Breathing Heavy!! + losing boost.

[Ross]

Hi,

well I hoped it'd be a while since I posting a cry of help but here goes!! To me it seems like a classic boost leak but I thought the Samco hoses were pretty much immune? She was going fine, stopped at a stealer (scared her perhaps?!) for a bulb, pulled back onto the dual carraigeway and gave it some in 2nd and there just a weak pull, rather than the back-in-your-seat thrust I'm used to! So, did a few test in the remaining few miles home;

Symptoms are as follows:

Boost builds slowly, a little erratically and only to .5-1bar (usually a quick, solid 1.5)
Boost drops real fast, (as soon as i backed off) to -0.5
A few times boost did build quickly and car felt as per normal
Much louder 'whoosh' when i backed off/change gear
Idle seems a little rough
No Smoke


I took it easy apart from a few 'test' applications of throttle, and when slowly applying throttle it seemed like i had to give it loads to bring boost even to 0. Driving off turbo the car is fine. With the window down I could hear what i assume was the turbo spooling up, even before boost was building (it was like having mega turbo lag), and worried it'd overrev trying to build full pressure - is this possible?

Any advice on this one fully appreciated!! I'm fine driving it like a grandma for a few days, but I won't if it can cause damage..
cheers,

Ross

[rotoryboy]

sounds like a boost leak, do you have the Mark H mod?

[Ross]

I'm pretty sure I have the H-mod; will have to double check (too dark now!)
cheers

[S2central.net]

Deffo sounds like an air leak... Especially if you are hearing it so easily - should be easy to find if its thats bad.

Check all your hose clips are nice and tight. Also check the TBV and the WGFV.

Paul

[Ross]

Am I risking any damage to the turbo if it's spinning up and not pressurising anything? That's my biggest issue, I'd hate to have to replace it. mainly coz I'd want a bigger one seriously if it'd be best parking up I can get the train to work in the morning... I know Chris had a boost problem a couple of times, with the DV i believe, I'd best check with him on that one. Cheers for the tips though, I'll update tomorrow-

Thanks
Ross

[S2central.net]

You could be overspining the turbo as it tries to build up pressure... To play safe just go easy on the right foor while you have a problem.

[Ross]

Wow, this is gonna take some self discipline... it was hard enough letting an Elise floor it as he past me and get away with it! Perhaps I'll put a block under the pedal.

Anyway, I did a quick test run earlier and he's a video clip, need quicktime i think, what to look out for is the boostguage at the start of the clip - a good example of what happened when i floored it @ 50 in 4th (and the noise is the wastegate pipe if anyone wants an idea of what one sounds like)... notice how boost climbs quickly in this instance to 1bar, drops off to about .7 and then jumps up again at high rpm.

http://www.rossburton.com/castlecoombe/Boostleak.MOV

[Ross]

OK, so an update on the situation, I spent the morning with David (what a guy - thanks pal!! I owe you a beer ) and, after tightening some hoses it seemed the car was building boost better but still hesitating; I did however realise that I'd put some nasty 95ron fuel in the tank about 3 miles previous to the problem; so a quick trip to Camberley Tesco's and £50 of 99RON later the car seems to be running much nicer!! Strange thing is, the 'high volume' turbo whine and breathing still exists, maybe I just had the radio louder before and didn't notice?! (i do have a cone filter) Although it still doesn't quite feel quite right to me, but that could be in my mind...

BUT my question now is, anyone ever had a car throw a 'tantrum' over bad fuel? I would've thought it would affect performace a little, but not cause the car to run like ****!! It's a 3B with a remap btw. I guess we'll see how it goes...

cheers-
Ross

[s2driveruk]

was pulling like a train to 1.5 bar peak before bleeding off some pressure at high rpm. Slight hesitation between 1.1 -1.3bar but momentary only and all sounds pretty good to me. The car is definaltey got a fair bit of oil running round the breather system and we found a kink in the hose running off the back of the rocker cover no idea if that could have caused an issues in the amount of oil residue in the metal pipe...

DV is fine, I think it could be a dodgy connection maybe on the maf or wgfv as all the hoses are now airtight or maybe the intake temp sensor noticing a rise/spike in temps and causing it to stutter a tiny bit. Failing that if could just have been crappy fuel in the last dregs of the tank. Cleaned the ISV too... and tightened up sparks on cyls 4 & 5 which were a good half a turn off tight. Oh yeah and we got rid of that (!)

Hope it runs better, that separate w'gate pipe sound is pretty brutal at full chat! and hopefully the rear caliper won't stick as much now too.

Oh btw Ross, did you go back to Kwik Fit and b**lock them about your tyre fitting - one of the fronts felt out of balance, they well over tightened those bolts (to the point that i managed to sheer off an extension on my torque wrench!!!!!!) Idiots hadn't even bothered to put any slip on them before putting the wheels on!!!!!!!!

[Ross]

OK, gave the car a quick thrashing for a few miles this afternoon - still some slight hesitation about 1.1bar, a few times it only pulled to 1.3 throughout the gears, yet on my final 'stint' to the house some geezer in a brand new 330Ci got right into my personal space at 60mph and she responded; here's the story:

I heard him gear down and floor it as the short dual carraigeway started; I responded in like manner - she held 1.5bar and pulled hard through 3rd & 4th to about 100mph (took it to about 5K, so there was more to go but I'd already embarrassed him enough at that point). With about 20yds on him I slowed off and let him fly by, only to floor it in 5th at about 75 - 1.5bar again, pulled like a train through a hard corner and was nipping at his heels, but then let him go - he seemed a bit agitated though!!
330Ci 0 - 1 S2

So, I'm still not quite convinced - seems to still be a bit of a problem there, albeit intermittent - I'm still tempted to replace the WGFV if that could be a problem?

Haven't got back to Kwik Fit yet - I guess I've only myself to blame for taking the car there, but still I think they need a right rollocking for that one!! The alignment is terrible and the car is all over the road too, so I'm thinking of dropping the car off at micheldever in the morning and getting it sorted.


cheers
Ross

PS: car is idling much nicer, and i can crawl along in 2nd at 1000rpm without kangarooing - cleaning the IFV must've made the difference!

[Doug_RS2]

It is worth pressure testing the car.

Any codes?

[dan_b]

The hesitation issue you're talking about sounds familar - have you:
cleaned the MAF
checked/changed your sparkies
checked the HT leads
checked the distie/rotor

yes my mapped 3B also throws tantrums over bad fuel - if I run a few gallons of "normal" unleaded through it it kicks up quite a fuss - poorer throttle response and clearly lower power on full boost, and noticably worse fuel consumption as well.

[Ross]

Hi guys-

again thanks for the input, short on time atm (aren't we all) and it seems my only spare hours are when it's dark and throwing it down! Hence, I've not had chance to do much with the car. I'm driving it daily albeit usually only for a half hour or so; Doug I'm not sure how to get the codes - any good guides or tips as to how to pull these from the ECU? Do I need to reset it first (if so, how?) and then drive for a bit? Please appreciate I'm a complete newbie at this stuff!

Plugs were tightened, but didn't check them out for damage - I'm not 100% sure but I think plugs + leads are quite new - more things to add to the list of 'things to check when i get chance' i guess!

Another quick question; still wanting to test the WGFV before i rules it out; what's the best way to do this? My logic is that if i unplug it, then boost will be governed mechanically - so if it boosts to a lower level, but reliably, then it could be a pointer int he right direction. But then again, I wouldn't wanna screw something much more expensive up in the process...

cheers,
Ross


PS alignment fixed today; they made alot of changes! Was told to watch my language @ Micheldever, upon mentioning Kwik Fit Front was hugely toed out on one side as expected - it's great to be able to drive in a straight line again... camber is still a bit imbalanced though; perhaps they had problems adjusting it?!

[S2central.net]

Take a trip to http://s2central.net and navigate your way thru the technical pages in the engine/motronic area for a simple way to pull fault codes.

Renewing the WGFV cannot hurt and its not expensive. You can safely disconnect the current one. You should see no more than ~0.4bar with the WGFV disconnected.

Still suspect an air leak though.

Reset the ECU, if you haven;'t got VAGCOM, in order to clear any fault codes.


Paul

Hi guys-

again thanks for the input, short on time atm (aren't we all) and it seems my only spare hours are when it's dark and throwing it down! Hence, I've not had chance to do much with the car. I'm driving it daily albeit usually only for a half hour or so; Doug I'm not sure how to get the codes - any good guides or tips as to how to pull these from the ECU? Do I need to reset it first (if so, how?) and then drive for a bit? Please appreciate I'm a complete newbie at this stuff!

Plugs were tightened, but didn't check them out for damage - I'm not 100% sure but I think plugs + leads are quite new - more things to add to the list of 'things to check when i get chance' i guess!

Another quick question; still wanting to test the WGFV before i rules it out; what's the best way to do this? My logic is that if i unplug it, then boost will be governed mechanically - so if it boosts to a lower level, but reliably, then it could be a pointer int he right direction. But then again, I wouldn't wanna screw something much more expensive up in the process...

cheers,
Ross


PS alignment fixed today; they made alot of changes! Was told to watch my language @ Micheldever, upon mentioning Kwik Fit Front was hugely toed out on one side as expected - it's great to be able to drive in a straight line again... camber is still a bit imbalanced though; perhaps they had problems adjusting it?!

[Ross]

Just thought I'd update on this one... stopped by at MRC this afternoon, car was running really well when I had Minneha in the car (typical) but i think bad fuel could be the main culprit as this problem seems to have gotten less frequent no way near as servere! A pressure test revealed a broken PSV valve though, replacements on it's way - till then I'll be the tree-huggers worst nightmare as she exhales oily fumes into the atmosphere... no faulty codes either.

big cheers to Doug + Minneha, top blokes!! And know their stuff, too

Ross