Turbo Boost

[Slugger]

Ok.. Installed the boost guage organised from Guageworks by Phantomxr6 (Thanks Phantom ).

Took it out for a drive, and on the first run, car went well, with the guage hitting about 7 on the dial. But.... EVERY other time I hit the go pedal, no matter how much I tried, the car felt sluggish, and the dial would not go over 5, and generally read between 4 and 5.

Parked the car for about an hour. Took it out again, and the first run, the car felt GREAT.. Floored it and the guage went up OVER 8 !!! In first, second, and briefly third gear (Anchors were slammed at this point... Looked up and a Hyundai was VERY RAPIDLY reversing into me !!!--- Damned guage !!).

The guage confirms what I have been (frustratingly) feeling for a long time now. Sometimes the car goes great, but most time, very ordinary.

Does anyone have ay ideas on what the problem might be ???

[justind]

I don't have a gauge but I have the same sensation as you. After much research I found two possible causes. 1. something sticking in the turbo.(some sort of spring thing I don't really know much about but it makes sense) and 2. OIL. Yep that simple. Oil aint Oil after 10000kms. The service intervals on a turbo motor should not really be so long. As the oil thins the performance does as well. I didn't believe it at first but I have tried it twice myself and found it to be true. After about 8,000km the car slowly get sluggish. Oil change and hey presto back to what I would have expected from it. I tried it twice and did no other work to it just the oil. It doesn't use any it just gets thin and doesn't like it much. I get the impression that many on this post regularly change thier own oil and I cannot recall any of them mentioning this fault.

[Slugger]

1. something sticking in the turbo.(some sort of spring thing I don't really know much about but it makes sense) and 2. OIL. Yep that simple. Oil aint Oil after 10000kms. ...

. I get the impression that many on this post regularly change thier own oil and I cannot recall any of them mentioning this fault.

Oil ??

I can understand if there is something in the turbo, but mine is not sluggish after 10,000km... It was like this from new. I've now done 15,000 kms, had the oil changed at 4000 kms.

But why does it sometimes go like a rocket, even now...?? It's not a gradual decline in performance..

Just an erratic boost randomly ??

[justind]

Sorry my mistake I didn't fully understand you circumstances. From new you say? Gee that wouldn't make me too happy. Good luck and sorry I wasn't able to help

Edited 09/04/04 01:54 PM by justind

[Slugger]

Sorry my mistake I didn't fully understand you circumstances. From new you say? Gee that wouldn't make me too happy. Good luck and sorry I wasn't able to help

No, no.. Thanks for your response. I appreciate that you did, and that thing about the 'spring in the turbo sounds interesting. Any info on that?

[ZAP]

I would guess your car is overboosting then going into limp mode.

The T should not go above 7psi in boost, so if yours is going above 7psi, then the ECU may be limping to prevent engine damage due to overboost.

Have you put a bleed valve on the car or tried any backyard performance mods ?

Have you taken the car back to Ford service and told them about the problem ?

It is possible a vacume hose has fallen off and causing overboost, or your car is not happy, but Ford should be able to fix it.

[Slugger]

I would guess your car is overboosting then going into limp mode.

The T should not go above 7psi in boost, so if yours is going above 7psi, then the ECU may be limping to prevent engine damage due to overboost.

Have you put a bleed valve on the car or tried any backyard performance mods ?

Have you taken the car back to Ford service and told them about the problem ?

It is possible a vacume hose has fallen off and causing overboost, or your car is not happy, but Ford should be able to fix it.

Thanks, Zaph.

I have made no modifications whatsoever. The only thing I have done is install a boost guage today. And more so to confirm what I have been feeling.

Took it to Ford at the 4000 km service. They gave me the standard answer - "no error codes show up, and it is running perfectly".

As I had no other proof except for what I was feeling, the boost guage was bought and installed.

It's booked in for Tuesday, but I want to explain and point them to possible areas to look at.

[justind]

Found it hope it helps

HI guys,  We had a xr6t which was driving the owner crazy, normal power for 90 percent of the time approx 180 kW then the power would drop away to approx 120 Kw for a short period before returning to normal.The owner had it back to the dealer many times,  and the dealer was really trying to sort the problem though they gave up after five attempts.We have seen this type of problem before on other turbo cars so we started by graphing the boost pressure, after sixth dyno test we saw turbo pressure fall away to nearly zero from that point we suspected a sticky swing valve in the turbo housing,our guess proved to be correct.Removed the turbo freed up the swing valve hey presto problem solved without much drama.Checked for fault codes all was clear and the engine is now running fine and making good power

Edited 09/04/04 03:19 PM by Dagabond

[Slugger]

Found it hope it helps

we suspected a sticky swing valve in the turbo housing,our guess proved to be correct.Removed the turbo freed up the swing valve hey presto problem solved without much drama.

Thanks Jusind.

We'll see what the dealer says about this..

(although I suspect I will get repy number 83 form their manual.." we had a look, but could find no fault codes, and nothing wrong".)

I'll let you know after the visit.

[xrdreaming]

G'day Slugger,

To be honest I don't think that the dealer will take much notice of your boost gauge. I had a very well known expensive brand of gauge and it was found to be reading 1.5 psi higher than the actual boost of the car.

I am not doubting that the quality of the gaugeworks gauges or your install, I am just saying that they can be wrong and I have found that dealers don't pay any attention to them.

If you go back to the dealer and they say they the car is ok, you could always go to a workshop and have the car run on a dyno and get them to print you a boost graph. Maybe even take it to 2 independant dyno places and show them the boost graphs if they support your claim.