intermittent boost loss

[kyles95]

Hi everyone, im new to this forum and im hoping someone can help. So for awhile now Ive seemed to have intermittent boost loss in my 99 saab 9-5. Check engine like comes up for code P1549 ( boost control valve malfunction) so i put a new valve in, checked the hoses and cleared the code. Two hours later i was accelerating in 3rd gear and i lost power again. Same code popped up. I noticed if i shut the car off and started it again boost is back to normal. Ive been searching for weeks on every forum and site i can find, but cant find anything. Ive tried plugging the evap hose on the boost control valve, but it didnt change anything. If anyone has any ideas i would greatly appreciate it.

[bobthebuilder]

Hi everyone, im new to this forum and im hoping someone can help. So for awhile now Ive seemed to have intermittent boost loss in my 99 saab 9-5. Check engine like comes up for code P1549 ( boost control valve malfunction) so i put a new valve in, checked the hoses and cleared the code. Two hours later i was accelerating in 3rd gear and i lost power again. Same code popped up. I noticed if i shut the car off and started it again boost is back to normal. Ive been searching for weeks on every forum and site i can find, but cant find anything. Ive tried plugging the evap hose on the boost control valve, but it didnt change anything. If anyone has any ideas i would greatly appreciate it.

Make sure the hoses to your intercooler are in good shape and securely attached on both ends.

[HOT Aero 315]

sounds like it could be dump valve opening. check pipework on boost control valve. block pipe to dump valve and test. if cured, fault is incorrect fitment of pipes. can be tricky but they eliminate (almost) any turbo lag. check pipework to blow off valve as well. It may be a good idea to replace all the smaller pressure piping that controls turbo boost. when it is sorted, your big grin will be back...(smiles)

[swisssaabist]

NEVER EVER DOING That i try to do that on mine now my engine are failed with heavy smoke huge loss of oil thinking now the turbo is kaput maybe worse (piston rings or other ) plugging the evAP HOSE IS A FALSE GOOD IDEA !!!!!!!

[southsaab]

Definitely recheck all hose connections again, possibly a small leak not detected. Outside chance it could be ignition problem, DIC or plugs. T7 issues are elusive, sometimes not giving a code. Another area is cobra pipe and intercooler hose connections. Eliminate turbo components and hoses first as a problem.

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[MrTone]

NEVER EVER DOING That i try to do that on mine now my engine are failed with heavy smoke huge loss of oil thinking now the turbo is kaput maybe worse (piston rings or other ) plugging the evAP HOSE IS A FALSE GOOD IDEA !!!!!!!

Oh man that doesn't sound good.