Quick question

[elenitro]

I've finally got my car back with my rebuilt gearbox but whilst reminding myself what it was capable of doing i noticed it not boosting properly and the dial only going to .3bar.
Now before i go and moan at them for not putting it back together properly as the cats were faulty i had decat pipes put on.....would this be what's causing it? if so will i just need a remap?


Leon

[alex s]

elenitro said:

I've finally got my car back with my rebuilt gearbox but whilst reminding myself what it was capable of doing i noticed it not boosting properly and the dial only going to .3bar.
Now before i go and moan at them for not putting it back together properly as the cats were faulty i had decat pipes put on.....would this be what's causing it? if so will i just need a remap?


Leon

Nope. If anything would have the opposite effect..
I would be checking all hoses and boost pipes for leaks first

[elenitro]

I've checked all the pipes...they seem to be all fitted ok and secure...i've checked the vaccum pipes as well and they seem ok.
I spoke to the dealer who did the work and they seem convinced that removing the cats has caused a loss of back pressure and so is the cause of the problem and also the lambda sensor readings will be out and so need to be tuned?


Leon

[Adrian W]

elenitro said:

I've checked all the pipes...they seem to be all fitted ok and secure...i've checked the vaccum pipes as well and they seem ok.
I spoke to the dealer who did the work and they seem convinced that removing the cats has caused a loss of back pressure and so is the cause of the problem and also the lambda sensor readings will be out and so need to be tuned?


Leon

Dont want to be rude, but thats complete bks! check all the vac pipes again and that the one under the tb hasnt been pushed in to far

[caccobra]

I agree with Adrian. The cats are not that restrictive. It is the y-pipe section of the stock exhaust that causes more restriction than you need. If you left that part of the exhaust alone, you really haven't gained much of anything by removing the cats (they are high flow cats).

[YellowShed]

Almost certainly, they have got the air temperature and boost solenoid wires connected to the wrong items. Hence now you don't have any boost control and are running the 0.3 bar that's the wastegate pre-load.

Simply swap over and you should be back in business.

YellowShed

[elenitro]

YellowShed said:

Almost certainly, they have got the air temperature and boost solenoid wires connected to the wrong items. Hence now you don't have any boost control and are running the 0.3 bar that's the wastegate pre-load.

Simply swap over and you should be back in business.

YellowShed

The only thing I've done in the engine is to fit a dump valve so I know where the vac pipes are, Adrian is the one you're talking about the back turbo pipe?

Yellowshed, are these 2 wires easy to find/get to, to do myself or should I just take it back?

They said they had road tested it twice before giving it back to me so i'm suprised they didn't pick up on this?

Both cats were knackered so the decat pipes were just a quick alternative to the stealer replacements.

Leon

[YellowShed]

Yes, both connectors are easy to find and swap about. The air temp is under the pipe going to the throttle body, and the wastegate valve is on the back (as in to the rear of the car) of the manifold just next to the map sensor.

Do it yourself no problem.

YellowShed

[elenitro]

YellowShed said:

Yes, both connectors are easy to find and swap about. The air temp is under the pipe going to the throttle body, and the wastegate valve is on the back (as in to the rear of the car) of the manifold just next to the map sensor.

Do it yourself no problem.

YellowShed

Thanks....it sounds easy.....I think I know where they both are...you take the air temp sensor off the pipe to remove it when installing a dump valve? and the wastegate valve is to the right of the map sensor as you look at the car from the back?

Leon

[peterguk V6 KWK]

elenitro said:

I spoke to the dealer who did the work and they seem convinced that removing the cats has caused a loss of back pressure and so is the cause of the problem

Just choked on my coffee ... What utter st!!

[NobleGuy]

peterguk V6 KWK said:

elenitro said:

I spoke to the dealer who did the work and they seem convinced that removing the cats has caused a loss of back pressure and so is the cause of the problem

Just choked on my coffee ... What utter st!!

LOL! This was a Noble dealer? They really don't help themselves do they?
I was about to comment that maybe the garage thought the car was quick even at 0.3 bar if they've little experience of Nobles, but a dealer...

[AMG Merc]

So who is the knowledgable dealer then - name please for possible future avoidance?!

[Jenx]

AMG Merc said:

So who is the knowledgable dealer then - name please for possible future avoidance?!

Best posted on NobleParts I think

[elenitro]

OK I've checked the wiring but it seems to be correct....the lead with the red/white wires going to the boost solenoid. I've removed and refitted all the vaccum pipes i could reach...the wastegate(?) for the rear turbo moved if i pulled what the spring was attached to....is this right?
I guess it's back to the dealer that i've mentioned on nobleparts now unless anyone else has any suggestions?

Leon

Edited by elenitro on Sunday 26th October 16:33

[elenitro]

After a lot of discussions with the dealer they are still insisting that it's the decat pipes that are causing the problem and so the only way forward is for me to take it to a 3rd party engine tuner that can tell me what's wrong. JNM may be a long drive for me but it may be worth it!
With <0bar pressure I get noise from both wastegates and <.3bar a loud release from the dump valve

How do you check if the boost solenoid is working? Can i put a multimeter on the connector? if so is it just a matter of revving the engine and seeing what reading i get?
Is it also possible that the other end of the air temp/boost solenoid wires are the wrong way round rather than the ends I can see which seem to be right?

Cheers,

Leon

[NobleGuy]

AMG Merc said:

So who is the knowledgable dealer then - name please for possible future avoidance?!

Edited by NobleGuy on Saturday 1st November 18:12

[NobleGuy]

elenitro said:

With <0bar pressure I get noise from both wastegates...

I refitted my front turbo last week and it did exactly the same with no boost at all.
I've been refitting again today and should be finished tomorrow to confirm if it was just an air leak as I expect. All my vac hoses are good as far as I can see too.

[peterguk V6 KWK]

Slightly OT, but we had an MR2 in the workshop today for fitting of a decat. After fitting, we had an EXTRA 1 psi of boost which is exactly what i would have expected.

[ThatPhilBrettGuy]

elenitro said:

After a lot of discussions with the dealer they are still insisting that it's the decat pipes that are causing the problem

They are clowns, pure and simple.

[Jenx]

elenitro said:

After a lot of discussions with the dealer they are still insisting that it's the decat pipes that are causing the problem

Then get them to put the cats back in...if it cures the problem you're happy, if it doesn't then they have to fixthe car for free and again you'r happy.