Leon FR TDi - worrying engine rattle

[englishhaggis]

Hi everyone

I have a lovely shiny red 56 plate Leon FR TDi. Problem is that sometimes, at around 2,500rpm, the engine develops a rattle like an old tractor. Give it a few more revs and the noise disappears. As I say, it only happens occasionally and I can't predict when it will happen again . I'm going to take it to the dealers for a check up, but I wondered if anyone had any ideas as to what they should be looking at?

Thanks in advance

 

[k4ith]

i sometime get a rough idle, once in a while, but apart from that all ok. started using millers diesel sport 4 in the fuel now, as seen in prev posts.

 

[t-"RACY"]

Hi everyone

I have a lovely shiny red 56 plate Leon FR TDi. Problem is that sometimes, at around 2,500rpm, the engine develops a rattle like an old tractor. Give it a few more revs and the noise disappears. As I say, it only happens occasionally and I can't predict when it will happen again . I'm going to take it to the dealers for a check up, but I wondered if anyone had any ideas as to what they should be looking at?

Thanks in advance

Hi englishhaggis,

my hubby has seen your thread and having an extensive background in diesel powertrain he has suggested the following -; Check oil level, Diesels have an appetite for oil in their early stages of life (especially high performance engines) he said that the noise you describe could be a result of oil starvation, as whilst at idle speed the oil pump is not generating too much pressure and if low on oil will not be picking up much oil from the sump. When you rev the engine the oil pressure builds up and lubricates the cam lobes, hydraulic cam lifters which explains why the rattle disappears when you rev the engine.
(These components that are a potential cause of the rattle).

Check the oil level and top up if neccessary, all should then be OK. If not it looks like a potential bearing issue in one of the auxillary components i.e water pump, alternator or idler pulley (cam belt or fan belt).

My Hubby said of the more extreme you could be looking at a new Turbo

(P.S I have not got a clue what he is talking about!)

Hope this info helps.

Tracy

 

[englishhaggis]

A particularly helpful reply, thanks Tracy!

I've checked the oil and it's about half way between Min and Max - will top it up though just to be on the safe side. In fact, I think I'll go and get a full oil change at the weekend as the car's at 6,000 miles now and it can only do it some good.

I think a trip to the dealers would be a good idea anyway just to make sure there's nothing more serious going on.

Thanks again!

Paul

 

[MartH]

That happens when its clearing out the DPF, rough idle and rattle at lower revs. Thrash it for a few miles and should clear it!

 

[Tam]

Yep, was going to say sounds like DPF cleaning..

 

[englishhaggis]

Aaahhh... brilliant, thanks guys.

Still going to get it checked out though - especially with all this talk about contaminated fuel.

Cheers

 

[Carnivor]

Yer defo sounds like the DPF Transit Van mode, do you get a bit of a burning smell aswell? we do.

I didnt think the contaminated fuel was including diesel aswell??!?

 

[fivetones]

Yer defo sounds like the DPF Transit Van mode, do you get a bit of a burning smell aswell? we do.

Interestingly we have the transit van sound right now. Thought it was low oil but that's been checked now.

 

[englishhaggis]

I didnt think the contaminated fuel was including diesel aswell??!?

I've no idea - I've just heard the words 'contaminated fuel' bandied around.

 

[leonfrtdi@chan]

Does it happen when you lift off the accelerator?

Makes a low and dull humming noise coming from the front of the centre console?

If so, I've had this problem too and I only had a guess at what it was as I've heard of a similar fault on the MK5 Golf DPF TDI. It was to do with a faulty turbo solenoid. Got mine replaced under warranty and (touch wood) it hasn't come back. It does affect performance slightly and don't know what long term damage it could cause. If I was you I'd go to your dealer and ask them to investigate.

 

[Carnivor]

yer turbo solinoid is being checked on ours next week, one of the 7/8 things on my list

 

[englishhaggis]

Does it happen when you lift off the accelerator?

Makes a low and dull humming noise coming from the front of the centre console?

If so, I've had this problem too and I only had a guess at what it was as I've heard of a similar fault on the MK5 Golf DPF TDI. It was to do with a faulty turbo solenoid. Got mine replaced under warranty and (touch wood) it hasn't come back. It does affect performance slightly and don't know what long term damage it could cause. If I was you I'd go to your dealer and ask them to investigate.

It only happens when I accelerate to about 2500rpm. Over 3000rpm it sounds fine and I haven't experienced any loss of power. Although the rough idle thing I have had but I put it down to aircon/weather/engine temp/global warming and thought nothing of it.

The DPF cleaning thing sounds very plausible as from further observation it seems this noise only manifests itself following a bit of town driving - no such problems after a blast down the M6...

One thing I have noticed (and has been picked up by another thread) is that the MPG is surprisingly poor and much lower than the manufacturers claimed figures. I get about 38mpg on my bi-weekly 300 mile jaunt down to London at around 80-85. In fact, my old FR 150 was doing about 5-6mpg more even when I ragged it. I'm now wondering if it's all connected

Anyway, it sounds as though I'm not alone and I do still love the FR, despite these little niggles. I don't know, cheap plastics, rattly noises, poor mpg... it just doesn't seem to matter all that much. In fact, it's kinda nice that it's not perfect - gives the car a soul and gives us something to talk about, doesn't it?

 

[chillcupra]

I was just wondering if you got this sorted out as I maybe having the same problem.

 

[englishhaggis]

I put it down to DPF cleaning which seems to make sense. I went to the dealer the other day to see if they could take a look but they were too busy and told me to ring up and book the car in - which I haven't done yet. But today I'm going to ring them because weirdly I'm now experiencing the same noise as leonfrtdi@chan describes, which is even more irritating...

 

[MartH]

A kind of mooing sound if you blip the throttle or lift off in slow moving traffic, thats the N75 valve, had mine replaced a couple of months ago and so far hasn't come back.

 

[Daff]

Mine is now doing this! 2500 miles in an 07 Ref Sport 2.0 Tdi & at about 1250 revs & just feathering the throttle in 6th I get what can only be described as an "Agricultural" rattle from the engine. I know it's not normal having come from a mk5 Golf 1.9 tdi - what exactly should I be telling the dealer to look for? And is it worth booking it in now or waiting until first service?
Any thoughts?

 

[englishhaggis]

My rattle was down to DPF cleaning. It's only the FR which as the DPF I think, so I guess you have a different problem.

I managed to get the 'mooing' noise fixed though. Dealer replaced the 'boost pressure valve' (is that the same as N75?) and the noise has gone. Thanks to MartH for the suggestion.

 

[Tam]

We've just had a 170ps engine in an A3 at work surge and rev all by itself.

Was being driven the other week when it surged off by itself without the driver pressing the accelerator, dropped the clutch and the engine redlined, pulled into a laybay engine still on the rev limiter.

Turned the ignition off, still reving all by itself. Suddenly went bang and stopped.


A seal had failed somewhere in the turbo which meant it sucked all the oil out the engine and ran on that until it had drained the engine of oil and seized.

New engine on the way from Audi. Only 800 miles on the clock too.

 

[Michael B]

^^ I bet they didn't but one lol..

Seriously though, first time ive heard of anything like this happening on the 170s