Some help needed from fred, edde, ben etc...

[Frasers Cup]

Today I had to put my 172 cup back into a renault dealer as there was a metallic buzzing noise coming from the engine bay at around 4000rpm.

It only seemed to last for 200 rpm max and it didnt matter if the engine was under any load and what gear/speed it was doing, it would always happen about 4000rpm.

I therefore thought the worst as its a recon renault engine and thought it had something to do with the valve timing as I'd heard thats when the engine steps up in terms of performance.

Got a call back from the dealership however who said that the noise has nothing to do with the engine and its actually the exhaust springs that need replaced??? Do any of the experts know if this sounds reasonable and whether the cost of £117 sounds decent??

Oh and i've been checking the oil regularly and it doesnt seem to be burning any which seems good.

Advice and thoughts would be greatly appreciated...

Cheers

Fraser

 

[MarkCup]

I had the exact same thing.

Turned out to be the fuel rail guard (the slab of alloy sticking out the front of the engine) was loose and was resonating/vibrating at certain revs.

Took it off and binned.

 

[dangreen17]

i have a 172 cup thats totally standard and have the same noise at about 4k - metallic buzzing sound. so i shall try and fix it tonite! cheers

 

[Frasers Cup]

Big hammer sounds good right now....

 

[dwjeviltwin]

Had a similar thing, only happened about 4K, they said it was the exhaust being loose on the downlink and rattling on the heat shield at in the engine bay.

 

[Frasers Cup]

^^Sounds similar to the diagnosis I got....

I'll be mad paying £117 for something that doesnt fix the problem though...

I'll let you know....

 

[alexbleubolt]

just pay the money, easier than trying to change the downpipe to cat joint bolts

 

[davo172]

I had this on mine went in 4 times under warranty to sort it and eventually said it was the baffles in the exhaust centre section and swopped it and the cheeky b*****ds tried to charge me £364 as the exhaust is a wearing part , car had only done 6000 miles !! Didnt pay it complained to reno uk and they soon sorted it .

 

[fmp_]

when they say exhaust springs, do they mean the nut, bolt and spring setup that holds the cat to the manifold?

If so, £117 is a complete rip off.

It is a fiddley job, but buy the parts, and do it yourself.

if its not that bit, then ignore me!

 

[BSC 182]

Today I had to put my 172 cup back into a renault dealer as there was a metallic buzzing noise coming from the engine bay at around 4000rpm.

It only seemed to last for 200 rpm max and it didnt matter if the engine was under any load and what gear/speed it was doing, it would always happen about 4000rpm.

I therefore thought the worst as its a recon renault engine and thought it had something to do with the valve timing as I'd heard thats when the engine steps up in terms of performance.

Got a call back from the dealership however who said that the noise has nothing to do with the engine and its actually the exhaust springs that need replaced??? Do any of the experts know if this sounds reasonable and whether the cost of £117 sounds decent??

Oh and i've been checking the oil regularly and it doesnt seem to be burning any which seems good.

Advice and thoughts would be greatly appreciated...

Cheers

Fraser

Sound about right or could be a heat shield loose or sumet like that, but the exhaust spring could certainly make the noise you describe.

 

[John D]

I had the exact same thing.

Turned out to be the fuel rail guard (the slab of alloy sticking out the front of the engine) was loose and was resonating/vibrating at certain revs.

Took it off and binned.

Do you mean you now don't have a fuel rail guard fitted? Is that not a bit dodgy in the event of a front impact, I thought it was there to stop fuel getting sprayed everywhere.

Fraser - are you sure the noise is coming from the engine bay? or from underneath i.e. the exhaust, in which case it sounds like the 4k rattle I had. Most noticable on the over-run I found. Do you have OE exhaust? I never found out exactly what caused it as the OE back box dropped off fairly soon after it started and I had a cat back system fitted - which cured the problem at least!

 

[Graham Gooch]

I had the exact same thing.

Turned out to be the fuel rail guard (the slab of alloy sticking out the front of the engine) was loose and was resonating/vibrating at certain revs.

Took it off and binned.

Lol, I hope you never have a big front end impact crash in your car!

 

[fmp_]

think u will find that in a frontal impact all electrics are cut, which means the fuel will stop pumping, which in turn will stop it from spraying out of the now exposed fuel rail (well apart from the small amount in there).

And if the impact is that hard, no fuel rail protector is gonna help!

but any who.... back on topic!

 

[Graham Gooch]

Well Renault know their stuff on safety so mines staying put.

 

[Lagerlout]

No Ralph take it out. Renault just put it there for the sake of it!

 

[Frasers Cup]

No the noise is definitely from around the engine bay and its really annoying!! Cant wait to get it back....

I've got a micra 1.2 speed machine at the mo!!

 

[davebem]

Not sure what you mean by metallic buzzing, sounds like the 4k rattle to me, check the heat shield near/under the manifold is on tight, tighten the bolts that hold it on (b**ch to get to) and bend it out of shape so its as far away from the exhaust as possible, especially the area where the manifold joins the cat.

My car did this when I got it and the above resolved, infact the shield was loose on the bracket and was vibrating when the engine hit 4000revs.

 

[Evil Ally]

Mine was the fuel rail guard, which the dealer hadn't put back on properly after a service. Worth checking!

 

[Fred@BTM]

£20 for the parts, £97 for labour, tell them to do one!

 

[MarkCup]

£20 for the parts, £97 for labour, tell them to do one!

What's your take on the fuel rail Fred?

 

[JAY172]

Today I had to put my 172 cup back into a renault dealer as there was a metallic buzzing noise coming from the engine bay at around 4000rpm.

It only seemed to last for 200 rpm max and it didnt matter if the engine was under any load and what gear/speed it was doing, it would always happen about 4000rpm.

I therefore thought the worst as its a recon renault engine and thought it had something to do with the valve timing as I'd heard thats when the engine steps up in terms of performance.

Got a call back from the dealership however who said that the noise has nothing to do with the engine and its actually the exhaust springs that need replaced??? Do any of the experts know if this sounds reasonable and whether the cost of £117 sounds decent??

Oh and i've been checking the oil regularly and it doesnt seem to be burning any which seems good.

Advice and thoughts would be greatly appreciated...

Cheers

Fraser

that diagnosis isnt totally unreasonable. My mate caught his exhaust on a speed bump and he had this aweful noise after that. I ended up changing the springs and realligning the exhaust - noise gone. The cost however - 117 quid sounds very expensive

 

[Fred@BTM]

£20 for the parts, £97 for labour, tell them to do one!

What's your take on the fuel rail Fred?

very common!

 

[.GAZ.]

i bought the cat 2 manifold fitting kit from k-tec then got my local exhaust place 2 replace it.. cost me £40 all in iirc!!

 

[.GAZ.]

Today I had to put my 172 cup back into a renault dealer as there was a metallic buzzing noise coming from the engine bay at around 4000rpm.

It only seemed to last for 200 rpm max and it didnt matter if the engine was under any load and what gear/speed it was doing, it would always happen about 4000rpm.

I therefore thought the worst as its a recon renault engine and thought it had something to do with the valve timing as I'd heard thats when the engine steps up in terms of performance.

Got a call back from the dealership however who said that the noise has nothing to do with the engine and its actually the exhaust springs that need replaced??? Do any of the experts know if this sounds reasonable and whether the cost of £117 sounds decent??

Oh and i've been checking the oil regularly and it doesnt seem to be burning any which seems good.

Advice and thoughts would be greatly appreciated...

Cheers

Fraser

that diagnosis isnt totally unreasonable. My mate caught his exhaust on a speed bump and he had this aweful noise after that. I ended up changing the springs and realligning the exhaust - noise gone. The cost however - 117 quid sounds very expensive

thats wot im thinking!! cnut of a job tho!!

 

[MarkCup]

What's your take on the fuel rail Fred?

very common!

Not the problem, the safety issue? Dangerous/idiotic to remove?

 

[Dan@SJM]

im not running one, its only ever going to be a problem in a HEAVY front impact, enough to push the slam and crossmember back about 10 inches into the fuel rail. so a lamp post really.

 

[Fred@BTM]

very common!

Not the problem, the safety issue? Dangerous/idiotic to remove?

yeah, as its there to protect the plastic fuel rail from front end smashes

 

[.GAZ.]

im not running one, its only ever going to be a problem in a HEAVY front impact, enough to push the slam and crossmember back about 10 inches into the fuel rail. so a lamp post really.

considering mark tracks his car quite alot i'd have thought it'd be dangerous.

 

[Fred@BTM]

as long as you know the risks, we've got customers that don't have them

 

[Fred@BTM]

im not running one, its only ever going to be a problem in a HEAVY front impact, enough to push the slam and crossmember back about 10 inches into the fuel rail. so a lamp post really.

considering mark tracks his car quite alot i'd have thought it'd be dangerous.

especially with his driving! http://www.youtube.com/watch?v=v8_vgI7QOGY

 

[Chris n nic]

My fuel rail cover did the same thing but for the sake of tightening a few screws I would keep it on.

Chris

 

[fmp_]

Like i mentioned, electrics are cut if the impact is hard enough, so its not an issue.

plus if you have hit something that hard, its gonna be one of many worries!

Also, cars with throttle bodies lose the rail gaurd too, does this mean they are unsafe?

As usual, seems people are making a mountain out of a mole hill.

 

[Chris n nic]

fair enought m8y...but it raises the questioin of why is it there? I assume it is a safety reason. TB'd cars don't have them but then again they aren't manufactured like that so it isn't an issue. Recently near me a clio was involved in an accident where he hit another car head on and ended up being a ball of flames where they both died in the clio but the other car was just smashed so I guess it can happen whether the electricity is cut off or not.

Chris

 

[JAY172]

there will still be fuel pressure in the rail for a split 2nd after the impact switch has cut the pump. enough to spray over the engine bay if the rail was smashed. I f you have the standard inj/fuel rail why take the alloy cover off? if it come loose tighten it up

 

[alanhprice]

I'm with Jay 172 on this one. You have to depressurise the fuel rail before dismantling on any fuel-injection engine, usually by taking the pump fuse out and turning over on the starter. The pressure can stay in there for days!

If the electrics are cut off, the injectors won't open and if the engine has already stopped turning, the pressure stays in the rail. Escape of fuel would be in a high pressure mist, perfect for a LETHAL fire. Assuming that the engine will keep turning long enough to depressurise is one BIG IF....

Removal of guard = removal of insurance? :dapprove: OK we're off topic but when guys start suggesting mods like this, somebody's got to step in. C'mon guys, the guard is there for a reason, if a throttle-body set-up means losing it, then YES it's unsafe! Have you seen those low-speed shunts staged by Top Gear etc? Radiator 1, fuel rail (without a goalkeeper) 0, game over.

 

[Fred@BTM]

doesn't matter if the electrics are cut or not, there's 3.5bar in that fuel rail, and believe me it sprays f**king everywhere if the pressure is released!

 

[Frasers Cup]

£20 for the parts, £97 for labour, tell them to do one!

The parts were only £14 supposedly... But the woman at the desk said it was an hour and a half's labour which did the damage.... Oh and they did a health check free of charge as well whatever that is!?! lol

However it has solved the buzzing noise at 4k rpm which is good.

Now i need to stop the banging from the engine mounts....

I've had the ktec lower mount fitted and a new gearbox mount but its maybe needing another changed as the engine is still making noises when accelerating hard off the line....

 

[MarkCup]

I'm with Jay 172 on this one. You have to depressurise the fuel rail before dismantling on any fuel-injection engine, usually by taking the pump fuse out and turning over on the starter. The pressure can stay in there for days!

If the electrics are cut off, the injectors won't open and if the engine has already stopped turning, the pressure stays in the rail. Escape of fuel would be in a high pressure mist, perfect for a LETHAL fire. Assuming that the engine will keep turning long enough to depressurise is one BIG IF....

Removal of guard = removal of insurance? :dapprove: OK we're off topic but when guys start suggesting mods like this, somebody's got to step in. C'mon guys, the guard is there for a reason, if a throttle-body set-up means losing it, then YES it's unsafe! Have you seen those low-speed shunts staged by Top Gear etc? Radiator 1, fuel rail (without a goalkeeper) 0, game over.

Very valid point.

However, in the event of a knock I'm sure just about any type of impact could damage the fuel rail - I mean, this guard...it's not like it's a close custom fit that encloses the entire fuel rail and makes it 100% un-reachable - it's just a slab of alloy sticking out the front.

Wouldn't take much impact of any kind to get to the fuel rail, protector or not in my opinion.

I wait to be corrected though...

 

[mini-valver]

I'm with Mark TBH. Renault may be made to add a guard by law?? I can't see that peice of alloy that bareky covers the rail anyway doing much.....

 

[Sam_Clio16v]

mine has come loose 4 times in 6 months, really starting to piss me off....