hpoolsteve

iTrader: (4)

Currently on a 200 miles trip. When accelerating boost gets upto 15 psi then drops to 5 then up to 10 back down to 5 then back up to 15 and so on. Then it will just settle at 5.

What could be causing this.

Thanks

My00 uk turbo

turbo2000dent

Hey up

I got same my00 and have no boost gauge but had similar prob, only when I used boost I see my wifes head in passenger seat going forward ond backward like its boost no boost n so on like its pulsating, it did this for about 2 months n then check engine light came on, which was maf problem so changed that n now it runsas smooth as a babies *** all the way up the rev range,

Could be same problem

TonyBurns

iTrader: (3)

It could be the boost solenoid, it could be if you have a full decat exhaust and your hitting the boost cut on the ecu etc, if you have a list of modifications it would be good to post them too.

Tony

hpoolsteve

iTrader: (4)

Hi

It has a scoobysport downpipe and magnex back box. Bailey DV thats it mate.

On 2 occasions on the way down the boost topped at 20 psi never gone that high before

Never had a problem with this before. The maf is only a year old.

Hope this help. I will be setting off again in an hour or so on the return leg of my journey (200 miles)

Thanks

Splitpin

This doesn't immediately sound like a MAF sensor-related issue, but as Dent's experience demonstrates, anything is possible. When you say your sensor is only a year old, does this mean you bought a brand new sensor a year ago, or does it mean you bought a secondhand sensor over the last few months from someone who told you it was bought around August 2009? Also, is it running behind an OEM, or quality air filter?

It sounds as though you are getting a simple boost overshoot that the ECU is struggling to control. There are a number of potential causes for this sort of problem. Given that you're out on a trip, did you, by any chance, top the oil up before you left? If you did, check it again now, with the engine hot, about five minutes after switching off. If it's any higher than the full hole (that's the hole, not the notch), try taking the boost control pipework off the turbo compressor bleed and actuator nipples and shoving a piece of white tissue inside them. If either piece comes out soaked in oil, take it all (and the solenoid) off and spray it out with brake cleaner.

If the pipework is clean and/or the oil level below the full mark, let us know.

Stealth

iTrader: (4)

As suggested it could be the Boost solenoid going up the spout but it could also be signs that the actuator is knackered and flapping about when the car is trying to make boost, this would give VERY poor boost control as well

hpoolsteve

iTrader: (4)

well just arrived home and 2 miles from home i have now lost all boost. Sounds like exhaust is blowing as well never noticed that until lost the turbo.

please help

Splitpin

With the best will in the world Steve, none of us here is Harry Potter, and therefore nobody is going to be able to wave a magic wand.

Given your updated description of the symptoms the best thing you can do is get it looked at. If you've got a holed up-pipe or similar that'd easily explain what you're reporting, but there are too many other possibilities here to offer much more than wild stabs in the dark. You'll get a reliable result quicker if you get it in front of a dealer or specialist tomorrow.

If the actuator was knackered it's unlikely he'd have been seeing the pronounced overboost that was being reported earlier. Too many conflicting/confusing symptoms here to give a reliable diagnosis via the interweb. As above, specialist help needed.

hpoolsteve

iTrader: (4)

I understand that splitpin.

I have a garage up here that can carry out the work but god knows if they will be able to diagnose the problem without turning round and saying your turbo is knackered lol. Will check the exhaust first and go from there I guess. So a holed up pipe can cause complete loss of boost?

Stealth

iTrader: (4)

yes of course, the turbo relies on the hot gasses from the engine to spin (out the heads through the manifold and up the up pipe), if the gasses are escapin the exhaust system via a split in the up pipe there is nothing there to spin the turbo = loss of boost and any real use of your turbo

hpoolsteve

iTrader: (4)

just to update u guys my dv was seized have now stripped it down and touch wood boost is back. lets hope it stays lol

Splitpin

Throw the Bailey in the bin and put a standard one on. Easiest way to prevent a recurrence. Your engine will run better too.

hpoolsteve

iTrader: (4)

Have been keeping my eye out on here for a standard one but have not seen one yet

hpoolsteve

iTrader: (4)

Dv now works but still got pulsating boost. Could some point in the direction of the boost solenoid and boost pipes that I need to check/clean.

Thanks

Splitpin

Can you describe the pulsations you are now getting in more detail? What is their magnitude, what's the frequency etc?

The boost control solenoid is the greeny-blue plastic barrel fixed to the plate on the offside front suspension turret. As per #5, the pipe you should check first for oil contamination is the turbo compressor bleed outlet. Location of that should be self-explanatory. Also, did you double-check your oil level (with the car warm and on a flat surface)? If so is it above or below the top hole?

SiofChester

iTrader: (2)

I've got a standard dump valve you can have posted for a few beer tokens

hpoolsteve

iTrader: (4)

As per post 1 splitpin with regards to the pressures. This happening all the time and in every gear. It will tend to boost up and down and the stay at around 5 psi and go no further.

The oil level is fine not to high just below max.

I will look tomorrow at the parts I need to clean.

hpoolsteve

iTrader: (4)

Check the things you suggested with white tissue all clean and good. Have too the solenoid of and cleaned that. Still the problem persists.

hpoolsteve

iTrader: (4)

Right I have just come back after a run. The car boosts fine for about 10 minutes then goes back to the original problem

john5f

iTrader: (3)

Any chance the Coolant Temperature Sender could cause this?
Maybe Splitpin knows for sure.

Splitpin

Coolant temperature sensor certainly shouldn't be causing behaviour like this. It has no direct control or influence over boost pressure management. Sounds quite likely that heat buildup is affecting something though.

Steve, when you say it works fine for 10 mins, is that for 10 minutes if you start from a stone cold engine? What happens if you drive round for 15 minutes (thereby provoking the problem), park up and stop the engine a couple of mins, and then go again? Do you get another 10 minutes of proper operation or does it muck about from the start?

john5f

iTrader: (3)

Is it not possible then that the ECU is overfuelling, thinking that the engine is cold, then sensing something is wrong and dropping boost to limp mode then releasing limp mode when apparent normality is sensed, then cycling through it all again?
(not sure if I explained what I mean that well)

hpoolsteve

iTrader: (4)

By the time I get onto roads were I can open her up the engine is warm. So from that point I get 10 minutes of normal operation. If I then park up and switch ignition off and then carry on the problem persists.

Splitpin

I get what you're saying but from an ECU program execution point of view I can't think of a scenario where that would happen. Aside from anything else the only method it has to "determine something is wrong" under those circumstances is feedback from the O2 sensor, and provided it has stabilised (it certainly should be after far less than 10 minutes running) and the engine is running under closed loop, all it will do is take overfuel out, it can't instigate limp/boost disable mode by itself. The ECU isn't anywhere near clever enough to do that sort of thing.

Aside from anything else, the thing that really suggests it isn't in limp mode is that if it was, the Check Engine light will come on. We've heard nothing from the OP yet to indicate that's the case (although if you could confirm one way or the other Steve, and do the black plugs if it has, that'd help).

hpoolsteve

iTrader: (4)

Hooked it up to laptop earlier and there are no codes. Also checked black plugs to make sure and it was just a constant flash. No check engine light as come on whilst driving

hpoolsteve

iTrader: (4)

Have uploaded a quick video to youtube of my boost gauge. This is whilst in 5th gear and accelerating.

http://www.youtube.com/watch?v=QQFPiD6TpQ8

Should i do an ECU reset after cleaning the bits you have suggested?

Splitpin

That's an interesting video Steve. Was this done on wide open throttle, or not, and can you tell us what happens at around 7-8 seconds to cause the pressure to dip momentarily into vacuum?

You could try an ECU reset but I wouldn't count on it changing much. Well worth doing though just to see what if any alterations in behaviour it provokes. Do it with the black + green plugs rather than disconnecting the battery.

Might also be worth getting hold of some 4mm fuel pipe so you can test it on actuator pressure.

hpoolsteve

iTrader: (4)

Hi Splitpin

The drop of pressure is me taking my foot off for a split second. Yes this is with wide open throttle.

I will do a ECU reset just to be on the safe side. Is it ok to do the ECU reset with ECUExplore.

Dont understand what you mean when you say "test on actuator pressure"

Thanks

Splitpin

Cool, I was hoping you were going to say that as it would have been flipping odd to explain any other way!

You can, it'll work fine, but my personal preference under these circumstances would be to do it the "long" way with the black and green plugs. The reason I'm suggesting that is because that method performs an active error check on every sensor before it gives you the all clear. If you haven't seen the check engine light yet I doubt it'll tell you anything interesting, but it's worth a try.

To save me a bit of typing, I'm going to suggest you have a good read of Simonds1's thread here. It'll tell you about the direct actuator connection. However, before you try anything like that, earlier in same thread, you'll see me ask Simonds1 to do a little datalogging of his car when it's acting up. Given that you're suffering a very similar set of symptoms, and seeing as you have the laptop and ECUExplorer there, it'd be worth you doing exactly the same to see if there's anything that sticks out of the data.

Can you do a brief WOT run, around the same length as your Youtube video, but with Explorer's logger running, and when it's obviously mucking about? If you can get another video of your boost gauge while you do it, even better (although far from essential).

The only data parameters I need to see in the log are engine speed, road speed, throttle sensor voltage, mass airflow sensor voltage, manifold relative pressure and wastegate duty cycle. So tick only those (untick everything else to speed up the sample rate), get the log, and post it up.

hpoolsteve

iTrader: (4)

Hi

Here is a log file of a 30 min round trip. Not sure if this is to long or what if it then im sorry.

The journey started at 11.00 and ended at 11:30 ish, at around 11:15 through to about 11:20 the boost was playing up again. I have had a look at the csv file but its double dutch to me lol

I HAVE REMOVED THE LINK, IF YOU REQUIRE THE LOG PLEASE PM ME.

I did i ECU reset prior to doing this log. No codes were shown

Thanks

Had a quick look at the log file and from time 977249 is were it starts to play up.