Octavia 4x4: 2 tech questions!!!

[ctwr]

Hi Guys!!! im new to the forum this weeked but have to say its full of excellent info! (just finished reading up on how to clean my throttle body!)

i bought an 2001 octavia 4x4 back in january, it had been lying up for about 2 years!! was in good nick tho and passed mot with very little work (oil service, timing belt and brakes) running very well in general. 2 things id like to pick all your brains on tho!!!

firstly i was reading the owners manual the other nite, it says the haldex clutch system should get an oil change every 30k, my car has 95kish and i doubt its ever had this changed, i got it with 92k on it after that 2 year period off road. does this need done??

secondly ive noticed a few times since ive owned it and its becoming more regular is that when pulling off from the lights the dump valve hisses and the car jerks a bit, it can do this if i pull of the lights hard or just normally, very frustrating at times, specially if the brides in the car!! its also done it a few times in as high as 3rd gear. is this a common fault with this model??

id be grateful for your help!!!

Many Thanks

Chris

[KenONeill]

1) Yes. In fact, I'd suggest doing it now, and repeating in about 1_000 miles, using the first change as a flush.

2) I'd suggest getting the fault codes read. I have a suspicion about the N75 valve, but it needs the codes reading to confirm or deny this.

[chicken_eyebrow]

Has it got a standard or an aftermarket divertor (dump) valve?

If it's an aftermarket one then it may be set up so that the spring is weak in which case it is leaking boost out when it shouldn't be.

[will_]

I've heard conflicting advice about Haldex oil. I thought it was supposed to be changed every 10k but my local Skoda specialist (formerly a dealer) swears it's 20k. I change mine every 20k.

[auroan]

Haldex is definately not every 10k. It tells you in the service book what the intervals are.

[will_]

Thanks, auroan, you're right. I've just found some more info about when (and how) to change the Haldex oil here:

VWvortex Forums: Changing the Haladex Oil

[ctwr]

thanks for the replys! sounds like i better get it done ASAP!! im not sure if it has ever been done, the car did have a regular dealer service up until 70k or so so hopefully they have done it at least once, the service manual i have says it should be done every 30k. ive contacted the local skoda dealer to see wot the charge and if the even know how to do it lol. looking on ebay there i found a vw haldex service kit listed with the follow numbers:

Haldex oil filter 02D 525 558A

Drain plug 02D 525 729

Haldex oil G 052 175 A1 (275 ml tube)

Haldex Filter Tool: (VW TOOL PART NO T10066 REF ONLY).

im gonna call my local TPS center and see if these are suitable for the octavia too.

i had the fault codes checekd but nothing was coming up and theres no warning lights displayed, it was however just a basic code reader so perhaps a better more professional system mite give me a better picture. as far as i know the dump valve is just a standard part, it seems to be well buried behind the engine and i cant get a good look at it!!!

i noticed today a bit of a flat spot around 3000 rpm could be connected perhaps???

[ctwr]

Thanks, auroan, you're right. I've just found some more info about when (and how) to change the Haldex oil here:

VWvortex Forums: Changing the Haladex Oil

thats a pretty handy link btw! i saved the pics for when i can get under the car! a goods heads up tho theres also i diagram with a wee walk thro, just have to see if im brave enuff to attempt it meself! lol

[will_]

When I had some turbo-related problems (that turned out to be a faulty diverter valve), I found it difficult to get my head around all the related plumbing so I wrote this to help me (and others) understand it:

http://briskoda.net/ask-tech/clarrification-dv-bov-n75-n249-wastegate/73087/

[auroan]

CTWR just for future reference, the VAG 20V Turbos don't run a "dump" to atmosphere valve. The VAG equiv is a closed circuit resirculation system. If you're hearing any form of pssht on gear change etc then you need to get the turbo and ancilleries checked for any obvious signs of damage.