Problems With 2.0 8v Turbo, Any Suggestions?

[Headling 0]

Hi Guys, going to run through this with Whizzer71 but thought I would throw this problem out there to see what you guys reckon.

 

I was on the way home from Le mans, did 700 miles in the pug no problem, got to the local test ground, quarter mile to bridge on A28, was going really well, the boost ran over 1 bar, then the red engine light came on, I backed off then got home ok.

 

Went out in after a few days, the car only boosted to 0.5 bar, had a look at bleed valve and wound it out some more, not much of a change to the boost, even fully open it can just do 0.6 bar boost.

 

Spec wise: it has a DKZ cam, Bailey Dump Valve, Fensport Bleed valve, cossie 4wd intercooler, magnex exhaust. It has new plugs/leads and has been running fine for 2 months.

 

I have checked the boost pipes for holes/leaks, this seems ok.

 

Have I knackered the turbo? waste gate? What else shall i check?

 

I miss 0.8 bar!

[tom_m 0]

have you re-set the ecu since you clipped the boost cut? if you've got a stored fault the ecu may be in limp home mode.

 

be VERY careful with messing around with bleed valves, melted pistons are at the end of that road.

 

unplug the ecu from the loom for 10 secs and try it again.

[Headling 0]

oh cool,I will give that a try and wind the bleed valve in and start winding it out will i get to 0.8 bar if it makes it.

 

I did not realise the ECU was that sopisticated!

[whizzer71 0]

oh cool,I will give that a try and wind the bleed valve in and start winding it out will i get to 0.8 bar if it makes it.

 

I did not realise the ECU was that sopisticated!

 

 

Too clever for their own good ,Tom is spot on dont try and make it have too much or it could end in a costly mistake,If you cant sort it mail me and we can arrange a time for you to drop by to get it sorted.

 

[Headling 0]

Yes going to try it later and see what happens, If im stuck i'll give you a shout tris! if turbos had it its a good excuse for a TT manifold,T28 and saab injectors!

[bales 1]

If your going to use any sort of non-ecu controlled boost control I would defiantely say use a proper ball and spring MBC not a bleed valve.

 

They aren't that much more expensive and are alot more reliable and control the boost more accurately, though the downside is due to the nature of a MBC boost comes in a lot more aggresively than the usual solenoid control.

[whizzer71 0]

If your going to use any sort of non-ecu controlled boost control I would defiantely say use a proper ball and spring MBC not a bleed valve.

 

They aren't that much more expensive and are alot more reliable and control the boost more accurately, though the downside is due to the nature of a MBC boost comes in a lot more aggresively than the usual solenoid control.

 

He has an MBC on it.

 

[Headling 0]

well tried the ECU trick but it made no difference! I noticed that when the engine is at idle air is rushing out of the bailey dump valve, upon speaking with Whizzer71 it seems this could be at fault! I am going to take it off and make a blank up and try it.

 

Any other ideas to try would be appreciated!!

[Headling 0]

Well just got back from a test drive with out dump valve, i blanked this off where the dump valve was fitted.

 

I noticed that it was -6 bar at idle and with out dump valve itis reading -2, dont know if this means anything?

 

Also when i have opened bleed valve up, it will only boost to 0.4 bar w/o dump valve, and just about 0.6 bar with d valve.

 

I have checked the idle control valve hoses,they are ok.

 

I noticed when w/o the dump valve i can hear the waste gate making a sort of high pitch worble, getting louder when the boost was higher, is this knackered and causing lack of boost?

[whizzer71 0]

Well just got back from a test drive with out dump valve, i blanked this off where the dump valve was fitted.

 

I noticed that it was -6 bar at idle and with out dump valve itis reading -2, dont know if this means anything?

 

Also when i have opened bleed valve up, it will only boost to 0.4 bar w/o dump valve, and just about 0.6 bar with d valve.

 

I have checked the idle control valve hoses,they are ok.

 

I noticed when w/o the dump valve i can hear the waste gate making a sort of high pitch worble, getting louder when the boost was higher, is this knackered and causing lack of boost?

 

Sounds like the dump valve IS leaking air hence the rise in vacuum and the warbling noise you can hear is

compressor stall ,Bring it down for me to take a look at it I have another dump valve that we can fit to it ,to raise the boost you want to wind the MBC in (manual boost controller) which is what you have fitted to your car,Winding it out release the tension on the spring allowint the boost to lift the ball of its seat and then open the waste gate,tightening it has the opposite effect Ie the turbo has to create more boost to lift the ball of its seat owing to the increased spring tension before it allows pressure to actuate the wastegate.

Wind in for more boost and out for less,feel free to call me if you like !

 

Good luck

 

Tris

Edited July 3, 2008 by whizzer71

[Headling 0]

Just got in from taking car out for the evening, noticed it has sprung an oil leak, also when im cornering the oil pressure gauge is moving down then once round the corner it goes back to normal?

 

Seems a bit weird? any ideas?

 

Could the turbo be knackered and leaking oil?

[whizzer71 0]

Just got in from taking car out for the evening, noticed it has sprung an oil leak, also when im cornering the oil pressure gauge is moving down then once round the corner it goes back to normal?

 

Seems a bit weird? any ideas?

 

Could the turbo be knackered and leaking oil?

 

 

I wouldnt drive it any more than you help mate and then get it down to me so i can take a look at it for you,the lack of oil pressure is prob because you have low oil level in the sump and thus when you corner the oil is going to one side of the sump and not being picked up by the oil pump.

Check the oil level and top up if req'd then get it down to us and we'll see whats going on for you (Pref on a trailer) Im sure its something very simple !

 

[Headling 0]

Ok mate, will have a look at the oil level and get it over to you ASAP, thanks alot.