Rev 3 turbo low boost

[azznwab]

Hi all i have had my tubby since December and have noticed of recent it isn't boosting as high as it use to. Sometimes i hear a pulsating and can see boost gauge flickering in the midrange. Also on and off throttle use to be quite noisy, like a mechanical fart sound (im guessing is the wastegate?) Which doesn't happen so much any more and when does is definitely alot quieter. Boost use to peak 15-16psi now about 13psi.


My mods are decat, apexi, scorpion exhaust and omori boost gauge, which all came fitted to car

Servicing jobs include plugs, dizzy and rotary arm.
And i have changed the clutch(obviously dropped engine a little) so maybe something could of been knocked then.

Thanks in advance for any help, i have little knowledge of turbos

[chrismit]

Hi

Well if your boost is not as high as it was previously you are losing pressure somewhere. I would reseat and check your hoses (from intake to throttle body) for splits, in regards to the wastegate, if it was stuck open you would notice it was a lot slower coming onto boost than previously and if it was stuck somewhere in the middle or shut you would be over-boosting not under. Highly unlikely but other alternative the turbine could have been damaged in some way so its unable to spool as effectively.

[androo007]

Yeah likely to be a boost leak

[azznwab]

Well thanks guys i will get back on it over weekend and l will report back to ket you know how i get on, i have already been over all boost clips and inspected the pipes so i will go back over with more scrutiny. Cheers

[rgb]

its probably got a leak somewhere . the fart noise is the dump valve. have a search for goose honk mr2

[azznwab]

Hi i haven't done as much as wanted due to other car in household going bad so the 2 is being used more often than not (ouch).
But i did re tighten all boost pipes and did temporary see 15 psi at 4k rpm but then dipped again after couple of seconds and never returned regardless of revs even after another pinch up. Planning on pinching up again but not sure how much more the clamps can take, i may have to upgrade clamps and suggestions are welcome cheers.

[azznwab]

Hi all. Still got this boost issue. i have gone over boost claps/hoses, from what i can tell hoses ok but clamps could maybe be better but all are tight. I have also replaced ecu temp sensor as it was boosting same with old one plugged in and unplugged but still same with new one fitted maybe this will give some clues??? Is there any bypasses i can do to rule sensors/components out. What benefits does manual boost controller have. Thanks again in advance

[2mad]

This is pretty text book ... split hose ... strip down the boost hoses and inspect mate ... if there ok look at vac lines ... done this so many tines over 20years its not funny ... happy hunting mate

[2mad]

Ow and bov's can do this .. remove and blow into it .. if it leaks under lung pressure you have a problem .

[azznwab]

Thanks but what is ow and do i blow into this?. I take it i am blowing into bov from pressurised side?

[2mad]

Thanks but what is ow and do i blow into this?. I take it i am blowing into bov from pressurised side?

Sorry mate that was me just saying ow by the way


Yeah remove the valve a make a tight seal with your mouth and blow (yes the side that sees boost) , if its not air tight under lung power under boost its going to leak like a sieve.

[azznwab]

Just tried this above and not air tight. Took a good blow to break seal but Once seal leaked it easily stayed that way. Am i best buying new or is this going to rob me of my arms and legs