Odd 'popping' noise...guess the condition

T

TroyTempest69

A2OC Donor
Ok, it's another 'guess the noise' question & I know this is rather vague & I do plan on booking the car in the garage first thing Monday morning, but there's an odd noise coming from the engine bay.

Hard to describe, but sounds like a low 'popping' noise. Sometimes I can drive for days without hearing it, other times I hear it every time I blip the throttle. It does seem to get louder the quicker I go, but the tone & speed of the sound stay the same.

I've taken the bonnet off whilst the car is parked up & blipped the throttle & it seems to originate from the rear of the engine area...somewhere. Any ideas to put my mind at rest over the weekend

The cars a 1.4 TDI, on 115k, FASH. Cambelt, tensioners, waterpump & thermostat recently just done.
 
Prob sounds like the N75 valve.

I have 1.4 TDI on 92K and Mine was dying a slow death and started doing that annoying noise. Took me a while to figure it out.

Put a new one in and hey presto noise gone.

N75 valve is on the RHS when looking at the engine bay, right at the back above the coolant tank

John
 
John

Thanks for the heads up. Other than this noise there are no other issues...car runs sweet..plenty of power, no mis-fires. I'm worried the turbo might be on the way out...but figure there would be more symptoms than an odd noise like this!

Pete
 
sods law...car was in the garage last week & the car was sooo quiet...no odd noises...nothing....not even any fault codes.

Not that the noise has gone...still there...however, happened to be driving past the garage today, and as the car was making this stupid noise popped in to show them. They had a quick look and said it's more than likely the EGR valve sticking as when they held the valve with the engine running they could 'feel' it unsticking & making the popping sound..if thats makes sense!

Ok, so a few questions.

1) If I do nothing can it cause any serious damage to the engine....suppose I'm worried a piece may come off & get sucked into the turbo? If not I may just live with it until Sept when the cars due a service...although I do drive serious miles.
2) Are they straightfoward to change? (I have a whole day free & a good selection of spanners/tools - I'm assuming its an allen key/bolt arrangement...although access looks a pig)
3) Any ideas on part numbers (1.4 TDI 75BHP). Is this suitable..looks a good price?

http://cgi.ebay.co.uk/NEW-EGR-Valve...arts_Vehicles_CarParts_SM&hash=item3ca9e6ae2a

Thanks...as always

Pete
 
IIRC some people actually diasble the EGR valve anyway, as it prevents sooting/clogging of the inlet, better idling and some even claim better acceleration performance. I am not sure I would bother replacing mine if it were stuck closed. Probably quite pricey too.

Cheers,
 
Hi Pete,

I concur with their EGR diagnosis. When mine was sticking it sounded a bit like a sub woofer "ump" (or a glug!) from the passenger footwell, which I could get to happen if I touched the throttle whilst crawling in trafiic with the engine warm. The repair work was done under warranty, but the dealer started by changing the accuator / EGR switch (?), then when that didn't cure it the whole EGR valve assembly was replaced. I would guess £350 is around the mark for a dealer to do the work (my bill shows £0! sorry). Since it is a VW engine you could try a local VW garage, they might be cheaper.
Since being replaced we have used Millers diesel additive and standard Shell diesel, 30k miles later no problems.

Cheers,

David
 
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