen to it and give input before I pull the timing cover. Once the cover is pulled I really hope there's an explanation for the noise.

 

Sigh

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By the way, removing the timing chain cover will be a PITA. The duratec has a keyless crank. Rotate the engine and check that TDC and the cams align after tightening the crank pulley. Apparently, the pulley on my engine had slipped during tightening, perhaps when the builder changed cams. My crank timing was off by about 18 degrees. When I rebuilt it, I found slight indents in the pistons where the intake valves had made contact.

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hi there. i have a basic question too (similiar to Maurice1) -- how is it running? by that, I mean does it start immediately? idle properly? and most importantly, is it pulling strongly and smoothly? in a manner like you'd expect a race tuned Duratec? what's the oil pressure look like when it's warmed up? is the needle steady at idle or fluctuating? what reading does it give at hot idle and hot 5k rpm?

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I've got the timing tools coming in, so hopefully that will aid in the cover removal.

 

I've checked the oil (although I'm still not 100% sure what the manual is talking about with the "baffles". I've got the triangular tank) and it seems fine. Level is just below the "baffle" with the big holes in it while running. But, maybe I should dump a quart in and see what happens?

 

The motor fires up and runs like normal. I'm still breaking it in so I haven't been over 5k, and I parked it right away when this noise fired up. Fortunately I was right by my house. Oil pressure at idle is steady and it builds as you'd expect with rpm. I don't have specific readings though.

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