Ongoing problems.

[williebob]

Not sure if there's a central cause to these problems.

My car is just way down on power, it's almost as if the turbo isn't working, but it is - just very gently. Also if I go much beyond about 3000 rpm when driving something seems to cut in and I lose even more power.

I initially thought the problem and the accompanying engine management light were related to an EGR valve problem that I had, but I replaced that part last week but still some problems persist.

Also over the last two days the brakes have developed a worrying problem. If i'm in a situation where I need to hit the brake pedal a few times in the space of just a few seconds the pedal gets harder and harder and consequently less effective - leave the pedal alone for a couple of seconds and it returns to normal. It can get quite hairy!

Any ideas? Thanks.

[rwbaldwin]

The car is going into 'limp' mode to protect the engine.

You need to get the car scanned.

[skippy41]

Get them to check the wiring loom directly below the air intake box, we had a similar power problem and found that the loom was bucked

If this is the case you can cut the bad section out and join the 2 ends cost us 10 drink tokens

[KenONeill]

No info about the engine fitted means I can't even guess about the engine problem.

The brakes sound like you might have a vacumn leak somewhere, probably in the hose from the inlet to the servo, but possibly in the servo. If so, the brakes will continue to work, but you will need to press the pedal harder to achieve a given level of retardation.

Edited 2 February, 2009 by KenONeill
Addl info.

[williebob]

Sorry it's the 1.9td PD.

Best case will be that the car has gone into this limp mode - I guess that is easily remedied?

[Gizmo]

First thing to do is to get a full diagnostic check, either at a dealer or someone local to you on the VAG-COM owners map.

Once scanned you will have a fault code pointing you in the right direction of the fault.

[Supurbia]

BOB, is it flat from the off? if so if you've had the hoses off check the thin one that runs to the airbox, it's braided black, it should join a white plastic valve, if it's off the valve it will stop the turbo working, hth.

[williebob]

Yep, it's flat right from the start, and increasing the revs is pointless because it can't use them, the result is i'm driving like an oap in a micra.

Might check those pipes tomorrow, it's getting a little late to start poking about under the bonnet. It could well be something like that because I did three jobs on it last week - egr valve - coolant sensor and alternator belt, so I guess I could well have knocked something loose etc?

[KenONeill]

With a PD I'd agree; a code check will reveal more about the flat engine. I've a notion the PD has a vacumn pump to drive the servo rather than using engine vacumn, but the thought about a loose hose still applies, other than where it's connected at the engine end.

[williebob]

It's booked this friday - couldn't get it in any earlier.

So in theory could the flat engine and dodgey brakes be connected, or is that impossible?

[rwbaldwin]

Could be. No vacuum would give you no braking assistance and no turbo.

I've known a bad vacuum pump give these symptoms so I guess it could also be a split hose.

Can you here a hiss?

[williebob]

Can't say i've heard a hiss - what area would it be coming from?

[rwbaldwin]

Find the vacuum solenoid valves at the rear of the engine bay (in front of the plenum chamber) and follow all the vacuum hoses to check then not disconnected, split or leaking.

A quick test to see if the brake vacuum servo unit has vacuum would be:

1. With the engine off, press the brake pedal hard 4 or 5 times.

2. Hold the pedal down and start the car. You should feel the pedal give.

[Supurbia]

Bob it's simple, take the cover off the airbox, look on top of the airbox where all the plumbing goes and you should find one of the thin pipes is off a small white unit about the size of a 10p piece, just push it back on, it's a sod for falling off anytime you do any work on them.

[williebob]

Sorted!

Thanks for all the help and words of advice. It turns out that one of the lines/hoses had become detatched (see pic), as was suggested. Must have done it when I did the egr last week as it is right behind where I was working.

I'm sure there's a moral to this story.

Thanks.

[williebob]

I should just add that replacing that pipe sorted both the lack of power problem and the brake issue. Anybody know what that pipe is?

[skippy41]

Posably a vacum pipe for the servo????????? glad your now back in the land of the living though.

I wonder why Skoda did not fit a jubalee clips to the hoses???

[KenONeill]

If it's the manifold to servo vacumn line, you'd have low vacumn in the servo, which is exactly how you described the brakes, and unmetered air feeding the engine after the MAF, which would confuse the ECU, and lead to it selecting a low power mode.

[williebob]

If it's the manifold to servo vacumn line, you'd have low vacumn in the servo, which is exactly how you described the brakes, and unmetered air feeding the engine after the MAF, which would confuse the ECU, and lead to it selecting a low power mode.

Yes, that what I was thinking.