Car getting dephaser done

[Charlie-silver172]

Well it happened!

My dephaser shat itself the other day, it's sounded rough for a while but it suddenly became pretty much undriveable e.g making a bad buzzing/rattling noise under load, flat spots all over the revs with odd pop out the exhaust which I'm assuming is because it's playing havoc with the timing

i dropped it off last night for it to get the new dephaser and belts, when it's done do I have to 'run' the dephaser in as such?

 

[Chip-mk1]

No you dont have to run a dephasor in.

Your symptoms sound worse than I have ever seen from just a dephasor going, but maybe your timing was a bit out to start with.

 

[MartinR]

As mr chips said above that aint dephaser symptoms.

Where is it being done?

 

[Charlie-silver172]

http://youtu.be/IV1DwfGp7Hw

Sounds like this when under load above 1500rpm, before it had the slight knock which disappeared at 1500rpm but does that noise instead with a major loss of power. All noises are coming from the dephaser area too

The engine itself is mint, uses no oil etc.
A while before the dephaser got worse I had a race with my mates 172 and they were identical so I cant see it being the timing out.

Being done one by a guy that works at elmsleigh in manor trading estate but being as I know him he's doing it as a private job

i wish I'd video'd it

 

[MartinR]

Dephaser still won't cause large power losses.

My money is on it being something completely different.

Take it to your local specialist. Injector maybe!

 

[Charlie-silver172]

A dodgy injector would cause a misfire wouldn't it?

 

[MartinR]

Yep

will Also run and sound s**t. And be down on power.

 

[Charlie-silver172]

The fact it's down on power I've put down to the dephaser not working properly,

its not a misfire, it just starts surging and bogging down a little when it goes past 3k

If I put my hand where the dephaser is, and someone else gave it a rev so that the rattle in the video link above came, I could feel it quite easily,

I think I know what you mean by injector noise when they make a loud ticking, this is more of a fast rattle

 

[Kyle 86]

Who ya took it to charlie

 

[Charlie-silver172]

Heard of elmsleigh invacar at manor trading estate in Benfleet?

 

[Charlie-silver172]

Dephasers been done

still makes the noise

he said the oil pressure drops right off when it makes the noise

Fucked off is an understatement. What could it be ?!

 

[Dan@SJM]

Well you've answered your own question. Oil pressure issue, probably spun bearing caused by low pressure.

Tbh any decent tech would've known that a noise caused by low oil pressure wouldn't have sounded like a dephaser. Although if the garage diagnosed it as a dephaser and it didn't fix it they can't charge for it.

 

[Charlie-silver172]

He just rang me, he unplugged the dephaser/vvt solenoid and the noise disappeared

but what would cause that to be noisy and the oil pressure to drop off? Knackered oil pump?

 

[clioben182]

IIRC a few years ago I think there was an issue with the dephaser solenoid where the little ball bearing failed in the end of it?
I remember changing a few under warranty

 

[Charlie-silver172]

Not too sure,

But the oil pressure dropping when revved would be the pump?

Think he he measured it before the switch

 

[Fred@BTM]

He just rang me, he unplugged the dephaser/vvt solenoid and the noise disappeared

but what would cause that to be noisy and the oil pressure to drop off? Knackered oil pump?

cam timing being WAY out, that sounds like the valves hitting the pistons to me (yes it'll still run if they're just clipping) seen it several times


Has he not checked cam timing yet?

 

[Charlie-silver172]

cam timing being WAY out, that sounds like the valves hitting the pistons to me (yes it'll still run if they're just clipping) seen it several times


Has he not checked cam timing yet?

The car went in, he changed the belt and dephaser, let it warm up, gave it a rev and it made the same noise as it did before

Done some research, unplugged the solenoid and it then run/drove better than it ever did before

Before the solenoid was unplugged, the oil pressure dropped to 2.5bar and that was with the timing correct aswell

 

[Dan@SJM]

I'm with Fred on this. I think the timings out.

 

[Charlie-silver172]

So if the timing was out wouldn't disconnecting the solenoid not make a difference?

 

[Scattle]

If you wanted to try another garage mate, I take mine to Two Techs Renault specialist next to Bluewater in Dartford, i used them for my 172 and now my megane.

 

[Dan@SJM]

So if the timing was out wouldn't disconnecting the solenoid not make a difference?

If the inlet cam is too far advanced, it'll idle perfectly, then at 1500 start sounding like an old fiesta.

 

[Chip-mk1]

Were proper Renault tools used to time it or did it end up covered in tipex?

if he used the correct tools, even if he got it a bit wrong I would have expected that to fix it if it was tapping the valves on the pistons as he wouldn't put it back as badly out as it was to start with.

these engines are way more timing sensitive than most engines. Stick to specialists who realise this. Nearly always works out cheaper in the long run as normal little garages almost always get it wrong!

 

[mikeh]

I still don't get how anyone with the cam and crank locking tools (which seems to be most mechanics I've spoken to) can mess this up!

 

[bloke]

I still don't get how anyone with the cam and crank locking tools (which seems to be most mechanics I've spoken to) can mess this up!

You can miss the locking point on the crank and end up in the wrong hole!!!!

 

[Dan@SJM]

Or you can bend the tools.

 

[Charlie-silver172]

He tried undoing the bottom pulley but it was seized on so that hasn't moved at all, and he's got the cam locking tool so he can't see it being the timing out

 

[bloke]

don't think you can get the belt out with the bottom pulley in place? i stand to be corrected though as i've never actually tried

 

[Fred@BTM]

bingo we have a winner!

 

[Mar172]

He tried undoing the bottom pulley but it was seized on so that hasn't moved at all, and he's got the cam locking tool so he can't see it being the timing out

My advise is remove you car before the engine is scrap and take to a specialist and get it done .

 

[mikeh]

Have you paid yet?

 

[mikeh]

You can miss the locking point on the crank and end up in the wrong hole!!!!

This is surely a case of the mechanic being a r****d in general rather than not understanding the F4R though, surely?

Who would do it without checking TDC and timing marks?

Unless this hole is at TDC for 2/4? Which would be ridiculous?

 

[Chip-mk1]

This is surely a case of the mechanic being a r****d in general rather than not understanding the F4R though, surely?

Who would do it without checking TDC and timing marks?

Unless this hole is at TDC for 2/4? Which would be ridiculous?

There are some balance holes in the crank that are very near to the TDC hole, although ive never come across one where the pin goes all the way in properly.

 

[bloke]

This is surely a case of the mechanic being a r****d in general rather than not understanding the F4R though, surely?

Who would do it without checking TDC and timing marks?

Unless this hole is at TDC for 2/4? Which would be ridiculous?

i'm guessing that whoever did it 'found' tdc using the end of the cams and the locking pin slid in to the balance hole?

i could be wrong but when i had a mess round to find out what had happened the slide in pin will go in the balance hole, btdc? and the screw in pin atdc, think this was after the cam web so it would 'lock' the crank if you turned it anti clockwise as the web hit the pin but it was free to turn clockwise.

 

[Chip-mk1]

i'm guessing that whoever did it 'found' tdc using the end of the cams and the locking pin slid in to the balance hole?

i could be wrong but when i had a mess round to find out what had happened the slide in pin will go in the balance hole, btdc? and the screw in pin atdc, think this was after the cam web so it would 'lock' the crank if you turned it anti clockwise as the web hit the pin but it was free to turn clockwise.

That would explain it still being in the safe place as before if they did it that way.

 

[Charlie-silver172]

I was cruising at 40mph when the noise suddenly started so I can't see the timing being out, doubt it would've jumped either as it had a belt put on it just before I bought it, he has the correct tool to do it and has checked the timing loads of times

new dephaser - didn't cure it

disconnect the solenoid - cures it but I can't use it like that

with the solenoid connected, the oil pressure drops to 2.5bar when it starts making the noise

And no I haven't paid him, all I've paid for is the parts.
He's not a cowboy, he's a genuine bloke that my uncle has known and used for years

 

[Fred@BTM]

If you disconnect the solenoid the dephaser won't advance, so if it only makes a noise with it connected its 100% cam timing

 

[Charlie-silver172]

If you disconnect the solenoid the dephaser won't advance, so if it only makes a noise with it connected its 100% cam timing

Ok mate, reckon the timing had skipped a few teeth then?

 

[Chip-mk1]

Ok mate, reckon the timing had skipped a few teeth then?

It's not the belt slipping on the teeth normally it's the pulley slipping

 

[Charlie-silver172]

Fair enough!

Thing is, when the car is in neutral I can slowly bring the revs up to 5k and it'll be fine
when I'm driving it, it'll make the noise as soon as I touch the throttle, what's that all about?

Thing someone earlier on said the drop in oil pressure is due to the timing

I'm not really an engine person, otherwise I'd be doing it myself lol

 

[Chip-mk1]

Where are you getting your oil pressure reading from?

Dephasor shouldnt really effect that much as it doesnt flow a lot.


What are the specific values you are getting for oil pressure with and without it at various RPM?