doobiedooo

my MY99 UK turbo has started to judder during acceleration. :-O

When I put my foot down (most noticeable in 5th) the pull is smooth up until apx 2500rpm but then when the turbo kicks in it is wobbly and judders.

....any ideas??? HELP!!!

[Edited by doobiedooo - 7/14/2003 9:58:22 AM]

Pete Croney

I would get your Mass Air Flow sensor checked asap.

doobiedooo

Thanks for the response....please excuse my lack of tech knowledge

I asume that is what people refer to as the "MAF" sensor?? What is it!!?? Will is cost big to check and / or fix if its faulty???

Cheers.

doobiedooo

Just been out and tried an ECU reset as advised in another post but no change.

Very irritating!!!! Any more suggestions??

greasemonkey

Like Pete said, get your MAF sensor checked quickly. If it's f*****, a replacement element for your MY99 car will cost abou £70 plus fitting (although it's an easy DIY job).

As to what it is and where it is, it's the gadget that measures the amount of air entering the engine. If it over-reads, it'll make your car run lean, which could cause detonation, and damage. It's located in the straight piece of intake pipe immediately after the filter box.

Probably worth mentioning that aftermarket air filters that need to be oiled are well known for causing MAF failures, so if you're running one, you might want to change it.

It's also worth connecting the Read Memory connectors under the dash to see if the ECU has logged any error events. If a sensor is failing (rather than failed), it probably won't have, but it's worth looking anyway as this might clue you in to something else being wrong.

Edited to say that if you've reset the ECU, you'll also have cleared any error log entries. Did you do the read memory thing before the reset, or didn't you bother?


[Edited by greasemonkey - 7/14/2003 4:16:09 PM]

doobiedooo

Thanks.

I am all a bit new to cars with Turbos are lots of electric bits so please be patient with me !!!

My air filter is standard.

I took it down to the dealer earlier and the guy there plugged in his diagnostics tool which didn't tell him anything when parked and running but when he took it out for a drive it showed that the O2 sensor (????) is not working above apx 3000rpm.

Again, he said to change the MAF sensor. I asked him about cleaning it and he said it wouldn't work??

Worth a clean or not??? The car is a Nov 98 but 99 spec - From what I've read I beleive the sensor changed around this time??

All help greatly appriciated!

Cheers.

Eddoe

Take the sensor out and clean it with brake cleaner in an aerosol can, it does work!! i have done it on mine, the standard filters can cause this, i have changed to a blitz sus one( it has no oil).

doobiedooo

So the actual cleaning process.... (like I said please be patient with me)

I have found two very different ideas of how to do this....

1.Remove the air-box connection and the MAF housing will come off the car, best way is to remove the actual sensor from the housing...this has 'tamper-proof' screws, either use correct bits or small 'mole grips'...dont round off the heads.

With sensor out of housing, spray and watch the cr4p come off it, DO NOT WIPE it cos it is fragile

When youre happy its clean, put back in and try it

..........&............

2. Take the top off the airbox (where the filter is)
start the car
hold it steady about 3000 revs,
and spray into the airbox (two or three sprays should do it)
it will suck it in and magically clean the MAF sensor.


Which is the recommended technique????

Cheers

LG John

How bad is it? My MY99 has always juddered a little in 5th gear but despite a SN search ages ago I could find no cures. Its not really noticeable, just very slight. The car has also been to JB at least once since it started happening Should I be worried about the MAF as well or does it really need to feel bad before there is an actual problem?

doobiedooo

Mine is pretty bad.

Anyone know which technique to clean the sensor??

ta.

doobiedooo

OK...is this my MAF sensor?? Not what I was expecting but I couldn't take this bit apart any more than this.

Anyway, I filled this with brake cleaner and its done dowt!!



HELP

[Edited by doobiedooo - 7/14/2003 9:47:46 PM]

greasemonkey

Yeah, that's the MAF sensor. You should have been spraying the brake cleaner over the wire element which is near the end.

If cleaning it doesn't make any difference, and connecting the read memory connectors doesn't reveal any error codes, you should really get it down to a main dealer so they can diagnose properly with a Select Monitor.

doobiedooo

I took it to the dealer yesterday and they said the O2 sensor wasn't behaving but still suspected that the MAF was the cause.

My problem is I don't wanna spend £70 on a new one to find out that there's nothing wrong with it.

......gonna call the dealer back and see if they can give me a 100% diagnosis for a small fee.

...or... has anyone got a spare MAF kickin about that I can try???

nom

IMHO, you want a new MAF anyway...
They are so critical to the health of the engine, and the original ones were pants. If you buy a new one, they are of a new design and much, much tougher.
Basically, if the original MAF hasn't gone wrong yet, it will do at some point anyway. An seeming that a dodgy reading MAF can blow the engine up within 50 miles (this is before the CEL comes on), caution seems like a good idea to me

Jza

Dude - im no expert - but if your MAF is faulty - you could blow your engine big time - so spend the £70 - the risk isn't worth it.

Its 4 years old - so at least you know its clean and new... and you can remove it from the equation if it still judders.

Pete Croney

If it didn't cure the problem (and I'm sure it will) then I would take it back out and not charge you. I'm sure your dealer will do the same.

doobiedooo

Thanks guys.

A very nice chap who fitted my clutch last week (calls himself "Rally Colin" I beleive) is gonna lend me a MAF this afternoon.

doobiedooo

...and just to conclude...

it was the MAF. You're all bloody genius's .

Thanks for all your help chaps and an especially big thank you to Colin Minton (Rally Colin). Colin has not only lent me a MAF sensor to test the problem, but has ordered a new one for me and let me keep his spare until the replacement arives on Friday.

TOP BLOKE!

I can defo recommend him to all (contact details are on here if you search)

LG John

Back to the original question. Exactly how unsmooth was the boost?

doobiedooo

It was really bad. It started as a judder in 5th only but got progressively worse.

Now I have a replacement MAF it is so much better but I'm still gonna get my Local Subaru to test it again when I have it serviced in a couple of weeks.

If you have a small wobble in 5th then its probably not what I had but don't take my word for it.....I belong in the muppet forum much more than this one .... take it to your dealer and get them to plug in their box of tricks. They shouldn't charge you for that.

Or you could post one on here and let one of the clever people answer rather than me

LG John

Cheers, I think mines is fine. It only sometimes in 5th at about 70mph uphill that I can feel a very slighty shudder in the boost. Its probably just a little natural fluctuation rather than anything else