Dephaser - after a technical description

[Henry]

Can anyone offer a detailed technical description of how the dephaser operates please?

If anyone has one, a photo would be really handy.

Thanks in hope!

 

[lemonnobby]

Dephaser adjusts the timing via oil pressure it is on the inlet cam. so body more techinal will be here shortly im sure

 

[Henry]

thanks for that; can anyone add?

cheers

 

[Fred@BTM]

There has been much talk of feeling the vvt kick in on the 172...

fact.. you dont

I just went out and tested my theory.. hooked up a dvm to the vvt actuator in the head, and heres the results..

VVT *Varaible valve timing* is actuated at 1200 rpm !!!.. it is then on al the way to redline..

the only time it is off is on idle, on *very* light throttle, and on over-run..

the mechanism used by renault is a phase shifting device on the inlet cam only.

A solenoid plunger in the head casting allows oil pressure to be fed to the phase shift unit.. this effectively increases advances the inlet cam timing.
there is NO VARIATION.. it is actuated, or not actuated.. ie.. full on, or full off.

so.. now you know.. what you feel at 5k is PURELY the cam coming on.. nothing more.. you cannot even feel the vvt when it actuates.. it is there for a slight torque increase during acceleration (From 1200 rpm).. and off at idle to make the idle smoother and reduce emmisions.. same on very light throttle and over-un..

another myth dispelled..

Cs.

 

[Henry]

thanks

can i ask why they 'whistle'? mine is and, whilst i understand that it doesn't cause the engine any damage, it's annoying me and i'd like to understand what's going on (it's one of several bones of contention with the dealer who sold me the car)

 

[Lagerlout]

Bring back Captain Slarty!

 

[Fred@BTM]

last time i spoke to him he was in the med on a boat (he sold everything he owned, bought a boat and fucked off round the world)

 

[Lagerlout]

What a f**king legend. lol.

 

[edde]

last time i spoke to him he was in the med on a boat (he sold everything he owned, bought a boat and f**ked off round the world)

What a guy.

The cam 14 or 16 dgerees do a search all the info is there its only at higher map pressure and when the oil is warm enough.

 

[Mark5290]

If anyone has one, a photo would be really handy.

 

[Martin_172]

thanks

can i ask why they 'whistle'? mine is and, whilst i understand that it doesn't cause the engine any damage, it's annoying me and i'd like to understand what's going on (it's one of several bones of contention with the dealer who sold me the car)

the whistle is the air-con, if you switch it off it goes away, or mine does anyway

 

[-Leigh-]

thanks

can i ask why they 'whistle'? mine is and, whilst i understand that it doesn't cause the engine any damage, it's annoying me and i'd like to understand what's going on (it's one of several bones of contention with the dealer who sold me the car)

the whistle is the air-con, if you switch it off it goes away, or mine does anyway

Mine whistles with the air con on or off. It occurs at about 6k and continues until the red line. And I find it useful as I use it to just when it's about time to change gear lol. After it start whistling I wait a second or so and then it's at 6.5k and I change.

 

[Henry]

cheers for the additional replies and the photo

will have a good read of the stuff on search

 

[GordonD]

If anyone has one, a photo would be really handy.

I can see the alternator and the A/C compressor.

Where are the power steering pump and the water pump?

 

[16v_jon]

^ thats the 197 engine unit it has electric power steering and the waterpump is powered by the cambelt.