SEAT Leon (1999 - 2005) - Rough running at lower revs, warning light

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Mon 5 Nov 2007 00:29
Rough running at lower revs, warning light - andymc {P}
Seat Leon TDi 110, 100k miles, regular servicing every 8k miles including cambelt change at 95k.

Towards the end of a 10-mile trip this evening, I thought the engine was starting to sound slightly ?buzzy?. Once it was started up again later on, it was running very harsh and the ABS warning light appeared (some years ago this light came on to indicate a faulty injector at the time, long-since rectified). Checked oil which was slightly low but not below minimum and had no real choice but to drive home. I noticed that intermittently, the harsh running sound seemed to suddenly disappear and asked des. driver (aka wife) to vary engine speeds and gears.
The engine appears to run suddenly normally at various rpm in various gears. In first gear it?s harsh up to 1600 rpm, after which it suddenly sounds normal again. In second and third the harshness suddenly disappears after 1800 rpm, while in fourth and fifth the harshness suddenly disappears after 1900 rpm. This is very consistent ? e.g. it could be running normally at 2000 rpm in fourth, but if revs are allowed to fall back to 1500 rpm the harshness returns until revs reach 1900 again. Same consistency of symptoms exists whether accelerating through the gears or varying speed in individual gears.

Last week I went for a longish trip of 190 miles and due to an unexpected extra 90 minutes of stop-start traffic caused by a couple of accidents en route, the ?fuel remaining? display was intermittently indicating zero with about ten miles to go. I was able to fill up about a mile before our destination and had been driving cautiously up to then, coasting in neutral where possible etc. However there were no problems on the same 190-mile return journey ? I?d have thought that any problems with dirt in the fuel would have manifested themselves before getting home. Although I wasn?t the driver tonight, wife said she didn?t notice any drop-off in power so I?m not sure that it?s the MAF. With the window down I could just about hear the turbo spool up as normal. I?m guessing either dirt in the fuel system or a faulty injector, but would welcome any other suggestions/advice/solutions!

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andymc
Vroom, vroom - mmm, doughnuts ...
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Mon 5 Nov 2007 12:05
Rough running at lower revs, warning light - beachboy
I have a Leon Tdi 110 but I am afraid that I cannot offer any explanation for the symptoms you describe.

If you have not already done so, I suggest that you send a post to:

www.seatcupra.net

It is an excellent site for all things SEAT and I am sure that somebody on there will be able to help you.
Go to forums and then the Tdi section.
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Mon 5 Nov 2007 12:58
Rough running at lower revs, warning light - Screwloose
Andy

Maybe getting the codes read would be a good start. "Harshness" could be many odd things.
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Tue 22 Mar 2011 07:28
Rough running at lower revs, warning light - unarmedrob

Hey,

I know it was a long time ago, but did u ever work out the cause?

reason i ask is because my 110tdi has just started running as you described

Many thanks

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